Tunable Diode Lasers. Simply Better Photonics

Transcription

1 Simply Better Photonics

2 New Focus: Simply Better Photonics Founded in 199 with the mission of providing Simply Better Photonics Tools, New Focus has built a portfolio of high-performance products that includes tunable lasers, opto-electronics, high-resolution actuators, stable opto-mechanics, vacuum and ultra-clean solutions, and OEM engineered solutions. Our products are used in demanding applications around the world in semiconductor equipment, bio-medical research, industry, test and measurement and advanced research. As part of Newport we continue our focus on making great tools for scientists and researchers. We are taking all the engineering we have learnt in the industrial world and have remade all our legacy tunable lasers and high speed electronics products. We believe tools that you use in the lab should be just that, simple and reliable tools, not an experiment in a box. Need a wavelength or tuning range that you do not see? Smoother linearity or a tighter linewidth? Let us know, these are the real-life challenges we get excited about trying to solve. We still know that good engineering requires an in-depth knowledge of our customers, their visions and problems, and how technology can make their applications really work. Optomechanical modal spectroscopy of the natural vibrations of on-chip micron-scaled spheres. Experimental setup for studying the collisions of ultracold Rb atoms with ND3 molecules. And we still want to have fun helping researchers do the best science they can. Talking face to face is great so let us know if you are going to be in the Silicon Valley. We would love to show you around our facilities, or just drop by our booth at a trade show or conference. We look forward to hearing from you. Microtoroid resonator emitting 41 nm light.

3 New Focus Application Guide Spectroscopy Microcavity Resonators NV-centers TLB-67 Velocity nm Wide and fine mode-hop free tuning Interferometry Metrology Atomic clocks Laser cooling TLB-68 Vortex Plus nm Mode-hop free precision fine tuning Laser cooling Magneto-optical traps BEC Atomic clocks TLB-71 Vantage nm Wide tuning and mode-hop free fine tuning Laser cooling Magneto-optical traps BEC Amplification of CW diode lasers TA-76 VAMP Tapered Semiconductor Amplifiers nm Fixed Wavelength Raman spectroscopy Interferometry Tetrahertz generation Data encryption LIDAR SWL-75 Single wavelength nm Fixed Wavelength Fiber-Bragg sensing Spectroscopy Telecom Metrology TLB-66 Venturi Swept Wavelength and TLM-87 OEM Tunable Laser Modules nm Swept Wavelength, Wide hop free tuning 1

4 Tunable External Cavity Diode Lasers Tunable External Cavity Diode Lasers (ECDLs) are employed in many applications, including coherent optical telecommunications, atomic and molecular laser spectroscopy, laser cooling, atomic clocks, environmental sensing, and optical micro-cavities. In addition to tunability, these applications often require narrow linewidth single mode operation. Semiconductor diode lasers typically operate with several longitudinal modes lasing simultaneously, leading to low coherence and large linewidths. One method of extracting highly coherent light from a semiconductor-based laser requires that the diode is equipped with and anti-reflection (AR) coating, so it acts only as a gain element. The diode can then be placed in an external cavity that contains wavelengthselective optics, so that only a single mode lases at any given time. Littrow vs. Littman-Metcalf Configuration Output a) b) Mirror Output is not as critical as it is for the Littman-Metcalf design. Therefore, many diodes, particular in the blue and other exotic wavelengths can be incorporated into a Littrow cavity and not in a Littman-Metcalf cavity. The Littman-Metcalf achieves mode-hop-free tuning ranges over 1-1 nm whilst the Littrow conifguration has typically less than a tenth of a nanometer mode-hop free tuning. Mode-hop-free Wide Tuning New Focus Lasers True single-mode tuning requires that the optical feedback to be dominated by the external optics and not by reflections from the diode facet. Using AR coated diodes reduces the residual reflectivity to below.1 which guarantees single-mode operation. HR Coating AR Coating Laser-Diode Chip Tuning Element Wavelength Tuning Laserdiode Lens Diffraction grating Laserdiode Lens Diffraction grating Collimating Lens Diffraction Grating Tunable external-cavity diode lasers in Littrow (a) and Littman-Metcalf (b) configuration. To enable tuning across the diode gain band two configurations, Littrow and Littman-Metcalf, are typically employed. These utilize a grating to provide optical feedback into the diode chip, as illustrated in Figure above. In the Littrow design, a single mode is selected by rotating the diffraction grating. In the Littman-Metcalf design, the grating remains fixed and the mode selection occurs by rotation of an additional mirror in the cavity. There are advantages and disadvantages to both the Littman Metcalf and Littrow cavity designs. In general, the Littrow design results in higher output laser power; however, advances in chip manufacturing technology and optical coatings have led to higher power Littman-Metcalf ECDLs. The optical feedback in a Littrow is much stronger and high quality AR coating on the diode facet, which can be challenging, A modified Littman-Metcalf configuration. Laser Output In the Littman-Metcalf configuration, a grazingincidence diffraction grating and a tuning element provide all the necessary dispersion for single-mode operation. The amplitudes of non-lasing modes are suppressed to 4 db below the lasing mode. The wavelength in a modified Littman-Metcalf laser is changed by tilting the retroreflector, which changes the diffracted wavelength fed back into the cavity. To prevent mode hopping, the cavity length must be kept at a constant number of wavelengths as the laser tunes. This requires that the pivot point around which the element tilts to be positioned with sub-micron accuracy. Using a patented pivot-point location technique, laser with truly continuous, mode-hop-free tuning across tens of nanometers are built. 2

5 Wavelength Drift Power (mw) TLB TLB-6716 Wide, Mode-hop free tuning of the Model TLB-6712 and the TLB Linewidth and Frequency Once single-mode operation is established by the optics in the external cavity, the linewidth of the laser can be affected by acoustic coupling and cavity temperature variations, each of which can be changed by the cavity length. It is also affected by electrical noise coupling, which causes changes in the index of refraction of the diode and in the piezo length (also affecting the cavity length). Since various noise contributions occur on different timescales (thermal > acoustic > electrical), the length of time over which a linewidth measurement is taken is important. Representative linewidths are usually measured over milliseconds LB15 Servo Controller. Longer time wavelength drifts (over seconds) of narrow-linewidth tunable lasers occur due to floor vibrations, small temperature drifts, and even acoustic noise from people talking in the vicinity of the laser. The free-running linewidth, or short-term stability of the laser, is often not quite adequate for many applications without active stabilization of the laser frequency. The wavelength can be stabilized by using feedback control of the tuning element. In order to do this, an optical reference such as an atomic gas cell or high finesse optical cavity is used to provide feedback to the piezoelectric transducer which controls the grating or tuning arm to shift the laser wavelength so that it remains fixed to the stable resonance line shape of the reference, regardless of external perturbations. Laser Safety Features For systems with modular laser heads and controllers, critical diode settings, maximum current and optimum temperature are stored in the laser head. These critical parameters are determined and set at the factory during the build of each individual laser unit. The corresponding controller calls this information from the laser head on startup ensuring top performance. Power (db) These critical settings stored in the laser head prevent fatal damage to the tunable laser system, particular to the laser diode or tapered amplifier chip. The preset maximum current value prevents the user from delivering too much current. Additionally each tapered amplifier has a safety shutoff feature that is enable when the seed drops below a safe power Frequency (GHz) Heterodyne beat note of two Velocity TLB-6712 lasers, 5 ms integration. Deconvoluted linewidth <2 khz. 3

6 TLB-67 Velocity Widely Tunable Lasers Key features Guaranteed mode-hop-free tuning range using motorized piezo control. Internal permanent fiber coupling. Improved stability, <2 khz linewidth. LabView control available. The Velocity offers unprecedented access to many wavelength ranges, whilst maintaining mode-hop free operation. With this unique class of lasers, guaranteeing a narrow linewidth lasers beyond the previously only accessible telecom wavelength range, many novel applications can be satisfied. Quantum dots, micro cavities or even molecular spectroscopy are now in the realm of possibilities and require lasers which are easy to operate, widely tunable and ensure highest precision. The novel resonator design of the Velocity allows fully motorized and precise wavelengths scans, additionally the user can modulate the laser diode current, when fast and precise control over the laser frequency is required. Figure 1 shows an overview over the available wavelength ranges and their respective output powers. We are capable of extending our wavelength range to many others, for additional wavelengths do contact New Focus. TLB-67 - New Platform Subsequent years of engineering and feedback of valued customers have led to a Velocity platform that is reliable, robust whilst maintaining the easy of use and a small footprint. Detailed reworking of the mechanical components allows for higher output power and lower noise. Mechanical schematic of the TLB-67 laser platform. More Robust The enlarged drop-tested and shock proof housing ensures a robust system. Thicker insulation increases thermal and mechanical isolation. Integrated optical isolator and fiber coupling eliminates fiber misalignment. Armored fiber output. Higher Power A novel redesigned system is now capable of incorporating larger diodes, which results in higher output power of the Velocity laser. Low Noise A more powerful temperature control reduces wavelength drift and power fluctuations. Magnetic damping stabilizes the tuning arm and reduces vibrational noise. The redesigned laser controller delivers more current. Options Free space Optical isolation stage (-OI) Fiber coupling (-P) 4

7 Power (mw) Wavelength (µm) Tunability (pm) Figure 1: Overview over the different wavelength available within the Velocity range. For other possible wavelengths do contact New Focus. TLB-67-LN: Laser Controller Key features Higher current - 2 ma standard. The 67 Tunable Laser Controller has been engineered with direct feedback from our customers. We have increased the current to allow higher power from the laser and reduced the noise even further resulting in a more narrow linewdith. The 67 controller monitors the Velocity lasers current, temperature, and wavelength. Each head comes with optimized and adjusted factory settings. The 67 controller will read the laser s optimum settings and automatically limit the current and scan ranges to protect the laser diode cavity. With the controller the wavelength and output power can either be set on the front panel or via the USB GUI. Minimum and maximum wavelengths points can be entered and the Velocity will continuously scan back and forth between them. TLB-67LN controller. Lower noise <25 na RMA at 2 ma. Wavelength monitoring of the Velocity laser head. Complete tuning control - set a wavelength range for multiple scans. USB interface allows for remote user control via GUI. The Velocity Widely Tunable Laser Series offers complete single-mode tuning across its entire specified wavelength, over tens of nanometers and a piezoelectric transducer allows for fine tuning over 5-1 GHz. In Figure 2 typical output powers for three different models of the Velocity are shown. Note, these output powers are fiber coupled. For each model in the bottom line the tunability around the requested center wavelength is shown. The Velocity allows for a huge mode-hop-free tuning range, whilst providing a <2 khz linewdith. The 67 series laser incorporated a simple, stable mechanical design with a minimal number of optical components. Low noise analog circuits precisely set critical operating parameters, such as diode temperature and current. Digital control facilitates remote operation and computer interfacing. The TLB-67-LN controller is a modular unit and will work with any 67 series laser head. 5

8 Output Power (mw) Wavelength around 775nm (pm) 4 35 a) PZT (%) Wavelength around 15nm (pm) 4 35 b) Output Power (mw) PZT (%) Wavelength around 13nm (pm) Output Power (mw) c) PZT (%) Figure 2: Output power as a function of wavelength for TLB-6712 (a), TLB-6721 (b) and TLB-6725 (c) in the fiber coupled version. Bottom line shows the scan as a function of Piezo voltage. The Velocity uses a DC motor controlled by a feedback loop to move to a given location. The feedback for the position comes from a magnetic position sensor. Digital Signal Processor (DSP)-based motion control allows you hands-free wavelength-scanning capability. The only required input parameters are start and stop wavelengths as well as the scanning speed. The unique laser cavity design enables continuous mode hop-free tuning. If the laser wavelength is to be stabilized to a final value, the LB-15 servo controller is the one-box solution. The controller has an intuitive front panel for independent control of the P-I corner frequency, overall server gain, and low frequency gain limit. whispering-gallery-mode. These oscillations are then monitored by measurement of the modulated transmitted power. Perturbations in these structures result in degeneracy splitting of the vibrational modes, analogous to Stark splitting of atomic and molecular excited states. Applications Photo courtesy of Ashley Marker, Andrea Armani lab, University of Southern California. Photo courtesy of Tal Carmon (U of Michigan) in collaboration with Kerry Valhala (Caltech). Optomechanical Modal Spectroscopy (OMMS) of the natural vibrations of on-chip micron-scaled spheres is described by Tal Carmon (U of Michigan) and Kerry J. Vahala (Caltech, PRL 27). CW optical power evanescently coupled into these silicon spheres induces excitation of eigen-frequencies via the centrifugal radiation pressure of the optical Microtoroid resonators are photonic devices capable of confining and storing light for up to several hundred nanoseconds. Laser light propagating through a tapered optical fiber waveguide is evanescently coupled into a microtoroid initiating a second, longitudinally propagating wave through the rim of the microtoroid. The image, obtained in the lab of Prof. Andrea Armani (USC), shows light at 41 nm being coupled into a silica microtoroid. These longitudinal whispering gallery modes can be used as probes of the microtoroid s environment. 6

9 Specs 1 Mode-hop free tuning range 2 Tuning range (fine frequency) Free space output power (mw) Maximum tuning speed (nm/s) Beam size (mm) TLB nm >8 GHz/11 pm 8 mw 638 nm 5 1.x1. TLB nm >8 GHz/15 pm 5 mw 78 nm 8 1.5x1.2 TLB nm >6 GHz/15 pm 5 mw 85 nm 1 1.3x.6 TLB nm >5 GHz/16 pm 15 mw 89 nm 1 1.2x.8 TLB nm >5 GHz/18 pm 4 mw 98 nm 1 1.8x.9 TLB nm >5 GHz/2 pm 6 mw 164 nm 1 1.8x.9 TLB nm >5 GHz/2 pm 4 mw 18 nm 1 1.8x.9 TLB nm >5 GHz/28 pm 3 mw 111 nm 1 1.9x1.7 TLB nm >5 GHz/29 pm 3 mw 13 nm x1.7 TLB nm >3 GHz/2 pm 45 mw 145 nm x1.3 TLB nm >3 GHz/21 pm 2 mw 148 nm x1.7 TLB nm >3 GHz/24 pm 3 mw 155 nm 2 1.9x1.7 TLB nm >3 GHz/26 pm 3 mw 16 nm 2 1.9x1.7 TLB nm >2 GHz/26 pm 1 mw 178 nm 2 1.9x1.7 TLB nm >2 GHz/26 pm 2 mw 23 nm 2 1.5x2.5 TLB nm >2 GHz/36 pm 4 mw 24 nm 5 1.x1. Specifications 1 Linewidth (5 ms integration time) Wide tuning resolution Fine frequency modulation bandwidth Max current modulation bandwidth 3 Max current modulation bandwidth 4 <2 khz (5 ms integration time) khz.1 nm 2 khz 1 MHz 1 MHz 1 Specifications are subject to change. 2 Contact Newport for all available wavelength ranges. 3 Current modulation through controller. 4 Current modulation directly to diode through laser head SMA port. 7

10 TLB-68 Vortex Plus Tunable Lasers Key features Exceptional ease of use. Wide hop free tuning. Widest mode-hop-free piezo tuning of any commercially available tunable ECDL including blue wavelengths. Star-Flex Actuation of the tuning arm for maximum stability. Function generator built into the TLB- 68-LN controller. The Vortex 6 Series was introduced in 1996 and offered narrow linewdith and low-noise performance built to customer s wavelength specifications. This was right around the time when the first Bose- Einstein Condensate was created in Jila and many groups around the world were researching in the exciting field of laser cooling. Based on a proven monolithic design, there were no adjustable components, so misalignment over time became obsolete. The laser cavity and drive electronics were designed to provide maximum frequency-modulation capabilities, allowing for modulation above the frequency of mechanical noise sources. Options Free space Optical isolation stage (-OI) Fiber coupling (-P) The New Focus engineering team was once again facing the challenge to step up the performance of the laser so it would help the atomic spectroscopy community and others by providing low frequency jitter and low drift mode-hop-free tunable laser. The Vortex II 69 Series, which was the third generation of the fine tuning ECDL was released in 28. It proved to be even more resistant to acoustical and mechanical perturbations than its predecessor. The technical challenge presented itself to stiff rotational motion without any translation. It was under this mandate that Star-Flex motion actuation and the patented technique of magnetic damping were born. Star-Flex Actuator design of the TLB-68 Vortex Plus Laser. Vortex in 1996 (left) and 212 (right). In 22, New Focus and JPL in Pasadena partnered to develop the next generation atomic clocks for microgravity measurements and GPS space development, as part of an experimental setup to test many of the predictions of Albert Einstein s theory of relativity. Following this fruitful collaboration, New Focus proudly released the Stablewave 7 Series in 24. To deliver truly reliable performance, these lasers used an exceptionally rugged, patented laser cavity. The Vortex Plus is the latest addition to the New Focus line of finely tunable Littman-Metcalf lasers. Conserving the same robust cavity and the Star-Flex actuator, New Focus has adapted the Vortex II to accept larger diode chips, resulting in significantly higher output power among the popular infrared wavelengths. The Vortex Plus operates with the low noise TLB-68-LN laser controller, reducing the laser linewidth from 3 khz to 2 khz. Additionally the Vortex Plus can now be current modulated up to 1 MHz, an SMA port has been added for this. 8

11 Power (mw) Tuning range (GHz) Wavelength (µm) Figure 3: Overview over the different wavelengths available within the Vortex range. For other possible wavelengths do contact New Focus. Applications Low Noise The Star-Flex design significantly improved the tolerable noise on the Vortex Laser and was engineered to be robust enough to withstand a space shuttle launch environment and operate for years in space. The design had to pass strict tests to meet the requirements for space readiness. -5 Vortex-plus Previous design -6 Response(dB) Strontium Optical Lattice - Courtesy of Prof. Jun Ye, UC Boulder, JILA, NIST. The strontium optical lattice clock at JILA works by referencing an ultra-stable clock laser to a trapped laser-cooled cloud of strontium atoms. Strontium is one of the nature s highest-q frequency references, with a quality factor of 118. This clock takes advantage of the lower quantum projection noise of many-body quantum system to achieve new records in clock precision, stability and total systematic uncertainty. The cooling transition of Strontium is at 461 nm which is provided by a diode laser Frequency (khz) Frequency response of the Vortex II in comparison with the original Vortex. The Vortex II has improved stability due to the Star Flex design and magnetic damping. 9

12 Power (mw) a) Piezo (%) Piezo (%) Power (mw) b) Piezo (%) Piezo (%) Figure 4: Output power as a function of wavelength for TLB-6813 with a center wavelength of 766 nm (a) and 78 nm (b) in the fiber coupled version. Bottom line shows the scan as a function of piezo voltage. TLB-68-LN Low Noise Controller Key features The Vortex laser is best operated with the TLB-68- LN laser controller, which can also be used for the TLB-71 Vantage Tunable Laser. The controller allows for easy fine tuning and adjusting the output power or bias current with the press of a button or, via the USB/RS-232 interface. There is no need for an external function generator to drive the piezo of this tunable laser as this driver comes with a built in one. The Star-Flex design was engineered to be robust enough to withstand a space shuttle launch environment and operate for years in space. The design had to pass strict tests to meet the requirments for space readiness. You can see just how The controller has a built-in feature to recognize and much of a difference the new design made to the RIN test of protecthe the Vortex laser in head the above andplot. in particular limiting the current on the actual photodiode. TLB-68-LN Low Noise Controller Interchangeable laser heads High-speed current modulation Easy frequency modulation Complete control of laser parameters Frequency responce of Vortex II in compareson with original Vortex (1 db white noise test). The Vortex II has improved LabView stability due to the control Star-Flex design and magnetic damping. Detector and general-purpose input Built in function generator The title page does show to Vortex-plus lasers in action, one at 632 nm and one at 46 nm. The output of the red laser was at 7 mw - whilst the blue Vortex plus gave 3 mw. Interchangeable laser heads High-speed current modulation Easy frequency modulation Complete control of laser parameters Complete computer control and LanVIEW TM programs Detector and general-purpose input Built-in function generator TLB-68-LN low noise controller. The Model TLB-68-LN laser controller is designed to operate with either the TLB-68 Vortex Plus Tunable Lasers or TLB-71 Vantage Tunable Lasers. The controller allows you to easily fine tune and Vortex-plus adjust the output at New power or Focus. bias current with the press of a button or, via the USB/RS-232, interface with the click of a mouse. There is no need for an external function generator to drive the piezo of your tunable laser with the built in function generator. The TLB-68-LN controller has easy to access front panel controls, digital interface, and real buttons to make your lab life easier. 1

13 Specs 1 Available wavelengths 2 Mode-hop free tuning range Free space output power (mw) TLB nm >25 GHz 4 mw 455 nm TLB nm >25 GHz 4 mw 461 nm TLB nm >12 GHz 8 mw 638 nm TLB nm >1 GHz 7 mw 78 nm TLB nm >9 GHz 5 mw 852 nm TLB nm >9 GHz 3 mw 91 nm TLB nm >8 GHz 25 mw 965 nm TLB nm >6 GHz 7 mw 164 nm TLB nm >6 GHz 3 mw 14 nm TLB nm >3 GHz 3 mw 155 nm Specifications 1 Linewidth (5 ms integration time) Frequency stability Modulation frequency Modulation frequency <2 khz (5 ms integration time) khz 2 pm over 12 h at T 1 C 1 Hz (1 GHz amplitude) 1.5 khz (2 GHz amplitude) 1 Specifications are subject to change. 2 Contact Newport for all available wavelength ranges. 3 TLB and TLB-682 only available in free space option. 4 Further specs upon request. 11

14 TLB-71 Vantage Tunable Diode Laser Key features Tuning arm window allows you to effortlessly return to desired wavelength. Low wavelength range especially in the UV. Piezo fine-tuning and manual coarsetuning to access the entire diode gain band. Feed forward for extended mode-hop-free tuning. The wavelength stability in the UV around 46 nm is shown in the figure on the right over the period of 36 h, showing a minimal drift in wavelength. The data was measured using a wavemeter with a 1 pm resolution. Wavelength around 852nm (pm) pm pm TLB-68-LN Controller with built-in function generator. The Vantage adopts the Littrow design to offer higher power at a variety of wavelengths to meet your experimental needs. Each laser unit is optimized at a user-specified wavelength to provide top performance and mode-hop free piezo tuning whilst there is still the option to coarse tune to another wavelength within the diode gain band. Together with the TLB- 68-LN low noise current controller and its feed forward feature the mode-hop free tuning range can be extended. Figure 5 on the next page the output power tuning curves are shown for various wavelengths. The selection of available wavelengths is constantly expanding, please do contact New Focus for availability. Additionally for the entire wavelength range New Focus offers sole laser diodes that can be replaced in an existing Vantage at no effort. Typical output power curves for the Vantage for different center wavelengths Time (hours) Figure 5: Wavelength stability for a TLB around 852 nm. Applications Experimental setup for studying the collisions of ultracold Rb atoms with cold ND3 molecules. The atoms are cooled and trapped at the intersection of the (red) laser beams. A beam of cold ND3 molecules is created by the pulsed valve at the lower right, then slowed and trapped by metallic rings and rods. Collisions occur when the atom trap is moved to overlay the molecule trap. According to theory, in the absence of an electric field, ND3 molecules will be mostly unaffected by collisions. Experimentally, electric fields increase the chances, that collisions will cause an ND3 molecule to flip inside out and change its quantum state. 12

15 Power (mw) 15 1 Power (mw) Power (mw) Power (mw) Typical output power curves for the Vantage for different center wavelengths. Specs 1 Available wavelengths 2 Mode-hop free tuning range 2 Free space output power (mw) TLB nm 1 GHz 15 mw 397 nm TLB nm 5 GHz 1 mw 423 nm TLB nm 1 GHz 15 mw 43 nm TLB nm 15 GHz 2 mw 671 nm TLB nm 1 GHz 25 mw 72 nm TLB nm 5 GHz 9 mw 78 nm TLB nm 5 GHz 9 mw 852 nm TLB nm 5 GHz 2 mw 895 nm Specifications 1 Linewidth (5 ms integration time) Frequency stability Frequency stability Modulation frequency Modulation frequency Max Current modulation bandwidth 3 Max Current modulation bandwidth 4 <3 khz (5 ms integration time) khz 1 pm over 1 h 5 pm over 36 h 1 Hz (1 GHz amplitude) 1.5 khz (2 GHz amplitude) 1 MHz 1 MHz 1 Specifications are subject to change. 2 Contact Newport for all available wavelength ranges. 3 Current modulation through controller. 4 Current modulation directly to diode through laser head SMA port. 13

16 TA-76 VAMP Tapered Amplifier Key features Fiber coupled input ensures fast, easy and reliable alignment. Active input monitoring ensures that selflasing will not damage the tapered amplifier chip. Use the Vortex Plus or any seed laser for a complete MOPA system. Optical isolation of the amplifier output standard on all models. Semiconductor tapered amplifier chips are available for a large range of wavelengths. Alignment onto the front facet of the chip is critical for the performance and can be challenging. The VAMP tapered amplifier circumvents that problem by having a fiber-coupled FC/APC input port. Two onboard photodiodes are used to monitor the input and output powers. Active input power monitoring helps preventing damage to the tapered amplifier chip through self-lasing at low seed power. Active output power monitoring helps ensure a long term output power stability within 1 %. The amplified output power can be fiber coupled, although a free space option is available. plenty of power. The photograph shows a cloud of 2 billions Rb atoms which are.5 mk cold inside a vacuum cell. Relative Signal (dbc) Seeding and Controlling VAMP When seeded with a low-ase source such as the Velocity or Vortex-Plus lasers, the VAMP faithfully reproduces the narrow linewidth and high contrast ratio. The VAMP will also accept other seed sources, including many home-made ECDLs. The fiber-coupled input ensures consistent precise alignment. Applications Min output power (W) Min input power (mw) Rubidium atoms in a Magneto-Optical Trap (MOT). Credit: Sylvi Haendel, Uni Durham. Trapping a large cloud of neutral atoms requires large beam intensities, so a good size beam diameter with The VAMP is controlled using the TA-76-LN Controller. Full control is made possible through the easyto use front panel interface. Additionally the USB or RS232 communication ports on the rear panel can be used. The controller allows for the monitoring of the 14

17 tapered diode temperature via a temperature sensor that has been mounted on the diode block. Thermoelectric coolers are used to control the temperature of the diode. When seeded with a low-ase source such as the Vortex Plus or Velocity lasers, the VAMP faithfully reproduces the narrow linewdith and high contrast ratio. The VAMP will also accept other seed sources, including many home build ECDLs. The VAMP will require fiber coupled input to consistently ensure precise alignment. VAMP and Controller. Vortex Plus and VAMP. Specs 1 Available wavelengths 2 Center wavelength 2 Min output power 2 Fiber coupled output power Min input power TA nm 765 nm 1.5 W.5 W 15 mw TA nm 78 nm 1 W.5 W 2 mw TA-7613-H nm 78 nm 2 W N/A 2 mw TA-7614-H nm 795 nm 1.8 W.5 W 2 mw TA nm 85 nm 1 W.5 W 15 mw TA nm 915 nm 1 W N/A 1 mw Specifications 1 Beam divergence <1.5 mrad Beam pointing stability <5 µrad (±2 C) ASE (at max power) <45 db (.1 nm OSA resolution) Long term stability (Power, closed loop) <1% Operating temperature range 15-3 C Max input power at FC/APC connector 1 mw Linewidth and Jitter Seed laser dependent 1 Specifications are subject to change. 2 Contact Newport for all available wavelength ranges. 15

18 SWL-75 Single Wavelength Diode Lasers The SWL-75 series laser offers extremely narrow linewdith in an OEM-ready platform designed for stability and longevity. This laser offers our market leading narrow linewdith in a single longitudinal mode at a single fixed wavelength. With a footprint smaller than a business card, the laser can integrate into most instruments designs with room to spare. These lasers have been carefully designed to operate continuously on a single longitudinal mode and have minimal frequency drift, making them ideal for any imaging, metrology, or spectroscopy measurement. 15 Spectral Content Specs 1 Center wavelength 2 Long-term side mode suppression ratio measurement with no multimoding or mode hops. Power, dbm Center wavelength stability 2 Output power Wavelength, nm Amplified Stimulated Emission (ASE) spectrum with low background interference and clean, unambiguous signal. Rated life SWL nm ± 1.5 pm 8 mw >5 hrs SWL nm ± 1.5 pm 7 mw >6 hrs SWL nm ± 1.5 pm 7 mw >6 hrs Specifications 1 SWL-754 SWL-7513 SWL-7521 Center Wavelength 633 nm 785 nm 164 nm Center Wavelength Stability ±1.5 pm Output Power nm nm nm Power Stability <2% Linewidth <2 khz ASE >-65 dbc Side Mode Supression Ratio <-5 dbc Rated Life >5 hrs >6 hrs >6 hrs 1. Specifications Specifications 1 are subject to change. 2. Please specify center wavelength to 1pm when ordering. SWL nm ± 1.5 pm 9 mw >6 hrs SWL nm ± 1.5 pm 9 mw >6 hrs SWL nm ± 1.5 pm 9 mw >6 hrs Beam divergence <1.5 mrad Beam pointing stability <5 µrad (±2 C) ASE (at max power) <45 db (.1 nm OSA resolution) Long term stability (Power, closed loop) <1% Power Stability <2% Operating temperature range 15-3 C ASE >-65dBc Side mode suppression ratio <-5dBc Linewidth >2 khz 1 Specifications are subject to change. 2 Contact Newport for all available wavelength ranges. 16

19 TLM-87 OEM Swept-Wavelength Lasers Key features Ultrawide 11 nm mode-hop-free tuning Just like all of our benchtop tunable lasers, these modules carry our reputation as the leading supplier of test-and measurement tunable lasers. For specific needs, please contact New Focus - most likely the required system has been build or can be tested for the individual customer. The TLM-87 OEM laser module is just one example of the OEM component portfolio. New Focus designs, develops, and manufactures custom optical solutions for a broad selection of companies in all branches of the photonics industry. Tuning speeds greater than 2 nm/s OEM-proven reliability (>1-million cycles tested) TLB-66 Venturi Swept-Wavelength Tunable Lasers Key features Ultrafast 2 nm/s tuning enables true real-time measurements Ultrawide 1 nm mode-hop free tuning >7 db ASE low-noise version for highdynamic range test and measurement Multiple integrated options available Tuning speed (nm/s) Wavlength (nm) The TLB-66 laser delivers it all. They combine the best in tunability - ultrafast, ultrawide and modehop free - with low noise, high accuracy and repeatability. Because the lasers are based on an award winning design, they are extremely dependable with OEM-proven 24/7 reliability (over 1 million cycles tested without failure). Ideal for fiber sensing, spectroscopy, laser seeding, metrology and fiber-optics testing. These lasers are available with a variety of options so most systems can be build with those ones. Tuning linearity for the model TLB-66-H-CL. In order to enable real-time measurement capabilities, the Venturi lasers offer up to 2, nm/s tuning with excellent linearity. The TLB-66 Venturi guarantees single-mode, mode-hop-free tuning across the entire specified wavelength range. 17

20 Specs 1 Mode-Hop free tuning range Output power (fiber coupled) ASE Integrated dynamic range Fiber type Integrated options available 2 TLB-66-H- CL nm >6 mw >4 db >15 db SM or PM PWR, VOA, PC, RM TLB-66-L-CL nm >1 mw >7 db >55 db SM or PM PWR, VOA, PC, RM TLB-66-H-O nm >4 mw >4 db >15 db SM TLB-66-L-O nm >1 mw >7 db >55 db SM Specifications 1 Tuning speed Wavelength Reset-ability Absolute wavelength accuracy (with PWR option) Output power Flatness (swept) Fiber optic connector 2-2 nm/s ±15 pm <1 pm >5 dbc FC/APC 1 Specifications are subject to change. 2 PWR-Precision Wavelength Reference, VOA - Variable Optical Attenuator, PC - Polarization Controller, RM-Rack Mount. Contact New Focus for further details. To simplify operation, the TLB-66 controller is designed with an easy-to-use color touchscreen, or it is possible to use all-button operation. With the latest in remote interfaces including Ethernet, USB, and GPIB (IEEE 488), it can easily interface to any computer to set and monitor parameters. The touchscreen allows for intuitive setting and monitoring of laser parameters including tuning range, sweep speed, sweep mode, output power and others. For measurements requiring high dynamic range, such as the characterization of fiber-bragg gratings, choosing the low-noise version is advised. It offers greater than 7 db ASE suppression and an integrated dynamic range of greater than 55 db. Available with a variety of integrated options, the TLB-66 is a flexible system configured for specific needs. For exceptional absolute wavelength accuracy, a precision wavelength reference option is available (<1 pm). For this choosing the polarization controller is recommended. A variable optical attenuator option is also available for up to 2 db adjustment in optical output power. These options are available for the SM version only. Power (dbm) TLB-66-L-CL model. 18

21 Integrated Precision Wavelength Reference Module Accuracy Repeatability Insertion loss Polarization dependent loss (PDL) Valid Sweep Rates Wavelength range excluded Fiber type (input/output) Model Wavelength reference option available for CL version only. <1 pm <1 pm 1. db (max).1 db (max) 1-2 nm None SM/SM TLB-66-PWR Integrated polarization controller, 6-State SOP generated 6-SOP: -45,, 45, 9, RHC, LHC SOP repeatability ±1 on Poincare sphere SOP switching speed 25 ms Rotation angle wavelength dependence.68 /nm Insertion loss 1 db (typical) Insertion loss variation with SOP.1 db (max) Insertion loss variation with wavelength.2 db (max) Fiber type (input/output) PM/SM Model TLB-66-PC Polarization controller option available for the CL version. When ordering the integrated polarization controller (-PC) option, please order a polarization maintaining fiber output (-PM) to couple the light to the -PC. The final output will be from a single-mode (-SM) fiber. Integrated variable optical attenuator Attenuation range Accuracy Excess loss Polarization dependent loss (PDL) Fiber type (input/output) Model Gain and P-I corner are independently adjustable. >2 db.1 db (typical across range) <.7 db (max).2 db (max) SM/SM TLB-66-VOA 19

22 Definitions of Characteristics Absolute Wavelength Accuracy The maximum difference between the measured wavelength and the displayed wavelength of the laser system. Amplified Sponaneous Emission (ASE) The ratio of the optical power at the center of the laser linewidth to the optical power at a given distance, as measured using an optical spectrum analyzer with a set resolution bandwidth. Coarse-Tuning Resolution The smallest wavelength change you can make with the coarse-tuning DC motor on the Velocity laser. Current-Modulation Bandwidth The highest rate at which the laser diode s current can bechanged. This is the 3 db frequency of the directmodulation input located at the laser head. Fine-Frequency Modulation Bandwidth The highest rate at which the fine-tuning ZT in the laser cavity can modulate the laser frequency. The specified bandwidth is for a 3-dB drop from a low-frequency baseline under small-signal modulation. Fine-Frequency Tuning Range The frequency range over which the laser can be piezoelectrically tuned. (If λ is the wavelength of the laser and c the speed of light, the tuning range expressed in frequency, ν, and wavelength, λ, is related by ν = cλ/2. Keeping in mind that 3 GHz is equivalent to 1 cm 1.) Integrated Dynamic Range The ratio of the signal to the source emission, integrated overall wavelengths. This is measured by observing the spectrum of two cascaded fiber-bragg gratings with a total rejection ratio of >1 db and a.8 nm window, and is a realistic expectatio nof the dynamic range of your measurement. Linewidth The laser s short-term frequency stability. The linewidth varies as a function of integration time. New Focus laser linewidth is specified for 5 ms integration time. cavity loss with wavelength, the laser s output power is not constant as it tunes. Output Power The typical power that the laser will output across the entire tuning range. Power Repeatability The typical difference in power between scans for a given wavelength. Power Stability The maximum deviation in power as the laser sits at a specific wavelength over a 1 hour period. Side-Mode Suppression Ratio The ratio of the carrier to the nearest side mode. Tuning Range The span of wavelengths over which the laser is able to tune. Tuning Speed The speed over which the laser can sweep over the entire tuning range. Typical Maximum Power The maximum output power you can expect over the laser s tuning range. Due to changes in diode gain and cavity loss with wavelength, the laser s output power is not constant as it tunes. Wavelength Repeatability The largest measured deviation that may occur when the laser returns to a given set wavelength. This is a measure of how well the laser returns to a set wavelength over many attempts and when approached from different directions. Wavelength Resolution The smallest step the laser can tune. Wavelength Stability The maximum amount of drift the laser will exhibit over a specified period of time and temperature variation. Maximum Coarse-Tuning Speed The highest guaranteed speed at which the Velocity laser can tune using the coarse-tuning DC motor. The actual maximum coarse-tuning speed for individual systems may vary, but will always be at least this fast. Minimum Power The lowest power that the laser will output across its specific tuning range when the current is set to its recommended operating value. Due to changes in diode gain and 2

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