Method for detecting large-caliber large-relative-aperture parabolic reflector surface shape error

Abstract

The invention relates to a method for detecting a large-caliber large-relative-aperture parabolic reflector surface shape error. An existing method is high in cost and low in accuracy and efficiency. The method includes the steps of selecting a transmission standard lens, adjusting the position of a laser wave surface interferometer, adjusting a focus of a tested parabolic reflector to be coincided with a focus of the laser wave surface interferometer, adjusting the optical axis of the tested parabolic reflector to enable the optical axis of the tested parabolic reflector and the optical axis of the laser wave surface interferometer to be coaxial, adjusting a standard plane reflector, rotating the laser wave surface interferometer to enable the laser wave surface interferometer to be aligned with a first annular sub-aperture A, and repeating the sixth step and the seventh step according to a sub-aperture division scheme. The method for detecting the large-caliber large-relative-aperture parabolic reflector surface shape error is low in cost and high in accuracy and efficiency.

Description

technical field [0001] The invention belongs to the technical field of optical testing, and mainly relates to a method for detecting the surface shape error of a rotationally symmetrical large-aperture and large-relative-aperture parabolic mirror. technical background [0002] The optical system with a parabolic mirror as the main mirror has been more and more widely used in high-tech fields such as astronomical optics, space optics, and military affairs. In order to increase the light-gathering ability and peak light intensity of the optical system, the outstanding features of the optical system are Large caliber and large relative aperture. The manufacture of large-diameter and large-relative-aperture parabolic mirrors requires corresponding inspection technologies. However, there are still many challenges in the high-precision inspection of large-diameter and large-relative-aperture parabolic mirrors. [0003] In the polishing stage of the paraboloid, the usual quantitat...

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Problems solved by technology

The self-collimation method uses a pair of conjugate aberration-free points (geometric focus and infinity) on the paraboloid. When the point light source is precisely located on the geometric focus, a high-precision flat mirror with the same diameter as the measured parabolic mirror can be used. Realize conjugation, however, it is difficult and expensive to manufacture high-precision flat mirrors required for large-diameter parabolic mirrors, and it is even more difficult to achieve self-collimation for super-large-diameter parabolic mirrors, and it is necessary to choose a larger relative aperture parabolic mirror The relative aperture transmission standard mirror, with the increase of the relative aperture, the transmission standard mirror can no longer satisfy the detection of the large relative aperture parabolic mirror; the compensation mirror zero position inspection method is to convert the plane wavefront or spherical wavefront to The parabolic wavefront coincides with the theoretical shape of the tested parabolic mirror, and its biggest advantage is that the diameter of the compensation mirror is much smaller than that of the tested parabolic mirror. However, in order to obtain a reliable parabolic wave front, the manufacture of the compensation mirror And the assembly accuracy puts forward very strict requirements. At the same time, the relative aperture of the compensation mirror must be larger than the relative aperture of the parabolic reflector to be tested in order to realize the detection of the full-aperture surface error. With the increase of the relative aperture, the compensation mirror can no longer be used. Inspection of parabolic mirrors with large relative apertures

[0004] In the Chinese patent application number "200710034359.0" "Large Aperture and Large Relative Aperture Aspheric Mirror Medium and High Frequency Error Detection Device and Method", Li Shengyi and others realized the medium and high frequency error detection of aspheric mirror through the designed five-axis motion adjustment platform and area data splicing algorithm. The measurement result is the deviation from the best fitting sphere, and the detection of the parabolic surface shape with a large deviation is limited by the density of interference fringes

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