Method for machining off-axis aspherical mirror

Abstract

The invention discloses a method for machining an off-axis aspherical mirror. The method comprises the steps that 1, a rotary aspherical matrix structure is designed; 2, a through hole for inlaying of a daughter structure is excavated in a matrix blank; 3, a cylindrical integral workpiece is formed by combining a matrix and a daughter; 4, an initial spherical surface is machined; 5, grinding is guided through the surface shape error detecting result of a contourgraph, and the surface shape error between the initial spherical surface and a rotary aspheric surface is corrected; and 6, polishing is guided through the surface shape error detecting result of an interferometer or knife-edge tester, and the off-axis aspherical daughter is taken out after polishing is completed. The method is characterized in that the caliber D of the initial spherical surface is equal to the diameter of a cylinder of the integral workpiece, and the curvature radius R of the initial spherical surface is equal to the radius of a circumcircle of a triangle formed by a vertex in a rotary aspheric bus equation and a first point and a second point which are located at the position with the caliber of 1.414 D on a rotary aspheric bus. According to the method, the problem of the influence of the fringe effect in the prior art is solved, the efficiency of aspherical surface machining is improved, and machining difficulty is reduced.

Description

technical field [0001] The invention relates to a processing of an optical element, in particular to a processing method of an off-axis aspheric mirror. Background technique [0002] In the prior art, the optical system using the off-axis aspheric mirror structure has the characteristics of fewer components, no obstruction, long focal length, large field of view, wide band, strong ability to suppress stray light, and high modulation transfer function. It is a space optical system, astronomy and Indispensable optics for high-precision measurement systems. The three-mirror reflection system is its most typical application. As the core component of the space telescope, it can avoid central occlusion, reduce the volume and weight of the system, and improve the imaging quality of the system at the same time. In view of the above advantages, research and development of new aspheric optical element processing technology has always been an important task in the field of optical pro...

AI Technical Summary

Problems solved by technology

[0007] The purpose of the present invention is to provide a processing method for off-axis aspheric mirrors, which is used for processing concave quadratic aspheric mirrors with conic constant K<0. It does not need to rely on high-precision and complicated instruments and equipment, and does not need to spend special energy on processing. The edge error of the off-axis aspheric sub-mirror to solve the technical problem of low processing efficiency of the workpiece edge caused by the edge effect in the grinding stage

Images