Imperfections of Scalar Approximation in Calibration of Computer-Generated Holograms for Optical Surface Measurements

Applied Sciences

Tianbao Chen¹  Xu Wang¹  Ruoqiu Wang¹  Zhiyu Zhang¹  Yingying Bai¹  Xuejun Zhang¹ 

[1] Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China;

关键词: computer-generated hologram;    optical testing;    diffraction optics;   

DOI  :  10.3390/app11156897

来源: DOAJ

【 摘 要 】

Computer-generated hologram (CGH) null correctors are used as accuracy standards for interferometric measurements of optical surfaces and optical systems. Diffractive optics calibrators (DOCs) have been developed to evaluate the phase tolerance of CGHs based on scalar approximation by measuring variations in duty cycle and etching depth. However, if the grating period of a CGH < 5λ, the scalar approximation is not accurate for phase analysis and reconstruction. In this study, the measurement errors of DOCs with small-period CGHs were investigated and experimentally verified. Results show that the imperfections of scalar approximation in CGHs cannot be ignored and the development of rigorous evaluation methods to improve the measurement accuracy of CGHs is of great practical significance.

【 授权许可】

Unknown