Absolute distance measurement system and method based on phase method and synthetic wavelength method

Abstract

The invention provides an absolute distance measurement system and method based on the phase method and the synthetic wavelength method. The output laser of a femtosecond laser is reflected by a polarization beam splitting prism I and then returned along an original path by a 0-DEG reflector after passing through an acousto-optic modulator; the reflected light is transmitted through the polarization beam splitting prism I into a polarization beam splitting prism II into two beams, one beam is a reference arm light path and is received by a photodetector I, the other beam is a measuring arm light path and is received by a photodetector II, and the photodetectors are electrically connected with a computer through a phase meter. The system and the method are advantaged in that a technical problem that the range and measurement accuracy cannot be simultaneously satisfied in the absolute distance measurement process in the prior art is solved; an erbium-doped femtosecond laser frequency comb is utilized as a light source, the pulse repetition frequency is high, and distance measurement accuracy is improved by utilizing higher harmonics; through interference between femtosecond optical comb pulses, combined with the phase method and the synthetic wavelength method, the large extended measurement range is realized; the system is simple in structure and easy to operate.

Description

technical field [0001] The invention relates to the technical field of detection, in particular to an absolute distance measurement system and measurement method based on a phase method and a synthetic wavelength method. Background technique [0002] Distance measurement is an important aspect in the field of detection technology, especially for high-end equipment manufacturing, ship repairing, automobile manufacturing, traffic engineering construction and other fields. At present, the distance measurement methods mainly used at home and abroad are: phase method, time-of-flight method, laser interferometry and so on. The phase method is a traditional ranging method, which does not require a cooperative target and can achieve long-distance ranging. However, in large-scale measurement, the measurement accuracy is limited to the order of mm. The time-of-flight method has the advantage of measuring distances from a few meters to hundreds of kilometers. It is not only widely us...

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Problems solved by technology

[0003] In order to solve the technical problem that the measurement range and measurement accuracy cannot be satisfied at the same time in the prior art, the present invention provides an absolute distance measurement system and measurement method based on the phase method and the synthetic wavelength method, so as to expand the measurement range and improve The purpose of measuring accuracy

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