Optical path balanced high-speed and high-resolution laser heterodyne interferometry method and device

Abstract

The invention relates to a light path balanced type high-speed and high-resolution laser heterodyne interference measurement method and a light path balanced type high-speed and high-resolution laser heterodyne interference measurement device, belonging to the technical field of laser application. The invention adopts reference light and measurement light which are spatially separated from each other, and a light path balance design is carried out; meanwhile, the method generates two interference measurement signals with opposite Doppler frequency shifts, and selectively uses the two measurement signals for carrying out interference measurement according to the movement direction and speed of a measured target. The method and the device provided by invention not only reduce the influence of temperature change on the measurement, but also eliminate the frequency aliasing phenomenon in an interferometer, thus improving the measurement accuracy of heterodyne interference measurement; and furthermore, the problem of the limitation of laser source frequency difference to the measurement speed can be solved.

Description

technical field [0001] The invention belongs to the technical field of laser applications, and mainly relates to an optical path balanced high-speed and high-resolution laser heterodyne interferometry method and device. 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 and production efficiency; at the same time, new challenges are raised for the measurement accuracy, resolution and speed 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...

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Problems solved by technology

[0008] Aiming at the shortcomings of the above-mentioned existing laser heterodyne interferometer, the present invention proposes an optical path balance type high-speed and high-resolution laser heterodyne interferometry method and device, which improves the measurement accuracy of laser heterodyne interferometry and solves the problem of laser light source frequency difference measurement. speed limit problem

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