Method and device for calibrating morphology compensation type four-optical-axis angular displacement laser interferometer

Abstract

The invention relates to a method and a device for calibrating a morphology compensation type four-optical-axis angular displacement laser interferometer and belongs to the technical field of laser measurement. According to the invention, four measurement beams of the calibrated laser interferometer pass through a middle through hole of a four-axis hollow laser interference mirror set and the four measurement beams of the calibrated laser interferometer are placed in parallel at the middle positions among four parallel standard measurement beams; vertical distances between the standard measurement beams and the measurement beams of the calibrated laser interferometer are very small and the air refractive indexes of the standard measurement beams are very approximate to those of the measurement beams of the calibrated laser interferometer; a measurement displacement error caused by the surface morphology of the reflecting surface of a target reflector is compensated into an angular displacement measurement result so as to ensure accuracy of an angular displacement measurement value.

Description

technical field [0001] The invention belongs to the technical field of laser measurement, and mainly relates to a laser interferometer calibration method and device. Background technique [0002] Angular displacement laser interferometer is a standard measurement technology with high precision. It is widely used in precision and ultra-precision machining, microelectronic equipment, nanotechnology industrial equipment and national defense equipment. It can be used for micro-displacement components, mobile platforms and lithography Monitoring of machine angle changes. The angular displacement laser interferometer can provide high measurement accuracy, and can dynamically measure the relative swing angle in motion, which is a unique advantage different from other instruments. In order to ensure the accuracy of the angular displacement laser interferometer measurement, the Calibration of the displacement laser interferometer is very important. The realization of the angular di...

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Problems solved by technology

[0003] In view of the large Abbe error in the above-mentioned existing angular displacement laser interferometer calibration device, the serious air refractive index inconsistency and the problem of not being able to calibrate two sets of laser interferometers in an accurate sense, the present invention proposes and develops a shape compensation A calibration method and device for a four-axis angular displacement laser interferometer, the invention makes the vertical distance between the standard measurement beam and the calibrated laser interferometer measurement beam very small, thereby reducing the Abbe error and the influence of air refractive index inconsistency , and in the accurate sense two sets of laser interferometers are calibrated

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