Optical fiber distributed vibration sensing system and phase discrimination nonlinear error correction method

Abstract

The invention discloses an optical fiber distributed vibration sensing system and a phase discrimination nonlinear error correction method, which relate to the technical field of signal processing. The optical fiber distributed vibration sensing system includes a continuous laser source, a first coupler, an acousto-optic modulator, an optical fiber amplifier, a circulator, an optical fiber coupler, a balance detector, an analog phase discrimination circuit module, a control display terminal and an acousto-optic modulator driver which are connected in series. The optical fiber distributed vibration sensing system further includes a signal generator connected with the analog phase discrimination circuit module. The acousto-optic modulator driver is connected with the acousto-optic modulator. The output end of the first coupler is connected with the acousto-optic modulator and the optical fiber coupler. One output end of the circulator is connected with the optical fiber coupler, and the other output end is connected with a sensing optical fiber and a piezoelectric ceramic in turn. The analog phase discrimination circuit module is a dual-path reference phase discrimination circuit. The problems solved in the invention are as follows: (1) required digital signal detecting and processing equipment with high performance costs high; (2) the traditional digital phase discrimination process using DCM and inverse tangent is complicated.

Description

technical field [0001] The invention relates to the technical fields of optical fiber sensing and signal processing, in particular to an optical fiber distributed vibration sensing system and a corresponding correction method for nonlinear error of phase detection. Background technique [0002] In recent years, distributed optical fiber sensing technology has attracted more and more attention from the industry and national security departments due to its unique inherent advantages. Therefore, national security departments and safety monitoring industries have invested in distributed optical fiber sensing technology and research and development, and is expected to be widely used within a few years. The basic theory of all these distributed optical fiber sensing systems is based on the elastic-optic effect of the optical fiber, using external parameters such as disturbances in the sensing area, sound waves, temperature, pressure, electromagnetic force, etc. to act on a certain...

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Problems solved by technology

Ordinary analog phase detection circuit modules can only identify 0°-180° and canno

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