Method and device for measuring vertex radius of off-axis optical aspheric mirror

Abstract

The invention relates to a method and a device for measuring off-axis optical non-spherical mirror vertex radius. The method includes: using the feature that normal of different points on an off-axis optical non-spherical mirror intersects with an optical shaft at different points and combining reflector law and triangular function relation of light to determine the included angle of normal of used point on the off-axis optical non-spherical mirror and the optical shaft and the aperture height; building mathematical models of non-spherical geometrical parameters and the normal according to a non-spherical formula and derivation; and using a least square method for data processing and solving. By the method and the device, the problem that the off-axis optical non-spherical mirror vertex radius including quadratic coefficient and high order coefficient cannot be measured or measured accurately is solved.

Description

technical field [0001] The invention belongs to the technical field of optical detection, and in particular relates to a method and a device for measuring the vertex radius of an off-axis optical aspheric mirror. Background technique [0002] With the development of optical technology, the requirements for high resolution and large field of view imaging are constantly improving, which requires a longer focal length and reflective optical system. In order to meet the requirements of imaging quality and field of view, the form of mirrors has developed from the initial spherical surface to quadric surface or even high-order aspheric surface. The most typical one is the off-axis three-mirror system (TMA system). The mirrors are high-order aspheric or off-axis high-order aspheric. The biggest technical difficulty of the aspheric surface lies in the processing and detection of the aspheric surface. The surface shape of the off-axis aspheric surface can be detected by a compensato...

AI Technical Summary

Problems solved by technology

[0006] In order to solve the technical problem that the vertex radius of the off-axis aspheric mirror cannot be accurately measured, and the existing measurement method has low precision, or the mirror surface is scratched by contact measurement, the present invention provides a method that uses an off-axis aspheric surface detection compensator to determine Optical axis, combined with the law of thin beam mirrors to measure the normal angle of any point on the off-axis aspheric mirror, calculate the aspheric surface vector height; and perform multi-point sampling on the aspheric surface, according to the aspheric surface formula and trigonometric relationship, use Method and device for measuring the vertex radius of an off-axis optical aspheric mirror by fitting and solving the geometric parameters (including vertex radius, quadratic coefficient and high-order coefficient) of the off-axis aspheric mirror by least square method

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