Measuring large amplitude surface figure error using coordinate metrology

Autor: Manal Khreishi, Raymond G. Ohl, Shahid Aslam, Edgar Canavan, Tilak Hewagama, Rongguang Liang, Ryan S. McClelland, Melville P. Ulmer, Ron Shiri
Rok vydání: 2021
Předmět:
Zdroj: Optical Engineering. 60
ISSN: 0091-3286
DOI: 10.1117/1.oe.60.8.084103
Popis: Advances in optical testing are as important as advances in fabrication because one can make only what one can measure. A high-precision metrology capability is utilized to close the gap between interferometric testing and lower precision metrology, laser radar, or contact-probe-based coordinate measuring machines (CMM) to accurately measure surfaces with large form error. This nearly universal optical testing method employs a precision CMM equipped with a non-contact, confocal probe. This technique was developed to characterize and align a broad spectrum of optical surfaces including ones with high slopes that are nearly impossible to measure using traditional interferometric testing without custom-made optics. 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 processed using custom-developed routines to determine the optic’s alignment, the departure from design surface, and the as-built prescription parameters. This information was used to verify and guide the development and fabrication of novel optics.
Databáze: OpenAIRE