Method and device for calibrating optically biaxial return and gas bath type angular displacement laser interferometer

Abstract

The invention relates to a method and a device for calibrating an optically biaxial return and gas bath type angular displacement laser interferometer and belongs to a laser measurement technology. According to the invention, two measurement beams of the calibrated laser interferometer pass through a middle through hole of a biaxial hollow laser interference mirror set and the two measurement beams of the calibrated laser interferometer are placed in parallel at the middle positions between two 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 two standard measurement beams are very approximate to those of the measurement beams of the calibrated laser interferometer; a stable gas bath environment formed by a gas bath device enables the air temperature, the humidity and the air pressure to be approximately and uniformly distributed and enables the air refractive indexes of the two standard measurement beams to be more approximate to those of the measurement beams of the calibrated laser interferometer; and microinching equipment is used for carrying out real-time return compensation on a target reflector according to an average value of derivative displacements measured by two beam position detectors so as to enable the incidence positions of the measurement beams on the reflecting surface of the target reflector not to be changed.

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 air refractive index and inaccurate calibration of two sets of laser interferometers in the existing angular displacement laser interferometer calibration device, the present invention proposes and develops a dual 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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