Method for measuring contour of large-caliber aspheric surface optical element at grinding stage

Abstract

The invention discloses a method for measuring the contour of a large-caliber aspheric surface optical element at the grinding stage, and relates to the field of aspheric surface optical element measurement. A contour line of the large-caliber aspheric surface optical element at the grinding stage is divided into sections, the number of the sections is set to be M, and overlapping areas need to be reserved between every two adjacent sections and are set to be p1, p2, ..., pm-1. The divided M sections are respectively measured through a measuring device, and the measuring data of each section are obtained. The measuring data of the divided M sections of the large-caliber aspheric surface optical element are spliced based on the multi-body system theory, the Taylor series, the principle of least squares and the data of the overlapping areas. Redundant data, produced when the sections are spliced, of the overlapping areas are removed based on the curvature principle and the aspheric surface equation least square fit method. The contour of all the sections with the redundant data removed is comprehensively optimized, and the overall measuring result of the contour of all the sections is obtained.

Description

technical field [0001] The invention relates to the measurement of aspherical optical elements, in particular to a method for measuring the profile of large-diameter aspherical optical elements in the grinding stage. Background technique [0002] With the rapid development of space technology and electronic information technology, as well as the needs of aerospace, astronomy, national defense and other fields, large-aperture aspherical optical components have the advantages of correcting phase difference, improving image quality and reducing the size and weight of optical systems. Advantages, the demand continues to increase. At the same time, the precision requirements for aspheric surfaces are getting higher and higher, which brings new challenges to processing and inspection. [0003] For the precise measurement of large-aperture aspherical optical components, there are currently two main technical means: 1) Manufacturing large-scale, high-precision testing equipment; (L...

AI Technical Summary

Problems solved by technology

(Wang Xiaokun, Wang Lihui, Zhang Xuejun. Detection of aspheric surface by sub-aperture splicing interferometry [J]. Optical Precision Engineering, 2007, 15(2): 192-198.) However, it is impossible for large-aperture aspheric optical elements in the non-polishing stage using this technique to measure

The main reason is that optical components generally have to go through three processing stages of rough grinding, fine grinding and polishing to meet the precision requirements. The final surface shape error is generally on the order of 3-5 microns. At this time, the surface shape error deviates greatly from the theoretical value, and the surface roughness is not good.

Images