Optical frequency modulation method picometer-level resolution and large-stroke laser measuring device

Abstract

The invention discloses a picometer-magnitude resolving power large-stroke laser measurement device adopting an optical frequency modulation method and belongs to the technical field of precision measurement. The device mainly comprises an interference measurement module, an optical demodulation module, a subdivision control module and a control and information processing module, wherein the interference measurement module comprises a light source collimator, a first polarizing beam-splitting prism, a first 1 / 4 wave plate, a modulation reference mirror, an FP interference cavity, a second 1 / 4wave plate, a measurement mirror, a third 1 / 4 wave plate, a second polarizing beam-splitting prism, a first photoelectric receiver and a second photoelectric receiver. The problem that FP interreference cavities cannot meet long-distance interference measurement with a light frequency decimal modulation method is solved, the resolving power is further improved to the picometer magnitude on the basis of original interference resolving power while long-distance laser interference measurement can be met, and long-distance and picometer-magnitude resolving power laser measurement is realized. Thedevice is relatively simple in structure and easily realizes dynamic characteristic measurement in a high-precision manner.

Description

technical field [0001] The invention relates to a laser measuring device with a picometer-level resolution and a large stroke using an optical frequency modulation method, which belongs to the technical field of precision measurement. Background technique [0002] Laser interferometry is an important application technology in precision measurement. The principle of non-contact measurement makes laser interferometry have the advantages of short response time, high measurement accuracy and good reproducibility. The laser interferometry method is widely used in the precision measurement technology field of geometric quantities and related quantities. It is an important means to realize high-precision displacement measurement at present, and has very important scientific research and engineering application significance. At present, when the laser interferometry method realizes long-distance measurement, due to the influence of factors such as its optical structure, interference...

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Problems solved by technology

[0003] In order to solve the problem that the large measurement range and high measurement resolution cannot be achieved in the existing long-distance interferometry, the purpose of the present invention is to provide a laser measurement device with picometer-level resolution and large stroke by optical frequency modulation method. The device has a large The characteristics of measurement range and high resolution, the method of laser interference is used to achieve long-distance measurement, and the method of frequency modulation is used to subdivide and improve the resolution of interferometry to the picometer level (0.1pm ~ 100pm), While satisfying long-distance laser interferometry, its resolution can be further improved to the picometer level on the basis of the original interference resolution capability, and the measurement of picometer-level resolution of long-distance laser interferometry can be realized

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