A Multi-beam Cascade Step Angle Mirror Laser Interferometer

Abstract

The invention discloses a multi-beam cascaded step angle mirror laser interferometer, which includes a laser source, a beam splitter, a step plane angle mirror group, a moving angle mirror, and a photoelectric detector group, wherein the laser source includes n parallel lasers beam, n≥2, the photodetector group includes n photodetector devices, the step plane corner mirror group includes m step plane corner mirrors and m-1 conventional corner mirrors, m≥2, the step plane corner mirror group The two reflective step surfaces of the reflector are composed of n step planes, and the distance between two adjacent reflective planes is k, which is a natural number. The conventional corner reflector includes two reflective planes at right angles, and the moving corner reflector includes two a reflective plane. The laser interference phenomenon generated by the laser interferometer is not only related to the laser wavelength, but also related to the height difference of the stepped reflection plane. The photodetector group can detect the displacement with an accuracy of λ / 2n level, which significantly improves the measurement accuracy.

Description

technical field [0001] The invention relates to the field of precision testing technology and instruments, in particular to a multi-beam cascaded step angle reflector laser interferometer. Background technique [0002] The emergence of lasers has enabled the rapid development of ancient interferometric technology. Lasers have the characteristics of high brightness, good directionality, monochromaticity and good coherence. Laser interferometry technology has been relatively mature. The laser interferometry system is widely used: the measurement of precision length and angle, such as linear ruler, Grating , gauge block , Precision screw detection; positioning detection systems in precision instruments such as control and calibration of precision machinery; positioning detection systems in special equipment for large-scale integrated circuits and detection instruments; measurement of tiny dimensions, etc. In most laser interferometric length measurement systems, Michelson ...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the shortcomings of existing laser interferometers that the measurement accuracy is limited by the laser wavelength and the measurement accuracy is difficult to improve, and to provide a multi-beam cascaded step-angle reflector laser interferometer, which is installed in the existing Michelson Based on the laser interferometer, the n-light source n-step plane angle reflector group is used, and the measurement accuracy can reach Improve the measurement accuracy of the laser interferometer

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