Orthogonal polarization laser feedback interferometer

Abstract

The invention provides an orthogonal polarization laser feedback interferometer. The orthogonal polarization laser feedback interferometer comprises an orthogonal polarization laser module outputting two equidirectional lasers which are superposed in space; a spectroscope dividing the laser output by the orthogonal polarization laser module into reflected light and transmitted light; a polarization spectroscope dividing the reflected light emitted by the spectroscope into parallel polarized light and vertical polarized light; a photoelectric detection module converting optical signals into electric signals; one acousto-optic frequency shift module carrying out frequency shift on the transmitted light; a diaphragm transmitting the laser subjected to the frequency shift of the acousto-optic frequency shift module; a half-wave plate arranged on an optical path of the laser emitted from the diaphragm; a polarization coupling lens coupling the laser emitted by the half-wave plate into a first polarization maintaining fiber; a fiber polarization beam splitter dividing the laser into first linearly polarized light and second linearly polarized light; a second polarization maintaining fiber for reflecting the first linearly polarized light to form a reference optical path; and a third polarization maintaining fiber outputting the laser to irradiate an object to be detected to form a measuring optical path.

Description

technical field [0001] The invention relates to the technical field of laser measurement, and relates to a feedback interferometer, in particular to an orthogonally polarized laser feedback interferometer capable of compensating most of the space. Background technique [0002] Laser interferometers are widely used and occupy a very important position in the field of modern precision measurement. Due to its high precision, traceability, and wide application, it can be called the "king of measurement". [0003] Laser interferometers can be seen in machinery manufacturing, IC manufacturing, laboratories and other occasions. Most of the existing laser interferometers with mature technology and wide application adopt the basic structure of Michelson interferometer. We collectively call this type of interferometer with similar structure traditional laser interferometer. The advantages of traditional interferometers are stable performance, mature technology, and wide application, ...

AI Technical Summary

Problems solved by technology

[0004] However, the existing laser interferometer can only partially compensate for the space-range disturbance inside the instrument, and the measurement accuracy is reduced when the external disturbance is large during long-distance measurement, and crosstalk is easily generated between the measurement light and the reference light, which brings measurement error

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