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CAD Models
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- CAD Model: CGH-S9-C9_A.step
- CAD Model: CGH-S9-C0_A.step
- CAD Model: CGH-S6-C6_A.step
- CAD Model: CGH-S6-C0_A.step
- CAD Model: CGH-S3-C6_A.step
- CAD Model: CGH-S3-C3_A.step
- CAD Model: CGH-S3-C0_A.step
- CAD Model: C6XXXC_A.step
- CAD Model: C4XXXC_A.step
- CAD Model: C3XXXs_A.step
- CAD Model: C2XXXS-BC.step 2-Inch Cylinder CGH
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Documentation
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- Customer Drawing: MP6-BLANK_A
- Customer Drawing: MP3-BLANK_A
- Customer Drawing: VRT-050_A
- Customer Drawing: CRT-050_A
- Customer Drawing: C6AC3_A
- Customer Drawing: C6R_A
- Customer Drawing: FP9-H600_A
- Customer Drawing: FP6-H600_B
- Customer Drawing: FP6-H425_B
- Customer Drawing: FP3-Z-H600_B
- Customer Drawing: FP3-Z-H425_B
- Customer Drawing: FP3-H600_A
- Customer Drawing: FP3-H425_A
- Customer Drawing: CGH-S9-C9_A
- Customer Drawing: CGH-S9-C0_A
- Customer Drawing: CGH-S6-C6_A
- Customer Drawing: CGH-S6-C0_A
- Customer Drawing: CGH-S3-C6_A
- Customer Drawing: CGH-S3-C3_A
- Customer Drawing: CGH-S3-C0_A
- Customer Drawing: C6XXXC_A
- Customer Drawing: C4XXXC_A
- Customer Drawing: C3XXXS_A
- Customer Drawing: C2XXXS-BC 2-Inch Cylinder CGH
- Customer Drawing: FP6-Z-H650_A
- Show Remaining Articles ( 10 ) Collapse Articles
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Publications
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- [2023] New Applications of Computer Generated Holograms for Optical Testing
- [2023] Rapid surface metrology of freeform shapes using CGH interferometry
- [2022] Snapshot measurements with CGH interferometry to support volume production of freeform optics
- [2022] Computer generated hologram (CGH) education kit for hands-on learning of optical metrology for complex optics and systems
- [2022] CGH-assisted metrology testbed for the Thirty Meter Telescope primary mirror
- [2021] Metrology Testbed for the Thirty Meter Telescope Primary Mirror
- [2019] Interferometric Metrology for the TMT Primary Mirror Segments: Design and Analysis
- [2018] Infrared computer-generated holograms: design and application for the WFIRST grism using wavelength-tuning interferometry
- [2016] Optical Alignment with CGH Phase References
- [2014] Precision Alignment And Calibration Of Optical Systems Using Computer Generated Holograms
- [2014] Diffractive optics calibrator: measurement of etching variations for binary computer-generated holograms
- [2013] Optical testing with computer generated holograms: comprehensive error analysis
- [2013] Design and analysis of an alignment procedure using computer-generated holograms
- [2011] Low uncertainty alignment procedure using computer generated holograms
- [2010] Imaging issues for interferometry with CGH null correctors
- [2010] Measurement of aspheric mirror segments using Fizeau interferometry with CGH correction
- [2009] Fizeau interferometer with spherical reference and CGH correction for measuring large convex aspheres
- [2007] Fabrication error analysis and experimental demonstration for computer-generated holograms
- [2007] Optical alignment with computer-generated holograms
- [2007] Optimal design of computer-generated holograms to minimize sensitivity to fabrication errors
- [2007] Coupling of surface roughness to the performance of computer-generated holograms
- [2006] Analysis of phase sensitivity for binary computer-generated holograms
- [2006] Absolute calibration of null correctors using twin computer-generated holograms
- [2006] Use of computer generated holograms for alignment of complex null correctors
- [2005] Testing an off-axis parabola with a CGH and a spherical mirror as null lens
- [2004] Efficient testing of segmented aspherical mirrors by use of reference plate and computer-generated holograms. I. Theory and system optimization
- [2004] Efficient testing of segmented aspherical mirrors by use of a reference plate and computer-generated holograms. II. Case study, error analysis, and experimental validation
- [1999] Efficient testing of off-axis aspheres with test plates and computer-generated holograms
- [1999] Error analysis for CGH optical testing
- [1999] Diffraction wavefront analysis of computer-generated holograms
- [1995] Applications of computer-generated holograms for interferometric measurement of large aspheric optics
- Show Remaining Articles ( 16 ) Collapse Articles
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FAQs
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- What is a CGH?
- How are CGHs used?
- What is a "null"?
- What is a "UUT"?
- How is a CGH mounted and adjusted?
- What types of surfaces can be measured using a CGH?
- What is the typical accuracy of a CGH?
- What are the benefits of using a CGH for metrology?
- What is CGH substrate error and how does it get subtracted?
- What are fiducial dots and how are they used?
- Are CGHs delicate?
- How do you clean a CGH?
- What is a Metrology Platform?
- What type of interferometer do I need to use a CGH?
- What is diffraction efficiency?
- What is the difference between an amplitude and a phase CGH?
- How is a CGH different from other types of holograms?
- What size CGHs does AOM produce?
- Do CGHs require regular calibration?
- Show Remaining Articles ( 4 ) Collapse Articles
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How-To's
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Technologies
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- Arc Focus Reference Alignment Patterns (AF)
- Crosshair Point Focus (PF-X)
- Line Focus Reference Alignment Patterns (LF)
- Confocal Point Focus Alignment Pattern (PF-C)
- Catseye Pair Alignment Pattern (CE-P)
- Catseye Single Alignment Pattern (CE-S)
- Collimation Alignment Pattern (CO)
- Visual Point Focus Alignment Pattern (PF-V)
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[2013] Design and analysis of an alignment procedure using computer-generated holograms
Coyle, Laura E., Matthew B. Dubin, and James H. Burge. “Design and analysis of an alignment procedure using computer-generated holograms.” Optical Engineering 52.8 (2013): 084104-084104.
Abstract:
A procedure that uses computer-generated holograms (CGHs) to align an optical system’s meters in length with low uncertainty and real-time feedback is presented. The CGHs create simultaneous three-dimensional optical references, which are decoupled from the surfaces of the optics allowing efficient and accurate alignment even for systems that are not well corrected. The CGHs are Fresnel zone plates, where the zero-order reflection sets tilt and the first-diffracted order sets centration. The flexibility of the CGH design can be used to accommodate a wide variety of optical systems and to maximize the sensitivity to misalignments. An error analysis is performed to identify the main sources of uncertainty in the alignment of the CGHs and to calculate the magnitudes in terms of general parameters, so that the total uncertainty for any specific system may be estimated. A system consisting of two CGHs spaced 1 m apart is aligned multiple times and re-measured with an independent test to quantify the alignment uncertainty of the procedure. The calculated and measured alignment uncertainties are consistent with less than 3 μrad of tilt uncertainty and 1.5 μm of centration uncertainty (1σ ).