Laser heterodyne interferometry method and device for diagonal incident light based on corner cube

Abstract

The invention relates to a diagonal incident light laser heterodyne interference measurement method and a diagonal incident light laser heterodyne interference measurement device on the basis of a pyramid prism and belongs to the technical field of laser application. The method disclosed by the invention adopts two beams of spatially separated parallel light with different frequences; incidence points of the two parallel light beams on an unpolarized beam splitter prism are positioned on a diagonal line of an incident plane and are symmetrical around a center point of the incident plane; the pyramid prisms are used as a reference prisms and measurement prisms; by the method, two interference measurement signals with reverse doppler frequency shifts are finally generated to carry out interference measurement; the method and the device which are disclosed by the invention are insensitive for inclination of a measured object; the frequency aliasing phenomenon in an interferometer is eliminated; measurement accuracy of heterodyne interference measurement is improved; and meanwhile, resolution of heterodyne interference measurement is doubled.

Description

technical field [0001] The invention belongs to the field of laser application technology, and mainly relates to a method and device for measuring diagonal incident light laser heterodyne interferometry based on a corner cube. Background technique [0002] Laser heterodyne interferometry is widely used in ultra-precision machining, lithography machines, and three-coordinate measuring machines because of its strong anti-interference ability, large measurement range, high signal-to-noise ratio, and easy realization of high precision. With the continuous development of ultra-precision engineering, higher and higher requirements are put forward for machining accuracy; at the same time, new challenges are raised for the measurement accuracy and resolution of heterodyne interferometry. [0003] In laser heterodyne interferometry, the nonlinear error severely limits the further improvement of measurement accuracy and resolution. Scholars at home and abroad have done a lot of resear...

AI Technical Summary

Problems solved by technology

However, the optical structure of this method is asymmetric and is easily affected by the ambient temperature.

[0006] To sum up, none of the existing laser heterodyne interferometry methods can meet the high precision and resolution requirements of the interferometer for ultra-precision machining measurement, which severely limits the development of the field of ultra-precision machining measurement.

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