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Measuring Large Amplitude Surface Figure Error using Coordinate MetrologyAdvances in optical testing are as important as advances in optical fabrication, because one can make only what one can measure, particularly for unconventional prescriptions, like aspheric and freeform optics. A new, high-precision metrology capability is utilized to close the gap between interferometric testing and lower precision, contact-probe-based coordinate measuring machines or laser tracker/radar metrology to accurately measure surfaces with large figure error. This nearly universal optical testing method employs an ultra-precision coordinate measuring machine equipped with a non-contact probe. It was developed to characterize a broad spectrum of optical surfaces including ones with high slopes, impossible to measure using traditional interferometric testing. Optical components, covering a wide range of prescriptions, such as large convex conics, high-sloped aspherics, grazing-incidence x-ray optics, and highly deformed flats, were successfully measured. The resulting data were reduced using custom-developed routines to determine the optic’s alignment, surface departure from design, and the as-built optical prescription. This information guided the fabrication and modeling of these optical components
Document ID
20205006878
Acquisition Source
Goddard Space Flight Center
Document Type
Other - Technical Paper
Authors
Manal Khreishi
(Goddard Space Flight Center Greenbelt, Maryland, United States)
Raymond G Ohl
(Goddard Space Flight Center Greenbelt, Maryland, United States)
Ryan Mcclelland
(Goddard Space Flight Center Greenbelt, Maryland, United States)
Ron Shiri
(Goddard Space Flight Center Greenbelt, Maryland, United States)
Tilak Hewagama
(Goddard Space Flight Center Greenbelt, Maryland, United States)
Shahid Aslam
(Goddard Space Flight Center Greenbelt, Maryland, United States)
Melville P Ulmer
(Northwestern University Evanston, Illinois, United States)
Edgar Canavan
(Goddard Space Flight Center Greenbelt, Maryland, United States)
Rongguang Liang
(University of Arizona Tucson, Arizona, United States)
Date Acquired
August 27, 2020
Publication Date
September 25, 2020
Subject Category
Optics
Funding Number(s)
WBS: 432938.09.01.04.45.11
WBS: 432938.09.01.04.45.27
WBS: 432938.09.01.04.40.48
CONTRACT_GRANT: NNX16AL31G
Distribution Limits
Public
Copyright
Use by or on behalf of the US Gov. Permitted.
Technical Review
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