Multi-wavelength interference real-time absolute distance measurement device on the basis of femtosecond optical comb synchronization frequency locking

Abstract

The present invention provides a multi-wavelength interference real-time absolute distance measurement device on the basis of femtosecond optical comb synchronization frequency locking. The multi-wavelength interference real-time absolute distance measurement device on the basis of femtosecond optical comb synchronization frequency locking comprises: a multi-wavelength generator on the basis of the femtosecond optical comb synchronization frequency locking configured to emit a plurality of high-frequency stable object wavelength lasers; a heterodyne interferometer configured to receive lasers outputted by the multi-wavelength generator after the femtosecond optical comb synchronization frequency locking, returning measurement light and reference light after generation of interference through the heterodyne interferometer being coupled in single mode fibers by lens focusing to form mixed multi-wavelength heterodyne interference signals; and a synchronization phase demodulation module configured to separate the mixed multi-wavelength heterodyne interference signals obtained by the heterodyne interferometer through wavelength demodulation to obtain interference signals corresponding to each wavelength and perform synchronization phase measurement processing of the interference signals corresponding to each wavelength to finally obtain an accurate absolute distance value. The multi-wavelength interference real-time absolute distance measurement device on the basis of femtosecond optical comb synchronization frequency locking is high in traceability of values, high in measurement precision, large in non-fuzziness measuring range, fast in update rate and easy to measurement on site in real time, and is applicable to the fields of the industrial production, the equipment manufacture and the large-size precision measurement.

Description

technical field [0001] The invention mainly relates to the field of laser ranging, in particular to a multi-wavelength interference real-time absolute ranging device based on femtosecond optical comb synchronous frequency locking. Background technique [0002] Laser ranging is currently the most accurate distance measurement method and technology. Traditional ranging methods are mainly divided into two categories: laser incoherent measurement and interferometric measurement. The former has been widely used in space long-distance measurements such as observation and positioning of the earth and the moon, but limited by the electronic resolution capability, the measurement accuracy can only reach the order of mm. Although laser interferometry technology based on homodyne and heterodyne theory can achieve nanometer positioning accuracy, it has been relatively maturely applied in the field of precision engineering, but because its measurement principle is based on fringe counti...

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Problems solved by technology

[0004] The classic heterodyne interferometer is generally based on the optical path of the Michelson interferometer. The dual-frequency laser light source emits linearly polarized light with a fixed radio frequency difference and the polarization directions are perpendicular to each other. When the light source passes through the polarization beam splitter and enters the reference path and the measurement path respectively, there will be polarization. Leakage of components, resulting in polarization aliasing of heterodyne interference signals, resulting in non-linear errors in measurement results

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