A device and method for centering and adjusting large-aperture aspheric mirrors

Abstract

The invention discloses a device and method for centering and adjusting large-diameter aspheric mirrors, and belongs to the technical field of optical-mechanical assembly and adjustment. Its main technical feature is to fix the aspheric mirror to be adjusted on the rotary adjustment mechanism of the centering device, use the eccentricity measurement system in the device to measure the deviation between the optical axis of the aspheric mirror and the reference axis in real time, and The position and direction of the deviation are displayed on the display. By adjusting the position and posture of the aspheric mirror, the coincidence error between the optical axis of the mirror and the reference axis is less than the design tolerance value, thereby completing the centering adjustment of the aspheric mirror. The device and method solve the centering problem of the large-diameter rotationally symmetrical aspheric reflector, and have the characteristics of simple instrument erection, convenient operation, high centering precision, and the like.

Description

technical field [0001] The invention belongs to the technical field of optical-mechanical assembly and adjustment, and in particular relates to a device and method for centering and adjusting large-diameter aspheric mirrors. Background technique [0002] Under the background of information-based warfare, weapons and equipment require optical imaging and stabilized aiming systems to have a wider spectral range and a longer operating distance. Therefore, the design utilization rate of large-aperture aspheric mirrors is getting higher and higher. Compared with the traditional spherical transmission system, the optical system using aspheric mirrors has a more obvious impact on the image quality from the center deviation, which needs to be strictly controlled during the assembly and adjustment stage. Different from spherical optical elements, aspheric mirrors have "uniqueness of optical axis", and their optical axis is the symmetry axis of the aspheric surface. If there is a devi...

AI Technical Summary

Problems solved by technology

[0004] 1. Method 1 can only find the image of the center of the sphere, but cannot locate the vertex image of the surface, so what is adjusted is not the real optical axis of the aspheric surface, that is, the axis of rotational symmetry;

[0005] 2. Method 1 will also calibrate the axis of symmetry by locating the centers of curvature of two different rings (regions) on the aspheric surface. In this method, since the curvature difference between the rings of the aspheric surface is not large, each center of curvature The axial positions are very close to each other, resulting in very low centering accuracy, which cannot reach the arc-second level

[0006] 3. Method 2 is limited by the measurement accuracy of the dial indicator, and the measurement error introduced is relatively large; and this method is a contact measurement method, which has certain damage to the aspheric surface element

[0007] In the article "Determination of the Optical Axis of Parabolic Mirrors" published in "Applied Optics" in March 2008, a method for determining the optical axis of parabolic mirrors by using incident parallel beams was introduced. When the mirror rotates, the actual normal changes of each point in the incident area are not the same, so it is difficult to obtain a spot pattern with a complete motion track on the CCD; and for different DUTs, the incident and reflection directions are random, and the CCD receiving device The placement position is not fixed, and it is very difficult to realize; at the same time, the tested sample adopts the vertical side-hanging installation method, and there is a large technical risk for large-diameter components

In the same year, the utility model patent "An Aspheric Lens Eccentricity Measuring Device", publication number: CN201096611Y, is the same author as the above-mentioned paper, and its invention content is compared with the method described in the paper, changing the incidence of wide beam to laser The beam is incident, but there are the same problem of spot receiving angle and safety problem, which is difficult to realize in actual operation

[0008] In the article "Research on Aspheric Interferometric Centering Method" published in "Acta Photonica Sinica" in July 2008, a method of using the principle of interferometry to judge the eccentricity error by observing the change of the interference pattern is proposed. This method is greatly affected by environmental vibration. , the actual measurement results are not necessarily accurate, and the introduction of an interferometer, the entire experimental device has a large structure and is difficult to erect, which cannot meet the actual needs of trial production and batch production.

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