Optical element contour detection method and device based on fringe tracking and storage medium

Abstract

The invention discloses an optical element contour detection method and device based on fringe tracking and a storage medium, and the method comprises the steps: testing the surface of a standard optical element through a Michelson interference system, and obtaining an interference fringe pattern; obtaining an optical path difference according to the interference fringe pattern, extracting phase information from the optical path difference, and obtaining vector height information of the surface of the standard optical element according to the phase information; constructing and training a first neural network by taking the interference fringe pattern as input and taking vector height information of the surface of the standard optical element as output; similarly, performing point-by-point scanning on the surface of the to-be-measured optical element to obtain a to-be-measured interference fringe pattern; inputting the to-be-measured interference fringe pattern into a first neural network, and obtaining vector height information of each point on the surface of the to-be-measured optical element; and obtaining the three-dimensional contour of the to-be-measured optical element according to the measurement point coordinates of the Michelson interference system during point-by-point scanning and the vector height information of each point on the surface of the to-be-measured optical element. The detection method is wide in detection range and high in measurement precision.

Description

technical field [0001] The invention relates to the field of surface shape detection, in particular to a fringe tracking-based optical element profile detection method, device and storage medium. Background technique [0002] For the measurement of the free-form surface shape of the high-precision, large-scale optical elements in the synthetic aperture telescope, its accuracy is probably below 1 micron and above 50 nanometers. However, on the meter-scale scale, there is still no good method for detecting such changes at the micron level with sub-micron level accuracy. [0003] In the prior art, surface measurement mainly aimed at free-form surfaces is generally performed using computer-generated holograms (Computer-Generated Holograms, CGH), swing-arm profilers, laser trackers, or sub-aperture splicing methods. These methods have their own shortcomings, such as insufficient precision, the detection range cannot reach a large range, and the dynamic range is not enough when m...

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These methods have their own shortcomings, such as insufficient precision, the detecti

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