Method for detecting wavefront aberration for optical imaging system based on grating shearing interferometer

US10969274B2 · kind B2 · utility

Assignee

• Shanghai Institute of Optics And Fine Mechanics, Chinese Academy of Sciences · CN

Inventors

• Yunjun Lu · Shanghai, CN
• Feng Tang · Geneva, US
• Xiangzhao Wang · Shanghai, CN

Key dates

• Filing date: Nov 15, 2019
• Grant date: Apr 6, 2021
• Expiry date: Nov 15, 2039

Classification

• Technology area (CPC G): Physics
• CPC primary: G03F7/706
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Method for detecting wavefront aberration for optical imaging system based on grating shearing interferometer, the grating shearing interferometer system comprising a light source and illumination system, an optical imaging system to be tested, a one-dimensional diffraction grating plate, a two-dimensional diffraction grating plate, a two-dimensional photoelectric sensor, and a computing unit. The one-dimensional and two-dimensional diffraction grating plates are respectively placed on the object plane and the image plane of the optical imaging system to be tested. By collecting interferograms with phase-shifting amounts of 0, π/2, π, 3π/2 and N sets of α, π-α, 2π-α (where, s is the shear ratio of the grating shearing interferometer system), combined with a certain phase retrieval algorithm, the influence of all high-order diffraction beams on the phase retrieval accuracy is eliminated, and finally the detection accuracy of wavefront aberration for the imaging system to be tested is improved.