Three-dimensional displacement measurement system and measurement method based on laser self-mixing grating interference

Abstract

The invention discloses a three-dimensional displacement measurement system and measurement method based on laser self-mixing grating interference. The system includes a semiconductor laser sensor head, a plane mirror, a reflective two-dimensional plane grating, a data acquisition card and a computer. The laser light emitted by the head is incident on the reflective two-dimensional grating, and the corresponding diffracted light is fed back to the semiconductor laser sensor head along the original optical path to generate self-mixing interference. The self-mixing interference signal is converted into an electrical signal by the built-in photodetector of the semiconductor laser, and output To the data acquisition card, after computer processing, the three-dimensional displacement of the target to be measured is obtained. The invention solves the problem of the limited range of the traditional grating interferometer when measuring the out-of-plane displacement, and is more compact than the traditional grating interferometer, and maintains the advantages of self-collimation of the laser self-mixing interferometer, and can realize simple structure, a large number of High-resolution, high-resolution three-dimensional real-time displacement measurement system and measurement method.

Description

Technical field[0001]The present invention belongs to the field of precision displacement measurement, and in particular, to a three-dimensional displacement measurement system and measurement method based on laser self-mixing grating interference.Background technique[0002]Precision displacement measurement is a key technology for advanced manufacturing development and the forefront of the entire nano-technology field. With the development of semiconductor manufacturing technology and ultrafine processing technology, the demand for real-time high-precision three-dimensional positioning system has grown rapidly. The laser interferometer and the grating interferometer are widely used in high-precision displacement measurements due to non-contact, high resolution, and wide dynamic measurement range. The laser interferometer is typically used to measure the surface displacement of the target, and its accuracy can reach the nanometer level, and the measurement range can reach tens of met...

AI Technical Summary

Problems solved by technology

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a three-dimensional displacement measurement system and measurement method based on laser self-mixing grating interference, which solves the problem of limited range of traditional grating interferometers in out-of-plane displacement measurement, and at the same time compared with traditional The grating interferometer is more compact and maintains the advantages of self-collimation of the laser self-mixing interferometer, which can realize a simple structure, large range, high-resolution three-dimensional real-time displacement measurement system and measurement method

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