Four-optical axis returning and air bath type angular displacement laser interferometer calibration method and device

Abstract

The invention discloses a four-optical axis returning and air bath type angular displacement laser interferometer calibration method and a four-optical axis returning and air bath type angular displacement laser interferometer calibration device, and belongs to the technical field of laser measurement. Four measurement light beams of a calibrated laser interferometer penetrate through a middle through hole of a four-axis hollow laser interference mirror group, and are arranged in parallel at the middle positions of four parallel standard measurement light beams; the standard measurement light beams are at short perpendicular distances away from the measurement light beams of the calibrated laser interferometer, and air refractivity values of the standard measurement light beams are approximate to those of the measurement light beams of the calibrated laser interferometer; air temperature, air humidity and air pressure in a stable air bath environment formed by an air bath device are approximately uniformly distributed, so that the air refractivity values of the standard measurement light beams are more approximate to those of the measurement light beams of the calibrated laser interferometer; and a micromotion device is used for performing real-time returning compensation on a target reflector according to an average value of derived displacement measured by four light beam position detectors to keep the incident positions of the measurement light beams on the reflecting surface of the target reflector unchanged.

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 relatively large Abbe error, serious inconsistency of the air refractive index and the inaccurate calibration of two sets of laser interferometers in the existing angular displacement laser interferometer calibration device, the present invention proposes and develops a four-axis optical axis Calibration method and device for return and air bath 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 reducing the inconsistency of air refractive index influence, and it is accurate sense that two sets of laser interferometers are calibrated

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