Phase-sensitive optical time-domain reflectometer based on linear frequency-modulation pulse and measurement method of phase-sensitive optical time-domain reflectometer

Abstract

The invention relates to a phase-sensitive optical time-domain reflectometer based on a linear frequency-modulation pulse and a measurement method of the phase-sensitive optical time-domain reflectometer. The phase-sensitive optical time-domain reflectometer comprises a laser device, a single side band modulator SSBM, an acoustic optical modulator AOM, an erbium-doped optical fiber amplifier EDFAI, an EDFAII, an arbitrary waveform generator AWG, an optical fiber circulator, a fiber Bragg grating filter FBG, a photoelectric detector, a data collection module and a to-be-measured optical fiber, wherein laser enters the single side band modulator SSBM and is modulated into pulsed light by virtue of the acoustic optical modulator AOM, and the pulsed light is amplified by virtue of the erbium-doped optical fiber amplifier EDFAI and enters the to-be-measured optical fiber through the optical fiber circulator; and a backward Rayleigh scattering signal is output through the optical fiber circulator, a backward Rayleigh scattering optical signal is amplified by virtue of the erbium-doped optical fiber amplifier EDFAII and is detected and converted into an electric signal through the fiber Bragg grating filter FBG, and the data collection module executes data collection and data analysis. By the utilizing linear frequency-modulation pulse, the measurement time is shortened, and the dynamic performance of a system is improved; and the scheme provided by the invention is convenient and feasible, and the structure of the system is relatively simple.

Description

Technical field [0001] The invention relates to a phase sensitive optical time domain reflectometer, in particular to a phase sensitive optical time domain reflectometer based on a chirp pulse and a measurement method. Background technique [0002] Distributed optical fiber sensing technology uses the sensing optical fiber itself as the information transmission medium and sensing unit at the same time, and adopts advanced methods and technologies to realize simultaneous measurement of external physical quantities at hundreds of thousands of points on the optical fiber path, and the optical fiber itself has a volume Small size, light weight, corrosion resistance, electrical insulation, low cost, passive, good windability, etc., which determine that the distributed optical fiber sensing system has incomparable advantages compared with ordinary electrical sensors: corrosion resistance, insulation Good performance, resistance to strong electromagnetic interference; small size and lig...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a chirp-based phase-sensitive optical time-domain reflectometer and measurement method for the problems of low dynamic performance and complex demodulation technology of the current technical solutions, which have the advantages of simple structure, convenient and feasible demodulation technology, and real-time Dynamic distributed phase-sensitive optical time domain reflectometer, which can be applied to real-time dynamic quantitative monitoring of strain, temperature and vibration

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