Method for wavefront measurement of optical imaging system based on grating shearing interferometry
US11009336B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 2019 |
| Grant date | May 18, 2021 |
| Priority date | — |
| Expiry date | Nov 15, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01M11/0271
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for wavefront measurement of optical imaging system based on grating shearing interferometry, the grating shearing interferometer 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 diffraction grating plate and the two-dimensional diffraction grating plate are respectively placed on the object side and the image side of the optical imaging system to be tested. By collecting N sets of interferograms with a phase-shifting interval (where, s is the shear ratio of the grating shearing interferometer), 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 wavefront measurement accuracy for the optical imaging system is improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.