Optical fiber Fizeau interferometric array distributed vibration sensing system and method

Abstract

The invention discloses an optical fiber Fizeau interferometric array distributed vibration sensing system and method. The system comprises a laser light source, a first optical fiber coupler, a first optical frequency shifter, a second optical frequency shifter, a second optical fiber coupler, a delay device, an optical circulator and an optical fiber Fizeau interferometric array. The system also comprises a photoelectric detector, a data acquisition and control card, a first radio frequency signal source and a second radio frequency signal source; light emitted by the laser light source passes through the first optical fiber coupler so as to be divided into two beams of light, wherein the first beam of light and the second beam of light pass through the first optical frequency shifter and the second optical frequency shifter respectively so as to be subjected to frequency shifting, and therefore, the first beam of light and the second beam of light can be modulated into a first optical pulse and a second optical pulse with different frequencies; after the second optical pulse passes through the delay device, the second optical pulse and the first optical pulse are coupled into a pulse pair at the second optical fiber coupler; the pulse pair passes through the optical circulator and enters the optical fiber Fizeau interferometric array, and as a result, a plurality of reflected pulse pairs can be generated; the reflected pulse pairs go back to the optical circulator; and the reflected pulse pairs are subjected to heterodyne interferometry at the photoelectric detector.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensors, in particular to an optical fiber Fizeau interference array distributed vibration sensing system and method. Background technique [0002] Distributed optical fiber vibration sensing uses optical fiber as the sensing element and transmission medium to detect vibration signals around the sensing link. It not only has simple optical fiber sensing technology, but also has high sensitivity, high temperature resistance, corrosion resistance and electromagnetic resistance. interference and other advantages, and can better reflect the advantages of optical fiber distribution and extension. Any point in the sensing link can be modulated by the vibration signal, so as to realize the no-miss detection of the vibration signal. The interferometric distributed optical fiber vibration sensing technology is The vibration sensing technology based on the principle of light wave interference modulati...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problems of Mach-Zehnder interferometer and Michelson interferometer, etc., because the signal light and reference light travel in different optical paths, resulting in the interference fringe instability caused by different external disturbances (such as vibration, temperature fluctuations, etc.), we provide a A Distributed Vibration Sensing System and Method for Optical Fiber Fizeau Interference Array

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