BOCDA (Brillouin Optical Correlation Domain Analysis) distributed optical fiber sensing device and method based on physical random code modulation

Abstract

The invention relates to a distributed optical fiber sensing system, and particularly relates to a BOCDA (Brillouin Optical Correlation Domain Analysis) distributed optical fiber sensing device and amethod based on physical random code modulation, so as to solve the problems of a limited sensing distance and spatial resolution deterioration existing in the existing BOCDA distributed optical fibersensing system. The device comprises a distributed feedback semiconductor laser, an electro-optic phase modulator, a physical random code generator, a first optical isolator, a 1*2 optical fiber coupler, a high-speed electro-optic modulator, a microwave signal source, a variable optical delay line, a first optical amplifier, an optical polarization scrambler, a second optical isolator, a sensingoptical fiber, a second optical amplifier, an optical circulator, a tunable optical filter and a optical power detector. In comparison with a time domain system, the spatial resolution is higher, thesensing distance is longer, the problem of spatial resolution deterioration caused by existence of a weak period of chaotic laser signals is avoided, adjustment on the high spatial resolution acquisition is extremely convenient, and the signal-to-noise ratio of the sensing system is effectively improved.

Description

technical field [0001] The invention relates to a distributed optical fiber sensing system, in particular to a BOCDA distributed optical fiber sensing device and method based on physical random code modulation. Background technique [0002] Distributed optical fiber sensing uses optical fiber as the sensing element and transmission element, which can realize the measurement of temperature and strain at different positions on the entire optical fiber. Compared with traditional sensing technology, distributed optical fiber sensing system has the advantages of distributed measurement, long monitoring distance, high spatial resolution, fast response time, anti-electromagnetic interference, etc., and has been widely used in aerospace, petrochemical, Power industry, nuclear industry, civil engineering and military and other fields. [0003] At present, the distributed optical fiber sensing system based on Brillouin scattering has become a research hotspot in the field of distribu...

AI Technical Summary

Problems solved by technology

[0007] The present invention provides a BOCDA distributed optical fiber sensing device and method based on physical random code modulation in order to solve the problems of limited sensing distance and deteriorated spatial resolution existing in the existing BOCDA-based distributed optical fiber sensing system

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