LuphoScan platforms. Dr. Gernot Berger (Business Development Manager) APOMA Meeting, Tucson, years of innovation

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1 125 years of innovation (Business Development Manager) APOMA Meeting, Tucson, 2016

2 HQ in Berwyn, Pennsylvania $4.0 billion in sales (2015) 15,000 colleagues, 150 manufacturing locations, 30 countries Businesses Aerospace & Defense Chemical Products Engineered Materials Interconnects & Pack. Floorcare & Specialty Motors Instrumentation & Specialty Controls Materials Analysis Measurement & Calibration Technologies Power Systems & Instruments Precision Motion Control Process & Analytical Instruments Test Measurement (Tires) Ultra Precision Technologies BU s of the Ultra precision Technologies: Taylor Hobson, TMC, ZYGO, Creaform, Precitech, Reichert Technologies, Solartron Metrology, Sterling Ultra Precision 11-Nov-16

3 Established in 1886 World leader in surface and form metrology Analysis capabilities include 3D topography, surface finish, contour, form, radius, roundness, harmonic analysis, straightness, flatness, Nov-16

4 Talyor Hobson instruments for metrology of optics The industry standard for precision optics metrology Measurement of multiple optics (batch testing) and molded lens trees Automated one-touch 2D and 3D aspheric optics measurement Fast, ultra-precise non-contact, 3D form measurement of aspheric surfaces 11-Nov-16

5 LuphoScan measurement applications Steep sphere Axicon Multi-focus lens Segmented Asphere Gullwing Annular lens D-cut lens Asphere (cx) Freefrom Mold Asphere (cv) Aspherodiffractive 11-Nov-16

6 Outline Background idea Sensor technology Platform overview Measurement approach Reference concept High definition LuphoScan Design Reproducibility, Accuracy Extensions/ Add-ons Overview Measuring asphero-diffractive and Fresnel lenses Determination of wedge errors and decenter errors Measuring freeforms 11-Nov-16

7 LuphoScan background idea High precision metrology of optics State of the art 2010 Mechanical Measurements Profilometry Tactile probes ( line scan ) Coordinate measuring machines (CMM) Atomic force microscopy Optical surface testing Spherical wavefront interferomtry Null testing Computer generated holograms Stitching interferometers Major disadvantages: Contact to the object can harm surface Poor flexibility Lenses with large spherical departure Segmented surfaces Optics with diffractive structures Ground (rough) surfaces in noncontact systems 11-Nov-16

8 LuphoScan background idea Desirable metrology solution Combination of the advantages of scanning measurements of interferometric measurements geometric flexibility non-contact, highest accuracy Photo: Taylor Hobson Photo: Deltaoptics Photo: Ed Jones, cloudynight Photo: Zygo LuphoScan Scanning Interferometer based on an optical point sensor 11-Nov-16

9 MWLI sensor technology (Multi WaveLength Interferometry) Non-contact, optical measurement Extremly high accuracy (< 2 nm (2), < 1 nm possible, reproducible) Large working distance and extreme accuracy (Working distance up to 20 cm) Large working range and extreme accuracy (Up to several cm) Absolute measurements (Tolerates signal interruption and measures step heights up to 1.25 mm) Different surface types and materials Transparent, opaque, specular, polished, rough Varying reflection coefficients From 0.1% up to 100% 11-Nov-16

10 LuphoScan metrology platforms Scanning interferometers based on an optical MWLI point sensor (MWLI = multi-wavelength interferometry) Non-contact 3D form measurement of rotationally symmetric optics and freeforms LuphoScan family: LuphoScan 260, LuphoScan 420, LuphoScan 600, LuphoScan 260HD High accuracy Better than ± 50 nm (3) 260 HD Key advantages: Fast measurement speed (typically 2-6 min. (LS260), incl. set-up time) High flexibility (strong aspheres, segmented and discontinuous parts,...) HD: Extremely high reproducibility ( best shot-to-shot stability ) HD: Highest accuracy at steep slopes HD: High accuracy even under adverse conditions 11-Nov-16

11 LuphoScan: Measurement principle 4-axis layout Object: 1 rotary stage (C) (air bearing) Sensor: 2 linear stages (R, Z) 1 rotary stage (T) (roll bearings) T Z R R C Object probe 11-Nov-16

12 LuphoScan: Measurement principle Scanning point measurement Spiral scan Sensor presented normal, equidistant to surface Sensor follows design curvature while measuring distance towards object R Measurement result 3D map showing deviation from design curvature Ideal object: flat error map 11-Nov-16

13 LuphoScan: Reference frame concept Z reference probe T reference probe Object probe Reference frame Open loop metrology frame (Invar) 3 reference probes determine position of object probe within the reference frame Error handling R reference probe Compensation for first order errors of R, Z, T stage following Abbe principle (No compensation of C stage errors) Online calibration Beam housing Form measurement accuracy: < ± 50 nm (3) up to 90 (HD), up to 50 (SD) Reproducibility: < 20 nm (3) (HD), (Dominated by temperature effects) 11-Nov-16

14 LuphoScan Relevant specifications Measurement volume 260: 260 mm 75 mm 420: 420 mm 100 mm 600: 600 mm 160 mm Maximal slope 90 (convex), 65 (concave) Spherical departure Unrestricted probe follows curvature Data density (adjustable) up to points/mm 2 Spotsize 4 µm Mounting Hydraulic expansion chuck (3-jaw chuck, C&L table) No additional costs All required reference objects are included, No wearing parts Calibration User operable: 15 min for complete calibration cycle 260 Footprint 0.85m 1.0m, 1.0m 1.15m, 1.15m 1.3m 11-Nov-16

15 LuphoScan measurements Example D = 75 mm, Roc center = 30 mm (slope = 63 deg.) T = 5 min 25 sec (50 points/mm 2 ) 11-Nov-16

16 LuphoScan Measurement results and analysis 11-Nov-16

17 LuphoScan Summary: Standard measurements Measuring any rotational symmetric optics Aspheres, Spheres, Flats Polished, fine ground, continuous surfaces (discontinuous surfaces with add-ons) 11-Nov-16

18 LuphoScan 260 HD high definition optical metrology Hardware More components made of Invar 4 temperature sensors 1 air pressure sensor Additional reference object (cylinder) Improved manufacturing tolerances New flange design New anti turbulence housing Software Dynamic compensation of temperature and air pressure changes Extended fundamental calibration procedure comprising o Thermal response of system o High spatial frequency noise Spoke filter with adjustable spatial frequency

19 LuphoScan 260 HD Reproducibility (raw data) Test measurements of a calibration ball D = 25 mm, measured up to 90 o Data set 1 LuphoScan 260HD in demo lab in Tokyo, Japan Time period 1 hour o Data set 2 LuphoScan 260HD in Weiterstadt, Germany Time period 13 hours No other instrument provides this shot-to-shot stability!

20 LuphoScan 260 HD Reproducibility and accuracy Measurement reproducibility (repeatability) (defined for D=25mm, max. slope 90 ) Power PWR (4) < ± 20nm + x Peak-to-valley PV99 (4) < ± 5nm + y Where x, y are functions of temperature changes and time Example Repeat measurements over 4 hours, while temperature change of 1 C results in reproducibilities of PWR < ± 50nm and PV99 < ± 19nm (valid up to 90 slopes) Accuracy Form measurement accuracy: ± 50 nm (3) up to 90

21 Outline Background idea Sensor technology Platform overview Measurement approach Reference concept High definition LuphoScan Design Reproducibility, Accuracy Extensions/ Add-ons Overview Measuring asphero-diffractive and Fresnel lenses Determination of wedge errors and decenter errors Measuring freeforms

22 LuphoScan Add-ons Segmented optics Annular optics Axicons Asphero-diffractive optics annular segmented axicon LuphoSwap Determination of wege and decenter errors Measuring lens thickness asphero-diffractive Interlignment module Characterizing molds (decenter, tilt) Positioning of optical surfaces with respect to rim

23 Segmented optics (software add-on) Based on absolute measurement capabilities Underlying object shapes: aspheric, spheric, flat Form measurement accuracy: +/- 50 nm (2) Example: Deviation of an rectangular cutout of an asphere (Roc = 71mm)

24 Measurement of asphero-diffractive vs. Fresnel lenses Measurement of Asphero-diffractive lenses Sensor follows the normal aspheric shape of lens Input of diffractive steps manually or by analytical description Tilt of probe always perpendicular to aspheric shape Step heights up to ±600µm Removal of steps during analysis

25 Measurement of asphero-diffractive vs. Fresnel lenses Measurement of Fresnel type lenses Horizontal movement of sensor Adapting tilt of probe, probe follows design shape in each zone Step heights up to ±600µm Shadowing of inside edges Removal of steps during analysis

26 LuphoSwap hardware & software extension Determination of Wedge error () Decenter error (x) Thickness (T) LuphoSwap holder 3 parts 3. Lens mount (made by customer) 2. Reference ring 1. Fixture Assembled LuphoSwap holder

27 LuphoSwap principle Measurement procedure: a. Form measurement of 1. First side of lens, 2a. Referencing axial and 2b. radial runout b. Manual turn over of reference ring with lens c. Form measurement of second side of optics, and referencing axial and radial runout a,c Measurement time (incl. manual turn over): 5 10 min. (depending on size, shape, data density) b

28 LuphoSwap example measurement Lens (D = 25 mm) with 2 aspheric sides Side 1: Roc = mm Side 2: Roc = 29.6 mm Automatic determination of Wedge, decenter and thickness: Step 1: Measuring first surface Step 2: Measuring second surface

29 Interlignment module Spatial relation to any reference Characterisation of lens positioning: Optical surfaces with respect to rim / mount Example: Asphero-diffractive lens with positioning (reference) ring User defined reference ring Measured height and tilt of optical surface with respect to reference ring

30 Interlignment module Mold characterisation Correlation of optical surface to the rim / barrel Various measurement modes: A. Apex-ring height Line scan on front side Levelling & Tilt B. Ring tilt Single line scan on front side Tilt C. Ring decenter Single line scan on barrel Decenter D. Barrel positioning 3D scan of barrel section Decenter & Tilt

31 Outline Background idea (Sensor technology) Platform overview LuphoScan measurement approach Reference concept LuphoScan 260 HD Improvements Reproducibility, Accuracy Comparison to SD systems Extensions/ Add-ons Measuring discontinuous surfaces LuphoSwap Interlignment module Measuring freeforms

32 Custom-designed module Freeforms Sensor alignment LuphoScan optimised for rotationally symmetric parts sensor always normal Missing tilt axis for freeform parts: Object probe cannot be tilted in Y direction Exploiting angular acceptance range of probe optics Tolerable tangential slopes: standard probe ±5 (work dist. 2.7mm) high NA probe > ±15 (work dist. 1.1mm) Radial slopes still can be: 90 (convex), 65 (concave)

33 Tangential slopes of freeform surfaces Sphere / Asphere Tangential slope = 0 Mild Freeform Tangential slopes < ± 5 Stronger Freeform Tangential slopes = max. 15 t =0 Example: t,max =5.5 Example: t,max =14 Standard in all Measureable in all Measurable in LuphoScan platforms with HNA probe HNA = high numerical aperture

34 Custom-designed module Summary Freeform measurement characteristics Tangential slopes up to ± 7 or ± 15 (Radial slopes up to: cx = 90, cv = 65 ) Accuracy better ± 150nm (vs. ± 50nm) Measurement procedure Data import by means of point cloud Spiral path of sensor is projected onto freeform surface Probe movement optimized for minimal tangential slopes Position error caused by non-normal presentation compensated Probe follows height variation of object surface Assisted part alignment for ease of use Key features Powerful tool that measures arbitrary shapes Measure e.g. Complex rotationally symmetric parts (e.g. multi focus lenses), Torics, Off-axis parts, Freeform parts Rotationally symmetric, but multiple surfaces

35 Summary Fast 3D measurement Follow Abbe principle LuphoScan 260 HD platforms Extremely high reproducibility Highest accuracy at steep slopes Very low system noise More stable under adverse conditions Important add-ons: LuphoSwap (wedge and decenter errors) Interlignment module (positioning to rim/ mount)