Fiber Optics nm Laser Beam Couplers PM Singlemode Fibers Fiber Collimators Construction Kit multicube Laser Sources Customized Solutions

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1 INTERFEROMETRY 9 E PM: OW-TIE PM: PND PM: OVL INNER LD SINGLE- MODE PF Laser eam oupler for Singlemode Fibers inclined fiber coupling axis Fiber Optics nm Laser eam ouplers PM Singlemode Fibers Fiber ollimators onstruction Kit multicube Laser Sources ustomized Solutions pplications: of Scratch detector Open rain Stimulation Magneto ptical OTrap Optical Tweezers LSERS FOR SPE for djustment Laser and lignment Read- Out of Imaging Plates Particle Measurement FiberOpticsTitle_9_E_neu.indd Made in Germany

2 9 E ontents eam ouplers Inclined fiber coupling axis Fiber ables PM: OW-TIE PM: PND Fiber ollimators Special ollimators PM: OVL- INNER LD Singlemode PF Fiber Optics Laser beam couplers SMS-... Page For singlemode and polarization-maintaining fibers djustable and focussable For lasers with 7 - nm wavelengths Inclined or coaxial coupling axis for connectors of the types F-P and DIN-VIO (F-SM and ST available but without angle) dapters for the "multicube"-system and other standard laser systems Laser beam expanders 8EO-... Page 7 Different expansion, for higher coupling efficiency Singlemode fiber cables SM- Polarization-maintaining fiber cables PM-... Photonic crystal fiber PF-... Wavelengths - nm F-P and F-P onnectors (connectors of the types ST, DIN VIO and F-SM available on request) Vacuum feed-throughsv-kf-... and F-SF-... Polarization-maintaining, singlemode or multimode fiber cables Two different flange types: small flange KF and screw-type flange M x mm F-P and F-P onnectors (connectors of the types ST, DIN VIO and F-SM available on request) Fiber optical beam splitter FS-... Wavelength - nm Standard splitting ratio : F-P and F-P onnectors (connectors of the types ST, DIN VIO and F-SM available on request) Fiber delay lines PM/SM-S-... Fiber cables, spooled in a compact cassette Singlemode or polarization-maintaining F adapters without optics and F mating sleevs For connecting fiber cables Various designs Fiber collimators F-... ollimating optics with focal lengths f =.7 - mm for beams with beam diameters. - mm Focussing mechanism Inclined coupling axis for connectors of the type F-P Tilt adjustment for aligning the optical axis with the mechanical axis for f mm Pilot laser beam Front connection for the attachement of optical adapters Micro-focus optics M-.../M-... The collimated laser beam is focussed onto a laser spot with, μm Polarization filters PF-.../PF-... For increasing the polarization extinction at the end of a fiber cable Retardation optics WP-... For adjusting the polarization axis and changing the state of polarization Iris diaphragms L-..., L-..., L-... and L-... For adjusting the collimated beam diameter Fiber collimators F-Q... with integrated quarter-wave plate For the direct implementation of circularly polarized radiation Fiber collimators with retro reflector With integrated quarter-wave plate For reflection of polarized light without changes in polarization state Fiber collimators with integrated power monitor For online control of laser power and fluctuations Fiber collimators with dichroic beam combiner Laser beams of different wavelength are combined and collimated Espacially for wavelength which can not be guided in one singlemode fiber Page 9 Page Page Page Page Page Page 8 Page 9 Page 9 Page 9 Fiber collimators with elliptical beams Page Gaussian profile Elliptical axis ratio e.g. : mm Page Page Page Page namorphic beam shaping optics N-... Page focal beam-shaping optics transform the elliptical shape of a collimated laser diode into a rotationally symmetric profile Form factors:.,.,., and. orrection of laser diode astigmatism FiberOptics_Inhalt_9_ED_gruen.indd Page RGV RED GREEN LUE VIOLET Laser Pattern Generators P... Page Miscellaneous pattern Focusable with integrated mechanism daptable to F-... fiber collimators RGV fiber optics pochromatic corrected optics for the simultaneous coupling of, /88, and nm laser beams with high efficiency RGV laser beam couplers and collimators Integration unit for combining RGV lasers, each coupled to a polarization-maintaining singlemode fiber Dichroic mirrors for combining lasers with different colors Polarization-maintaining broadband fiber cables for the wavelength range - nm Photonic crystal fiber cables with singlemode operation from the UV to 8 nm Page 7 Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

3 9 E onstruction Kit Opto-Mechanics and Optics "multicube" system For integration of laser beam couplers, beam combiners, beam splitters, retardation optics and polarizers For rugged and distortion free setups without the need for an optical breadboard Microbench compatible eam splitter and combiner, polarizers and retardation optics With adjustment mounts for the "multicube" systemm dapters and ccessories Fiber-fiber couplers FF-... For coupling fiber cables with different types of connectors For singlemode coupling fibers with different numerical apertures For coupling polarization-maintaining fiber cables with high polarization extinction ratio pplications for "multicube" Fiber port cluster -to- Two-fiber system - laser beam source nm Fiber port cluster fiber-to-fiber coupler with Faraday isolator Page Page Page Page Page Laser OUT Laser IN Laser attenuators 8T-F-... Page Reproducible and precise attenuation of fiber-coupled laser power Polarization maintaining oupling of various fiber and connector types For fiber connectors of the types F-P, F-P and more Electro Optics Electro-magnetical shutter EMS-- + SK97 Page 7 perture Ø mm i-stable For use with the "multicube" system ontroller with US interface Fiber coupling for chopper SK -... Page 8 Optical choppers are used for the periodic modulation of light, such as for lock-in detection purposes when the laser cannot be modulated directly OM acousto-optical modulators Page 8 n acousto-optic modulator (OM, ragg cell) diffracts light using sound waves Used for Q-switching, signal modulation and frequency control OTF acousto-optic tunable filters coustic waves of different frequency for dependet diffraction of the beam For wavelength separation or diffraction of broadband sources at one common point EOM electro-optical modulators with fiber optics Page 9 Electro-optical modulators (EOMs) are used for amplitude, phase or frequency modulation of laser beams Ruggedized systems for many different modulation tasks can be implemented using the fiber optic com ponents from Schäfter+Kirchhoff Page 8 Laser Sources Faraday isolators - Page Standard wavelengths - 8 nm Isolation > d, insertion loss <. d pertures Ø mm or Ø mm ompatible with multicube and micro-bench systems pplications for Faraday isolators Page Fiber couplings with beam shaping and feedback protection ascadable fast laser switch with back reflection protection E laser with polarization-maintaining fiber optics Fiber couplings of a single pulse picosecond laser system Fiber coupled laser beam sources Laser diode collimator 8TE-SOT-... Page For laser diodes in 9 mm (TO 9),. mm (TO.) or TOW housings Laterally adjustable and focussable Integrated thermoelectric cooling ollimating optics for the wavelengths 7 - nm FiberOptics_Inhalt_9_ED_gruen.indd Page LOW NOISE and REDUED SPEKLE LOW NOISE and REDUED SPEKLE Laser diode beam source nanofm- Page Polarization maintaining singlemode fiber coupled diode lasers Low noise version with decreased coherence length Wavelengths - nm Laser source with multiple outputs Laser diode beam source nanofi-... Page 7 Fiber coupled diode lasers with integrated Faraday isolator Low noise version with decreased coherence length Polarization-maintaining singlemode fiber Wavelengths - nm Laser diode beam source 8FM- Page 8 Fiber coupled diode lasers Polarization-maintaining singlemode fiber Wavelengths - nm HeNe laser with fiber optics, singlemode and polarisation-maintaining Page 9 Fiber coupling of HeNe lasers from various manufacturers Output powers up to 8 mw Polarization maintaining High coupling efficiency Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

4 9 E Laser safety and measurement Laser safety Page Laser safety goggles Laser safety signs eam detection cards Page fiber core slow axis Index F connector stress inducing structure PM-fiber, Type PND Polarization analyzer SK978-VIS/NIR universal measurement and test system for laser beam sources with polarization-maintaining fiber optics Measurement of all three Stokes parameters for display on a Poincaré sphere dapter for fiber connectors and micro-bench system Plug & play device, connected to a US interface Page pplications Fiberport cluster Page Fiber optical beam delivery and splitting system Polarization-maintaining Variable power splitting ascadable number of input and output ports Optionally dichroic for combining and splitting several distinct wavelengths ustomized fiber couplings Page 9 oupling of OHERENT Innova lasers nm / nm Switchable multi-colour system 7, 88 nm, nm, and nm for fluorescence microscopy oupling of OHERENT Sapphire HP laser with external, fiber-coupled OM Outer space applications Notes FiberOptics_Inhalt_9_ED_gruen.indd Page Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

5 9 E Laser eam ouplers SMS-... for diode, gas and solid state lasers 7 - nm Laser eam oupler for Singlemode Fibers inclined fiber coupling axis.. X Inclined or coaxial fiber coupling axis Singlemode fibers with 8 -inclined polish (P) avoid directly reflected radiation in the laser source and are used with Schäfter + Kirchhoff laser beam couplers that have an inclined coupling axis. These inclined laser beam couplers ensure a coupling efficiency as high as those using a coaxial coupling axis with polish. F DIN VIO P P P P..... TILT Figure : Fiber optics Laser eam oupler SMS-. Tightly fitting cylinder with circular V-groove Ø 9. mm. Tilt adjustment with integrated adjustment and locking screws (hex screwdriver WS. - type HD-.. ).. Internal lens focusing mechanism (with eccentric key EX-). Lens locking (with screwdriver Ø. mm type 9D-). Option: dditional fixing of the fiber ferrule (with screwdriver Ø.) dapter flange 9.-F to connect laser beam source. onical screws for system locking (with hex key WS.) Singlemode fiber with F connector X djustment of polarization axis Inclined coupling axis, 8 -polish fiber Suppression of back reflection into the laser resonator. The laser spectrum does not change D. FP-P DIN VIO--T ST ST. oaxial coupling axis, -polish fiber bout 8% of laser radiation is reflected back into the laser reso nator causing multimode emission and optical noise. Mismatched components fiber with 8 polish mismatched with a coaxial laser beam coupler, or vice versa, a fiber with polish mismatched with an inclined laser beam coupler, can reduce coupling efficiency dramatically (by up to %) because of the geometric mismatch of the components. D F-SM This opto-mechanical device with integrated precision optics and mechanical fine-adjustment elements provides an efficient coupling of a collimated laser beam into a singlemode fiber with MFD > μm and multimode fiber respectively. The system covers 7 different coupling focal lengths and more then R coatings with > nm bandwidth. The inclined fiber coupling axis of type P fiber connectors prevents back reflection into the laser resonator. The major performance features include: Singlemode and multimode laser beam coupler. Inclined or coaxial coupling axis. Integrated tilt and focussing adjustment. selection of 7 different coupling lenses. Sensitive alignment of the polarization axes ensured by a circular V-groove with tightly fitting cylinder. different fiber connections, F or for space applications with DIN- VIO connector, each with an inclined or coaxial coupling axis as well as ST and F-SM, predestinated for multimode coupler. Nickel silver or titanium made. arbide bearings for the locking screws of the tilt adjustment guarantee a sensitive, repeatable, lateral setting of the focal position. n additional grub screw, locks the fiber ferrule to prevent displacement or rotation. dditional Schäfter+Kirchhoff fiber optics: polarization-main taining singlemode fiber cables PM-..., fiber collimators F-..., micro-focus optics, see Dimensions Laser beam coupler SMS--... with inclined or coaxial fiber coupling axis for F connector P-onnector.. P-onnector Ø9. Ø. Laser beam coupler SMS-SM--... with coaxial fiber coupling axis for F-SM connector ( polish).. Laser beam coupler SMS-VIO-... with inclined or coaxial fiber coupling axis for DIN-VIO connector P-onnector P-onnector dapters for laser beam coupler SMS-... oupling of Lasers lateral beam displacement causes lower coupling efficiency. Therefore, the optics must be centered to the optical axis of the laser beam using adapter 9.-F. The laser beam coupler is simply replaced by an aperture (e.g. L- ). y adjusting the adapter position concentrically (using the oversized mounting holes) while... Laser beam coupler SMS-ST--... with coaxial fiber coupling axis for ST connector Iris diaphragm L- dapter 9.-F measuring the laser power, the transmitted power can be maximized. For a detail description see adjustment of laser beam coupler SMS-..., page 8.. Lasereamoupler_9_ED.indd Page * * * * Figure : Typical fiber connections Laser beam coupler SMS-... No. and have an inclined coupling axis for accepting 8 -polish P fiber connectors * grub screw for additional fixing of the fiber ferrule * oupling efficiency Output powers >8% of the initial power are achieved when coupling laser sources with rotationally symmetric beams of high quality (M <.). Sources for loss are: Transmission loss of the laser beam coupler ~ % Imaging aberration, stray loss, and beam distortion (M = )... ~ 8% Fresnel reflection loss at fiber endfaces % Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

6 9 E Laser eam ouplers SMS-... Parameters and s Lens types The coupling lenses provided by Schäfter+Kirchhoff not only correct spherical aberration but also are optimized for the diffraction-limited focussing of monochromatic laser radiation over a wide wavelength range. Three different kind of optics are available, type M (laser monochromats, doublets), type (aspheres) and type RGV (apochromat). The focus position of type und = asphere M optics varies with wavelength (more with aspheres than with 8 mono chro mats) so that the laser beam coupler has to be refocussed manually after any chan- ges to the wavelength. spheres are designed for use with a single wavelength, while Focus Position [μm] mono chromats can be used for two wavelengths over a limited M = laser monochromat or achromat range. 8 RGV lens Focus Position [μm] RGV = RG coupling lens (apochromat) Focus Position [μm] Rel. oupling Efficiency % Rel. oupling Efficiency % Rel. oupling Efficiency % Figure : Different types of lenses for laser beam coupler SMS-... Lenses of type RGV are achromatically corrected RGV coupling lenses designed for the simultaneous coupling of multiple wavelengths in the range to 7 nm. The RGV coupling lens offers diffraction-limited focussing for a constant focus position over the full range of wavelengths. RGV coupling lenses are ideal for confocal microscopy, especially when using various combinations of different reds, greens and blues as the laser radiation sources. For more information on RGV optics, see page 9 or at rgbv_e.pdf Selection of coupling diameter for an elliptical laser beam The effective beam diameter is critical for optimizing the coupling of an elliptical laser beam into a singlemode fiber. This is calculated from the small and the large diameters Ø and Ø of the collimated elliptical laser beam: Ø eff = Ø II Ø Option: stigmatism correction, anamorphotic beam shaping For methods to increase the coupling efficiencies of laser diode beam sources, see Selection of lens focal length Optimum coupling efficiency is reached when the beam diameter of the incoming beam equals one of the beam diameters listed in Table.. For an ideal Gaussian beam (M =), the convergence of the focussed beam equals the acceptance angle of the fiber while the laser spot on the fiber facet corresponds to the mode field diameter accepted by the single mode fiber E. Except for an 8% loss from Fresnel reflection during fiber entrance and exit, the ideal Gaussian beam is transported completely. E N = sin f Ø beam For fiber numerical aperture N values not listed in Table, the optimum focal length of the laser beam coupler at a given beam diameter is given by: f =. Ø beam /N. () The factor. accounts for the differently defined diameters of Gaussian beam (.% value) and numerical aperture (% value). beam diameter too small is inefficient as the laser spot is larger than the accepting mode field and, conversely, a beam too large suffers because convergence of the focussed beam is larger than the fiber acceptance angle. Example: eam diameter: Ø beam =. mm Numerical aperture (%-value) of fiber: N =. focal length: f =../. =. mm In this case, select lens. S with f =. mm * eam expansion The best coupling efficiency with beam diameters Ø beam <. mm is achieved when the laser beam is expanded in advance. Schäfter +Kirchhoff therefore offers beam expanders for SMS-... laser beam couplers. With the beam expander, the diameter of the beam is in creased which allows Ø the use of lenses of longer focal beam > Ø beam length and, thus, with fewer aberrations. s a result, the coupling efficiency is higher. See page 7 for more information. ** Multimode fiber When using a multimode fiber, it is important to ensure that the emitted beam has the same angle of divergence as the beam coupled into the fiber. ending can cause mode mixing and, especially for divergences smaller than the N of the fiber, results in unwanted beam characteristics. Therefore, coupling into a multimode fiber should always utilize the full extent of the N of the fiber. Table Lenses and beam parameter Laser eam oupler SMS-... row curr. no. ** Lens type..7. M. M.S M.S 7. 8 M8 RGV M M-NIR M 8 Focal length f' Numerical aperture N lear aperture max. [mm] orrection - monochromatic x x x x x x x x x x x x x x " - chromatic x x x x x x x Table. Input beam diameter [mm] (.%-Value) 7.9.*.9* *.* *.* Numerical aperture..8*.9* of the fiber..* * Lasereamoupler_9_ED.indd Page.**,,7,99,,,,,8,,7,88,9,9,, Table. Spectral range ode no. of R coating 7 - nm - nm - nm 7-7 nm nm nm - 98 nm 98 - nm nm 7 - nm nm 7-7 nm - nm 7 7 * usage of beam expansion is recommended, ** especially for multimode fibers Laser beam couplers SMS Standard with connector type F, see dimensions Optional: VIO = DIN-VIO connector, see dimensions ST--... = ST connector, see dimensions SM--... = F-SM connector, see dimensions dd T for titanium made SMS - - M - R coating, see Table. Lens focal length f in mm Lens type: = aspheric (beam parameters Table ) M = laser monochromat or achromat RGV = laser apochromat = inclined coupling axis, Fig. with P connector (8 -polish) = coaxial coupling axis, Fig. with P connector ( -polish) Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

7 9 E nti-reflection oatings The lenses of table, page and table -, page ff can be ordered with the following R-coationgs: dapters and Tools for laser beam couplers SMS- Descriptions and technical drawings are available at dapter dapter dapter dapter with integrated attenuator 9.-F Ø.8 9. M 9. M-L 9.-F-T M Ø9. Ø8 Ø9. M Ø Ø Ø Ø.8. Mounting Set 9.-F-MS Mounting set for 9.-F-... and HeNe laser pcs. screws - x /8" (similar DIN 9), washers and hex key / Plate 8M-MP-9. For Ø 9. mm components compatible with the micro-bench system dapter with integrated shutter 9.-F-S Ø9. 7 Ø.8. Tools for assembly and adjustment Eccentric key Screwdriver Ø. mm EX- 9D- Expansion Optics 8EO-... Hex screwdriver SW Ø. mm HD- Eccentric key with long handle as an alternative to EX- EX--L Iris Diaphragm Description see adjustment of laser beam coupler SMS-..., page 8. L-. eam expansion optics 8EO-... Wavelength depending correction Laser beam source with beam diameter <. mm. The best coupling efficiency with beam diameters Ø beam <. mm is achieved when the laser beam is expanded in advance. The beam expander allows the use of lenses of longer focal length and, thus, with fewer aberrations. s a result, the coupling efficiency is higher.. Expansion Optics 8EO-... 8EO : enter wavelength [nm] = housing with Ø. flange = Ø mm housing 9. Expansion: :, : (others on request) Lasereamoupler_9_ED.indd Page 7 namorphotic eam-shaping Optics N-.... namorphic beamshaping optics N-... orrection of laser diode astigmatism Laser beam source with elliptical beam profile Detailed information at page.. namorphic optics act one-dimensionally on the elliptical profile of the collimated beam produced by a laser diode. y reducing the larger beam diameter and matching it with the smaller beam diameter, a radially symmetrical beam is obtained. oupling efficiencies of 8% or more are possible with anamorphic beam-shaping optics, depending on the beam characteristics of the laser diode. namorphotic eam Shaping Optics N-... and Dimensions,, can be found at page. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 7

8 9 E Lasereamoupler_9_ED.indd Page 8 Laser eam oupler SMS- ssembly and adjustment For efficient beam coupling, the choice of coupling optics is made according to the diameter of the incoming beam and the numerical aperture of the coupled fiber. The precision adjustment mechanism is then used for the precise placement of the laser spot on the transmitted mode field of the fiber and - with polarization-maintaining fibers - for orientation of the polarization-maintaining axis of the fiber so that it is in parallel with the polarization plane of the incoming radiation. Four steps to perfect alignment:. enter the laser beam coupler with the laser beam propagation axis by using the adapter 9.F (or similar).. Move the mode field of the fiber laterally within the laser focus area using the tilt adjustment.. lter the preset factory setting of the focal plane (only needed for a wavelength different from specification or when beam splitting is experienced).. Rotate the laser beam coupler to align the polarization-maintaining axes (only PM-fibers). Rel. Efficency % oupling efficiencies with f - mm lenses for uncentered parallel beams. entering the laser beam coupler with the propagation axis beam displaced laterally from the optical axis causes it to focus onto the fiber center, but with inclined propagation in relation to the fiber endface. Parts of the beam exceed the acceptance angle of the fiber. The asymmetric propagation causes lens aberrations such as coma and astigmatism to appear. These are removed by centering the laser beam axis and coupling optic by using adapter 9.F. The laser beam coupler is simply replaced by an aperture (e.g. L-). The aperture diameter should be near the /e level of the laser beam. y adjusting the adapter position concentrically (using the oversized mounting holes) while measuring the laser power, the transmitted power can be maximized. The centering precision required is of the order of tenths of a millimeter. With a longer focal length lens, manual adjustment is totally adequate and quickly performed. Lateral adjustment of the mode field and the laser spot Lateral displacement of the laser beam focus from the mode field of the fiber arises because of production tolerances in the centering of the coupling lens and/or the centering of the fiber core in the fiber ferrule. With a mode field or spot diameter of - μm, the required precision is in the range of sub-microns D. Rel. Efficency % E,,,,8, Entrance eam Decentration / mm 8. mm. mm 8. mm mm mm,,,,8, Entrance eam Tilt / mrad oupling efficiencies for inclined beam propagation F oupling efficiencies for laser spots laterally displaced from the fiber mode field inclined laser beam propaga tion E. Using a mm focal length lens, a beam inclined by mrad results in a lateral offset of μm completely missing the mode field. y using the tilt mechanism of the laser beam coupler, the mode field of the fiber is then placed very precisely onto the laser focus area. yclical tightening and release F of the three radially arranged adjustment screws maximizes the coupled beam power. The final position is locked by the adjacent grub screws which have carbide bearings. Rel. Efficency % D 8... Lateral Shift / μm Focussing The positioning accuracy in the coaxial direction is less critical than for the lateral directions. From the depth of field of the laser focus (Rayleigh range), a decrease in coupling efficiency of a few percent occurs even with a displacement of only a few microns G. Schäfter + Kirchhoff laser beam nm 9 couplers are supplied already nm 8 nm adjusted for the coupled wavelength and re- 7 D focussing is not necessary for a highly collimated G Defocus D / μm laser beam. oupling efficiency with Refocussing can unfocussed lens be performed, however, by releasing two lens locking H screws (ac ces sible via small holes) using the screwdriver 9D- H. Use the eccentric key EX- to correct the location of the focal plane before tightening the locking screws again. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Rel. Efficency % I Laser beam coupler with schematic illustration of the functional and adjustable elements 7 Laser beam coupler SMS--- dapter 9.-F Laser beam source (HeNe laser) Singlemode fiber cable with F-P connector Grub screws for fixing the 8 fiber ferrule position oupling lens 7 Lens focussing mechanism 8 Locking screws for the indirect fixing of the coupling lens 8 9 djustment screws ( x tilt adjustment) Locking screws ( x tilt adjustment) 9 arbide bearings ( x) tilt fiber core slow axis F connector index stressinducing structure PM fiber, type PND K 8 L Entrance eam Twist / Grad Extinction ratio for polarization axis twisted in respect to the slow and fast axis of the fiber. Extinction Ratio d Orientation of the polarization axis Polarization-maintaining singlemode fibers guide radiation in the two orthogonal planes of oscillation (fast and slow), independently. When linearly polarized radiation is not exactly coupled in orientation with one of the fiber axes, the radiation is distributed between the fast and slow propagation speeds and recombines at the fiber end as elliptically polarized radiation L. Linear polarization losses are major and the state of polarization is sensitive to vibration, temperature and fiber bending. The laser beam coupler is rotated in the adapter 9.-F K (after releasing the locking screws of the adapter with screwdriver HD-) until the polarization analyzer shows a maximum and stable state of polarization, as confirmed by its resistance to physical displacement of the fiber. Lock the position by tighten the screws after adjustment The polarization analyzer SK978-VIS/NIR is specifically developed for analysis of the state of polarization at the fiber end. The analyzer evaluates the extinction ratio and visualize adjustments of the polarization directly. J K Polarization nalyzer SK978-VIS/NIR Measurement and test system for laser sour ces with PM singlemode fiber cables, see page. 8

9 9 E Polarization-Maintaining Fiber ables PM- and PF-... Polarization-maintaining and singlemode Singlemode Fiber ables SM- ccessories: Vacuum Feed-Through, Fiber-optical eam Splitter, F dapter PM: OW-TIE PM: PND PM: OVL INNER LD Singlemode PF The fibers from Schäfter+Kirchhoff are singlemode and polarization-maintaining. The provided fibers have either a polish (P) or a 8 polish (P) of the fiber facette, which avoids back reflection into the radiation source. The connector types available are F, DIN VIO, ST, E and F-SM. The SMS Laser oupler provides efficient coupling to the fibers, while collimation is performed using the F Fiber ollimators, both for P and P fiber types. Polarization-Maintaining Singlemode Fiber ables PM-... and PF-... Singlemode and polarization-maintaining Wavelength 8 nm Mode field diameter. μm Fiber with low attenuation for wavelengths < nm F-P or F-P fiber connection* Polarization direction is indicated by connector index Special: Photonic crystal fibers *optional: type ST, DIN VIO, E or F-SM Singlemode Fiber ables SM-... Wavelength 8 nm Mode field diameter. μm Fiber with low attenuation for wavelengths < nm F-P or F-P fiber connection* optional core-centering *optional: type ST, DIN VIO, E or F-SM ccessories: Vacuum Feed Throughs V-... Vacuum down to -9 Small flange or screw flange Singlemode or polarization-maintaining Wavelength 8 nm F-P or F-P fiber connectors* *optional: type ST, DIN VIO, E or F-SM Fiber Optical eam Splitter FS-... Wavelength 8 nm Standard splitting ratio : F-P or F-P fiber connectors* ore centering onnecting cable: mm Ø PV cable with Kevlar strain relief *optional: type ST, DIN VIO, E or F-SM Fiberable_9_ED.indd Page 9 F-P/P D Group delay τ [ns/m].. Ø mm housing micro-bench, tilt + standard flange Wavelength λ [nm] E micro-bench micro-bench + tilt pplication bearing flange, e.g. for adapting microscope optics Fiber Delay Lines PM/SM-S PM or SM fibers customized delay time compact design F-P or F-P fiber connectors* onnecting cable Ø mm strain relief cable *optional: type ST, DIN VIO, E or F-SM F Fiber daptors F fiber adapters are used for connecting fibers but have no integrated optics. For example they are used for telescopes or fiber-coupled spectrometers, according to requirements and customer choice. xial limit-stop of fiber ferrule for a reproducible focus position Grub screw for additional locking of the fiber ferrule Inclined or coaxial coupling axis for fiber connectors of the F-P or F-P type, respectively* Various designs Optional tilt adjustment for alignment of the coupling axis *optional: type ST, DIN VIO, or F-SM Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 9

10 Intensities.% 9.% 8.% 7.%.%.%.%.%.%.% Schäfter + Kirchhoff Intensity Profile Gaussian Hamburg Fit 9 E Fiberable_9_ED.indd Page Figure : Singlemode fiber cable with different types of polarization-maintaining singlemode fibers -, a standard single mode fiber D and photonic crystal fiber E. Polarization-Maintaining Fibers Polarization-maintaining singlemode fibers guide coupled radiation in two perpendicular principal states with different speeds of propagation, denoted the fast and slow fiber axes. Linearly polarized radiation not coupled exactly into one of these axes is transformed into an elliptical state of polarization because of these different speeds of propagation. Polarization-maintaining fibers are either step index fibers or photonic crystal fibers and the two unequal axes are caused by birefringence from stress-induction components in the fiber cladding, as in PND fibers, ow-tie fibers or Oval-Inner lad fibers. The slow axis is orientated in parallel with the stress-inducing elements ( PND and ow-tie fiber) or in parallel with the larger diameter of the inner cladding ( Oval-Inner lad fiber). The linearly polarized laser radiation is usually coupled into the slow axis, because of its lower sensitivity to bending, Fig.. The polarization-maintaining fiber cables made by Schäfter+Kirchhoff have the fiber axes aligned with the index of the F type fiber connector with extremely high precision (< ). The fiber cables made by Schäfter+Kirchhoff typically have a polarization extinction > : ( d), for > 78 nm > : ( d). Good lignment: onnector key axis = slow axis Output beam linearly polarized onnector Key ore ad lignment: onnector key axis slow axis Output beam linearly + circularly polarized Figure : Orientation of the axes of a polarization-maintaining fiber to the connector index Photonic rystal Fibers Schäfter+Kirchhoff provides polarization-maintaining photonic crystal fibers, PF, in addition to the standard singlemode and polarization-maintaining fibers. PFs are optimized for single-mode operation in a wide spectral range in combination with a relatively large mode field diameter and are made PF from fused silica, which makes the fiber extremely stable for radiation at short wavelengths. In contrast with step index singlemode fibers, it is the numerical aperture (and not the mode field diameter) that varies proportionally with the wavelength used. In addition, the fiber provides practically endless singlemode operation with no cut-off wavelength. In this regard, attenuation is approximately d higher at shorter wavelengths, in comparison with pure silica core fibers, and the beam only approximates to a Gaussian profile. PF-... PM-... MFD = const. N( ) N = const. MFD( ) Figure : Differences between polarizationmaintaining photonic crystal fibers PF (left) and standard single-mode fibers SM/PM (right). For PF fibers, N is function of wavelength, while MFD is constant. For SM/PM fibers, the converse applies and MFD varies with wavelength. PM: OW-TIE PM: PND PM: OVL INNER LD D Singlemode E PF ngular offset Polarization-Maintaining Singlemode Fiber ables PM-... Polarization-maintaining singlemode Wavelength nm Mode field diameter. μm Fiber with low attenuation for wavelength < nm F-P or F-P fiber connector Polarization direction is indicated by connector index Special: Photonic crystal fiber Singlemode SM-... Singlemode Wavelength nm Mode field diameter. μm Fiber with low attenuation for wavelength < nm F-P or F-P fiber connector ore-centering as an option Numerical perture The numerical aperture N of a singlemode fiber describes the angle of beam divergence (% level) of the Gaussian-shaped radiation that is emitted by the fiber and is defined as the sine of half the angle of beam divergence: N = sin /. The total angle of beam divergence in degrees is calculated from N via the equation: = N 8 /. N Example: numerical aperture N =. angle of beam divergence.. For singlemode fibers and for polarization-maintaining fibers, N is normally independent of the used wavelength. Ø.% Ø% ut-off Wavelength The cut-off wavelength co is defined as the shortest wavelength for which a guided wave is singlemode. The beam profile can only have a Gaussian intensity distribution and rotational symmetry above co. If the wavelength of the guided radiation is shorter than the cut-off wa velength specified, two or more modes are guided with decrea sing wavelength. The beam and intensity profile differ significantly from a Gaussian distribution. symmetry through bending of the fiber or temperature changes (butterfly effect) is worse. If the operation wavelength is longer than the cut-off wavelength, the guidance of the radiation becomes increasingly weaker. movement or bending of the fiber (even micro-bends) cause attenuation of the guided radiation. The wavelength range in which the fiber is singlemode depends on the fiber parameter and can reach. times co. The usable wavelength range of fibers with a pure silica core is smaller. When more than one fiber from tables,, and can be used for a particular wavelength then the fiber with a larger cut-off wavelength should be chosen. The cut-off wavelenth co of a fiber can be up to % different from the specified values because of manufacturing tolerances. Selected fibers with characterized values are available on request. singlemode multimode Figure : Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Ø% co operation range D typ.. co Laser eam nalysis: Ref.: SK977 Object: Fiber ollimator ollimating Lens M eam Diameter (/e ).8 mm E losses due to bending (schematic) SF SF Singlemode fiber ore diameter MFD = mode field Ø Intensity level.% Intensity level % N ( %) N (. %) Figure : eam profile of a sinlgemode fiber, definition of numerical aperture N, angle of beam divergence and mode field diameter MFD Operating wavelength range of a singlemode fiber Gaussian mode profile of a singlemode fiber and y using a fiber with a wavelength just below the cut-off wavelength, the multiple modes of the butterfly effect D and E are produced in this example: co = 78 nm = nm

11 9 E Fiber ttenuation The attenuation of fibers used for wavelengths below nm is dominated by Rayleigh scattering and, ad ditionally for wavelengths below nm, by UV absorption. The attenuation is approximately d/km for = nm. With decreasing wavelength, the attenuation increases to approximately d/km for = nm and to approximately d/km for = nm. For wavelengths below nm and standard fibers, additional solarization effects worsen the attenuation further. elow = nm, Schäfter+Kirchhoff recommends the use of pure silica core fibers, which do not show these solarization effects. Transmission [%/m] Wavelength [nm] Transmission [%] 8 PM- PM--Si PM- Fiber length [m] Figure : attenuation of singlemode and polarization-maintaining fibers (left) and for different fibers according to fiber length (right) Fiber onnectors Singlemode fiber cables made by Schäfter+Kirchhoff are equipped with fiber connectors of type F-P or F-P. Optionally, they can be provided with fiber connectors of type ST, DIN VIO, F-SM or with two fiber connectors of different types. ll of the fiber connectors of type F assembled by Schäfter+Kirchhoff have a type N alignment index of. mm width (or optionally with a mm width index, type R ). For fiber connectors of type F-P, the connector index is orientated with the 8 -angled polish as shown in Fig. 8. (optionally there are different orientations available, e.g. as in Fig. 8 ). The dimensions of different connectors are shown in Fig Fiberable_9_ED.indd Page Mode Field Diameter The mode field diameter MFD is the diameter of the beam profile at exit of the singlemode fiber. MFD dependends on the wavelength and the N of the fiber accordingly: MFD =..8 N On calculating the MFD, note that the N is typically given at the % level of the Gaussian profile but the MFD at its.% level. The conversion factor is.8. For both singlemode and polarization-maintaining fibers, the MFD approximately equals the core diameter but also is a function of the wavelength used. Types of Fiber ables Singlemode fiber cables made by Schäfter+Kirchhoff are either supplied with a Ø.9 mm buffer together with a Ø mm PV cable with Kevlar strain relief or with a Ø.9 mm buffer only. oth the PV cable and the buffer are black. Fibers without a buffer (Ø μm coating only) are optionally available. Fiber able with onnectors of Type F-P In order to avoid back reflection directly into the laser source, the fiber connector of type F-P has an 8 -angled polish of the fiber facet (fiber ferrule). For fiber cables with this type of connector, Schäfter+Kirchhoff provides fiber collimators (Fig. 7 ) and laser beam couplers (Fig. 7D ) with an inclined coupling axis. If a fiber collimator with coaxial coupling axis is used with F-P type connec tors, the beam is obstructed and its profile is distorted (Fig. 7 ). If a laser beam coupler with coaxial coupling axis is used with connectors of type F-P, the coupling is reduced by about % (Fig. 7D ). 7 F-P connector (8 polish of the fiber ferrule) F-P connector ( polish of the fiber ferrule) 7 7 Figure 7: oupling of laser radiation into a singlemode fiber cable and coupling of fiber guided laser radiation into a collimated beam with fiber connectors of F-P type. In order to achieve optimal coupling efficiency, both the laser beam coupler and the fiber collimator need to have an inclined coupling axis. ore entering ecause of tolerances during manufacture, fiber connectors can have a misalignment of optical and mechanical axes. The singlemode fiber cables SM-... (non-polarization-maintaining) from Schäfter+ Kirchhoff can be provided with core centering (offset. μm). The connector -F/F promotes direct connection of two fiber connectors with core centering for a low coupling loss (see page ). ore centering is not recommended with polarization-maintaining fiber cables because of a detrimental effect on polarization extinction. When coupling two polarization-maintaining fiber cables then the Schäfter+Kirchhoff FF-... Fiber-Fiber coupler is recommended. 7D 7E Figure 8: Orientation of the 8 -polish with the index of a fiber connector type F-P: standard (left), optional customized orientation (right). Singlemode Fiber ables PM-.../SM-... Ø.9 Ø L F connector for SM-... fiber cables, L = mm fiber cable Ø mm, L integr. Kevlar strain relief L F connector for PM-... fiber cables, (polarization-maintaining) L = 8 mm L F connector (Short) for SM-... fiber cables, L = mm fiber cable Ø.9mm (nylon buffer) L F connector (Short) for PM-... fiber cables, (polarization-maintaining) L = 9 mm, fiber cable Ø.9mm (nylon buffer) Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Ø.9 Figure 9: The different fiber cables with their different types of fiber connectors of type F. Pure Silica ore Fibers (Si) Standard singlemode and polarization-maintaining singlemode fibers have a core doped with germanium. Short-wavelength radiation interacts with the germanium to produce color centers which cause an increasing non-reversible attenuation of the fiber (solarization effect). For wavelengths < nm, Schäfter+Kirchhoff provides singlemode fibers and polarization-maintaining fiber cables with a pure silica core. These fibers do not show radiation-induced attenuation and so have a low attenuation that is stable over time. Pure silica core fibers are more resistant to gamma radiation than Ge-doped fibers. MFD Mismatch For both singlemode and polarization-maintaining fibers, the numerical aperture N and mode field diameter MFD may differ up to % from the specified values due to manufacturing tolerances. Selected fibers with characterized values are available on request. The theoretical coupling efficiency (overlap integral) between two intensity Gaussian distributions is still close to = even when the mode field diameter of a real fiber differs from the theoretical value. Since there is a linear relation between mode field diameter MFD and numerical apterture.99 N, this is valid also for a.98 mismatch in the values for N. Example: N =. N =. Overlap: =.99 When coupling two fiber cables with N /N = MFD /MFD <. oupling efficiency η then the Schäfter+Kirchhoff FF Fiber-Fiber coupler is recommended. Ø. L.97.9 L Ø Ø. L Ø. Ø a = MFD /MFD = N /N

12 9 E Polarization-Maintaining Singlemode Fiber ables PM-... Table Polarization Maintaining Fiber able PM-... row curr. no Nominal wavelength nom Si Si Si Si Si ut-off wavelength co* < < < < < < < < < 78 < 98 < 98 < < Operation wavelength range Mode field diameter MFD [μm]** The major parameters of a polarization-maintaining singlemode fibers are numerical aperture N, mode field diameter MFD and cut-off wavelenth co. Manufacturing tolerances mean specified values may differ by up to %. Selected fibers with characterized values are available on request. * Determined by the % level ** alculated from the N and from the wavelength Si For wavelengths < nm, Schäfter+Kirchhoff provides polarizationmaintaining singlemode fiber cables with extra low attenuation that have a pure silica core and are devoid of solarization effects.f Numerical aperture N* [μm] PM fiber type P P P P P P P P P P P P P 7 Large MFD X X X 8 Pure Silica core X X X X X Fibers with the current numbers,, and are fibers with a large mode field diameter and are used for coupling higher optical powers. Order Options The offered fibers in table are just an extract of all fibers deliverable. Please contact Schäfter+Kirchhoff if the required specifications vary from the listed values at table. y selecting the fibers it is possible for Schäfter+Kirchhoff to offer fibers with different MFD, N, cut-off wavelenth and operation wavelength then specified from the manufacturer. Selection diagramm for polarization-maintaining singlemode fiber cables PM-... PM-78-.-N--P--S PM fiber type: S = standard (fiber type not specified) P = Panda = ow-tie V = Oval-Inner lad Length in cm (standard = ) onnector Type: P = F-P (8 -angled polish) P = F-P ( -polish) XP = one end F-P, other F-P VIO, VIO-P cable type: = Ø mm PV cable with Kevlar strain relief (standard) = fiber cable with Ø.9 mm buffer (w. F conn. short design) Numerical aperture N Mode field diameter MFD at nominal wavelength Nominal wavelength (+Si when stated) PM = polarization-maintaining singlemode fiber cable Polarization-Maintaining Photonic rystal Fibers PF-... nm %-Level N.7 nm Polarization-maintaining photonic crystal fibers have a constant mode field diameter and the N depends on the wavelength. Therefore, the FWHM of the intensity profiles increase with the wavelength. Picture of the hexagonal micro structure of the photonic crystal fiber. The major advantages of this fiber are the large mode field diameter and the wide spectral range during singlemode operation. PF-UV N.9 MFD = const. N( ) 8 8 wavelength [nm] Spectral diagramm for polarization-maintaining singlemode photonic crystal fiber PF-... Fiberable_9_ED.indd Page 8 nm N. MFD [μm] wavelength [nm] N Polarization-Maintaining Photonic rystal Fiber PF-... curr. no Nominal wavelength nom UV ut-off wavelength co none Operation wavelength range UV - 8 Mode field diameter MFD [μm]. ±. Numerical aperture N [μm].87 7 nm More information about PF-... fibers, see page Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

13 9 E Singlemode SM-... Standard singlemode fibers are rotationally symmetric step index fibers with no defined axes of propagation. Rotational symmetry effects, produced during manufacture, cause irregular birefringence and the linearly polarized radiation coupled into the fiber is transformed into elliptically polarized radiation. The state of polarization also alters on fiber bending or temperature changes. Table Singlemode Fiber able SM-... row curr. no Nominal wavelength nom Si Si Si Si ut-off wavelength co < < < < < < < < 78 < 98 < Operation wavelength range Mode field diameter MFD [μm] Numerical aperture N [μm] Pure Silica ore x x x x 7 Large MFD Selection diagramm for singlemode fiber cables SM-... Vacuum feed-throughs V-... The fiber cables with vacuum feed-through made by Schäfter+Kirchhoff are equipped with singlemode or polarization-maintaining singlemode fibers for wave lengths from to 8 nm (fiber assort ment, see fiber tables,, and ). The feed-throughs are sui table for a vacuum down to -9. They have a small flange KF (DIN 8) H or a screw-type flange (M x mm) I. On the vacuum side, the fiber cables have a 9 μm buffer covered with a mm PV cable with Kevlar strain relief. For vacu um feed-throughs with singlemode fibers, the connector outside of the vacuum can be core centered as an option (<. μm). Vacuum SM--.-N--P-- Length in cm (standard = ) = standard = core centering onnector type: P = F-P (8 angled polish) P = F-P ( polish) XP = one end F-P, other F-P VIO, VIO-P cable type: = Ø mm PV cable with Kevlar strain relief (standard) = fiber cable with Ø.9 mm buffer (w. F conn. short design) Numerical aperture N Mode field diameter MFD at nominal wavelength Nominal wavelength (+Si when stated) SM = singlemode fiber cable V-KF - PM N P/P / S PM only: fiber type (see fiber table and ) able length in cm (inside/ outside)* Fiber connection (inside/ outside)*: P = F-P (8 -angled polish) OP = F-P ( -polish) Numerical aperture Mode field diameter MFD Nominal wavelength fiber type: SM = singlemode fiber cable PM = polarization-maintaining fiber cable V-KF = Vacuum feed-through with small flange KF V-SF = Vacuum feed-through with screw flange Mx mm * only one value given = same connector at both ends Vacuum H I F connector F connector Fiber-optical beam splitters J split the radiation guided in a singlemode fiber into two singlemode fibers. Fiber-optical beam splitters by Schäfter+Kirchhoff have a splitting ratio of : (± %) as standard. They are provided for wavelengths between and nm. The bandwidth is ± % of the designed wavelength. Inser tion loss is approx. d at - 7 nm and. d at 7 nm. F connector Fiber-optical eam Splitter FS-... F connector The two types of couplers have either or ports, respectively, for use in interferometric or other setups. Fiber-optical beam splitters have mm PV cables with Kevlar strain relief. The connectors are of type F-P, F-P, or core centered (<. μm). ustomized productions are available on request, with a different number of output ports, for example. Fiberable_9_ED.indd Page J Fused iconical Taper X Y FS - - X / P able length in cm (in/ out) Fiber connection (in/ out): P = F-P (8 angled polish) OP = F-P ( polish) Splitting ratio Number ports: X = -Port Y = -Port Nominal wavelength FS = fiber-optical beam splitter Please request Schäfter+Kirchhoff for other fiber otpical beam splitter. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

14 9 E F Mating Sleeves Mating sleeves provide a direct (physical contact) connection between two singlemode or two polari zation-maintaining fiber cables SM-... and PM-... respectively. Either two connectors of type F-P ( polish) or of type F-P (8 polish) can be connected. Mating sleeves for two F connectors (panel mount F ): -F/F Hybrid adapter for joining connector type E- to connector type F (panel mount G ): -F/E Fiber Delay Lines PM/SM-S-... F Ø, -F/F G -F/E 9, Ø Fiber cables are used as optical delay lines. The group delay g ( ) of a singlemode fiber is given by: 8. l n g( ) g( ) =, c dn eff ( ) n g( ) = n eff ( ) -. d Group delay τ [ns/m] Wavelength λ [nm] for the effective refractive index n eff ( ) s a good approximation, the effective refractive index of the singlemode fiber n eff ( ) is the same as the core index, n core ( ). The group delay for this approximation is shown (left) for a fiber with N. over a wavelength range of - nm. Schäfter+Kirchhoff offers singlemode fibers and polarization-maintaining fibers with lengths > m, also spooled in compact cassettes. The two fiber ends are pigtailed with Ø mm cabling, strain relief, and fiber connectors. Figure 9: PM-S-... Fiber-optical delay line with polarization-maintaining fiber PM S N-P--/-S Dimensions TE/ HE/ 8. Pigtail length in cm (in / out)* Fiber lengths in cm Fiber connection (in/ out)*: P = F-P (8 angled polish) OP = F-P ( polish) Numerical aperture N Mode field diameter MFD Nominal wavelength PM polarization maintaining fiber SM singlemode fiber * when only one value given = same connector at both ends } see fiber tables - F Fiber dapters without Optics F fiber adapters are used either for beam outputs, where no collimation or focussing of the beam is necessary, or for beam coupling to fiber connectors but without integrated optics, e.g. because microscope optics are used. Schäfter+Kirchhoff F fiber adaptors have a fiber connection with inclined coupling axis for use with fiber connectors of the F-P type or a fiber connection with co axial coupling axis for use with fiber connector of the F-P type (optional types: ST, DIN VIO, or F-SM). Other performance features include: xial limit stop of the fiber ferrule for a constant focus position, especially with fiber adapters with inclined coupling axis Grub screw for an additional locking of the fiber ferrule With integrated tilt adjustment for alignment of the coupling axis F fiber adapter with tilt adjustment and integrated quarter-wave plate for generating circularly polarized radiation. Typical application: magneto-optical atom traps (see F-P adapter F--F F-P adapter F--F F-... compact design with Ø mm diameter. F-P adapter F--F F-P adapter F--F F-... F adapter with Ø mm fit for micro-bench system e.g. for collimators with long focal length. F-P adapter M--F F-P adapter M--F M-... F adapter with Ø mm fit for microbench system with integrated tilt adjustment for aligning the axis of the emitted radiation. Fiberable_9_ED.indd Page F-P adapter 9.--F F-P adapter 9.--F F adapter with tilt adjustment for aligning the axis of the emitted radiation. With standard adapter flange Ø9. mm. x M Ø Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Ø F-P adapter F--F F-P adapter F--F pplication chromaticcorrected microscopy lenses F-... F adapter as OEM version with bearing flange. pplication Simultaneous fiber coupling of different laser sources by use of chromatic corrected microscopy lenses for fluorescence microscopy. F-P adapter with bearing flange

15 9 E Fiberollimators_9_ED.indd Page Fiber ollimators F- P or P connector interface F-T- Integrated beam alignment F-Q- Integrated retardation optics / ccessories: Micro-Focus Optics Polarizations Optics Polarization filter PF-.../PF-... Micro-focus Optics M-... und M-... Micro-focus Optics M-.../M-.../M-... Ø mm M-... / M-..., PF-... / PF-... Polarization filter PF-.../PF-... Fiber collimator F-T-... with integrated TILT adjustment The line F-T-... has a fiber connection with integrated TILT adjustment. In case of fiber collimators with large focal length (f mm to f mm) the emitted beam can accurately be aligned to the mechanical axis. Option: / Retardation plate F onnector Fiber ollimator F ny small beam deviations caused by attached optical devices can also be re-aligned. The deflections and aberrations caused by vignetting of the collimated beam are also obviated. Fiber ollimator F-Q... Option: Fiber Ferrule Ø. mm Figure : ack side few of the fiber collimator F-Q... with tilt adjustement and / retardation optics. window shows the axes of the retardation optics. F DIN VIO P P P P. * * * *. -TILT. Lens focusing. Lens locking by indirect clamping. Locking of the attachments. Grub screw M. for additional locking of the fiber ferrule ST F-SM Figure : Typical fiber connections Fiber collimators F... No. and have an inclined coupling axis for accepting 8 -polish P fiber connectors * grub screw for additional fixing of the fiber ferrule * The fiber collimators made by Schäfter+Kirchhoff transform the divergent radiation emitted at the end of a singlemode fiber into a collimated beam of. to mm diameter. The fiber collimators have a coaxial or inclined coupling axis for connection to a fiber connector of the types F-P and F-P. The fiber collimators have a fitting for the connection of micro-focus optics, used for generation of micro spots. μm, or for pola ri zation filters. Performance features of the fiber collimators are: ssortment of collimating lenses with focal lengths between.7 and mm R coatings 7 nm with > nm bandwidth each Inclined or coaxial coupling axis for fiber connectors of the type F-P and F-P, respectively (optional type ST, DIN VIO or F-SM, see Fig. ) Lens focussing with indirect clamping, even with adapters Front connection for the attachment of optical adapters F connection with axial limit stop for the fiber ferrule (constant focus position, in particular for fiber collimators with inclined coupling axis) F connection with grub screw for addi tional locking of the fiber ferrule (in creased pointing stability of the laser beam). Option: fiber collimators with integrated quarter-wave plate for circularly polarized laser beams. pplication: magneto-optical trap (MOT) ccessories: Micro Focus Optics / Polarization filters Micro-focus optics M-.../M-.../M-... (page 8) Micro-focus optics in combination with fiber collimators generate micro spots. μm. Micro-focus optics by Schäfter+Kirchhoff are designed for fitting to the fiber collimators, see tables -. Polarization filter PF-.../PF-... (page 9) Polarization filter with extinction ratio :. The optional front attachment of the polarization filter can again take adapters for a fiber collimator or micro-focus optics. Fiber ollimators F-T-... / F-Q... Fiber collimators of type F-... made by Schäfter+Kirchhoff are available with focal lengths from.7 to mm. If the focal length is mm, they optionally have an integrated tilt adjustment for adjusting the beam axis with respect to the mechanical axis. Fiber collimators of type F-Q... are fit with a quarter-wave plate directly generating circularly polarized beam. Table Fiber ollimator Overview Fiber ollimators Fiber connection Inclined for F-P connectors (8 polish) oaxial for F-P connectors ( polish) Internal lens focussing eam diameter (/e ) Focal length Housing diameter Table / curr. no. Ø [mm] f ' [mm] Ø [mm] [mm] Tab x x x x Ø 8 Tab., no x x x x x x Ø 9. Tab., no x x x x x x M7x. Tab., no x x x x x x Ø Fiber connection with integrated tilt adjustment flange Option: Fiber connection with integrated retardation optics Option: Fiber connection type ST, F-SM, or DIN-VIO Front fitting for additional optics Inclined and oaxial Fiber onnection (P/P) In order to avoid back reflection directly into the laser source, the fiber connector of type F-P has an 8 -angled polish of the fiber facet (fiber ferrule). Therefore, Schäfter+Kirchhoff provides fiber collimators with inclined coupling axis (Fig. ) and coaxial coupling axis (Fig. ). If a fiber collimator with coaxial coupling axis is used with F-P type connec tors (Fig. D ), or vice versa, a fiber wirth polish is used incorrectly with an inclined coupled fiber collimator (Fig. E ) then the beam is obstructed and its profile is distorted. F-P connector D (8 polish of the fiber ferrule) F-P connector ( polish of the fiber ferrule) Figure : oupling of fiber guided laser radiation into a collimated beam with fiber connectors of F-P and F-P type. In order to achieve optimal coupling efficiency, the fiber collimator need to have an inclined coupling axis for 8 polished fibers and a coaxial coupling axis for polished fibers. mismatch causes displacement and assymetric effects. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de E

16 9 E Ø mm Polarization filter PF-.../PF-... Micro focus optics M-... and M-... page Option: Fiber ferrule Ø. mm Figure : Fiber collimator F-..., housing Ø mm, focal lengths.7 mm For fiber collimators with longer focal lengths see F-T-... Table.. F onnector... Lens focusing. Lens locking by indirect clamping. Locking of the attachments. Grub screw M. for additional locking of the fiber ferrule Fiber ollimators F-... Fiber collimators in a Ø mm housing made by Schäfter+Kirchhoff are available with focal lengths from.7 to mm. The F-... fiber collimators are provided with internal focussing and a front fitting Ø 8 mm for connecting micro-focus optics of the series M-... and polarizers of the series PF-.... The values for beam diameter (/e -value of Gaussian intensity distribution) and divergence given in table refer to a wavelength = 7 nm and a fiber N =.. For other beam and fiber parameters see page. ll lenses are available R coated for wavelengths from 7 to nm with each of the coatings covering a few hundred nanometer range. = asphere The glass bi-aspheric lenses type show a fine structure (concentric rings) in the projected Gaussian beam profile, but not in the focus. That kind of lenses is suitable for UH vacuum applications. M = laser monochromat or achromat The lenses are corrected for spherical aberration (mono chromat) or for chromatic aberration (achromat). oth produce an undisturbed Gaussian beam profile. RGV = RG coupling lens (apochromat) Lenses of type RGV are achromatically corrected RGV coupling lenses designed for the simultaneous coupling of multiple wavelengths in the range to 7 nm. Table Fiber ollimator F-... with focal lengths.7 mm (housing Ø mm) row curr. no * 7 8 Lens type.7 M. M.S M.S 7. 8 M8 RGV M M-NIR M 8 M Focal length f' Numerical aperture N lear aperture max. [mm] ollimated beam diameter [mm] eam divergence [mrad] orrection - monochromatic x x x x x x x x x x x x x 8 " - chromatic x x x x x x x Spectral range ode no. of R coating for the RGV lens see page nm - nm - nm - 7 nm 7 - nm nm - 98 nm 98 - nm nm nm nm 7 - nm 7 7 Suitable for UH vacuum x x x x x x x x x Dimensional drawing ** Optional connector types St, Din-VIO or F-SM Table. eam divergence: beam expansion due to diffraction. eam diameter as a function of the working distance. collimated Lens type.7 M. M.S M.S 7. 8 M8 RGV M M-NIR M 8 M Focal length f' eam diameter in distance [mm] Distance. m m m Table. Diameter of focussed beam as a function of the working distance. For spot Ø < μm, micro-focus optics are used. 9 focussed Lens type.7 M. M.S M.S 7. 8 M8 RGV M M-NIR M 8 M Focal length f' Spot diameter in distance [mm] Distance. m m m Fiber collimator F... Straight coupling axis for F-P connectors ( deg. polish) inclined coupling axis for F-P connectors (8 deg. angled polish) The fiber connection has an axial limit stop to ensure a constant focus position, particulary for fiber collimators with an inclined coupling axis. Optional connector types: ST, DIN VIO and F-SM Fig. : With singlemode fibers of 8 deg. angled polish, only an inclined fiber coupling axis gives an axially centered beam profile with rotational symmetric Gaussian beam profile. Fig. : With straight coupling axis and singlemode fibers with 8 deg. angled polish, the beam profile is displaced and asym metrical. Fig : Ray path for a fiber collimator with Micro- Focus lens attachment. Intensity distribution and beam profile are preserved. dapters Polarization filter PF-.../ PF-..., page 9 Micro focus optics M-... and M-..., page 8 Diffractive optics P..., page or Hamburg.de Fiberollimators_9_ED.indd Page Table. W Pilot beam: approximately constant beam diameter across entire working range, obtained by fine adjustment. Position of beam waist is given by distance. eam diameter [mm] Tab. No. : M / f'=. Tab. No. : M / f'= Tab. No. : M / f'= Tab. No. : M / f'=. at at coll. at waist [m] at at coll. at waist [m] at at coll. at waist [m] at at coll. at waist [m] Working range. m m m m m m m Dimensions Ø Ø8 Ø Ø8 dapters for mirror mounts Ø mm, Ø. mm, and with system mount Ø 9. mm see page. Fiber collimators F with system mount Ø 9. mm (fit directly into the "multicube"- system), see page. djustment Tools Eccentric key (no. - ) EX- (no. -8) EX- as an alternative: Eccentric key with long handle (no. - ) EX--L (no. -8) EX--L Screwdriver 9D- Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Fiber collimators F- F--M- R coating (see Table, row 9 - ) Lens type (see Table, row ) = asphere M = monochromat or achromat Fiber connection: = F-P connection (8 polish) = F-P connection ( polish) dd T for titanium made s an option fiber connection of type: DIN-VIO, ST, and F-SM

17 9 E ad alignment: the beam is vignetted and diffraction patterns occure Figure : Fiber collimator F-T-..., with focal lengths - mm and tilt adjustment. For fiber collimators with shorter focal lengths see F-... Table. ccurate alignment of emitted beam to the mechanical axis -TILT Fiber ollimators F-T-... Fiber collimators of type F-T-... made by Schäfter+Kirchhoff are available with focal lengths from to mm. They optionally have an integrated tilt adjustment for adjusting the beam axis with respect to the mechanical axis. ll fiber collimators are provided with a focussing mechanism and with front fitting for adding micro-focus optics. Values for beam diameter and divergence given in table refer to a wavelength = 7 nm and a N =. for the fiber. For other beam and fiber parameters, see page. The collimating lenses of type M are corrected for spherical aberration (mono chromat) or for chromatic aberration (achromat). oth produce an undisturbed Gaussian beam profile. ll lenses are available R coated for wavelengths from 9 to nm with each of the coatings covering a few hundred nanometer range. The fiber collimators have a coaxial or inclined coupling axis for accepting the fiber con nectors F-P and F-P, respectively (optionally ST, DIN VIO and F-SM). The fiber connection has an axial limit stop to ensure a constant focus position, particulary for fiber collimators with an inclined coupling axis. s an option, these fiber collimators are provided with integrated quarter-wave plates, see F-Q-... on page. Table Lenses and beam parameters Fiber ollimator F-T-... with focal lengths - mm row curr. no Lens type M L M M M M M M L M L M7 M S M M M Focal length f'.. 7 Numerical aperture N lear aperture max. [mm] ollimated beam diameter [mm] eam divergence [mrad] orrection - monochromatic x 8 " - chromatic x x x x x x x x x x x x Spectral range ode no. of R coating nm - 98 nm 98 - nm nm 7 - nm nm - 7 nm 7 - nm 7 Tilt adjustment with T T T T T T T T T T T T T 8 w/o integrated quarter-wave plate Q Q Q Q Q Q Q Q Q Q Q Q Q onnector type * F-P F-P Housing diameter /(8) /(8) /(8) /(8) /(8) /(8) /. /. /. /. /9 /9 /9 Front fitting Ø 9. Ø 9. Ø 9. Ø 9. Ø 9. Ø 9. M 7x. M 7x. M 7x. M 7x. Ø Ø Ø Dimensional drawing ** with w/o 8 * Optional connector types St, Din-VIO or F-SM ** For other dimensional drawings, please call Schäfter+Kirchhhoff Table. eam divergence: beam expansion due to diffraction. eam diameter as a function of the working distance Lens type M L M M M M M M L M L M7 M S M M M 7 Focal length f'. 7 eam diameter in distance [mm] 8 collimated Distance m m m Table. Diameter of focussed beam as a function of the working distance. For spot Ø < μm, micro-focus optics are used. Lens type M L M M M M M M L M L M7 M S M M M Focal length f'. 7 Spot diameter in distance [mm] focussed Distance m m m Fiberollimators_9_ED.indd Page 7 Dimensions Ø Ø9. Ø Ø9... Ø8 Ø8 Ø Ø Ø8 More dimensional drawings see page lamp collars for fiber collimators see page Ø Ø9. 8 Ø Ø9. Ø ssembly and adjustment tools Eccentric key EX- for F-T-... with tilt adjustment and for all fiber collimators F-... starting with row 8 as an alternative: Eccentric key with EX--L long handle Screwdriver 9D- D Hex screwdriver HD- Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de D Fiber ollimator F-T- F-T--M- R coating (see Table, row 9 - ) ollimating lens (see Table, row = F-P = F-P T = tilt adjustment - = w/o tilt adjustment Q... = / plate, e.g. Q7 for = 7 nm s an option with fiber connection of type : DIN-VIO, ST, and F-SM dd T for titanium made 7

18 9 E Fiber ollimator with Micro-Focus Optics Fiber collimator F- Micro-focus optics M- and M-. Polarization filter PF-.../PF-... For locking of attachments pplications: of s Figure 7: Fiber collimator with micro-focus optics and polarization filter. The attachments are locked in position with radially arranged screws.. Micro-Focus Optics M-.../M-... Micro-focus optics transform collimated laser beams into micro-spots with diameters >. μm. Depending on focal length, micro-focus optics are assembled with a sphe ric lenses, achro mates or singlet lenses. Micro-focus optics from Schäfter+Kirchhoff are R coated for wavelengths 7 to nm with each covering a few hundred nanometers. The size of the micro spot Ø spot depends on the focal length ratio of micro-focus to fiber collimator and on the mode field diameter MFD of the singlemode fiber. Ø spot f micro-focus f fiber collimator MFD Singlemode fiber N. Wavelength Mode field Ø 8. μm. μm 78.7 μm 98. μm Figure 8: Optical path of a fiber collimator with attached micro-focus optics. Intensity distribution and beam shape are maintained. Table Micro-Focus Optics M-... for fiber collimators of table with outer Ø mm row curr. no Lens type M M M M M M M S S88 S S Focal length f' Numerical aperture N lear aperture max. [mm].. Spectral range ode no. of R coating 7 - nm - nm 7 - nm 8-7 nm nm nm - 98 nm 98 - nm nm 7 - nm Design S S S S S S S S S S S S S S S S S S S S Dimensional drawing 7 Length [mm] Working distance [mm] Suitable for UH vacuum x x x x x x x x x x x x x for fiber collimators from table, curr. no. - with outer Ø mm Table Micro-Focus Optics M-... row curr. no 7 Lens type M M M M S S S Focal length f' Numerical aperture N lear aperture max. [mm] Spectral range ode no. of R coating 9-7 nm - 7 nm 7-98 nm nm nm Figure 9: The Rayleigh range is the depth of sharpness of a laser focus with a Gaussian intensity distribution. Within the range z R the beam waist increases by a factor of.. z R = Øspot zr Ø Ø Ø 8 Ø 9. Design S S S S S S S Dimensional drawing Length [mm] Working distance [mm] Suitable for UH vacuum X X X. Øspot Ø spot = wavelength in μm Ø spot = beam waist in μm Fiberollimators_9_ED.indd Page 8 for fiber collimators from table, curr. no. 7- with outer Ø mm Table Micro-Focus Optics M-... row curr. no Lens type M M M M Focal length f' Numerical aperture N...8. lear aperture max. [mm] Spectral range ode no. of R coating - 7 nm 7 - nm Design S S S S 8 Dimensional drawing 9 Length [mm] Working distance [mm] Suitable for UH vacuum Micro-Focus Optics M- M - M - - S S = short design R coating, see table -, row ff Focal length f' in mm, see table -, row Lens type: sphere M chromat S Singlet Serien: M for fiber collimator with outer Ø mm, table. M for fiber collimator with outer Ø mm, table. M for fiber collimator with outer Ø mm, table. dd T for titanium made Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 8

19 9 E Polarization Filters PF-... / PF-... Table 7 Polarization Filter PF-.../ PF-... Dimensions PF-... PF Ø Ø8.9 Ø.9.9 Retardation Optics WP-... Fiber collimator F- Quarter-wave optics WP- Figure 9: Fiber collimator with quarter-wave optics for generating circularly polarized light. The optics are locked in position with radially arranged screws.. For the fiber collimators that generate larger collimated beam diameters use the Schäfter+Kirchhoff fiber collimators T-Q... with integrated quarter-wave plate, see page. Ø. Ø 9. Ø lear aperture (mm) Table 8 Retardation Optics WP-... For fiber collimators of table with outer Ø mm row curr. no Retardation / / / / / / / / / / / / / / / / Order L: low, Z: zero L L L Z L L L L L L L L L Z L L Wavelength [nm] lear aperture max. [mm] Ø 9. Polaization filter (short) Ø Ø 9. Polaization filter (long) -8 : >8-9 PF-P - -S PF-P - -L PF-P 7 - : >87-9 PF-P - 7-S PF-P - 7-L 8 - : >9-98 PF-P--S PF-P--L 9-8 : >9 PF- - -S PF- - -L - 7 : >9 PF- - -S PF- - -L PF : >9 PF- - 7-S PF- - 7-L 8-7 : >98 PF---S PF---L 9-8 : >8-9 PF-P - -S PF-P - -L PF-P 7 - : >87-9 PF-P - 7-S PF-P - 7-L 8 - : >9-98 PF-P--S PF-P--L - x : >98 8 PF- - -S PF- - -L - 7 : >9 PF- - -S PF- - -L PF : >9 PF- - 7-S PF- - 7-L 8-7 : >98 PF---S PF---L Ø 7 Row Series Polarizer typ Spectral range Extinction Transmission Drawing Drawing Ø 9. Polarization filters are used to generate linearly polarized light. Polarization filters produced by Schäfter+Kirchhoff have an extinction ratio of typically,:. They are provided for wavelengths from nm to nm and have a surface form deviation of /. The two different types of polarization filters (table 7): Polarizing beam splitter cubes (pola rizer type PF--... / PF--...) have a high trans mission of the parallel polarized radiation and deflect the unwanted orthogonally polarized radi a tion. Dichroic glass polarization filters (polari zer type PF-P-... / PF-P-...) have smaller dimensions because of their narrow mm thickness. In order to avoid back reflection directly into the optical path, the dichroic glass polarizer has an inclined mounting of (PF-...) and. (PF-...). ll Schäfter + Kirchhoff polarization filters are R coated. The residual reflectivity is <. % for incident polarized radiation. n optional front fitting allows their use between a fiber collimator and, for example, micro-focus optics with positive locking (,, and 8 ). Quarter-wave retardation plates are used for generating circularly polarized radiation. With half-wave retardation plates, the orientation of a linear state of polarization is rotated. The WP-... wave plates from Schäfter+Kirchhoff are directly fixed to the fiber collimators of series F-... with outer diameter mm, see table. The wave plates can be rotated and are locked in position with radially arranged screws. For fiber collimators with focal lengths f' mm, table, which generate larger beam diameters, Schäfter+Kirchhoff recommends the use of fiber collimators of type F-Q... with integrated retardation optics, see page. Retardation Optics WP- WP L Retardation L: low order, Z: zero order Wavelength [nm] Retardation for /, for / Series: WP Dimensions Design S S S S S S S S S S S S S S S S Dimensional drawing 7 Length [mm] Other retardation optics, e.g. other wavelengths or dichroic retardation optics on request. Iris Diaphragms L-..., L-..., L-... and L-... Table 9 Iris Diaphragms xx L-... row Series Ø min-max [mm] mount for fiber collimators L L Ø 8 mm Table, all L L - - Ø 9. mm Table curr. no. - L L - - Ø 9. mm Table curr. no. - L L - - M 7x. Table curr. no. 7 - L L - - Ø mm Table curr. no. - Iris diaphragms are used for truncating the diameter of a collimated beam. Schäfter+Kirchhoff offers iris diaphragms for all series of fiber collimators. For fiber collimators with outer diameter mm (focal lengths - mm), an iris diaphragm which can be closed completely is available. djustment and ssembling Tools for Fiber ollimators (Overview) Fiberollimators_9_ED.indd Page 9 Table djustment and ssembly Tools row used for fiber collimators... Eccentric key EX- F-... focal lengths f'< mm Table, curr. no. - Eccentric key EX--L D as alternative for and with longer handle Eccentric key EX- F-... focal lengths > f'> mm Table, curr. no. -8 Eccentric key EX- F-T-... and F-Q-... Table, with tilt adjustment Screwdriver 9D- E all Hex screwdriver HD- F F-..., f' > mm Table, all 7 djustment tool Z-8 G F-Q..., with quarter-wave plate Page Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de E D F G 9

20 9 E Dimensional Drawings Fiber collimator Fiber collimators F-... f =.7 - mm Ø Ø8 Ø Ø8 Fiber collimators F-... f' = 8 - mm Fiber collimators F-x--M L dapters for fiber collimators F-... with focal lengths f' =.7 - mm with diameter Ø mm to outer Ø mm, Ø" (. mm) or with system mount Ø 9. mm. -M M. M Ø H7 Ø h8 Ø H7 Ø. h8 Fiber collimators F-x--M7-... Fiber collimators F-x--MS-... Ø Ø9. Ø9. Ø H7 Ø h8 Ø Ø9. Ø8.. Fiber collimators F-x-... f' = - mm Ø Ø9. Ø8 Ø Ø9. Fiber collimators F-x--M Fiber collimators F-x... f' = - mm Fiber collimators F-x--M Fiber collimators F-x--M-... Ø Ø9. Ø Ø Ø9. Ø Ø9. Ø8 Ø Ø Fiberollimators_9_ED.indd Page lamp ollars Schäfter+Kirchhoff supplies clamp collars for the fiber collimators with outer diameter mm, mm, and mm. Table row for collimator Dimensions of the clamp collars clear aperture [mm] drillings ( x 9 ) Dimensions outer diameter Ø/ pitch circle D [mm] Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de depth E [mm] thickness F [mm] Table, No. - - Ø M. Ø/.8 Ø.7. Table, No Ø M Ø./ 9. Ø9.7 Table, No. - - Ø M Ø7/ Ø.8 8 ØD fiber collimator F-T--M-... clamp collar - Mounting plate F E Ø Ø Fiber ollimators for Use with the "multicube" System Schäfter+Kirchhoff offers fiber collimator with focal lengths up to mm which directly can be adapted to the "multicube" system. Such as the Schäfter+Kirchhoff laser beam couplers SMS-... the fiber collimators F have a system mount Ø 9. mm Dimensions Fiber collimators F with system mount Ø 9. mm (fits directly into the "multicube"- system) Ø. Ø9. Ø. Fiber ollimator F-9.- For the lens selection please see the order code on page 8.)

21 9 E Fundamentals of Fiber ollimators F-... Fiber collimators made by Schäfter+Kirchhoff are designed for singlemode fibers with F connectors (optional type ST, DIN VIO and F-SM). To combine fibers with 8 angled polish (F-P, for avoidance of back reflection into the optical path) the fiber collimators F--... and F-T--... have an inclined coupling axis. This ensures a centered and concentrically symmetric laser beam equal to that of the polished fiber and fiber collimator with a coaxial coupling axis (Fig. ). The fiber collimators have an axial stop for the fiber ferrule. In addition, the fiber ferrule can be locked by a grub screw., ensuring a constant focal position and highly reproducible stability. The eccentric key. is used to focus the fiber collimator and the desired position is locked using two radially arranged clamping screws.. Fiber ollimator F-... Opto- Mechanical djustment Fiber ollimator F-... Ø mm.. Polarization Filter PF-.../PF-... Micro-Focus Optics M-...,M-..., and M-... Option: Fiber Ferrule Ø. mm Focusing of the collimating lens Locking of the collimating lens Locking of lens attachments Grub screw M. for additional locking of the fiber ferrule. Fiber ollimator F--... with coaxial coupling axis for singlemode fibers with connectors type F-P ( polish). Fiber connection (coaxial).. Grub screw for an additional locking of the fiber ferrule Singlemode fiber with polish Diverging emission =. for a fiber with N =. (/e ) ollimating lens ollimated laser beam oncentrically symmetric beam profile with a Gaussian intensity distribution. F onnector Fig. : Fiber collimator F-... with lens attachments and adjustment tools Figure : Fiber collimator with coaxial fiber connection Figure : Fiber ollimator with inclined fiber connnection The 8 polish of the singlemode fiber causes the emitted radiation to be defracted and the optical path is inclined. The design of the inclined fiber connection this fiber collimator compensates for the beam deflection. The collimated beam is centered and concentrically symmetric.. Fiber collimator F--... with inclined coupling axis for singlemode fibers with connectors type F-P (8 polish). Fiber connection (inclined).. Grub screw for an additional locking of the fiber ferrule Singlemode fiber with 8 angled polish Diverging emission =. for a fiber with N =. (/e ) ollimating lens ollimated laser beam oncentrically symmetric beam profile with a Gaussian intensity distribution Figure : ombination Mismatch When a fiber with 8 polish is used incorrectly with a coaxially coupled fiber collimator, or vice versa, a fiber with polish is used incorrectly with an inclined coupled fiber collimator then the collimated beam is axially displaced, assymetric and differs significantly from a Gaussian beam because of the resultant diffraction Figure : eam Divergence In principle, even a collimated beam has a divergence greater then zero, i.e., the beam diameter Øbeam varies with distance from the fiber collimator. The beam divergence depends (for large distances ) on the beam diameter Øbeam at the position of the fiber collimator and on the wavelength oncomitantly, the beam diameter depends on the numerical aperture N of the singlemode fiber and the focal length f of the collimating lens. Example: Wavelength = 7 nm Focal length f =. mm Numerical aperture N =. eam diameter Øbeam =.8 mm eam divergence =. mrad Figure 7: Pilot eam with approximate constant beam diameter across working range The maximum working range of a pilot beam is limited because of diffraction, according to: where Øbeam is the collimated beam diameter as in figure. pilot beam is a Gaussiam beam of essentially constant diameter within a certain working range, which is achieved by fine-adjustment. The optimum position of the beam waist is defined as distance (see table.). Figure 8: Focussed Laser eam ild 8: Laserstrahlfokussierung Ø spot Ø beam Øbeam Øspot : eam diameter in focus : Working distance f : Focal length of collimating lens MFD : Mode field diameter of singlemode fiber The mode field diameter MFD is calculated from the the numerical aperture N at wavelength Deflection limits the maximum distance of the focus, where and Øbeam is the collimated beam diameter as in figure. Figure 9: Focussed Laser Spot: Fiber ollimator F-... and Micro-Focus Optics M-... / M-... / M-... Example: Fiber collimator f =. mm Micro-focus lens f = mm Mode field Ø MFD =. μm Spot diammeter Ø spot =. μm = Øbeam = f N.8 f + Ø beam Readjustment of the collimating lens generates a focus sed beam is. t distance, relative to the fiber collimator, a beam waist with diameter Ø spot is formed. Ø spot = MFD + f ) MFD =. N.8 Ø max = f + beam, 8 Focussing a beam using a fiber collimator alone is only suitable for longer working distances (figure 8) where the spot size of the focussed beam is a multiple of the fiber mode field diameter. Focused micro spots < μm are generated by using micro-focus optics. The micro-focus optics are form-fitted to the fiber collimators. The spot size is given by the focal length ratio, micro-focus / fiber collimator, and by the mode field diameter of the singlemode fiber. To a good approximation, the spot size is given by: Ø spot = f micro-focus MFD f fiber collimator Notice should be taken of the mode field diameter wavelength dependency (see table). small change in focus alters the focus position and the spot size. Singlemode fiber N. Wavelength [nm] Mode field Ø 8. μm. μm 78.7 μm 98. μm Fiberollimators_9_ED.indd Page Figure : eam Diameter The beam diameter is given by the focal length f of the collimating lens and by the numerical Ø beam aperture of the singlemode fiber. The beam diameter is defined as the /e level (.% value) of the Gaussian intensity distribution. For singlemode fibers, the numerical aperture N is given at the % level. To account for the differences in definition, a correction factor of.8 is introduced and the beam diameter calculated as: Example: eam diameter: Focal length f =. mm, Numerical pertur N =. Ø beam = f N.8 Ø beam =.mm..8 =.8mm Figure : Rayleigh Range The Rayleigh range is the depth of sharpness of the laser focus with a Gaussian intensity distribution. Within the range zr, the beam waist increases by a factor.. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Ø spot Example: Spot size: Ø spot =. μm Wavelength: = 7 nm Rayleigh range: z R z R =. μm = 9 μm.7 z R = Øspot

22 9 E Special Fiber ollimators for Quantum Optics and for M OT agneto ptical raps Fiber ollimators with Elliptical eams for D-MOTs In some quantum-optical experiments collimated laser beams with an elleptical cross section are used as cooling beams in so called D-MOTs ( dimensional magneto-optic traps). Schäfter+Kirchhoff offers fiber collimator F-E-... with an collimated elliptical beam. The state of polarization can be linear or circular. Special Fiber ollimators. Retro reflector. eam combiner. Elliptical beam. ircular polarisation. Power monitoring Output. Tilt adjustment Elliptical good bad Figure : Elliptical cross section of a collimated beam. The state of polarization can be adjusted with respect to the ellipse achses The main features are: Polarization extinction ratio > : Gaussian intensity profiles in x direction and in y direction Example: Elliptical beam.7 mm x mm (:) Spectral range - nm, design wavelength nm beam profile Input Singlemode fiber with circular emission profile -TILT Fiberollimators_9_ED.indd Page Schäfter+Kirchhoff offers a variety of fiber collimators with special features. Special fiber collimators are built up with standard collimator housings (see page ), with construction kit "multicube" (see page ) or with customized design. We combine all optics depicted at page, and 7 with retardation optics and polarization filters (see page 9), optics like beam combiner, splitter, photo diode (see page ), anamorphotic optics (see page ), diffractive optics (see page ), Faraday isolator (see page ), diaphragms (see page 9), special adjustment possibilities and more. The output can be collimated or focussed respectively. For example, we offer fiber collimators with integrated: Retro reflector and quarter-wave plate for the reflection of circular polarized light without changes in state of polarization, e.g. for magneto-optical traps. F-...-RR, see page eam combiner for the combination of different wavelength which are too different as to be guided by one single fiber. or for combining two fiber-coupled inputs in order to have different states of polarization F-8-..., see page namorphotic optics for elliptical beams with low deviation and Gaussian shaped beam profiles in x-y direction. F-E-... or Fiber collimators with cylindrical micro-focus optics for generating laser spots with elliptic cross section Quarter-wave plate for circularly polarized collimated beams, e.g. for a selective stimulation of individual Zeeman levels in a magneto -optical trap MOT. F-Q-..., see page Power monitoring for the online control of laser power and power fluctuations. F-8PD-..., see page Tilt adjustment to avoid a vignetting of the beam by aligning the optical to the mechanical axis. F-T-..., see page 9 ustomized optical and opto-mechanical designs are a speciality of Schäfter+Kirchhoff. The resulting products combine optimum optical performance with a ruggedized mechanical design. Dimensions F - Ex Figure : Optical scheme Fiber cable, Laser beam coupler used as fiber collimator namorphotic beam expander, Expansion optics spectral range = F-P = F-P Dimensions of elliptical axes long axis x short axis Fiber ollimators with Micro-focus Optics for Elliptical Spots Schäfter+Kirchhoff offers fiber collimator with cylindrical micro-focus optics generating a spot with eliptic cross section, as example: Elliptical spot μm x μm (:) Working distance mm Figure : Optical scheme Fiber cable, Laser beam coupler used as fiber collimator beam expander, cylindric focussing optics Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

23 9 E Fiber ollimators F-Q... with integrated quarter-wave plate Fiber ollimator F-Q... ollimating lens (achromat f = - mm) onnection for singlemode fiber cable with connector type F-P Tilt adjustment D Inner focussing mechanism E Locking of the collimating lens D E F Fiber collimator with quarter-wave retarder plate for a magneto-optical trap (MOT) fiber collimator transforms the divergent radiation at the end of a single mode fiber into a collimated beam, whose diameter and divergence are dependent on the numerical aperture (N) of the fiber and on the focal length f of the collimating lens. The F-series of fiber collimators made by Schäfter+Kirchhoff can produce beam diameters up to 7 mm from a input source of >. μm, have an integrated tilt adjustment and a threaded socket for coupling the input singlemode fiber cable using an F-P connector. Fiber ollimators F-... with integrated tilt adjustment The F-... series is supplied with a fiber cable connection with an integrated tilt adjustment. Emitted radiation is coaxially aligned with the mechanical axis of those fiber collimators with longer focal lengths ( f mm to f mm). F /-retardation plate Figure : Fiber ollimator F-Q... with f = 7 mm with an integrated quarter-wave plate. Table Fiber collimators with integrated quarter-wave plates F-Q... row curr. no 8 9 Lens type M L M L M7 M S M M Focal length f' 7 Numerical aperture N lear aperture max. [mm] 8 8 ollimated beam diameter [mm]* eam divergence [mrad]* orrection - monochromatic 8 - chromatic x x x x x x Spectral range 9-7 nm - 7 nm - 98 nm - nm 7 - nm nm Housing diameter /. /. /. /. /9 /9 Front fitting 7x. 7x. 7x. 7x. Ø Ø 7 Dimensional drawing More fiber collimators with integrated quarter-wave plate, see table, fiber collimators F-T-... * with fiber N., ** optional type ST, DIN-VIO, or F-SM djustment of quarter-wave plate n accurate alignment of the retardation optics is achieved using the computer-controlled Schäfter+Kirchhoff SK978 polarization analyzer, which is attached to the fiber collimator using a micro-bench adapter (Fig. ). fter loosening the two radially arranged fixing screws, the retardation plate is aligned using a cogged adjustment tool (Fig. ). The accuracy of the alignment and the circularity of the laser radiation is monitored on screen using the polarization analyzer. Screenshot. shows the state of polarization before alignment of the retardation plate (or of a fiber collimator without a wave retarder) and screenshot. shows a perfectly adjusted, circularly polarized state (indicated by the spot at the north pole on the Poincaré sphere, arrowed). ny small beam deviations caused by attached optical devices can also be re-aligned. The deflections and aberrations caused by vignetting of the collimated beam are also obviated. The fiber collimators of series F-Q... have an integrated quarterwave plate. The radiation emitted by these fiber collimators is used in magneto-optical traps (MOT) as + (left-hand circularly polarized) and - (right-hand circularly polarized) radiation for a selective stimulation of individual Zeeman levels, for example. Low order quarter-wave plates are used because of their low angular dependency. Fiber collimators of type F-Q... are provided for the wavelengths nm, 7 nm, 77 nm and 78 nm with other wavelengths available on request. The retardation optics are aligned after assembly by use of a special cogged adjustment tool and, finally, the desired position is locked using two radially arranged grub screws, see Fig.. Fiber collimators made by Schäfter+Kirchhoff of series F- Q... are designed for beam diameters up to mm. connection for singlemode fiber cables with connectors of the type F-P is provided and they have an integrated tilt adjustment. Figure : Rear view of fiber collimators F-Q... with integrated tilt adjustment and quarter-wave plate. The marked axis of the retardation plate is shown in a window. special cogged adjustment tool Z-8 is shown in place on the fiber collimator. Dimensional drawings -TILT. More dimensional drawings see page. F - Q M7 - R coating (see Table, row 9 - ) ollimating lens (see Table, row )) = F-P = F-P T Q... = tilt adjustment = / plate, e.g. Q7 for = 7 nm Fiberollimators_9_ED.indd Page Figure Polarization analyzer attached to a fiber collimator using a micro-bench adapter. Screenshot. shows an elliptical polarization state and screenshot. a circular state of polarization. fter removal of the special adjustment tool and tightening of the two locking screws, the retardation plate is fully protected against unintentional displacement during use or shipment. ssembly and adjustment tools Eccentric key EX- Hex screwdriver HD- WS. mm Screwdriver 9D- WS. mm D djustment tool Z-8 for wave plate Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de D

24 9 E Fiber ollimators with Retro Reflector Fiber collimators with retro reflectors have an integrated mirror to back reflect the beam into the fiber. It must be considered that circular polarized light changes its rotation direction after reflection. Therefore, Schäfter+Kirchhoff offers as an option retro reflectors with integrated quarter-wave plate. The quarter-wave plate transforms the circular polarized light into a linear state of polarization, which is uneffected by the reflection. When the beam passes the plate again it is transformed in the former circular polarization state. Retro reflector Quarter-wave plate Tubus and focus adjustment Focussing lens F-RR- Qxxx - T - - M7 - R coating (see Table -, row 9 ff) ollimating lens (see Tab.-, row ) = F-P = F-P Tilt adjustment Retardation optics Q + wavelength (nm) - = none The main features are: Integrated photodiode Integrated beam splitter 98: Great selection of collimation optics, see page ff daptable optics, e.g. beam expander Spectral range - nm compatible to "multicube" and micro bench robust design N connector Laser beam coupler SMS eam splitter 98/ Expansion optics Photo diode 8PD Fiber ollimators with Integrated Power Monitor Some laser sources show variations in laser power or in the state of polarization over time. In that case, a power monitor is usefull to check or log the laser power during use online. Schäfer+Kirchhoff offers fiber collimators with integrated beam splitter and photo diode for that purpose. The incomming beam is collimated and a polarizer suppresses radiation guided in the fast fiber axis due to cross talk. The radiation is split in such way that % of the power is detected by the photo diode. Since all parts are system mount, further optics can be adapted, e.g. with a beam expander. The design of the collimator takes into account that the beam gets an offset when it transmitts the beam splitter. F - 8PD - T - - M7 - - : eam expansion ratio R coating (see Table -, row 9 ff) ollimating lens (see Tab.-, row ) = F-P = F-P T = Tilt adjustment Photo diode Fiberollimators_9_ED.indd Page eam ombiner LP xxx Spectral range [nm] Reflection Transm. Pol. long pass LP s LP s LP7-9 - s LP p LP p LP s short pass SP -7-8 p Laser eam coupler SMS eam combiner 8 Expansion optics The described collimator is just an example of several possible solutions. Please contact Schäfter+Kichhoff for further information. The described collimator is just an example of several possible solutions. Please contact Schäfter+Kichhoff for further information. Fiber ollimators with Dichroic eam ombiner The "multicube" system is used to produce fiber collimators with dichroic beam combiner. Fiber collimators with two fiber connections are used, when the difference in the two wavelengths of the beams is too large to be transmitted by a common singlemode fiber. dditionally, by defocussing one of the input channels it is possible to compensate chromatic aberration of the exit optics. The main features are: Two or more input channels Great selection of collimation optics, see page ff daptable optics, e.g. beam expander Spectral range - 7 nm ompatible to "multicube" and micro bench robust design F T - - M7 - - : eam expansion ratio R coating (see Table -, row 9 ff) ollimating lens (see Tab.-, row ) = F-P = F-P T = Tilt adjustment eam combiner 8-8- Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

25 9 E namorphic eam-shaping Optics N-.... D namorphic eam- Shaping Optics N-... E eam cross-section, circular Laser eam oupler SMS-... Singlemode Fiber able with F-P onnector F namorphic lens with astigmatic correction namorphic prism lens E. namorphic beam-shaping optics N-... orrection of laser diode astigmatism Laser beam source with elliptical beam profile ircular beam profile Elliptical beam profile eam cross-section, elliptical ollimation Lens L-... / L-... Laser diode * Laser diode with astigmatic difference s* Often, the elliptical beam profile of laser diodes is not desired but a circular profile. namorphic optics act one-dimensionally on the elliptical profile of the collimated beam and reduce the larger beam diameter and matching it with the smaller one. Thus, a radially symmetrical beam is obtained. The anamorphic beam-shaping optics from Schäfter+Kirchhoff are cylinder lens systems and can, therefore, be used to correct the astigmatic difference, s, of the laser diode through a re-focussing of the optical system. oupling efficiencies of 8% to singlemode fibers or more are possible with anamorphic beam-shaping optics, depending on the beam characteristics of the laser diode. Radially symmetrical output beam by reduction of the longer elliptical axis (beam-shaping factor. -.) Maximum laser beam diameter mm Integrated astigmatism correction No lateral beam shift or beam deviation problems Spectral range 9 - nm High fiber-coupling efficiency (over 8%) Fully integratable with "multicube" system, collimators and adapters through Ø 9. mm mounting Laser diodes have large aperture angles vertically (s) and smaller aperture angles in parallel (p) with the light-emitting layer. These virtual emission sources of the s- and p-directions are manifest in the local displacement, s, of the optical axes. The collimating lens produces a collimated elliptical beam with a Gaussian intensity profile. The astigmatic difference, s, determines that the beam is parallel in only one of the directions and is divergent in the other. D The anamorphic beam-shaping optics contains both positive and negative cylinder lenses, reducing the longer elliptical axis to that of the shorter axis and correcting the astigmatism. To compensate for the divergence induced in the s-direction, the distance between the elements of the cylinder lens is increased (astigmatism correction). E The output beam profile of the anamorphic beam-shaping optics is circular and the beam is parallel (depending on the beam divergences of the laser diode and on the anamorphic form factor). fter astigmatism correction, the wave fronts are planar. The in put aperture of a laser beam coupler (see laser beam couplers SMS-... page ) is matched to the smaller output beam diameter (typically. mm). F The focussed laser spot of the coupling lens is not only circular but also has plane wave fronts. Without astigmatism correction (e.g. when beam shaping is performed using anamorphic prism optics), the focal area retains the curved wave fronts of the elliptic beam. Form Factor The anamorphic effect is described by the form factor F, which indicates the relative diameter change of the parallel beam. The target value is calculated from the ratio of the beam apertures Ø and Ø of the laser diode. The beam apertures at.% of the Gaussian beam profile are calculated from the % values (FWHM) of the laser diode aperture angles and according to the formula: N =.7 sin ( /). eam shaping and coupling into singlemode fibers The optically active axis of the anamorphic beam-shaping optics is orientated in parallel with the longer elliptical axis of the collimated laser beam. The circular V-groove at the inlet of the anamorphic optics provides a positive, rotatable and lockable socket connection with the laser diode collimator. When coupling into polarization-maintaining fibers, the polarization axis of the laser beam must be aligned with one of the two polarization axes of the fiber (usually the slow axis). The alignment of the polarization axis is facilitated by the rotatable and lockable adapter flange 9.M-L on the exit side of the anamorphic optics. On both the F connector and the laser beam coupler, a mechanical index not only indicates the polarization axis but also engages in a groove to provide a reproducible and positive locking of the desired orientation. namorphic beam-shaping optics dapter 9. M-L Laser beam coupler SMS-... D Laser beam source with elliptical beam profile D E Singlemode fiber with F connector Technical Data namorphic beam shaping optics ttachments Dimensions Form Wavelengths factor range [nm] F N-.-V N - - V N - - V N - - V N-.-V N-.-V N - - V N - - V N - - V N - - V-9 dapter 9. M-L Ø The adapter 9.M-L enables the laser beam coupler SMS-... to be positively and reproducibly locked into the beam-shaping optics. namorphicoptics_9_e.indd Page E Orientation and locking of the anamorphic beamshaping optics with the laser beam ellipse stigmatism correction Locking of optics for astigmatism correction djustment and locking of the polarization axis Eccentric key EX- Hex screwdriver WS. mm HD- Screwdriver WS. mm 9D- Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Tools Laser beam coupler SMS-... namorphic beamshaping optics

26 9 E Laser Pattern Generators P... Diffractive beam-shaping optics dapter for fiber collimator F-...-M- Miscellaneous patterns, consisting of single laser spots High diffractive efficiency precise structures, high power density and minimal granulation Optics for various working distances Focussable with integrated focussing mechanism Spectral range nm Minimal distortion of the beam pattern because of perfect Gaussian beam shape of the coupling beam Flexible handling because of the small desing and the singlemode fiber coupling Table Laser Pattern Generator P... Table. Grid Fan angle = eam Parameters Line Length Diameter L/D [mm] Line Distance d [mm] Line Width [mm] Working Distance [mm] Rayleigh Range z R [mm] Fiber collimator F-... Focusing Range [mm] Pattern Optics P PG-9x9-M PG-9x9-S PG-9x9-S Diffractive beam shaping is produced by diffraction at periodical and non-periodical microstructures (synthetic hologram). The diffractive optical elements from Schäfter+ Kirchhoff are multi-level or analogous phase structures of high transparency and generate line patterns with a regular structure, including grids, circles, crosses or multiple lines. The grid sizes, diameters or line distances specified in table are valid for the standard working distance of the beam-shaping optic. Working distances different from the stated focussing range can be achieved by simply refocussing, with the size of the generated pattern changing as a function of the chosen working distance. The more complex structures (such as grid, circle or cross) consist of a large number of single laser spots. In principle, all diffractive beamshaping optics show minimal geometric deviations from the ideal (distortion). In applications such as D profile measurements, cali bration techniques are used to account for pattern distortion. The diffractive optical elements used by Schäfter+Kirchhoff have a high diffraction efficiency and the desired pattern contains approximatly 7% of the laser power. The resulting laser power appears as an undiffracted central spot (th diffraction order) in the center of the pattern. Grid PG- Grid with 9x9 areas Fan angle 89 spots ircle P- ircle concentric to a central spot Fan angle 7 spots d L pplication rosshair PX- Two apposed perpendicular lines Fan angle spots Multi-line PL- lines Fan angle Line distance. ontour monitoring and D ob ject measurement with structured illumination L Table. rosshair Fan angle = PX-M PX-S PX-S D L d Table. ircle Fan angle = P-M P-S P-S Dimensions d. Table. Multi-line Fan angle = PL-.--M PL-.--S PL-.--S Ø Ø 8 Laser Pattern Generator P... Ø Ø8 Fiber ollimator F-... Laser Pattern Generator P- Pattern optics: PG - 9x9 - M + F - - M - Fiber collimators F-...: PG Grid pattern, table. F--M- with F-P connector PX rosshair pattern, table. F--M- with F-P connector P ircle pattern, table. PL Multi-line pattern, table. For more fiber collimators see page -7 More information obout pattern optics, e.g. laser diode modules with integrated pattern generators, see or LaserLine, Micro Focus, Laser Pattern Generators, Laser Diode ollimators catalog Laser Sources for Fiber ollimators with Pattern Generators 8FM-... pagepage 8 nanofm-... pagepage Laser_Pattern_P_E.indd Page HeNe--... page 9 Laser eam nalysis: Ref.: SK977 Intensities.% 9.% 8.% 7.%.%.%.%.%.%.% Object: Fiber ollimator ollimating Lens M eam Diameter (/e ).8 mm Wavelength nm Lasersource Singlemode Fiber Mode Field Diameter. μ m Numerical perture. Schäfter + Kirchhoff Intensity Profile LOW NOISE and REDUED SPEKLE Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Gaussian Hamburg Fit

27 9 E RGV RGV Fiber Optics Efficient combination of nm laser beams into a single polarization-maintaining output fiber Laser eam ombiner 8-RGV-.../ 8-RG-... Specially designed for quantum optics and confocal microscopy Laser radiation combination system, /88,, nm with fiber-coupled radiation collimated from upt to four RGV sources using up to three dichroic mirrors pochromatically corrected RGV laser beam coupler ombined beam coupled into a polarization-maintaining singlemode fiber ll necessary components are provided for the efficient combination of up to four laser sources of wavelength nm in a single polarization maintaining output fiber. The modularity of the RGV fiber optic components promotes their effective and simple implementation in a large variety of beam combination tasks. Optical Scheme RGV Laser eam ombiner OUTPUT P LP- PM SMS LP- PM INPUT RGV_p_9_ED_fg.indd Page 7 RGV Laser eam oupler for Singlemode fiber inclined fiber coupling axis RGV Fiber ollimator F---RGV-7 Divergent beams emanating from the output fiber are transformed into collimated beams of mm diameter. The apochromatically corrected optics ensure consistent collimation over the entire nm range. RGV Laser eam oupler SMS---RGV-7 PM Fiber able PM--... For a broadband wave guidance suitable for RGV purposes, Schäfter+Kirchhoff provides polarization maintaining singlemode fibers in a wavelength range of nm - nm and photonic crystal fibers for UV - 8 nm. The RGV laser beam coupler has apochromatically corrected optics for the full range of, /88, and nm laser beams. The collimated violet, blue, green and red laser beams are focussed onto a common point with optimum coupling efficiency over the entire - nm range: an extremely difficult task with conventional aspheric or achromatic optics. OUT Polarization Maintaining Fiber able PM-... / PF-... Nominal wavelength nom -Si -Si - ut-off wavelength co < < < none Operation wavelength range UV - 8 Mode field diameter MFD[μm] ±. Numerical aperture N [μm] Pure silica core x x x D The Schäfter + Kirchhoff RGV Fiber Optics, including dichroic beam combiners and collimation optics, are specifically designed for the combination of the designated wavelengths:, /8, and nm. Laser beam combiners couplers collimators D fiber cables & E laser sources are available for these and other wavelengths. ontact Schäfter + Kirchhoff for more information. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de PM Spectral Range SMS SMS Laser beam coupler PM PM fiber cable LP Long-pass filter ttenuator P Polarizer pochromatic orrection D LP- SMS PM SMS SMS PM INPUT V INPUT R INPUT G onventional lenses and optics show chromatic aberration which produces different focal lengths for the different wavelengths. pochromatic correction of this chromatic aberration over a desired spectral range helps to reduce the deviation in the focal plane by up to an order of magnitude in comparison with achromatically corrected optics. Schäfter+Kirchhoff offers the RGV optics apochromatically corrected for the spectral range - nm. Rel. oupling Efficiency % Transmission Spectra of eam ombiners Transmission R Single RGV Laser Sources urves Wavelength [nm] T R Focus Position [μm] Dimensions of Fiber ouplers and ollimators Laser beam coupler SMS--... with inclined fiber coupling axis for F-P connector (8 polish).. onnector T R Ø9. Ø. T LP LP Fiber collimator F--... with inclined fiber coupling axis for F-P connector (8 polish) Ø Ø8 LP7 Maximum coupling efficiency is at the conjoint focus position for the red, green, blue and violet laser beams. 7

28 9 E RGV Optical scheme RG Laser eam ombiner OUT PM RGV RGV SMS Laser eam oupler SMS--- RGV-... SMS Laser beam coupler PM PM Fiber cable LP Long-pass filter ttenuator P Polarizer Transmission R T R P T R LP- Optical scheme for 8--LP... beam combiner with s-polarization optimization: for all linear states of polarization perpendicular to the plane of incidence SMS SMS PM LP- PM SMS LUE PM 88 9 Wavelength [nm] T LP LP LP7 RED GREEN Transmission spectra of the dichroic beam combiners 8--LP... Dimensions Laser eam ombiner 8-RGV-.../ 8-RG-... See page 7 for optical scheme of laser beam combiner 8-RGV-... eam ombiner / Long Pass LP-... Spectral range Reflection Transm. Pol. nm 99% 9% s s s The Laser eam ombiner takes the individual beams, each incoupled via polarization-maintaining singlemode fiber cables, and produces a combined output into a single polarization-maintaining fiber. This particular modular system combines up to four wavelengths in the range - nm. The individual laser power sources of each wavelength can be attenuated separately so that any desired power relations can be obtained. The fully optimized dichroics from Schäfter+Kirchhoff superimpose the individual laser beams and have a. wedge profile to avoid interference from back reflected light (Etalon effect). Propagation through parallel plates causes a beam off-set, which is corrected by a compensatory axial displacement of the laser beam couplers. n attenuator allows the adjustment of the combined laser power. The tilt adjustement and inner focussing mechanism of the laser beam couplers, as well as the tilt adjustment of the dichroics, provide all of the degrees of freedom needed for alignment. The design ensures a highly stable structure that can be immediately put to use with confidence. Laser radiation combination system, /88, and nm for collimated fiber-coupled radiation pochromatically corrected RGV Laser eam oupler Long pass LP, broad transmission band for cascaded use of various long pass filters (transmission up to 9 % and reflection up to 99 %) Fused silica substrates with. wedge angle to suppress interference Inclined coupling axes to avoid back reflection RGV eam splitter and beam combiner with wedge-shaped substrate: Laser eam ombiner 8-RGV-... ombination of four different wavelength Three dichroics for superposition See page 7 for optical scheme and for dimensions RG Laser eam ombiner 8-RG-... ombination of three different wavelength Two dichroics for superposition See left for optical scheme and for dimensions Substrate without wedge: eams are reflected twice at the substrate/ air interfaces together with the primary beam. ll are focussed by the coupling lens onto the shared fiber input. Interference of the primary beam by these secondary beams causes intensity instabilities (Etalon effect). Substrate with wedge:the principle beam and the beams reflected at the substrate/air interface are inclined twice with respect to each other. The focussing optics transforms the different beams into distinct spots. The tilt mechanism of the laser beam coupler brings the principle spot onto that of the fiber input and the inclined secondary spots are lost. The loss of inter ference ensures intensity stability. Laser eam ombiner 8-RGV-... Laser eam ombiner 8-RG-... out 8 fiber fiber /Ø 9. out fiber fiber /Ø 9. RGV_p_9_ED_fg.indd Page 8 fiber fiber DIN 9 - M x (8x). 9 8 Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de fiber DIN 9 - M x (8x). 9

29 9 E RGV RED GREEN LUE Laser eam oupler SMS-... VIOLET pochromat Table Lenses and beam parameter row curr. no. Lens type RGV Focal length f' Numerical aperture N. lear aperture max. [mm]. orrection - monochromatic " - chromatic x Input eam Diameter Numerical aperture of.. the fiber.... R-coating - 7 nm 7 Rel. oupling Efficiency % Focus Position [μm] The RGV-... laser beam couplers are specially designed for coupling to polarization-maintaining singlemode fibers and provide apochromatic correction over the range - nm. Individual red, green, blue and violet laser beams are combined and focussed onto the same position with optimum coupling efficiency over the entire wavelength range. Major applications include confocal microscopy, quantum optics and fluorescence microscopy. Figure : Maximum coupling efficiency is at the conjoint focus position for the red, green, blue and violet laser beams. RGV Fiber ollimator F-... Fundamentals on fiber connection see page inclined coaxial Fig. : Fiber collimator F-..., housing Ø mm, focal lengths up to mm. For fiber collimators with longer focal lengths see F-T-... page 7. Table Lenses and beam parameters Fiber ollimator F-... (housing Ø mm) row curr. no Lens type M M.S 7. M8 RGV M-NIR M 8 M Focal length f' Numerical aperture N lear aperture max. [mm] ollimated beam diameter [mm] eam divergence [mrad] orrection - monochromatic x x x x x x x x 8 " - chromatic x x x x x x 9 eam diameter [mm] Spectral range ode no. of R coating 7 - nm 9-7 nm - 7 nm - 7 nm 7 Figure : pochromatic RGV lenses are supplied as: Laser eam ouplers SMS---RGV-7 or as Fiber ollimators F---RGV-7 Fiber collimators in a Ø mm housing made by Schäfter+Kirchhoff are available with a variaty of focal lengths (see page ). F-... fiber collimators are provided with internal focussing and a front fitting Ø 8 mm for connecting micro-focus optics of the series M-.... The values for beam diameter (/e -value of Gaussian intensity distribution) and divergence given in table refer to a wavelength = 7 nm and a fiber N =.. The collimating lenses of type M are corrected for spherical aberration (mono chromat) or for chromatic aberration (achromat). oth produce an undisturbed Gaussian beam profile. The collimating lenses of type are aspheric lenses. Their specific manu facturing process leaves micro-structures on the lens surface, which also affect the collimated beam but not the focussed beam. The fiber collimators have a coaxial or inclined coupling axis for accepting the fiber con nectors F-P and F-P, respectively (optionally ST, DIN VIO and F-SM). The fiber connection has an axial limit stop to ensure a constant focus position, particulary for fiber collimators with an inclined coupling axis. Fiber collimator F- F-9. with system mount Ø 9. mm (fits directly into the "multicube"- system) F--M- R coating Lens type: = asphere M = monochromat or achromat Fiber connection for: = F-P connection (8 polish) = F-P connection ( polish) RGV_p_9_ED_fg.indd Page 9 Order Option The 8-RGV-... Laser eam ombiner is supplied as a completly adjusted system with: 8-RGV RG-... dichroics for RGV combination 8--LP, LP, LP7 dichroics for RG combination 8--LP, LP7 Laser eam oupler with RGV optics and F-P connector SMS--RGV-7 Laser eam ouplers with F-P connector for input sources of the wavelength nm, /88 nm, nm and nm Laser eam ouplers with F-P connector for input sources of the wavelength /88 nm, nm and nm Schäfter+Kirchhoff recommends ordering fiber cables (PM-.../ PF-...) with P polish and fiber collimators, especially with RGV optics and F-P connector (F---RGV-7). Please do not hesitate to ask Schäfter+Kirchhoff about suitable beam sources or other specifications of beam combiners, e.g. with other combinations of wavelengths, different numbers of beam sources or other connectors according to your needs. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 9

30 9 E Polarization Maintaining Singlemode Fiber ables Schäfter+Kirchhoff supplies polarization-maintaining fiber optics with broadband wave guidance for RGV purposes PM-... Type Panda or Oval-Inner lad Depiction of a Panda fiber with the two stress induction components in the fiber clad ding that cause birefringence. s for all singlemode fibers, the PM fibers have a cut-off wavelength. Photonic rystal Fiber PF-... Depiction of the hexagonal pattern of the photonic crystal fiber micro structure. The major benefits include a larger mode field diameter and a wider spectral range for singlemode ope ration. MFD [μm] N 7 8 wavelength [nm] The MFD of PM fibers is a function of the wavelength while the N remains constant Typical intensity profile of a PM-... fiber. The diameter of the profile is independet from the wavelength. MFD [μm] wavelength [nm] The N of PF fibers is a function of the wavelength while the MFD remains constant. N Differences between step-index singlemode fibers SM/PM (right) and polarization-maintaining photonic crystal fibers PF (left). MFD = const. N( ) N = const. MFD( ) The N of PF fibers is a function of the wavelength and the MFD remains constant, while the converse pertains for SM/PM fibers. nm Gaussian intensity nm Intensitity profile profile at = nm. for nm. For 8 nm The laser source has lasers with %-Level N N N.7 a reduced coherence.9 long cohe rence. length (nanofm-.., length the intensity page ). The diameter of the in ten si ty distri bu tion is small at this wavelength. dis tri bution would differ from the Gaussian shape. Gaussian intensity profile at 8 nm. The laser source is again a nanofm-... with reduced coherence length. The diameter is obviously larger in comparison to nm and nm. This clearify the wavelength dependency of the N for PF-... fibers. Photonicrystal.indd Page Schäfter+Kirchhoff supplies polarization-maintaining singlemode fiber cables for RGV applications: Wavelength range: nm Pure silica core fibers for an increased transmission in the short wavelength range Mode field diameter.. μm F-P or F-P fiber connection Polarization direction indicated by the connector index For other PM fiber cables, singlemode fiber cables SM-... and the order codes, see page 9. Table Polarization Maintaining Fiber able PM-... row curr. no Nominal wavelength nom -Si -Si -Si ut-off wavelength co < < < < Operation wavelength range Mode field diameter MFD[μm] Numerical aperture N [μm].... PM fiber type PM-...-P PM-...-P PM-...-P PM-...-P 7 Pure silica core x x x PM--.8-N--P--P PM fiber type: P = Panda Length in cm (standard = ) onnector Type: P = F-P (8 -angled polish) P = F-P ( -polish) XP = one end F-P, other F-P VIO, VIO-P cable type: = Ø mm PV cable with Kevlar strain relief (standard) = fiber cable with Ø.9 mm buffer (for short F connector) Numerical aperture N Mode field diameter MFD at nominal wavelength Nominal wavelength PM = polarization-maintaining singlemode fiber cable Photonic crystal fibers optimized for singlemode operation have a wide spectral range combined with a relatively large mode field diameter. eing made from fused silica the fiber is resistant to solarization effects. The numerical aperture of photonic crystal fibers is a function of the wavelength used (unlike the more conventional step-index single-mode fibers where mode field diameter varies with wavelength). Photonic crystal fibers are capable of providing an essentially endless singlemode operation with no cut-off wavelength. It must be noted that attenuation is about d higher for shorter wavelengths in comparison with pure silica core fibers and that the beam only approximates a Gaussian profile. selection of different types of photonic crystal fibers is available, all manufactured by rystal Fibre, Please contact Schäfter+Kirchhoff for further information. Table PM Photonic rystal Fiber able PF-... row curr. no Nominal wavelength nom UV ut-off wavelength co none Operation wavelength range UV - 8 Mode field diameter MFD[μm]. ±. Numerical aperture N [μm] PM fiber type PF 7 Pure silica core x PF--P- Length in cm (standard = ) onnector Type: P = F-P ( -polish) F-P, VIO, VIO-P cable type: = Ø mm PV cable with Kevlar strain relief (standard) = fiber cable with Ø.9 mm buffer (for short F connector) PF = polarization-maintaining photonic crystal fiber cable Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

31 8 9 E onstruction Kit multicube 8M-... F ombination ubes and Plates 8M- pplications: see page Fiber port cluster for a magnetooptical trap D Laser beam coupler SMS, page. E. 8 Single-ube with through holes for linear arrangements, short design 8M-SM-9. Single-T-ube for T-arrangements 8M-LTS-9. F. Figure : multicube element. radially arranged screws M for fixing the connecting rods 8,. screws M for fixing components with 9. mm system mount, and. screws M for fixing a variety of adapter flanges. Polarization beam splitter, eam splitter, D eam combiner, E Retardation optics, F Laser beam coupler Double-ube with through holes for linear arrangements 8M-LI-9 Double-T-ube for T-arrangements 8M-LT-9. The multicube construction system is the perfect integration platform for laser beam couplers, beam combiners, beam splitters, polarizers or retardation optics. The multicubes are combined and supported using four Ø mm rods in parallel, which are compatible with established micro-bench systems. The rods are located in full through-holes or partial blind-holes at least diameters deep ( mm). Each rod is locked using two M screws (. mm Hex screwdriver) that are radially opposed across the multicube, ensuring high reproducibility by totally preventing any distortion. Self-supporting modules and laser beam sources can be created that are extremely resistant to torsion, by combining components such as a laser diode collimator 8T, a Faraday iso lator 8FI-- and the mounting console 8M. The design features of the Schäfter+Kirchhoff multicube components ensure highly rugged and warp-resistant setups, especially for singlemode coupling. Precision is everything: as the mode field diameter of a singlemode fiber at 78 nm is only μm - ten times thinner than a human hair! pplications: see the laser diode beam sources 8TE-..., page and fiber port clusters for magneto-optical traps (MOT) on page. Single-X-ube for X-arrangements 8M-LTD-9. Triple-X-ube for X-arrangements 8M-L-9. Mounting Plate Extended Mounting Plate for components with Ø 9. mm for components with 9. mm system mount or with Ø mm system mount or with mm 8M-MP-9. 8M-SP-9. 8M-MP- 8M-SP- Mechanical Shutter aperture Ø mm system mount Ø 9. mm 8T-S Fig.: Laser with two fiber system Mechanical Shutter with micrometer screw, aperture Ø mm system mount Ø 9. mm 8T- x-y djustment plate for lateral adjustment, translation mm 8M-9.-SXY- Multicube_9_ED.indd Page Fiber-optical components: Retardation optics / 8WP-- -L Polarization beam splitter 8PM-- Polarizer 8PM-S Laser beam coupler SMS-... Singlemode fiber cable PM Option: fiber collimator F--... Extended Mounting racket x mm or x mm, system mount Ø 9. mm 8M-9.- 8M-9.- Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

32 9 E Optics for the "multicube" System eam Splitter and eam ombiner Polarizers Polarization eam Splitter 8PM-... eam-splitting cube with internal dielectric and polarizing multi-layer coating. In adjustable mount, for mounting with clamp collar (included). : split ratio for linearly polarized input radiation with polarization direction =. Maximum transmission at = (p-pol.), maximum reflection at = 9 (s-pol.). extinction ratio, : aperture mm reflection angle 9 broadband R coating R <.% per surface pplication: eam splitter with adjus table splitting ratio, in combination with retardation optics 8WP--... Polarization eam Splitter 8PM - - Spectral range [nm] = - 7 nm = 7 - nm = - 7 nm eam Splitter ube / 8M-... : split ratio independent of polarization aperture mm reflection angle 9 broadband R coating per surface eam Splitter / 8M - - Spectral range [nm] = - 7 nm = 7 - nm = - 7 nm D Polarizer 8PM-... adjustable within adapter flange polarization: linear extinction ratio,: aperture. mm broadband R coating: R <.% per surface variety of designs Polarizer in adapter flange as 8M-9. 8PM-S-... Polarizer as 8PM-S decentered. mm for combining with beam splitter plate 8S-... 8PM-S-D-... D Polarizer with attenuator in adapter flange 8T-9.-S 8PM-T pplication: For increasing the ex tinction ratio after collimating the radiation of a polarizationmain taining fiber Polarizer 8PM - S - Spectral range = - 7 nm = 7 - nm = - 7 nm Multicube_9_ED.indd Page eam Splitter 98/ 8S--P In adjustable mount, for mounting with clamp collar (included). mm fused silica plate, uncoated. wedge angle for interference suppression. transmission 98% (p-polarization) reflection % per surface (p-polarization) aperture mm pplication: Separation of a partial beam for power monitoring eam Splitter 98/ 8S - - P eam ombiner 8--LP... Two laser beams of different wavelengths are coaxially combined into a single laser beam with equal polarization. In adjustable mount, for mounting with clamp collar (included). mm fused silica plate with wavelength-dependent dielectriccoating and. wedge angle for interference suppression long pass (LP) and short pass (SP) version optimized for angle of incidence, p-polarization fused silica plate coated reverse surface aperture mm reflection up to 99%, transmission up to 9%. pplication: For the coincident coupling of laser diode beam sources of different wavelengths and identical polarization into one singlemode fiber For a complete, fiber-coupled RGV-coupler, see page or eam ombiner LP xxx Spectral range [nm] Reflection Transm. Pol. long pass LP s LP s LP7-9 - s LP p LP p LP s short pass SP -7-8 p eam splitter and beam combiner with wedge-shaped substrate: Substrate without wedge: eams are twice reflected at the substrate/air interfaces in parallel with the primary beam. They are focussed by the coupling lens onto the shared fiber input. Interference of the primary beam by secondary beams (Etalon effect) causes intensity instabilities. Substrate with wedge: The principle beam and beams reflected at the substrate/air interface are inclined twice with respect to each other. The focussing optics transform the different beams into distinct spots. The tilt mechanism of the laser beam coupler brings the principle spot onto that of the fiber input and the inclined secondary spots are lost. The removal of inter ference ensures no intensity instabilities. Retardation Optics Retardation Optics / 8WP The /-plate rotates the polarization direction of a linearly polarized input beam. aperture mm in adjustable mount with self-locking tubular axis ( - ) to avoid interference and back reflection, the mount is inclined with respect to the longitudinal axis quartz plate type L: low order for low angle sensitivity type Z: zero order for low wavelength dependency Photo DetectorPhotodetektor 8PD-... Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de pplication: In combination with polarization beam splitter 8PM--..., beam splitter with adjus table splitting ratio Retardation Optics / 8WP L low order L zero order Z wavelength in nm Dichroic Retardation Optics 8WP-- -- The dichroic retardation plate is a /-plate for one wavelength and does not affect the polarization of another wavelength. The correctly positioned plate rotates two ortho gonally polarized input beams of different wave lengths into linear polarization states in parallel. aperture mm in adjustable mount with self-locking tubular axis ( - ) to avoid interference and back reflection, the mount is inclined at with respect to the tubular axis quartz plate of low order pplication: In combination with polarization beam splitter 8PM--..., beam combiner for two wavelengths too close for dichroic beam combiners ( < nm) Si-Detector 8PD-PX Dichroic Retardation Optics 8WP wavelength in nm / wavelength in nm photo diode PX spectral range - nm > n/lx, > mv/lx, 7 pf, ns active area 7 mm angled mount in housing for system mount Ø 9. mm diode and N connector galvanically isolated pplication: Power monitoring in combination with beam splitter 98/ 8S--P Photo Detector8PD-PX

33 9 E Flanges and dapters for System Mount Ø 9. mm dapter Flange For components with Ø 8 mm for fitting to Ø 9. mm system mount 8M-9. dapter -mount dapter for Ø 9. mm to -mount -mount-9. dapter For components with Ø mm for Ø 9. mm mounting M-9. Spacer With Ø 9. mm both ends 8S Filter Mount For filters with Ø. mm to Ø 9. mm mount 9.F.-S Light Trap For absorbing unused beams 8LT-9. dapter for Microscope Lenses dapter for Ø 9. mm to W.8 x/ W.8-9. dapter - oth ends with Ø 9. mm mount (v-groove) 9.9. ap With Ø 9. mm system mounting 8-9. For the "multicube" system, Schäfter+Kirchhoff offers suitable adapters and flanges. Standard adapters have a system mount with Ø 9. mm tightly fitting cylinder and V-groove, while flanges have through holes for the mounting in front of combination cubes with rods. The depicted adapters and flanges are just an extract of the possible components deliverabel by Schäfter+Kirchhoff, some more are listed at the table. Please contact for special dimensions. List of adapters Description: adapter with Hole basis fit Shaft basis fit 9. 9.V V. Internal thread External thread -mount M7 x. M7 x.7 Filter mount Ø. x Ø x Dimensions Model Picture -mount M7 x. M7 x.7 W.8"x/", (9. only ) (9. also in ),, 7 Iris perture Ø - mm L- perture Ø - mm L- ccessories dapter Flange with ttenuator From Ø mm to Ø 9. mm system mount 8T-9.-S Ø9. with Ø9. Flange V-groove Ø9. Tools for ssembly and djustment Ø9. Ø9... Ø. L Rod for combining cubes 8M--L L = L = 7 L = xxx = length of choice Hex grub screw DIN 9 Mx-conical for mounting Ø 9. mm components with v-groove - set of pcs. 8-M--9- Hex Screwdriver HD- Hex grub screw DIN9 Mx-flat for fixing rods to the cubes - set of pcs. 8-M--9- Hex Screwdriver HD- Eccentric tool for laser beam couplers SMS-... and fiber collimators F-... EX- EX- for focal length f mm Eccentric tool for fiber collimators F-T-... and F-Q... EX- Screwdriver WS. mm for grub screw at fiber ferrules and accessories M-... 9D- Hex screwdriver WS. mm for screws DIN 9, 9, and 9 HD- djustment tool for rotating quarter-wave plates in fiber collimators F-Q... Z-8 Multicube_9_ED.indd Page Hex screw DIN 9 Mx8 for mounting components Ø 9. mm with clamp collar - set of pcs. 8-M-8-9- Hex Screwdriver HD- Grub screw DIN M. x.-conical for mounting Ø 8 mm components with v-groove - set of pcs. 8-M.-.-- Screwdriver 9D- Grub screw DIN M.x for fixing fiber ferrules to F-... and SMS set of pcs. 8-M.--- Screwdriver 9D- Eccentric tool with longer handle for laser beam couplers SMS-... and fiber collimators F-... as an alternative to EX-, EX-, EX- EX--L EX--L EX--L Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de J K Polarization nalyzer SK978-VIS/NIR Measurement and test system for laser sour ces with PM singlemode fiber cables, see page.

34 9 E Fiber-Fiber ouplers FF-... ombination ubes and Plates 8M-... FF-... Fiber-fiber couplers are used to connect singlemode fiber cables with unequal numerical apertures and mode field diameters. large variety of fiber collimator lenses and (see Fiber ollimators F-...) and of laser beam coupler lenses (see Laser eam oupler SMS-...) is available. The fiber-fiber coupler can be aligned and focussed so that fiber cables with non-core centered connectors can be coupled with low coupling loss. dditionally, the polarization axes can be aligned. FF-... Fiber-fiber couplers are available with optics for wavelengths in the range 7 nm and with inclined and coaxial coupling axes for use with connectors of type F-P and F-P, respectively. core system is delivered with an extended mounting bracket, a laser beam coupler and a fiber collimator (with suitable adapters as required). core system can be expanded using any "multicube" optics and flanges, e.g. a polarizer or iris diaphragm. For extending the fiber-fiber coupler, a second mounting plate and more rods are supplied. Optionally, the FF-... Fiber-fiber coupler can be ordered with a maximum outer diameter of Ø. mm, either with or without a base plate 7. FF = Fiber-fiber coupler Laser beam coupler For versions of Laser eam oupler SMS-..., pages -8 FF SMS - - F - - L- Optics for "multicube" For versions of onstruction Kit 8M-..., see pages - Fiber collimator For versions of Fiber ollimator F-..., see pages - 7 Figure : FFF Fiber-fiber couplers. Modular system combined by the following components: Laser beam coupler SMS-... Polarizer 8PM-S-... Iris L- Mounting bracket 8M-9.- Mounting plate 8M-MP-9. Fiber collimator F ase plate FF--9. pplications Multicube_9_ED.indd Page Fiber-to-Fiber oupler with Faraday Isolator Fig.: Fiber-fiber coupler with Faraday isolator Set-up Pos. Description Explanation Laser beam coupler SMS is equivalent to fiber collimator F , adjustable Faraday isolator 8FI-... to avoid back coupling of laser radiation into the fiber onsole 8M9.- ttenuator/shutter 8T-/ 8T-S ttenuator or Shutter Mounting Plate 8M-MP-9. Input The fiber-to-fiber coupler with Faraday isolator from Schäfter+Kirchhoff supresses back reflections and offers an attenuator and shutter. The Faraday isolator consists of two polarizers with a distorted main axis and a Faraday crystal. The first polarizer is adjusted for incoming beam transmission without loss. y applying a strong magnetic field to the Faraday crystal, the polarization axis of this beam is rotated. The second polarizer is aligned with the distorted polarization axis. ack reflected light results in another transit of the beam through the Faraday crystal and the polarization axis is rotated yet again. The resultant polarization axis is perpendicular to the initial axis and so the distorted beam is blocked by the polarizer. fiber-to-fiber coupler with Faraday isolator is used to protect laser beam sources where the attached fiber connectors cannot be removed (e.g. a fiber pig-tail) or when a back coupling to the fiber is a desirable characteristic (e.g. in interferometry). Fiber Port luster for M OT agneto Fiber-coupled beam delivery systems, post card sized, replaces m sized bread board constructions. ssem bled with fiber optic components from Schäfter+Kirchhoff. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de ptical rap See New: Dichroic System Input: PM fiber cables, differing wavelengths, e.g. Sr: mm and 89 mm. Output: PM fiber cables, both wavelengths superimposed with linear polarization in parallel orientation For more information, see pages -9 In global use: ustria Germany France U.K. Italy US VR hina India

35 9 E Fiber Port luster to The fiber port cluster to from Schäfter+Kirchhoff allows the splitting of an entrance beam into four outputs. The power at the outputs can be adjusted individually. The system is built from "multicube" components, providing high flexibility with great stability and reliability. 8 9 Figure : Fiber port cluster to, mechanical set-up The optical scheme depicts the beam propagation. n incoming beam is polarized firstly that a weak polarization stability of the laser source does not cause disturbing side-effects. t the beam splitter <% of the beam is reflected onto a photodiode acting as a power monitor. The majority of the radiation passes the first / optics and enables the adjustment of the splitting ratio of the subsequent beam splitter. This combination of half-wave plate and beam splitter can be cascaded endlessly. The four split beams are directed into the laser beam couplers which act as outgoing ports to the attached fiber cables. Polarizing beam splitters produce a high degree of polarization in the non-deflected and a low degree in the deflected beam. Thus, it is necessary to use smaller additional polarizers to increase the degree of polarization of the outgoing beam. Two-Fiber System - Laser eam Source nm Set-up Pos. Description Explanation Laser beam is equivalent to fiber collimator SMS coupler F , adjustable Polarizer (small) to increase extinction ratio, off-set 8PM-S-D decentered correction for eam splitter 98: 8S--P reflects % of beam to photodiode 8PD- for monitoring Retardation optics manual adjustment of laser 8WP / outputs Polarization beam splits the polarization axes (: 8PM--... splitter, )* Polarizer (small) 8PM-S to improve extinction ratio before coupling* 7 onsole 8M9.- 8 ombination cube 8M-SM-9. 9 ombination cube 8M-LTS-9. Spacer 8S-9. to avoid gap between console and cube ap 8-9. Photo diode 8PD-PX together with adapter flange 8M-9. Rod 8M--... to stiffen the system *other angles than at 8PM--... causes lower extinction ratios Laser Source: oherent ompass - Output Power: mw cw eam Profile: Gaussian, M². Singlemode Fiber able: Polarization-maintaining, N., with F-P (8 angled polish) connectors on both sides Output power ex-fiber: typ. mw (8%), variably split up to the two output fibers Gaussian beam and intensity profile Linear polarization ex-fiber: better than : Principle: In the two-fiber system, the laser power is split between the two polarization-maintaining fiber cables. The splitting is performed by a polarization beam splitter. n arbitrary splitting ratio is achieved by rotating the polarization of the incoming radiation by means of a half-wave plate. t the polarization beam splitter, radiation perpendicular to the plane of incidence is deflected. In the deflected beam path, a small polarizer is used to increase the degree of polarization (polarization beam splitters produce a high degree of polarization in the transmitted beam only). With two laser beam couplers, the split radiation is then coupled into two polarization-maintaining fibers. Fig. : Laser with two fiber system Multicube_9_ED.indd Page Fig. 7: Optical scheme two-fiber system Fiber-optical components: Retardation optics / 8WP-- -L Polarization beam splitter 8PM-- Polarizer 8PM-S Laser beam coupler SMS-... Singlemode fiber cable PM Option: fiber collimator F--... Opto-mechanics and laser source: Laser beam source ompass M- ase plate 8MP- Extended mounting plate 8M-SP-9. Rods 8M--7 Single cube 8M-SM-9. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

36 9 E Laser ttenuators 8T-... Laser OUT Laser IN 8T-... Laser ttenuators are used for reproducible and precise laser output power reduction. precision ball on a reed bearing is transported by a scaled micrometer screw into the collimated laser beam and reduces the beam profile. The subsequent fiber coupling results in mode filtering. This mechanically stable attenuation method allows the precise and reproducible setting of the laser output power over a wide range (typically. to > d). ompared with power regulation by laser current control, the wavelength and polarization status of the laser beam are both preserved. - - ttenuation in d Micrometer Position (mm) Figure 8: 8T-... laser attenuator Photo diode Optional: 8-T-F-... Laser ttenuator with % partial beam separation for power monitoring Typical calibration curves,8,,, Relative Output Power Micrometer Position (mm) 8 T--F SMS- - - Input: Fiber ollimator F-... coaxial coupling axis for F-P connector = inclined coupling axis for F-P connector = ollimating lens ssortment see Fiber ollimator F-..., page - Output: Laser beam coupler SMS- oupling lens = for F-P connector = inclined coupling axis for F-P connector ssortment see Laser eam oupler SMS-..., page -8 Reproducible power attenuation and functional safety are only assured for singlemode fibers with a Gaussian intensity profile Fiber collimator and laser beam coupler with inclined or coaxial coupling axis for singlemode fibers with F-P or F-P connector (optionally SM) Insertion loss typically. d, extinction > d an be used as interface between different fiber or connector types Notes Multicube_9_ED.indd Page Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

37 9 E Electro-Magnetical Shutter EMS-- + SK97 pplications HeNe Lasers with fiber optics and electrical shutter Figure : EMS-- electro-magnetical shutter with SK97 shutter controller. i-stable Shutter No power consumption in OFF position Internal, external, automatic and manual trigger mode with US. and RS interface System mount Ø 9. mm compatible with multicube system Shutter Specifications Solenoid type...i-stable Shutter rise/fall time t rise / t fall. ms / ms ( V pulse) Holding voltage... V Maximum pulse rate... Up to Hz (steady), Up to Hz (< s burst) perture... mm Weight... g ontroller Specifications The bi-stable shutter operation means that it does not conform to laser safety rules according to IE 8- Shutter status indicator Voltage V +/- % D Power start up peak / m 9" Housing, HE / TE, g Timing Timing resolution... ms Shutter OPEN time t OPEN... ms Shutter LOSE time t LOSE.. ms (pre trigger) (Shutter open/close time programmable in software mode only) Trigger IN....TTL (N connected) Shutter open Shutter closed trise topen Operating Modes: Manual... User-controlled open/close Software.. P-controlled operation via US or RS Single... Open/close cycles by microcontroller (μ) uto... Multiple open/close cycles by microcontroller (μ) Extern... Externally TTL-triggered open/close EMS-- Shutter head SK97 ontroller with power supply, driver and control software 8M-SM-9.-SM multicube with shock absorbers Electrical scheme tfall tlose timing diagramm Dimensions. omponents HeNe laser,. Power supply for laser, Mounting console M-MG--.-F-R, Electrical shutter EMS--,. Shutter controller SK97,. Power supply for shutter,. "multicube" with shock absorbers 8M-SM-9.-SM, ttenuator 9.-F-T, Laser beam coupler SMS---..., Fiber cable SM--.../ PM Power supply SMS- EMS-. ontroller.. HeNe laser.8 nm.. Power supply Upon activation, HeNe Lasers require several minutes to reach a stable state of radia tion. To circumvent this latency, it is advantageous to use a shutter to block the beam, rather than subjecting the laser to a series of on-off cycles. In the present application, the shutter is mounted in a multicube immediately in front of the laser. Shock absorbers prevent any vibration caused by the shutter operation. The power of the laser radiation can be reproducibly modulated with the attenuator 9.-F-T. Subsequently, the beam is coupled using a highly efficent beam coupler into a singlemode SM-... or a polariziation-maintaining singlemode PM-... fiber. The coupling axes can be either coaxial F or inclined P to prevent back reflections into the laser source. For further information about this application, please see HE 7 Shutter_9-E.indd Page 7 For further information about this product, please see Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 7

38 9 E Fiber-oupling for hopper SK Figure : Polarization-maintaining fiber-coupled chopper. hopper head HMS with chopper blade. hopper mounting device Fiber optics. Singlemode fiber cable PM--.-N--P--P. Laser beam coupler SMS-.-. Micro-focus optics M-8-. Fiber collimator F--.- Fiber collimator F--... Polarization filter PF-... Micro-focus optics M-... Figure : Optical scheme for figure... hopper blade OM - coustic-optic Modulators Schäfter+Kirchhoff offers fiber-coupled acousto-optic modulators (OMs) from different manufacturers. The fiber-coupled acoustooptical systems provide high transmission and extinction with a longterm stability. They are sealed against light leakage, for laser safety, and against dust for application in the most demanding of industrial environments. Optical hopper SK -- Frequency stability ±.% at khz Refolution - / min hopper frequency Hz - khz with hopper- blade HMS / (with Hz and up to khz with special blades) OTF - cousto-optic Tunable Filters. Figure : cousto-optic modulator with polarizationmaintaining fiber coupling from Schäfter+ Kirchhoff. Fully customized monitoring systems with a beam splitter are also available. Optical choppers are used for a periodical modulation of light, such as for lock-in detection purposes when the laser cannot be modulated directly. Schäfter+Kirchhoff offers a chopper coupled to a polarizationmaintaining singlemode fiber. khz square wave modulation employing a standard blade ( slits) khz and higher when using specially designed blades Short rise and fall times of the signal edges by laser micro-spot and adapted beam waist With polarization-maintaining fiber optics for laser beam sources in the 7 - nm range Optionally: increased rise and fall times (equal to an open beam configuration) with a sinusoidal signal form obtained by placing the chopper head parallel to the beam. Fiber type: singlemode, polarization-maintaining fiber with F-P connectors producing a Gaussian beam intensity distribution. The quality of the wave front and the Gaussian intensity distribution of the primary laser beam source are conserved or substantially improved by the characteristics of the singlemode fiber. a Figure : Intensity characteristics of the chopped laser beam at a chopping frequency of khz. a Oscilloscope trace with a time scale of μs/division b Oscilloscope trace with a time scale of ns/division SK-- ench with beam-shaping optics, see Figure SK-HMS hopper head with D motor and reference pick-up SK-HMS/ hopper blade, Ø mm, slits SK-HMS hopper control, speed - rpm SK-Hood Protection cover for chopper blade The radiation arising from a polarization-maintaining singlemode fiber is collimated and passed through the acousto-optic cell. The zeroorder beam is blocked by a trap and the first refracted beam is coupled to the output fiber. To achieve shorter switching times, the radiation can be focussed into the acousto-optic cell. ll necessary adjustment possibilities are available and these can be locked in a desired position. IN standard OM is designed for use with monochromatic radiation. RF IN Figure : Optical scheme of an acousto-optic modulator with polarization-maintaining fiber coupling: Input and output fiber cables PM-..., polarization-maintaining, Laser beam couplers SMS-... for collimating from a fiber and for coupling into a fiber, and acousto-optical modulator OM. b OUT hopper+om_9_ed.indd Page 8 IN IN RF IN RF IN Figure 7: Optical scheme of an acousto-optic modulator versus an OTF: the beam modulated by the OM has a refraction angle determined by the incident wavelength. the beam modulated by the OTF has a refraction angle independent of the wavelength and so can be coupled to a common singlemode fiber,. OUT For broad band radiation applies: The modulated beam (first refraction order) is dispersive and its refraction angle is a function of the optical wavelength. Hence, the radiation cannot be coupled into a single singlemode fiber. To modulate multiple superimposed wavelengths simultaneously, an acousto-optical tunable filter (OTF) is used. This is a special OM in which the light dispersion is compensated for by applying different acoustic frequencies with different amplitudes simultaneously, so that the corresponding different optical wavelengths are switched or modulated precisely. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 8

39 9 E EOM Electro-Optical Modulators with Fiber Optics Modular construction system assembled from Schäfter+Kirchhoff system components, designed for self assembly and alignment. Electro-optical modulators (EOMs) are used Electro-Optic Modulator for amplitude, phase or fre quency modulation of laser beams. They are particularly well suited to the fast switching of laser beams because of their short response and rise times. Highly rugged systems for various modulation and switching tasks are readily implemented using the polarization-maintaining fiber optic components designed by Schäfter+Kirchhoff. The conventional breadboard becomes redundant and by confining the laser beams in optical fibers this enhances laser safety (Laser lass I). The offered EOMs are produced by Linos ( shown is a LM. Specifications: Rise time < ns Delay < ns Pulse width > ns Repetition rate < MHz Extinction < : Input/output jitter < ns Function n electrical field introduces bi-refringence into an optical crystal (Pockels effect). s the amount of birefringence is proportional to the field intensity, the crystal in an EOM acts as a voltage-controlled retarder. For amplitude modulation or switching tasks, the EOM can be placed between two crossed polarizers, for example, with the EOM retardation axis orientated at to the first polarizer. t a certain voltage, V, the EOM corresponds to a half-wave plate so that the polarization after the crystal is rotated by 9. pplication: Fast switching of a laser beam n EOM is placed between two crossed linear polarizers. t V=, the EOM does not act on the laser beam polarization and the beam is blocked. t V= V, the EOM rotates the polarization of the beam by 9 and the beam is transmitted. V V eam < ns < ns fter being combined by a polarizing beam splitter, the two input beams enter the EOM with crossed polarization. The beam appearing at the output fiber is selected with the EOM control voltage (V= or V= V ). V (V) V Output polarizer V eam eam Pockels cell Input polarizer pplication: Triggered Laser Seeding for LIDR RMR-LIDR (Rayleigh-Mie-Raman Light Detection and Ranging) is used by the LOMR (rctic LIDR Observatory for Leibnitz Institute for tmospheric Physics, Kühlungsborn, Germany Middle tmosphere Research) facility in Norway for measuring the temperature and wind velocity in up to 8 km altitudes. Laser radiation from two pulsed power lasers is directed into the atmosphere. The radiation scattered back by aerosols (due to the Rayleigh, Mie or Raman scattering) is collected by two.8 m telescopes. frequency stabilized seed laser is used to meet the stringent experimental requirements for pulse length and spectral stability. The power lasers are alternately seeded, pulse-by-pulse, using two electro-optical modulators. The demands of the seeding mean that the power lasers emit short pulses (~ ns) of high spectral stability at a repetition rate of Hz. ustomized EOM unit from Schäfter+Kirchhoff Input Fiber Power monitoring Laser eam oupler SMS Optical scheme Faraday Isolator The complete RMR-LIDR triggered laser-seeding system, manufactured by Schäfter+Kirchhoff for the Leibnitz Institute for tmospheric Physics, Kühlungsborn, Germany: eam combiner EOM Output Fiber Output LOMR Obs. < ns < ns System components from Schäfter+Kirchhoff Laser beam coupler SMS- tilt adjustment and inclined coup ling axis for connectors type F-P PM- pola ri zationmaintaining fiber cables for nm "multicube" system 8M-... D EOM_9-E_neu.indd Page 9 Faraday Isolator 8FI Retardation optics 8WP-... / plate for rotation of the polariza tion axis Polarization beam splitter 8PM-..., eam splitter 98/ 8S-..., for power monitoring Polarization nalyzer SK978 for polarization analysis and precise fiber adjustment Electromagnetic shutter EMS--, timing resolution ms The nm / nm seeding laser, the iodine reference cell, and the electro-optical modulator units are coupled to polarization-maintaining optical fibers with components from Schäfter+Kirchhoff. The fiber port cluster D is built with the multicube system from Schäfter+Kirchhoff and used for beam combination and distribution. This modular system dispenses with the requirement for a vibration-isolated optical breadboard. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 9

40 9 E Notes Notes.indd Page Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

41 9 E Faraday Isolators 8FI-... pplications: Laser sources with integrated Faraday Isolators D E Frequency-Stabilized HeNe Laser Frequency-stabilized HeNe Laser (typ. < khz over some minutes, < MHz over some hours). More information on page 9. Faraday isolator 8FI--8 to prevent unwanted back reflections from entering the laser system. Mechanical shutter 8T-S or attenuator for laser output power adjustment. Laser beam coupler SMS-... transfers the beam into polarizationmaintaining singlemode fiber PM-... or singlemode fiber SM-... and it emerges as a divergent, axially symmetric Gaussian beam. Mounting console M-MG-.-F-R with spring shock mounts for damping of shock and vibrations. Figure : Faraday isolator compatible with micro-bench system (aperture Ø mm or Ø mm, isolation > d, insertion loss <. d) Spectrum of an undisturbed laser beam source Disturbed spectrum because of back reflections (mode-hopping) Function Polarizing beam splitter eliminates the s-polarized portion (typically %) of the laser (diode) radiation Faraday crystal in a strong magnetic field rotates the input polarization plane Transmission Polarizing beam splitter eam input exactly aligned with the output polarization plane, i.e. by in comparison with the input polarization eam output Isolation Reflective or scattering 7 surface causes a polarized or depolarized reflected signal Polarizing beam splitter eliminates the s-polarized portion of the reflected signal Faraday rotator rotates the polarization plane by a further so that the polarization plane of the reflected signal is now rotated by 9 from the polari zation plane of the input beam 7 Polarizing beam splitter blocks the reflected signal,8 nm Frequency Stabilized D Frequency-defined Standards esides the conventional frequency-stabilized HeNe Lasers, Schäfter+ Kirchhoff also offers fiber coupling to HeNe laser sources used as frequency or primary length standards. These kinds of laser sources, such as from Winters Electro-Optics, Inc., are stabilized by iodine cells and provide long-term absolute frequency stability of khz. The average laser power is - μw. For laser sources whose frequency is used for standardization purposes, fiber coupling is only possible with a high feedback suppression of > d. This is ensured by Schäfter+Kirchhoff using only selected Faraday isolators for this task. The laser source and fiber coupling is mounted on a ruggedized platform with handles to facilitate transport. Frequency-stabilized < khz Singlemode and polarization-maintaining fiber coupling External attenuator No back coupling Robust and transportable platform E Dimensions,8 nm Ø Frequency Stabilized D Ø dimensions in mm FaradayIsolator-8FI_9_ED.indd Page Dimension [mm] perture enter [mm] Wavelength D [nm] x 8FI x 8FI-- 9. x 8FI x 8FI-- 9. x 8FI x 8FI x 7 8FI x 78 8FI x 8 8FI x 8 8FI x 98 8FI x 8FI x 8 8FI--8 Further pplications INTERFEROMETRY Laser Diode ollimator 8TE-SOT-F-... with Faraday isolator and Peltier Elements, see page. Fiber-to-Fiber oupler with Farady isolator, see page. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

42 9 E ustomized Solutions Fiber oupling with eam Shaping and Feedback Protection Sensitive laser resonators must be protected against back reflections of the emitted laser light. Schäfter+Kirchhoff couples singlemode and polarization-maintaining fibers to the laser source of a customer and integrates a Faraday isolator to prevent a laser feedback. complete system could have additional power monitors, as shown. To guarantee the highest coupling efficiencies, different kinds of beam shaping optics are used to reduce astigmatism and produce a circular beam. nm nm ascadable Fast Laser Switch with ack-reflection Protection Some applications like LIDR need a laser source with a relatively high frequency stability in combination with a fast switching operation. The depicted optical scheme reveals a solution. The Faraday isolator prevents the laser beam source from disturbing back reflections, while the EOM provides a fast pulse operation. polarization beam splitter together with retardation optics offers a stepless splitting of the laser power. This additional channel allows a cascading of the beam and can be automatically connected to an electro-magnetic shutter. Power monitors at the input and the output provide complete control. E-Laser E Laser with Polarization-maintaining Fiber Optics Diode laser at 8 nm with external resonator in Littman configuration, single frequency configuration. Faraday isolator 8FI--8 to prevent unwanted back reflections from the incident laser source. namorphic beam shaping optics N--V- reduce ellipticity and astigmatism of intrinsic laser beam. D eam splitter 8S-..., mounted in "multicube" 8M-SM-9., diverts % of the beam intensity for wavelength or power monitoring. E The two laser beam couplers SMS-... each transfer one beam into polarization-maintaining singlemode fibers PM-... F. oth beams emerge as divergent, axially symmetric Gaussian beam. beam inclined to the housing can be accommodated on a common mounting bracket with numerous adjustment possibilities, retaining the Faraday isolator and adjacent optical elements. Fiber oupling of Singlemode Pulse Picosecond Laser Systems FaradayIsolator-8FI_9_ED.indd Page F D E G Single laser pulses from a Mira Optima 9-P laser with Verdi V pump, emitting picosecond pulses at a repetition rate of 7 MHz, are selected by an acousto-optical pulse selector. Opto-mechanics and fiber optic components from Schäfter+Kirchhoff are used to couple the beam to a polarization-maintaining optical fiber cable. Laser feedback is prevented by use of a Faraday isolator. The fiber coupling is solidly mounted on an adjustable -axis translational and rotational stage. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Mira Optima 9-P picosecond laser F -axis translation and rotation stage from Schäfter+Kirchhoff G readboard cousto-optical pulse picker Faraday isolator 8FI--8 D Laser beam coupler SMS-... E Polarization-maintaining singlemode fiber cable PM-... Pulse Picker Mira Optima ps-laser Source Verdi Pump Laser

43 9 E LaseDiodeollimator8TE_9_E.indd Page Laser Diode ollimator 8TE-SOT-F-... with polarization-maintaining singlemode fiber, Peltier element / thermosensor and Faraday isolator Wavelength range 9 - nm Integrated Peltier element and temperature sensor for thermoelectric temperature control of the laser diode Faraday Isolator 8FI--... For encased laser diodes of Ø. mm and Ø 9 mm, optionally TO and TOW pplicable as DR laser diodes Universal modular system of laser diode collimators, designed for easy customer assembly and adjustment 9 Faraday isolators are used to protect laser sources from back reflection ( optical diode ). Radiation coupled back into a laser diode leads to mode hopping, noise, frequency instability and decrease in lifetime. Spectrum of an undisturbed laser beam source Disturbed spectrum because of back reflections (mode hopping) Laser eam oupler for Singlemode Fiber inclined fiber coupling axis 8 7 Laser diode base 8TE-SOT-... with integrated Peltier elements and temperature sensor for thermoelectrical temperature control ollimating lens Mounting bracket, microbench compatible Faraday Isolator namorphic beam-shaping optics Mechanical shutter or attenuator 7 Laser beam coupler for singlemode fiber 8 Polarization-maintaining singlemode fiber 9 Fiber collimator with F connection Micro-focus optics Optical Power Output Dependece of Wavelength TILT PM: OW-TIE PM: PND PM: OVL- INNER LD For a detailed description of the modular laser diode beam source 8TE-SOT-... see download: download/ldk8te_en.pdf oth temperature and the power influence the emitted wavelength of laser diodes. The wavelength center is shifted by.-. nm/k of temperature and either the modes hop, one-by-one, or many modes may be excited simultaneously. The wavelength center can drift by. nm in the range of -. onversely, when the laser power is increased from threshold up to the nominal power, the wavelength is increased by nm. For constant laser power, the thermo electric temperature control maintains the laser at a constant temperature and wavelength. Peltier elements establish a temperature gradient, which in magnitude and direction is regulated by the Peltier current by refererence to the measured signal of the temperature sensor. 7 Po=mW Po=mW Po=mW nm Wavelength vs. Temperature Wavelength p [nm] ase temperature T [ ] 8 9 Laser diodes 7 - nm Encased Ø. mm and Ø 9 mm mounted in Laser diode base 8TE-SOT Laser diodes with inte gra ted TE-ooler Laser diode ase TO mounted in Laser diode base 8-O-TO Laser diode Superlum ase TOW mounted in Laser diode base 8-O-TOW Laser Diode ollimator 8TE-SOT-... The 8TE-SOT-... consists of three basic elements: Laser diode base 8TE-SOT with: integrated Peltier elements and temperatur control for laser diodes with diameter. and 9 mm easy to handle x/y adjustment (see next page) solderless contacting and an optional fan 8L ollimation flange 8FS for system mount Ø 9. mm collimator adjustment with inderect clamping, even with adapters Diode collimator L focal length f' from.7 mm to 8 mm (up to mm with collimator L) N up to. spectral range - 8 nm For more information, see Faraday Isolator (optical diode) 8FI- For assembly in micro-bench systems. High precision through-holes for parallel rod guides. Ensures high mechanical stability and distortion resistance of the whole system. isolation > d laser beam aperture max. mm attenuation <. d See page standard wavelengths - 8 nm namorphotic eam Shaping Optics N-... ombination of cylinder lenses with integrated astigmatic correction. focal (i.e., non- focussing) beam shaping op tics that transforms the ellip tical beam profile of the collimated laser diode in to a near circular profile. laser beam aperture max. mm See page beam shaping factor,., and Mechanical Shutter 8T-S To block the laser beam manually See page for system mount Ø 9. mm aperture Ø mm Laser eam oupler SMS djustable and focussable for singlemode fiber cable with F connector focal length f' from mm to 8 mm N up to.8 See page spectral range 7 - nm Inclined (8, F-P) or paraxial fiber coupling axis Polarization-maintaining and Singlemode Fiber ables PM-.../ SM Singlemode, polarization maintaining MFD - μm See page 9 = - 8 nm Fiber connectors: F-P: 8 po lish of the fiber ferrule, supression of back reflexion into the laser source. F-P: polish Fiber ollimator and Focussing 9 Fiber ollimator F- Focussable Inclined or paraxial fiber coupling axis. oth beam diameter and divergence are determined by the focal length f of the collimating lens. focal length f' from.7 mm to mm N up to.8 spectral range 7 - nm pilot beam option Microfocus Optics, Series M- and M- See page These lens attachments for fiber collimators F-... focus the collimated laser beam onto a diffraction limited (. μm) Order Options The laser diode beam sources are delivered, fully assembled and adjusted, with laser diodes from our stocklist, according to customer specifications or with diodes from the customer. Detailed instructions for assembly and adjustment by the user are included. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

44 9 E Laser Diode ollimator 8TE-SOT-... Laser Diode ase 8TE-SOT I III II djustment with mounted collimator Main specifications: x/y-centering of the laser diode onto the optical axis with adjustment tool 8D Solderless contact for laser diode using spring contact connectors so laser diode galvanically isolated from collimator base Integrated Peltier element and temperatur sensor for thermoelectrical closed-loop control of the laser diode temperature Peltier-Element provides up to W heat transfer power I max. =., U max. =.8 V Temperatur sensor: thermistor (NT k ) Separate connection cables for power supply, for the monitoring of the laser diode and temperature control Modular fan 8L for increased thermal transfer efficiency (VD-. power supply is not designed for use with vibrationsensitive applications) ompatible with micro-bench ( mm pitch) The components are adjusted and fixed using radially located grub screws and for positive locking n elastomere diaphragm encloses the laser diode and prevents laser beam egress and dust ingress 8FS x/y-entering of the Laser Diode ase LaseDiodeollimator8TE_9_E.indd Page L Table eam parameters ollimation Lens L / L row curr. no ollimation lens ollimator flange L 8FS L 8FL Lens type G.7,. T M. 8 8 T TF M M Focal length f' Numerical aperture N lear aperture [mm] Max. active area [mm] Lens for UHV application x x x x x x x x x Spectral range ode no. of R coating nm 8 - nm 9 - nm - 7 nm - nm nm - nm - 98 nm 8 - nm - 7 nm nm Ø eam parameter for the collimated laser beam using a 7 nm laser diode with active area. x μm and beam divergence x (FWHM), beam-ø /e² (.%), # beam cross-section restricted by lens aperture 8 beam-ø [mm] #7 9 beam-ø [mm] #. #. #.8 # #. #7 divergence [mrad] divergence [mrad] eam parameter for the collmated laser beam using a nm irculaser Ø diode with beam divergence 8 x 8 (FWHM) beam-ø /e² (.%) [mm] divergence [mrad] Ø Order Options The 8TE-SOT-F-... laser diode collimator with Faraday isolator is supplied as a completly adjusted system consisting of laser diode base 8TE-SOT, with integrated Peltier element, diode collimator L, Faraday isolator 8FI-, anamorphic optics N, shutter 8T-S, laser beam coupler with F-P connector SMS-..., PM fiber or singlemode fiber cable PM-.../ SM-... and fiber collimator F. Please specify when ordering: Laser Diode wavelength, base type and output power Fiber able length and type Fiber ollimator focus size or collimation diameter Fan module option (with or without) Please contact Schäfter+Kirchhoff for details of suitable laser diode beam sources or other specifications of laser diode collimators. djustment fixture 8D For an optimum collimation of the laser beam free of aberration (e.g. coma), it is necessary to launch the center of emission onto the optical axis of the collimator optics. With the tripartite x/y-centering fixture 8D, the mounting plate of the laser diode can be adjusted laterally (for details, see assembly instructions). The lateral displacement is realized with the screws and, while provides the necessary counter force. dapters for Laser Diodes Ø. mm pplication: Laser diodes with Ø. mm housin are inserted into teh retainer for laser diodes with Ø 9 mm housing with the active area at the same position: the laser diode beam axis and the position of the emitter does not change. dapter L-. parts housing outer-ø 9 mm Retaining ring for laser diode Laser diode with housing Ø. mm D ssembly key LD9. D ollimator flange 8FS Internal lens focussing: a left or right turn with the eccentric key I offers fine adjustment of the collimation lenses and so of the focus position and the collimation, even with attached adapters. Lens locking II System mount Ø 9. mm for attachment of further beam shaping optics and adapters. The adapters have a tightly fitting cylinder with circular V-groove for fitting into the collimator flange. The adapters can be rotated and are locked by circumferential grub screws III. ssembly and djustment Tools Screwdriver 8SD- Hex screwdriver SW Ø. mm HD- Hex screwdriver SW Ø. mm for adjustment fixture 8D HD- Eccentric key for collimation lenses L-... EX- Focussing key for collimation lenses L-... LF- Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

45 9 E nanofi-.../nanofm-... Laser Diode eam Sources with singlemode and polarization-maintaining fiber cable P New nanofi-... with integrated Faraday isolator pplications: Fig. and Laser diode beam sources of type nanofm-... and nanofi-... have reduced power noise, reduced coherence length and low speckle contrast. They are used, e.g., for atomic force microscopy (FM), particle measurements and as pilot lasers during alignment applications. oherence length μm Noise <.% RMS (<MHz) Spectral range nm to 8 nm Laser output power up to mw Output power adjustable with potentiometer or ext. voltage control input Modulation inputs for analog and TTL control ( khz) Operation mode: constant power Singlemode fiber cable, polarization-maintaining or standard F-P connector (8 polish), optional DIN VIO, ST or E eam profile rotational sym metry with Gaussian intensity distri bution P dditionally, the nanofi features an integrated Faraday isolator (optical diode) for protecting the laser diode against disturbing back reflections. The nanofi laser source is predestined for applications which require high power stability, reduced coherence length and protection against radiation reflected back from the object under test. For fiberoptic FM setups (Fabry-Perot interferometers) For back reflection particle measurements vailable with directly connected fiber optical beam splitter (x- or y-coupler) pplication: Fiber optical Fabry-Perot Interferometers Title_nanoFM_9_E_.indd Page oherence length μm Noise <.% RMS (<MHz) Spectral range nm to 8 nm Laser output power up to mw eam profile rotational sym metry with Gaussian intensity distribution P F-P connector (8 polish), optional DIN VIO or E dvantages of laser beam source nanofm-... / nanofi-... Laser Speckles Laser Spectrum Noise Low speckle contrast from reduced co he rence length: uniform illumination of -quadrant diodes for FM, improved edge detection during position measure ments LOW NOISE and REDUED SPEKLE for increased accuracy and reproducibility in laser metrology and nano technology ack reflection particle measurement FIER OPTI FRY-PEROT Interferometer nanofi-... ccessories M Fiber ollimators F-... Micro focus optic M-... FWHM roadened spectrum (~. nm FWHM) with reduced coherence length (~. mm) as a result of RF modulation. No mode hopping appears Vacuum Feed- Throughs V-... %. nm F tomic orce icroscopy Optical Tweezers nanofm Pnoise peak value in % up: RF modulation results in constant mean laser power with noise <.% RMS (<MHz). down: power noise caused by back reflections and mode hopping. Lasers for djustment and lignment Fiber-optical eam Splitters FS-... min page ff page page Scratch Detector pplication: ack Reflection Particle Measurement Signal of particles at detector Fig. : optical scheme particle measurement Faraday isolator (FI) Polarization-maintaining fiber Fiber optical beam splitter nanofi-... Particle measurement with scattered laser light may be determined by measuring the light a particle deflects when passing through a laser beam. The radiation of the laser source is guided via a polarization-maintaining singlemode fiber and a fiber optical beam splitter to a particel flow. Particles transiting the focussed beam scattere the light and back reflect some of it to the fiber. That back coupled light is splitted at the fiber optical beam splitter were one part is guided to a detector and the other part to the laser source. Therefore, the laser source is protected by a Faraday isolator (optical diode). Without the Faraday isolator the back coupled light would cause spectral disturbances (mode hopping G ) and increased noise. Precise measurements require a low speckle contrast and constant laser power. y RF-modulation the coherence length is reduced, the spectrum broadend I and the power averaged. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de E FRY-PEROT Interferometer Fig. : scheme of a fiber optical interferometer Faraday isolator Polarization-maintaining fiber Fiber optical beam splitter D D E F Signal (V) Standard Laser Diode nanofi nanofi Laser spectra D Fiber collimator and focussing E Particel flow F Detector time (ms) Oszillogramm D F-P fiber coupler E antilever F Detector and interferometric signal With singlemode fibers it is possible to build up a compact interferometer e.g. for FM. The light leaving the fiber is back reflected at the fiber end facette (approx. %) and at a moving mirror or cantilever. The back coupled light is guided through a fiber optical beam splitter where one part is splitted to a detector for the interference measurement. The other part of the light is blocked by a Faraday isolator integrated in the laser source nano-fi-... The signals of fiber optical Fabry-Perot interferometers benefit from the power and wavelength stability of the nanofi-... The reduced coherence length is an additional advantage as disturbing interference is suppressed and only interference between the surfaces of interest contribute to the interferometer signal. ack reflection particle measurement nanofi-... F Laser Diode with FI G H I

46 9 E LOW NOISE and REDUED SPEKLE X.... Fig. : Laser Diode eam Source nanofm-... (Tab..). Singlemode fiber with. F-P connector. Key switch: ON/OFF - LED ON. Potentiometer (for reduction of laser power output) X onnector, ext. modulation and interlock ttachments: Fiber collimator, focusable, F-... Micro-focus optics M-... and M-... Figure : eam Parameters and advantages of the Laser Diode eam Source nano... Laser Diode eam Source nanofm-... with singlemode and polarization-maintaining singlemode fiber cable low noise reduced coherence length low speckle contrast pplications Laser diode beam sources of type nanofm-... have reduced power noise, reduced coherence length and low speckle contrast as a result of the internal RF modulation. The laser diode beam source nanofm-... is typically used for atomic force microscopy (FM) and as a pilot laser during alignment applications. Spectral range nm to 8 nm Laser output power up to mw Noise <. % RMS (< MHz) djustment and Output power adjustable with potentiometer or external voltage lignment by laser control input Modulation inputs for analog and TTL control (up to khz) Operation mode: constant power oherence length μm eam profile rotationally symmetric with Gaussian intensity Particle Measurement distribution P Optical Tweezers Singlemode fiber cable or polarization-maintaining singlemode fiber cable(polarization aligned to connector index) F-P connector (8 polish), optional DIN VIO, ST or E- Fiber cable with strain relief and protective sleeving (Ø mm) Laser safety according IE 8 / EN 8- by: Scratch Detector Key switch. LED-indicator for laser operation Interlock connection X Potentiomenter for reduction of power output Option: laser diode beam source nanofm-n-... OEM version without key switch and interlock on request. Does not meet requirements of EN 8-. Laser Speckles Laser speckles are interference arising from, e. g., the diffuse re flection of coherent radiation at rough surfaces. The degree of coherence (coherence length) determines the speckle contrast. Laser Spectrum roadened spectrum (~. nm FWHM) with reduced coherence FWHM %. nm length (~. mm) as a result of RF modulation. Noise..8 min P noise peak value in % RF modulation results in constant mean laser power. Power noise <.% RMS (<MHz). Laser Speckles Low speckle contrast due to reduced coherence length: uniform illumination of -quadrant diodes for FM and improved edge detection during position measure ments. Interferences Gaussian intensity distribution of collimated laser beam direct recorded with a D sensor. No interference patterns despite the protection window of the D sensor Figure : Disadvantages of standard laser diode sources with conventional fiber coupling Laser Spectrum Mode hopping: temporal shifts between modes. The short-term coherence of individual modes is > m, but effective coherence length is reduced. Noise Power noise from a laser source coupled to. a fiber. The fiber generates an external cavity.8 with the laser diode, min resulting in jumps in P noise peak value in % power stochastically. Laser Speckles The laser spot produced by a standard laser diode beam produces a speckle pattern, increasing the statistical uncertainty in position deter mi nations. Interferences ollimated laser beam recorded directly with a D sensor, whose protective window generates a disturbing interference pattern. nanofm_9_ed.indd Page Electrical Data Supply voltage standard V D (±.V) optional V D (±.V) Laser diode operation mode constant power Max. operating current m mbient temperature range - Modulation frequency analog D - khz TTL - khz With pot. adjustable output power < -% TTL modulation logic TTL high * nalog control voltage -.V depending on laser diode: see table, col. * Dimensions M Laser diode beam source nanofm-... X Potentiometer onnector Potentiometer onnector X Lumberg able for 8 ext. modulation M SV ( V) power and interlock SV ( V) supply F connector Singlemode fiber cable Ø mm F connector Singlemode fiber cable Ø mm 7 Ø Ø Front view L Laser diode beam source nanol-... Potentiometer X onnector ext. onnector Potentiometer modulation and 8 Lumberg M interlock able for X SV (V) power SV (V) supply Front view Laser Source with Multiple Fiber Outputs For special applications Schäfter+Kirchhoff offers a nanofm-... with fiber optical beam splitter converting the single laser input source to - fiber coupled outputs all integrated in a compact housing with bend protection of the singlemode fibers. The fiber outputs are collimated with a special F--M- fiber collimator with angular adjustment of the collimatedor pilot beam referring to a tilt- and mounting plate. -FM-S-7 For further information and combination possibilities please visit or contact Schäfter+Kirchhoff. Table Laser Diode eam Source nanofm... Row Wavelength out Fiber ase Spec- * Laser LD Supply Electr. Fiber connector op- length e Fiber ur. Version (mw) type type trum adjust- P Type MFD Power diode operation mode (V) tion tion (cm) (μm) ment % power connec- No. (nm) code ** nanofm S M9 P L S.9 < - nanofm S 7. H P M S. < - nanofm S N P M S. < - nanofm S M P M S.7 < - nanofm S P L S.7 < - nanofm S 8 M P M S.8 < - 7 nanofm S 78 H P M S. < - 8 nanofm S 78 9 N8 P M S. < - 9 nanofm S 8 7 P M S.9 < - nanofm S 8 N7 P M S.9 < - nanofm S 8 EY P M S 7. < - nanofm... - S M - P Laser Diode eam Source Safety: with key switch and interlock s without key switch and interlock (OEM)....N Laser diode operation mode: onstant power...p Supply power: V D (standard)... V D (option)... Electr. cable. m shielded x. mm as for, with connector SV (V) as for, with connector SV (V) cable specified by customer * ** Fiber collimators F-F--M- Length fiber cable in cm (standard = ) onnector option: = standard = core centered (singlemode only) Fiber type: 8 = singlemode fiber cable, F-P 8 = PM singlemode fiber cable, F-P optional: onnector DIN-vio, ST, E-. Typical laser output power, the actual power output may differ by ±%. With fiber N =. Housing with laser source and multiple fiber outputs -FM-S-7 Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

47 9 E LOW NOISE and REDUED SPEKLE for increased accuracy and reproducibility in laser metrlcs LOW and nanotechnology NOISE Faraday-Isolator and REDUED SPEKLE for increased accuracy and reproducibility in laser metrology and nano technology. X.. Fig. : Laser Diode eam Source nanofi-... (Tab. ). Singlemode fiber with. F connector. Key switch: ON/OFF - LED ON. Potentiometer (for reduction of laser power output) X onnector, ext. modulation and interlock Faraday-Isolator 8FI. The Faraday isolator is used to protect laser sources from back reflection ( an optical diode ). Radiation coupled back to a laser diode leads to mode hopping, noise, frequency instability and decrease of lifetime. Spectrum of an undisturbed laser beam source ack reflections disturb spectrum (mode-hopping) Laser Diode eam Source nanofi-... with singlemode and PM fiber cable and Faraday Isolator, stable mode of operation for back scattering sensing applications In addition to the reduced power noise, reduced coherence length and low speckle contrast of the laser diode beam source nanofm-..., the nanofi... features an integrated Faraday isolator to protect laser sources from back reflection ( an "optical diode"). Radiation coupled back to a laser diode leads to mode hopping, noise, frequency instability and decreased lifetime. For fiber-optic FM setups (Fabry-Perot Interferometer): a fixed fiber end face and a cantilever build a Fabry-Perot interferometer. Interference measurement signals are coupled back into the fiber for read-out after beam splitting. For back reflection particle measurement: stray light from particles is coupled back into distributing fiber. The protected diode produces stable signals. vailable with directly connected fiber optical beam splitter (x- or y-coupled). Easy mounting on all four sides of housing with profile TP--. Laser safety according IE 8 / EN 8- by: Key switch. LED-indicator for laser operation Interlock connection X Potentiomenter for reduction of power output Option: laser diode beam source nanofi-n-... OEM version without key switch and interlock on request. Does not meet requirements of EN 8-. pplications ack reflection particle measurement F M nanofi-... FIER OPTI FRY-PEROT Interferometer INTERFEROMETRY Fiber optical Fabry-Perot Interferometer Signals The signals of fiber optical Fabry-Perot interferometers benefit from the power and wavelength stability of the nanofi. The reduced coherence length is an additional advantage as disturbing interference is suppressed and only interference between the surfaces of interest contribute to the interferometer signal. Stable interferometer signal, recorded with a nanofi laser Unstable interferometer signals, recorded with a standard laser diode source Fluctuation of the amplitude caused by changes in coherence length. Signal (V) time (ms) time (ms) time (ms) Power Supplies for nano... Power supply for laser diode beam sources, elec trically isolated,. m cable with connector (IE-9) Lumberg series KV (female). Input - V Output with connector VD/ F VD /. F Europe PSE PSE Special Fiber options Fiber optical beam splitter: nanofi... is delivered with fiber optical beam splitter output as an option. Info: Vacuum feed-throughs: as an option nano...is delivered directly coupled with vacuum feed-through V-... Information and order code on page. nanofm_9_ed.indd Page onnector (female -pin) KV for V (pins compatible with SV) or pol. KV for V D version onnectors Lumberg connector (female) according IE -9 F Type KV (-pin) for connection to interlock chain and for ext. modulation Dimensions Laser diode beam source nanofi-... X onnetor Potentiometer Lumberg 8 M SV ( V) able for power SV ( V) supply F connector Singlemode fiber cable Ø mm ase Type L L 9 8 D 8 7 L L Potentiometer onnector X ext. modulation and interlock Power Supply Power cord for PS...E, IE pin line socket,. m,, V ountry Europe US/anada Great ritain PDE PUS P UK Picture DE US UK Ø Front view Table Laser Diode eam Source nanofi... Row Wavelength out Fiber ase MFD** Power Laser LD Supply Electr. Fiber connector op- length e Fiber ur. Version (mw) type type adjustment P Type * diode operation power connectiotion (cm) (μm) % No. (nm) code mode (V) nanofi S 8 M9 P < - nanofi S 7. H P < - nanofi S N P < - nanofi S. M P < - nanofi S 7 P < - nanofi S 8 8 M P < - 7 nanofi S 78 P < - 8 nanofi S 78 N8 P < - 9 nanofi S 8. P D.9 < - nanofi S 8 8 N7 P D.9 < - nanofi S 8 8 EY P D 7. < - nanofi - S M - P Safety: with key switch and interlock s without key switch and interlock (OEM)... N Laser diode operation mode: onstant power p Supply power: V D (standard) V D (option) Electr. cable. m shielded x. mm as for, with connector SV (V) as for, with connector SV (V) * cable ** With specified fiber N = by. customer * ** With fiber N =. Nominal average laser output power, the actual power output may differ by ±%. Typical laser output power, the actual power output may differ by ±%. Length fiber cable in cm (standard = ) onnector option: = standard = core centered (singlemode only) Fiber type: 8 = singlemode fiber cable, F-P connector (8 polish) 8 = PM singlemode fiber cable, F-P connector (8 polish) optional: Fiber connector DIN-vio, ST, and E-. Vacuum feed through and optical beamsplitter on request. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

48 9 E P. Laser diode beam source 8FM-. Singlemode fiber cable with. F-P connector. Key switch: ON/OFF - LED ON. Potentiometer (reduction of laser power output). able for power supply X onnector, ext. modulation and interlock ttachments: Fiber Optics Fiber onnector Laser Spectrum and oherence Length onnector index The wavelength spectrum depends on the laser diode used and varies with temperature and power output. Mode hopping appears. X.. Fiber collimator, focusable, F- Micro-focus optics M- F-P connector Technical data, see data sheets on Laser Diode eam Source 8FM- Fiber-coupled, singlemode and polarization-maintaining with F-P connector oncentrically symmetric beam profile with Gaussian intensity distribution P Singlemode fiber cable or polarization-maintaining singlemode fiber cable (polarization axis aligned with connector index) Spectral range nm to nm Laser output power up to 7 mw Fiber cable with strain relief and protective sleeving (Ø mm) F-P connector (8 polish) reducing power noise caused by back reflection into the laser resonator Output power adjustable using potentiometer or external voltage control input (-. V) ND-wired modulation inputs, analog and TTL, fmax = khz Operation mode: constant power (standard) and constant current Laser safety according IE 8 / EN 8 from: Key switch. and LED-indicator for laser operation interlock connection X Options: To fullfill lower laser safety requirements (e.g. laser class ), the laser source can be delivered with reduced maximum power output Supply voltage V (standard) or V (exception: Table, row is available with V supply voltage only), reverse voltage protection Protection of the potentiometer by protective cap Related products Laser diode beam source FM: Version w/o key switch and w/o interlock (for OEM purposes only) Laser diode beam source nanofm: Low Noise version with reduced coherence length and speckle contrast Laser diode beam source nanofi: Low Noise version with integrated Faraday isolator (reduced coherence length and speckle contrast) 8 Orientation of the fiber slow axis and axis with the linearly polarized radiation of the source. F-P connector: 8 polish of the connector ferrule and orientation of the principal axes of a polarization-maintaining singlemode fiber (type Panda) with the connector index S S S Spectral width (FWHM) nm, coherence length. mm, LD beam source Nr. (Y), low current Spectral width (FWHM). nm, coherence length. mm, LD beam source Nr. (Y), high current Spectral width (FWHM) ~. nm (red.. mode), coherence length ~ mm, e.g., laser diode beam source Nr. (H) 8FM_9_E.indd Page 8 Electrical Data Supply voltage standard V D (±.V) optional V D (±.V) Laser diode operation mode constant power optional constant current Max. operating current m mbient temperature range - Modulation frequency analog D - khz TTL - khz Power output potentiometer < -% TTL modulation logic Laser ON TTL high nalog control voltage Pmin to Pmax -.V See technical data sheet for timing diagram: ccessories onnectors Lumberg connector (female) according IE -9 F Type KV (-pin) for connection to interlock chain and for ext. modulation F Type KV (-pin) for V power supply F Type KV (-pin) for V power supply Power Supplies for 8FM Power supply for laser diode beam sources, elec trical isolated,. m cable with connector (IE-9) Lumberg series KV (female). onnector (fem.) pol. KV for V (pin comp. to SV) or pol. KV for V D version Power Supply Input - V Output with connector VD/ F VD /. F PSE PSE Power cord for PS...E, IE pin line socket,. m,, V ountry Europe US/anada Great ritain PDE PUS P UK Picture DE US UK Table Laser Diode eam Source nanofm... Row Wavelength Laser LD Supply Electr. Fiber Fiber ur. Type P out * Electronics type trum Fiber Spec- diode operation power connection option (cm) (μm) connec. length MFD *** No. (nm) (mw) code mode ** (V) 8FM M9 P/ S.9 8FM H P/ / S. 8FM 7 H P/ / S. 8FM 7 N P/ / S. 8FM M P/ / S.7 8FM M P/ / S.7 7 8FM R P/ / S.7 8 8FM 7./.9 T7 P/ / S.7 9 8FM 8 M P/ / S.9 8FM 78 /9 H P/ / S. 8FM 78 / Y P/ / S/S. 8FM 8 7 N7 P/ / S.9 8FM 98. W P/ / S.9 8FM /8 U P/ / S 7. 8FM. M P/ / S 9. 8FM H - P * ** Laser diode beam source (see table ) Laser diode operation mode: constant power (standard)....p constant current.... Supply voltage: V D (standard).... V D.... Electr. cable. m shielded x. mm... as for, with connector SV (V).... as for, with connector SV (V).... cable length specified by customer.... Typical laser output power. For the lower of two specified power outputs, the housing length is L = mm (standard). For the higher power value, the housing length is L = mm, see dimensional drawing. onstant power: n internal control loop keeps the laser power constant. dvantage: Temperature variations and aging of laser diode are compensated. Dimensions onnector Lumberg SV ( V) SV ( V) X F connector able for power supply Potentiometer onstant current: The internal control loop keeps the laser current constant. The power output depends on temperature. dvantage: reduced noise. With fiber N. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de *** Laser Diode eam Source 8FM- Singlemode fiber cable Ø mm 8 Fiber length in cm, standard onnector option: = standard = core centered <. μm (singlemode only) Fiber type: = singlemode fiber cable, F-P connector ( polish) 8 = singlemode fiber cable, F-P connector (8 polish) = PM singlemode fiber cable, F-P connector ( polish) 8 = PM singlemode fiber cable, F-P connector (8 polish) onnector type ST, DIN-vio, and E- on request M x M /() * x / X Potentiometer 8

49 9 E HeNeLaser_9_ED_Seiten.indd Page 9 HeNe Laser with Fiber Optics Singlemode and polarization-maintaining olor Green Yellow Red Infrared Wavelength [nm] Output Power ex Fiber [mw] Freq. Stabilized yes - Picture - H E GREEN. nm G F F D pplication Interferometry YELLOW 9. nm RED.8 nm RED.8 nm RED.8 nm RED.8 nm,8 nm Frequency Stabilized Universal eam Source for Interferometry and Frequency Standards The Schäfter+Kirchhoff HeNe lasers and fiber optics are polarizationmain taining, they provide a high coupling effi ciency and ex hibit extreme transport stability. large selection of coupling lenses is provided that match the different laser beam diame ters to the particular PM fiber chosen for use. To minimize laser back reflection and power noise effectively, both ends of the singlemode fibers are provided with an 8 polish (connectors Type F-P). oupling efficiency > 7%, typically 8% Degree of polarization at fiber end > : Fiber cable MFD =. μm, N =. F-P type connector for coupler and fiber end (others available on request) Fiber coupling solutions for HeNe lasers supplied by the customer Mechanical shutter or attenutator locked by a grub screw and usable with special tool to ensure laser safety Electro-magnetical shutter for all HeNe laser types Mounting consoles for strainless mounting with shock mounts to avoid vibration, shocks and thermal deformation suitable for industrial environment Power supplies and customized power supplies For more information and mechanical drawings of the laser sources please contact Schäfter+Kirchhoff or download product information at Green HeNe Laser HeNe P - LGP Polarization-maintaining singlemode fiber Wavelength. nm Output power >.7 mw leaving the fiber Yellow HeNe Laser HeNe P - LYP Polarization-maintaining singlemode fiber Wavelength 9. nm Output power >. mw leaving the fiber HeNe Polarization-maintaining singlemode fiber Wavelength.8 nm Output power >. mw - > mw leaving the fiber HeNe P - MG Polarization-maintaining singlemode fiber Wavelength.8 nm Output power >. mw - > mw leaving the fiber HeNe P - REO Frequency stabilized Polarization-maintaining singlemode fiber Wavelength.8 nm Output power > mw leaving the fiber Overall length of system approximately mm Faraday Isolator for frequency stabilized fiber coupling Infrared HeNe Laser HeNe P - LIP Polarization-maintaining singlemode fiber Wavelength nm Output power >. mw leaving the fiber Options,8 nm Frequency Stabilized ll HeNe laser sources can be combined with following options: dapter flange 9.-F, standard adapter Mechanical attenuator 9.-F-T dapter flange with integrated shutter 9.-F-S D Vibration absorbing support bracket M-MG-.-R E Mounting console with integrated flange for fiber coupling (increased long-term stability) M-MG-.-F-R, standard mount F Mounting console with integrated flange for fiber coupling (increased long-term stability) and with steel shock mounts type M-MG-.-F-S G Electromagnetic bi-stable shutter EMS-- For more information on the shutter EMS--, see page 7 H Faraday isolator 8FI--..., see page Fiber Optics ccessories Fiber ollimators F-... Micro focus optic M-... Page ff Seite ff Vacuum Feed- Throughs V-... Fiber-optical eam Splitters FS-... Page Page Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 9

50 9 E Overview: HeNe lasers,, 9, and nm output power. 8 mw ex fiber Table HeNe Laser olumn No. Wavelength [nm] Power ex fiber [mw] Polarization Laser Type HeNe - -, - P - LHP Wavelength [nm] Optical power ex fiber [mw] Polarization: linear (standard)....p random (option).... R Laser type Supply voltage: V (standard).... V.... V **... Shutter/ttenuator mechanical shutter *...S mechanical attenuator.... w/o.... Laser Power [mw] Supply Voltage Shutter/ttenuator Fiber Type Fiber onnector Option Fiber Length [cm] Shutter* Laser Laser Diameter [mm] Length [mm] Laser lass Power Supply Style Fiber able Red HeNe. P 7P HeNe. P LHP X. 7.. HeNe. P LHP X. 9.. HeNe 7 P LHP X. 8.. HeNe P LHP X. 7.. N MFD /e² [μm] HeNe 8 P LHP X rect... Green 7 HeNe.7 P LGP X... Yellow 8 HeNe 9.7 P LYP X...9 Infrared 8 HeNe. P LIP X.. 9. Mounting onsoles and ccessories Fiber length [cm] onnector option: = standard = core centered <. μm (singlemode only) Fiber / connector type: = singlemode fiber cable, F-P connector ( polish) 8 = singlemode fiber cable, F-P connector (8 polish) = PM singlemode fiber cable, F-P connector ( -polish) 8 = PM singlemode fiber cable, F-P connector (8 -polish), standard onnector type ST, DIN-vio, and E- on request dapters for laser beam couplers SMS- Schäfter+Kirchhoff offers different adapters for attaching the laser beam couplers SMS-... to HeNe laser with standard fitting x -, Ø" Mounting set with screws and washers 9.-F-MS M. 7 7 Ø.8 Ø.8 Ø.8 ** In case the laser has its own shutter, see table, column, an external shutter is dispensable. ** V OEM power supply only available for laser type 7P, Table row. Ø9.. Ø9.. Ø9.. dapter flange 9.-F dapter flange with attenuator 9.-F-T dapter flange with integrated shutter 9.-F-S Mounting onsole M-MG-.-R for HeNe lasers with diameter. mm /.7'' (set of two). Elastomer shock mounts are used for damping of shock and vibrations and for avoidance of thermal defor mations. The adapter 9.-F, 9.-F-T, or 9.-F-S is attached to the front plate of the laser. Mounting onsole M-MG-.-F-S for lasers with diameter. mm /.7'' (set of two). Wire rope shock mounts for improved damping of shock and vibrations, and for avoidance of ther mal defor mations in xyz-directions. For optimum sta bility, the console M-MG-.-F-S holds both laser and adapter. Mounting onsole M-MG-.- F-R for HeNe lasers with diameter. mm/.7'' (set of two). Elastomer shock mounts for damping of shock and vibrations, and for avoidance of thermal deformations. For optimum stability, the console M-MG-.-F-R holds both laser and adapter. Electro Magnetic Shutter EMS-- and shutter controller SK97. For more information, see page 7 Faraday Isolator 8FI--... See page for more information Dimensional Drawings for Power Supplies HeNe lasers from Schäfter+Kirchhoff are supplied along with power supplies. Desktop power supplies are available for V and V line voltage. For some HeNe lasers there are OEM power supplies with input voltage V D or / V. Key switch Power On/OFF 7 Style HV connect. Remote/interlock OEM power supplies with input voltage V D or / V are available for HeNe laser HeNe--,-P-7P (Table line ). OEM power supplies for other HeNe lasers are available on request. Power supply / V ccessories Socket head screws DIN9 - UN x /8'', set of pcs. 8---/8-9- Style.8 7. HeNeLaser_9_ED_Seiten.indd Page Key switch Power On/OFF 9 Key switch Power On/OFF StyleStyle HV connect. Main power HV connect. Remote/interlock Power supplypower supply V D Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de Holes = Ø Fitting tool: hex keyl HD-/

51 9 E Safety at Work Full Protection Goggles DIN EN 7 7.T8. Full Protection Goggles DIN EN 7 7.T8. VLT = % Usable Range Wavelength Protection [nm] Full Protection Goggles DIN EN 7.P. VLT = % Usable Range Wavelength Protection [nm] Full and lignment Protection Goggles DIN EN 7 / DIN EN 7.P. VLT = % 8 Optical Density OD Wellenlänge Wavelength in in nm Usable Range Protection Wavelength Protection max. Transmission (EN 7) Density (EN 7) (EN 8) max. Power max. Power [nm] Level lignment - R - - mw Full - 8 L - W/m - lignment protection goggles are for lasers in the - nm wavelength range Use full protection goggles for the - 8 nm wavelengths 8 Optical Density OD Optical Density OD ttenuation rea Wellenlänge Wavelength in in nm Protection Level max. Transmission (EN 7) max. Power Density (EN 7) Full - L - W/m - Full protection goggles for lasers in the - nm wavelength range 8 Optical Density OD Wellenlänge Wavelength in in nm nm Protection Level max. Transmission (EN 7) max. Power Density (EN 7) Full 9 - L - W/m - Full - L - W/m - llround googles as full protection for lasers in the 9 - nm wavelength range VLT = % Wellenlänge Wavelength in nm Usable Range Wavelength Protection max. Transmission (EN 7) Density (EN 7) (EN 8) max. Power max. Power Protection [nm] Level lignment - 9 R - - mw lignment protection goggles for lasers in the - 9 nm wavelength range max. Power (EN 8) max. Power (EN 8) Laser safety and laser adjustment goggles The use of laser safety goggles is recommended for work with lower power lasers from laser protection class R and beyond, such as all visible lasers from Schäfter+Kirchhoff with up to mw of output power. Laser safety goggles are mandatory for protection class and beyond, such as all invisible infrared lasers and all visible lasers from Schäfter+Kirchhoff with more than mw of output power. The correct handling and use of the laser safety goggles protects you and your colleagues against eye injuries from hazardous laser radiation. selection of E and GS certified laser safety goggles (manufactured by LaserVision, are provided for the lasers manufactured by Schäfter+ Kirchhoff. The two different protective functions of laser safety goggles need highlighting in full protection goggles and alignment goggles. The type of frame is dependent upon whether glass or plastic filters are fitted. Laser safety goggles with glass filters ( RX7) have a heavier frame with a facility for attaching personal spectacles, according to individual requirements.laser safety goggles with plastic filters are lighter and can be worn over normal spectacles. Laser Safety Goggles - Function and haracteristics Protective function. The two different protective functions of laser safety goggles need highlighting in full protection goggles and alignment goggles. Full protection goggles, conforming to European standard EN 7, provide personal protection against laser radiation. The laser radiation is blocked and is no longer visible. The protection levels (such as protection level L..) differ in the maximum spectral transmission of the filter glasses. The EN 7 standard specifies a maximum incident laser power density (power per unit area, in W/m ) for the laser power that is allowed to irradiate the filter glass. lignment protection goggles, conforming to European standard EN 8, reduce the visible laser radiation ( - 7 nm wavelengths) down to the power of a laser of class (EN 8-). The laser radiation remains visible, so that the alignment protection glasses can be used for adjustment tasks. The protection levels (protection level R..) describe the maximum power (Watts) of a collimated laser beam that is allowed to irradiate the goggles. Maximum power (EN 8): the maximum power of a laser beam in a specified wavelength range that is sufficiently attenuated by the alignment protection goggles (in accord with EN 8). Maximum transmission (EN 7): maximum trans mission (minimum attenuation) in a specified wavelength range (according to EN 8). Maximum power density (EN 7): maximum power density that the filter glasses can withstand over a longer period (according to EN 7). VLT: (visible light transmission): in addition to the specified wavelengths, laser protection goggles also attenuate the ambient light. The VLT is the percentage of daylight transmitted. OD (optical density): logarithmic scale for the attenuation of radiation at a specified wavelength. The OD at wavelength is defined as: OD = -log Damage aused to Eye Health by Radiation Keratitis and conjunctivitis (pink eye) Eye cataract Photochemical and thermal injury of the retina Eye cataract urning of the cornea SafetytWork_spalt_9_ED.indd Page Full and lignment Protection Goggles DIN EN 8/DIN EN 7.P. VLT = % Optical Density OD Usable Range Protection Wavelength Protection max. Transmission (EN 7) Density (EN 7) (EN 8) max. Power max. Power [nm] Level lignment - 8 R - - mw Full 77-8 L - W/m - Full 8 - L - W/m - Full protection goggles for lasers in the - nm wavelength range Wellenlänge Wavelength in in nm nm < nm - nm - nm - nm. - μm > mm X-ray and gamma radiation Insert for Prescription Glasses RX7 UV- and UV- UV- VIS and IR- IR- and IR- Microwave Wavelength s an accessory for the laser protection goggles type 7.T8. and 7.T8., the insert RX7 for personal prescription glasses is available. Please Note Typical density curves for the respective filters are shown for information only and are not guaranteed values. Only the protection levels (R.. or L..) are guaranteed by Schäfter+Kirchhoff. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

52 9 E IR Detection ard Invisible infrared radiation in the range 8 nm is converted to visible light by luminescence. The luminescence in the active detector layer indicates the position and approximate size of the beam. The detector cards should not be used for measurement tasks like the quantitative determination of the beam diameter. With high power lasers, even the border area of the beam with less than < % of the intensity maximum will be visible, additionally widened by scattering processes in the detector layer. With a low power beam, only the central area will be visible. IR Detection ard IR Laser Reflection max. sensitivity Spectral range active sensor area Detector cards of series SK...R diffusely reflect the luminescent radiation at the active layer. These cards are impermeable for the beam. onversely, the detector cards of the series SK...T are transparent. The beam traverses the layer and the diffusely luminescent radiation is also visible from the back of the card. SK R nm 7 - nm x mm² SK R nm 7 - nm x mm² Transmission Laser Safety max. sensitivity Spectral range active sensor area ccording to DIN IE 8-:7, every laser system must be signalized by a warning sign (triangle). dditionally, all lasers must be labeld with additional signs referring the laser class: lass : "LSS LSER PRODUT" lass M: " LSER RDITION, DO NOT VIEW DIRETLY WITH OPTIL INSTRUMENTS, LSS M LSER PRODUT" lass : "LSER RDITION, DO NOT STRE INTO EM, LSS LSER PRODUT" lass M: " LSER RDITION, DO NOT STRE INTO EM OR VIEW DIRETLY WITH OPTIL INSTRUMENTS, LSS M LSER PRODUT" lass R: " LSER RDITION, VOID DIRET EYE EXPOSURE, LSS R LSER PRODUT" lass : " LSER RDITION, VOID EXPOSURE TO THE EM, LSS LSER PRODUT" lass : "LSER RDITION, VOID EYE OR SKIN EXPOSURE TO DIRET OR STTERED RDITION, LSS LSER PRO- DUT" Furthermore, all lasers of class to must have a sign with laser specifications which indicates the laser source, the wavelength, the laser power or pulse energy. SK T nm 7 - nm x mm² SK T nm 7 - nm x mm² IR Detection ard SKR Left: active sensor area Right: plot of spectral sensitivity If the laser is enclosed but the sealing is removeable, the enclosure must be labeld with an caution shield with an information about the laser class and a warning like the list before. The different laser classes are defined as follows: lass : The laser is safe in any circumstance. The user cannot be exceeded the maximum permitted exposure (MPE). Enclosed high power laser systems with automatic shutdown option when opened are included in that laser class. lass M: The same like class except magnifying optics such as microscopes and telescopes are used. In that case the safety limits are exceeded. lass : Visible laser ligth ( - 7 nm) with < mw W and/or <. s exposure time (with an energy limit according to the standard) are save. dditional radiation below or above - 7 nm fulfill the conditons of class. lass M: The same like class except magnifying optics such as microscopes and telescopes are used. lass R: If handled carefully, the laser is considerd safe because only a low risk of injury exists. Visible W lasers in lass R are limited to mw. For other wavelengths and for pulsed lasers, other limits apply. lass : direct exposure to the eye is hazardous, but diffuse reflections such as from paper are not harmful. The limits apply to wavelengths and to operation mode (like W and pulsed lasers). Laser safety goggles are required when a direct view to the laser beam is possible. lass- lasers must be equipped with a key switch and a safety interlock. lass : Every laser greater then class. LSER RDITION VOID EXPOSURE TO EM LSS LSER PRODUT (DRH) LSS LSER PRODUT (DIN EN 8-:7) SK-L HeNe - x - I SafetytWork_spalt_9_ED.indd Page SK-L-T SK-L-T SK-L-T SK-L-T Size Triangle mm Triangle mm Triangle 9 mm Triangle 8 mm Laser classification, M,, M, R, (see list above) Wavelength [nm] Laser power [W] or pulse energy [J] Laser Type: HeNe Diode Nd:Yag others Option: E = Sign for removable enclosure = asic information sign without specifications I = Laser specification sign I = both and I Label size x mm type..x 8 x 7 mm type..x7 8 x mm type...8x Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

53 9 E Polarization nalyzer SK978-VIS--7 nm... SK978-NIR-7- nm... SK978-IR-- nm... Figure : Polarization measurement setup: nalyzer SK978, polarization-maintaining fiber with F connector, Display Figure.: PER measurement for high coherent sources Polarization Measurements High oherent Sources The Poincaré sphere view is used with high coherent laser sources for PM fiber alignment. The measured current state of polarization is displayed on a Poincaré sphere and used to adjust the linear or circular polarisation states within a small radius of deviation. Low oherent Sources For low coherent laser sources exiting a PM fiber, their low degree of polarization is linearized my minimising the elliptical representation (see applications). The polarization analyzer SK978-VIS/NIR is a universal measurement and test system for laser beam sources with polarization-maintaining fiber optics that was developed for ease of use (Figure ). The polarization analyzer is a plug & play device and connects to the US port of a standard computer. lignments and measurements are performed rapidly, especially in comparison with tedious and highly time-con suming standard methods. real-time interactive display shows the state of polarization and the oscillating axis of the linearly polarized fraction, as well as the orientation of the connector index should a fiber cable be attached. The radiation coupled to the polarization analyzer is collimated and passed through a rotary quarter-wave plate and a polarizer. The signal from the photo detector and the rotary angle are evaluated by an onboard chip and transferred via the US port to the computer. The software SKPolarimeter is used to ac quire and visualize the data. 'Plug & play' device, no interface card necessary Large spectral range: - 7 nm SK978-VIS 7 - nm SK978-NIR - nm SK978-IR onnection for fiber connectors of types F-P and F-P ompatible with micro-bench for beam optics Power attenuator djustable amplification factor real-time display with measurements per sec US interface, P operating system: Windows Technical Data Power range:. - mw Spectral range: VIS - 7 nm NIR 7 - nm IR - nm ccuracy:.,., Extinction ratio ER. d, Degree of polarization: % Sensor perture:.8 by.8 mm² Supply power: V D, >, DIN -pol. (male -pin) P interface: US Housing: 9 Rack HE-TE nalysis software: SKPolarimeter (included) for WINDOWS 7/Vista/XP (/ it) ccessories (included): Power supply: PS7, V US cable dapter for fiber connectors of type F-P SK978 - VIS Wavelength range: VIS - 7 nm NIR 7 - nm IR - nm Polarizationnalyzer_9_E.indd Page Figure.: adly aligned source in elliptical view Figure.: Well aligned source in elliptical view nalysis Software SKPolarimeter The software of the polarization analyzer displays the measurement results and the user settings in a comprehensible user interface, see Figure. The user interface provides the following settings and functions: Extinction ratio (ER) measurement Display of polarization state on Poincaré sphere Display of polarization ellipse (linear or logarithmic scale) djustment help for PM fiber coupling for high and low coherent sources Saving of measurement results in a log file Logging measurements over a period Extra editable field for user comments ontinuous measurement Dialog for user settings - number of averaging points - number of FFT points for analysis alibration of polarization zero phase and resetting to the factory setting ttachments dapter for fiber connectors of other wavelengths dapters for fiber connectors type F-SM, ST and DIN-VIO are available on request. dapter plate For attaching beam optical components with Ø 9. mm system mount or with Ø mm compatible with micro-bench systems 8M-MP-9. Ø 9. mm 8M-MP- Ø mm Rod for mounting to micro-bench system 8M--7 Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 7 mm dapters Figure : Polarization analyzer attached to a fiber collimator using a micro-bench adapter Sensor aperture for polarization analysis is.8 by.8 mm² onnector Type Spectral Range F-P - nm 978-SMS nm 978-SMS nm 978-SMS nm 978-SMS--.- F-P - nm 978-SMS nm 978-SMS--.-

54 9 E Software applications: PM fiber alignment PM fiber adjustment with coherent sources The extinction ratio, ER, of fiber-coupled radiation is the ratio of the optical power coupled to the two main axes of a polarizationmaintaining fiber. The polarization analyser can be used to optimize the couple alignment of polarization-maintaining fibers. pplication: Retardation measurement of quarter-wave plates The telecentric view of the D Poincaré Sphere makes other measurements possible, in addition to the current states of polarization and alignment with the PM fiber axes. Figure.: The states of polarization of a rotated quarter wave plate describe a figure on the Poincaré sphere similar to a figure of eight. For an ideal waveplate the turning points lie on the poles of the sphere. Polarizationnalyzer_9_E.indd Page Figure : Further measurement adjustments for PM fiber axes Left: When linearly polarized radiation is not coupled exactly to one of the fiber polarization axes, the actual state of polarization fluctuates with temperature or with fiber position. The measured states of polarization are mapped as a circle on the Poincaré sphere. The center of this circle represents the mean extinction ratio for the given alignment. For an ideal linear birefringent fiber, the center is on the equator of the sphere. The circle data point furthest away from the equator represents the lowest extinction ratio that can occur with the current alignment. The radius of the circle is a measure of the misalignement angle of the fiber with a smaller radius indicating an improvement in the alignment of the PM fiber coupling. For perfect coupling of linear polarized radiation to one of the main axes of a polarization-maintaining linear birefringent fiber, the circle degrades to a single point located on the equator of the Poincaré sphere. In the software modus ER, a series of measurements are performed and the data logged. For the modulation of the polarization state, the fiber is stressed or heated and a circular cloud of data points is generated on the Poincaré sphere. fter data acquisition, a circle is automatically fitted to the data. The aim of the subsequent adjustments is to cause the convergence of these data points on the center of this circle, by rotating the linear input state of polarization with respect to the fiber main axes. s additional help the reciprocal distance from the center is displayed continuously by means of a bar plot with a linear or logarithmic scale. Right: second measurement of the extinction ratio has been performed. This reduced radius indicates that the fluctuation of the current state of polarization is reduced. For a final ER measurement, the mean and minimum ER values are displayed on the linear or logarithmic bar plot. PM fiber adjustment with low coherent sources The ER measurement procedure described above applies only to coherent laser sources showing a degree of polarization close to %. For low coherent sources the light not coupled to the main axis of the fiber contributes to unpolarized light, described by an extinction ellipse, see figure. Figure : Polarization ellipse of PM fiber alignment with a low coherent laser source For a measured degree of polarization lower than 8%, an additional dotted polarization ellipse depicts the ratio between linearly polarized light and the sum of circular and unpolarized light. For better alignments of the fiber axes with the linear polarized fraction of the light then the dotted ellipse becomes smaller. Figure.: non-ideal quarter wave plate is indicated by measurement points not lying on the poles. dditionally, the quarter wave plate might may be asymmetrical for right and left circular polarization. For both images the blue measurement points are emphasised by blue lines. Figure.: y turning the Poincaré sphere, the points of the two halves of the figure eight become congruent. y connecting the center of the Poincaré sphere with one of the turning points of the figure eight, it is possible to calculate the retardance of the quarter wave plate from the included angle between this imaginary line and the equator, as follows: Dimensions Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 8. (HE) = tan ( ) = Figure.: For a non-ideal quarter waveplate, the points on the Poincaré sphere fail to touch the poles and the cross-section of the figure eight is not on the equator. y connecting the center of the Poincaré sphere with one of the turning points of the figure eight, the larger angle between this imaginary line and the equator supplies the retardance according to: = tan ( ) > 8 (TE) 7. 7.

55 9 E Fiber Port lusters Magneto for OT Fiber-coupled beam delivery sys tems. Postcard size replaces m bread board constructions. s sem bled with fiber optic components from Schäfter+Kirchhoff. ptical raps Fig. New Dichroic system: Input: polarization-maintaining singlemode fibers, e.g. Sr at nm and 89 nm. Output: PM-SM fibers with both wavelengths See www. superimposed, with parallel-orientated SuKHamburg.de/ linear polarization download/art_mot_e.pdf Optical scheme The cooling of an atomic cloud down to a very few micro-kelvin in an atomic trap brings thermal motion to a virtual standstill. To reach micro-kelvin temperatures, a magneto-optical trap produced from magnetic fields and laser radiation is used (Fig. ) magneto-optical trap (MOT) is often used for the initial cooling phase before other super-cooling mechanisms bring the temperature down for ose-einstein condensation. Experimental reproducibility when using cold atoms requires an extremely stable setup. This is achieved most effectively by using polarization-main tain ing fiber optics to mechanically decouple the vibration and temperature sensitive optics from the trap. Efficiency and reproducibility are the fundamental charac teristics of our multi mo du lar fiber delivery system (Fig. ). The optical scheme of the fiber port cluster (Fig. ) shows that the input ports are connected to their frequency-shifted sources by sing lemode fibers which maintain laser polarity. The light sources are then combined and are split between the output ports as required. t each out put port, the polarization of both frequencies is orientated in parallel and coupled into a polarization-maintaining singlemode fiber. The six output fibers and their fiber collimators, optionally fitted with integrated quarter-wave retarders, are attached to the MOT (Fig. ). The delivered fiber port cluster is assembled and pre-aligned, together with highly detailed manuals, if further adjustment is desired. The coupling of laser radiation into singlemode fibers and their correct orientation with the axes of polarization are performed using computerassisted beam and polarization analysis. This automation substantially reduces the alignment effort, especially in com parison with a more conventional breadboard configuration. Laser beam couplers, splitters and combiners, polarizers and retardation optics can be mixed together using multicubes to produce almost any desired system in a postcard size. The m and bigger breadboard arrangements are totally superseded by this fully integrated, ultra-compact, transportable sealed system. Fig. In global use: ustria France Italy hina Germany U.K. US India Fig. Designed for Isotope Wavelength Sr Yb Na 89 Li 7 Sr 89 Na 7 K 77 Rb 78 Kr 8 s 8 He 8 Special Fiber ollimators for M OT agneto ptical. Retro reflector raps. eam combiner. ircular polarisation. Elliptical beam. Power monitoring. Tilt adjustment Fiber-optical components made by Schäfter+Kirchhoff Polarization eam splitter 8PM-... Laser beam coupler SMS---.. Laser beam sources dapter 9.-F-S Laser eam oupler for Singlemode Fibers multicube System 8M-... -TILT tomictrap_rt_forfiberoptics_9_e.indd Page eam Splitter 98/ 8S-... for power monitoring D inclined fiber coupling axis Fiber collimator F-Q-... with integrated / plate D PM- pola rization maintaining fiber cables for - 7 nm For more information see: Retardation optics 8WP-... / plate for rotation of the polariza tion axis Made in Germany Schäfter+Kirchhoff offers a varriety of fiber collimators with special features. We offer fiber collimators with integrated: retro reflector for reflection without change in state of polarization, F-RR, see page beam combiner for the combination of different, F-8, see page quarter-wave plate for circular polarized ligth, F-Q, see page anamorphotic optics for elliptical beams, F-E, see page power monitoring F-8PD, see page tilt adjustment F-T, see page 7 Laser Measurement - Polarisation nalyzer SK978 'Plug & Play' device Large spectral range onnection for fiber connectors of types F-P and F-P Power attenuator 'real time' display, measurements US Interface Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

56 9 E Fiber Port luster Fiber port clusters made by Schäfter+Kirchhoff take the optical power carried by a polarization-maintaining single mode fiber and split it into multiple polarization-maintaining singlemode fibers with high efficiency. dditionally, numerous bulk-optical components can be integrated and, by use of actuating elements, the splitting ratio of the resultant beams can be adjusted arbitrarily and reproducibly. In principle, the cluster can be cascaded endlessly in order to generate any desirable number of outgoing ports. (for a fiber port cluster, see page ). lignment and eam nalysis using D cameras The quality of a fiber port cluster is determined by its polarization maintenance ability and the power efficiency of the coupled laser radiation. The plano-optics, beam splitters and combiners need a highly precise alignment. Even the smallest deviations of the beam from the optical axis can lead to obstruction, diffraction or aberration and, thus, to reduced coupling efficiency at the outgoing ports. The quality and precision of the connection between a laser beam coupler and its polarization-maintaining singlemode fiber cable is absolutely critical for the functionality of a fiber port cluster. Laser In Power Monitor x Retardation Optics. -. eam Splitter. -. Laser Out..... eam Profile eam Profile eam Profile.. tomictrap_rt_forfiberoptics_9_e.indd Page Figure : Fiber port cluster with integrated power monitor, retardation optics, beam splitter and laser beam couplers for singlemode fibers. Figure depicts a cluster with the incoming port connected via a laser beam coupler to a polarizer. The polarizer defines the incoming polarization state even in the case of a source with weak polarization stability. 98/ beam splitter combined with a photo-detector acts as a power monitor. The majority of the radiation passes the first halfwave retardation plate that is mounted in a self-locking bearing free from backlash. The half-wave retarder rotates the axis of the incoming polarization in the freely adjustable range from : to : and so defines the splitting ratio reaching the polarization beam splitter.. Rotatable half-wave retarders and a further set of polarization beam splitters. and. are placed at each outgoing port to divide the beams yet again. There are now a total of four beams passing through the laser beam couplers. -. which act as the outgoing ports. Polarizing beam splitters produce a high degree of polarization in the non-deflected beam (typically :,). onversely, the low degree of polarization in the deflected beam (typically :) necessitates the use of small additional polarizers to increase the degree of polarization of these deflected beams. Polarization-maintaining singlemode fibers are connected to the outgoing ports. Figure depicts the system components and the optical path arrangement schematically. onfiguration Scheme ase Plate 8M-9. multicube 8M-LTS-9. x multicube 8M-SM-9. Spacer 8S-9. ap 8-9. x Laser eam oupler SMS (laser IN) x Polarizer 8PM-S-... eam Splitter 98/ 8S--... D Photo Detector 8PD D dapter 8M-9. E Retarder 8WP F x Polarization eam Splitter 8PM- G x Laser eam oupler SMS (laser OUT) Optical Scheme D D G G Figure : System components for the fiber port cluster shown in Figure. E F E E F F G G Figure 7: Fiber port cluster with cameras attached to ports. to. for the monitoring of the alignment process. The laser beam couplers made by Schäfter+Kirchhoff (type SMS-..., Fig. ) are provided for a large variety of wavelengths and beam diameters. The tilt adjustment and inner focussing mechanism provide all of the degrees of freedom needed for alignment, while being compact and insensitive to unintentional displacement. The inclined coupling axis, provided by the fiber connectors of the F-P type, ensures that back-reflections into the optical path and laser source are avoided. The laser beam couplers have two different tasks in a fiber port cluster. One is to collimate the radiation that is emitted from the single mode fiber at the incoming port. The other is to couple the split radiation into the singlemode fibers at the outgoing ports. The multicube system from Schäfter+Kirchhoff is the integrating element for the fiber port cluster (Fig. ) and provides a warp-resistant assembly of laser beam couplers. To maintain optimal polarization and beam profile characteristics, an expert and careful selection of the materials is required. dditionally, we take the utmost care to obviate mechanical stress during fiber termination in the coupler. Polarization-maintaining singlemode fiber cables are provided by Schäfter+Kirchhoff in a variety of wavelengths. Figure 7 shows the fiber port cluster depicted in Figure during alignment adjustment. ll beam splitters and half-wave retarders are already mounted and, instead of laser beam couplers, D cameras have been attached to the outgoing ports. to.. The laser power incident on the sensitive cameras has to be reduced during the adjustment process. vignetting aperture is produced by rotating the half-wave retardation plates, restricting the collimated laser beam to % of its full strength. The computer-assisted image analyzer determines the quality of the laser beam being coupled and uses a two-dimensional Gaussian to center the beam. The screenshot (inset, Fig. 7) reveals the position of the collimated beam at the sensor of port. that originates from the input port. The left-hand beam profile shows that the beam is asymmetrically obstructed and, so, the laser beam coupler at port, employed as collimator, has to be realigned using its tilt adjustor. The middle and right-hand beam profiles show the beam aligned correctly. The beam positions at the outgoing ports. and. are now aligned by tilting their respective beam splitters. and.. Finally, the beam position at port. is aligned by tilting its beam splitter.. fter all adjustments have been completed, the cameras are replaced by laser beam couplers. The align ment of the fiber cable at the outgoing ports is performed using the tilt adjustment and, when needed, by fineadjustment of the focus for each of the four couplers. The fully aligned fiber port cluster is now stable for transport and can be utilized without any requirement for a space-consuming optical breadboard. Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de

57 9 E Polarization Maintainance and nalysis Laser beam propagation in polarization-maintaining singlemode fibers enables countless modular and compact systems to be devised for scientific experimentation and measurements. The advantages of the substantial flexibility in spatial arrangements are complemented by the high intensity and Gaussian distribution of the beam emanating from our singlemode fibers. Modular fiber-optical systems also eliminate the need for elaborate opto-mechanical spatial filtering, with its resultant beam intensity loss.the potential problem of polarization fluctuations are totally obviated using modular fiber-optic Figure 8: Polarization measurement. SK978 VIS/NIR nalyzer, polarization-maintaining singlemode fiber, display screenshot system components with specially designed and precise adjustment mechanisms. Polarization fluctuations in the fiber output is considered to hinder the effective replacement of a bulk-optical bread board by a modern fiberoptical system. While the use of inappropriate polarization-maintaining singlemode fibers can cause polarization fluctuations, it is usually the inadequate and suboptimal alignment of the polarization axis with the axes of the polarization-maintaining fibers that causes these problems. Polarization-maintaining singlemode fibers maintain the oscillation of the electromagnetic field in two orthogonal axes: one with fast and the other with slower light-propagating properties. When linearly polarized radiation is not coupled exactly with one of these axes, the beam is transformed into an elliptical polarization state because of the dif ferent light propagation speeds in the two axes. Temperature changes, fiber bending and even vibration can affect the polari zation state obtained at the end of the fiber. The SK978-VIS/NIR polarization analyzer (Fig. 8) is a plug&play US device developed for ease of use by practitioners in the field. lignment measurements and verification are achieved more rapidly than with the more time- con suming conventional methods. The state of polarization (SOP) is displayed in real-time as the Stokes parameter or as a point on a Poincaré sphere with azimuth and inclination angle. y maximising a bar display of the extinction ratio, the axial alignment of a polarization-maintaining fiber can be achieved. Figure : System omponents Optical system building blocks for self-assemby and alignment For examples and applications, see Figures and multicubes 8M-... The multicubes and form an integrated system for assembling laser beam couplers, splitters and combiners - H. Multiple function components, base plates and mounting plates can all be incorporated, producing a universal mounting kit. ll components have mm precision borings placed in a standardized mm microbench layout. Hardened steel rods with super-finish surfaces are used to mount and connect the single modules. With axially mounted grub screws (M/WS. hex allen key), the rods lock the components into a solid warp-resistant unit. Spacer 7 seals the assembly from dust ingress and light egress. The laser beam couplers from Schäfter+Kirchhoff efficiently launch a collimated laser beam into a polarization-maintaining singlemode fiber with a mode field diameter as low as. μm. Features include: Integral coupling lens, from f.7 to 8 mm, for highly efficient matching of beam geometries. Focus adjustment of integral lens with positive locking by non-contact grub screws. tilt adjustment with carbide inlay for lateral positioning of the beam focus on the mode field of a singlemode fiber in the F connector. F connectors with either the inclined coupling axis of the F-P type or the coaxial F-P type (optionally ST, DIN-VIO, F-SM) couple the singlemode fiber cable. The inclined coupling axis of the F-P connector prevents back-reflections into the laser beam source. F connector fiber cable ferrule positively located with M. grub screw. Tightly fitting cylinder system Ø 9. mm with a circular V-groove (to align polarization axis) containing an O-ring (for non-contact locking screws). Polarizer 8PM-S D E Photo Diode 8PD for Power Monitoring F 7 Laser beam coupler SMS-... The inclined fiber coupling axis eam Splitter 98/ 8S--P Polarization eam SplitterPM 8PM- Polarisation: linear,: perture Ø. mm Mounted in self-locking bearing with rotatable axis pplication: Suppression of the fractional p-polari zation (approx. %) falsely deflected by the polarization beam splitter eam splitting ratio 98: perture Ø mm mm fused silica plate Optimized for incident angle and p-polarization Wedge angle of the plate:. to obviate the formation of etalons Si-diode or Ge-diode perture Ø mm Electrical: N socket Mechanical: circular V-groove Ø 9.mm to fit adapter 8M-9. Polarization beam splitter cube Polarization: linear In transmission p-polarized, extinction,: In reflection (9 deflection) s-polarized : perture Ø mm Splitting ratio depending on degree and state of polarization of the incoming radiation G Retardation Optics 8WP- Low order quartz retarders perture Ø mm Self-locking adjustment flange Rotary axis inclined in order to avoid back reflection and etalons pplication: Rotating the axis of linearly polarized laser radiation tomictrap_rt_forfiberoptics_9_e.indd Page 7 Figure 9: Polarization analyzer software: measuring of extinction ratios Left When linearly polarized radiation is not coupled exactly to one of the fiber polarization axes then the state of polarization can fluctuate with temperature or fiber position. The misaligned polarization axis, indicated by a ring around H, is realigned by maximizing the extinction ratio using a continuously updated red-green bar display (inset). Right second measurement of the extinction ratio indicates that the polarization state fluctuation is reduced, the ring is reduced to a small spot at H on the equator, denoting a stable linear state of polarization. The final extinction ratio is displayed on a linear or logarithmic scale. Dichroic eam ombiner 8- Two laser beams of different wavelengths are combined to produce a coaxial beam with equal states of polarization mm fused silica with a wavelength-dependent coating optimized for incidence. plate wedge angle to obviate etalon formation Singlemode fibers are characterized by their numerical aperture (N), the mode field diameter (MFD) and the cut-off wavelength T. Polarization-maintaining singlemode fibers with polarization axis indicated by alignment marker Mode field diameter. μm Wavelength 7 7 nm, usable spectral bandwidth typically T to approx.. x T Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de H I PM Fiber able PM-... with inclined F-P onnectors 7

58 9 E Notes tomictrap_rt_forfiberoptics_9_e.indd Page 8 Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de 8

59 9 E ustomized Fiber Optical Solutions Figure : Fiber-coupled Sapphire HP laser with external acousto-optical modulator consisting of: OHERENT Sapphire 88 HP, mw, coupled to a polarization-maintaining fiber cable. Laser contol cousto-optical modulator, fiber coupled using the "multicube" components from Schäfter+Kirchhoff Driver for the acousto-optical modulator Over all coupling % of the intrinsic power Polarization extinction d Figure : Fiber coupling of OHERENT Innova Laser The fiber coupling system depicted is with a power dump and an adjustable power-splitting unit. The laser power is launched into two polarization-maintaining fiber cables. Innova I-x für for the visible range Innova I-x for the UV-range (wavelengths nm and nm) oupling 7 % of the intinsic power Polarizations extinction d RGV Figure : Switchable multi-colour system consisting of: HeNe laser nm, fiber-coupled rgon ion laser, multiline, 7 nm, 88 nm, and nm. RG(V) beam combiner, fiber-coupled with an apochromatic corrected optics cousto-optical tunable filter (OTF) to select the individual wavelengths. Fiber-coupled with an apochromatic corrected optics and with "multicube" components from Schäfter+Kirchhoff. ontrol for the OTF oupling throughout: % of the intrinsic power Polarization extinction: d Laser and Fiber Optic omponents for Space Fiber Optics for Life Science nm, 7/88 nm, / nm, nm tomictrap_rt_forfiberoptics_9_e.indd Page 9 Experiments Site Year Microgravity Experiments Texus / Texus 99 lpha Magnetic Spectrometer MS- Diffusion oefficients in rude Oil DO Protein Microscope for International Space Station promiss Plasma Kristall Experiment PKE Nefedov Protein rystallisation Diagnostics Facility PDF lpha Magnetic Spectrometer MS- Discovery 998 ISS 998 Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de ISS ISS ISS / - / 8 ISS 9

60 9 E Product atalogs: also available at OPTIS, METROLOGY ND PHOTONIS Y years of experience and substantial production know-how synergize in the advanced optical products and optoelectronic systems designed by Schäfter+Kirchhoff Orbital Tube Welding Head -VIS IORT Electron pplicator ustomized Line Scan amera D Object Profiling Flatbeam -Laser 7 Laser Diode Systems in Space FiberOpticsack_9_ED.indd Page IR illumination head International Patents: Germany DE 9 8 Europe EU O 87 TIG torch IR camera head German Patent: DE 9 88 Kieler Str., Hamburg, Germany Tel: Fax: info@sukhamburg.de X7