Digital Mohr phase shifting interference surface shape measurement method based on region location fitting algorithm

Abstract

The invention discloses a digital Mohr phase shifting interference surface shape measurement method based on a region location fitting algorithm. The method comprises the following steps: establishinga virtual interferometer, acquiring an ideal system residual wavefront on an image surface of the virtual interferometer, and pre-marking a solving error region; acquiring a single-breadth actual interferogram in an actual interferometer; solving a surface shape error by using a digital Mohr phase shifting interference method to obtain the surface shape error with the solving error region; selecting data in a solving correctness region for fitting of the surface shape error to obtain a fitting coefficient; and reconstructing the surface shape error by the fitting coefficient to finally obtaina surface shape error result without the solving error region. The digital Mohr phase shifting interference surface shape measurement method solves the problem of a solving error occurring at a largeresidual aberration wavefront caused by the adoption of the digital Mohr phase shifting interference method; the measurement dynamic range of the digital Mohr phase shifting method is extended to beequivalent to that of a traditional phase shifting method; and meanwhile, the real-time, anti-shock and high-precision advantages of the original digital Mohr phase shifting interference method are maintained.

Description

technical field [0001] The invention relates to the measurement of aspheric surface shape by laser interferometry, which belongs to the field of photoelectric detection technology. The digital moiré phase-shifting interferometric surface shape measurement method based on the positioning fitting algorithm realizes instantaneous, anti-vibration, and high-precision aspheric surface shape detection. Background technique [0002] Compared with optical spherical surfaces, aspheric surfaces have more surface degrees of freedom, which can greatly improve system integration, reduce system quality, and improve system imaging quality, even reaching the diffraction limit. Optical systems are used more and more widely. However, because of its complex surface shape, high-precision aspheric detection has always been a major problem in the field of optical detection. [0003] At present, the commonly used aspheric surface shape detection methods are mainly divided into two categories: con...

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Problems solved by technology

[0010] The purpose of the present invention is to solve the problem that the remaining aberration bandwidth is limited in the digital Moiré phase-shifting interferometry method, and only the remaining aberration bandwidth of the traditional phase-shifting interferometry method is 0.5 times, and propose a fitting algorithm based on regional positioning The digital Moire phase-shifting interferometry surface measurement method makes the residual aberration bandwidth of the digital Moire phase-shifting interferometry method equivalent to that of the traditional phase-shifting interferometry method, expanding the application range of the digital Moire phase-shifting interferometry method

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