Accuracy verification methodology for computer-generated hologram used for testing a 3.5-meter mirror based on an equivalent element  

作　　者：Kai Xu Haixiang Hu Xin Zhang Hongda Wei Zhiyu Zhang Xuejun Zhang 

机构地区：[1]Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Jilin 130033,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]State Key Laboratory of Applied Optics,Changchun,Jilin 130033,China [4]Key Laboratory of Advanced Manufacturing for Optical Systems,Chinese Academy of Sciences,Changchun,Jilin 130033,China

出　　处：《Light(Advanced Manufacturing)》2024年第2期41-49,共9页光（先进制造）（英文）

基　　金：supported by the National Natural Science Foundation of China(62127901,52375471,and 62305333);supported by the National Key Research and Development Program(2022YFB3403405);Youth Innovation Promotion Association of the Chinese Academy of Sciences(2019221);Young Elite Scientists Sponsorship Program of CAST(2022QNRC001);Young Elite Scientists Sponsorship Program of Jilin Province(QT202222).

摘　　要：Interferometry with computer-generated holograms(CGHs)is a unique solution for the highly accurate testing of large-aperture aspheric mirrors.However,no direct testing method for quantifying the measurement accuracy of CGHs has been developed.In this study,we developed a methodology for verifying CGH accuracy based on an element that is functionally equivalent to a large-aperture mirror in terms of accuracy verification.The equivalent element decreased the aperture by one or higher orders of magnitude,implying that the mirror could be replaced by a non-CGH technology in a comparison test.In this study,a 281 mm diamond-turned mirror was fabricated as the equivalent element of a 3.5 m aspheric mirror and measured using CGH and LUPHOScan profilometers.Surface error composition and root-mean-square(RMS)density analyses were performed.The methodology verification accuracy of the CGH was 4 nm(RMS)in the low-to mid-frequency bands,with a measured surface accuracy of approximately 10 nm(RMS).This methodology provides a feasible solution for CGH accuracy verification,ensuring high-accuracy and reliable testing of large-aperture aspheric mirrors.

关 键 词：Accuracy verification methodology Computer-generated hologram Large-aperture mirror testing Equivalent element 

分 类 号：TN26[电子电信—物理电子学]