Distributed optical fiber Brillouin sensor fused with optical fiber Brillouin frequency shifter

Abstract

The invention discloses a distributed optical fiber Brillouin sensor fused with an optical fiber Brillouin frequency shifter, which is a distributed optical fiber sensor manufactured through the frequency shift effect of Brillouin scattering of an optical fiber, an optical fiber broadband nonlinear optical amplification effect, the strain and temperature effects of Brillouin scattered light of coherent amplification, and an optical time domain analysis principle, and comprises a narrow linewidth single frequency optical fiber laser, three optical fiber branching devices, a pulse modulator, the optical fiber Brillouin frequency shifter, two optical fiber circulators, an erbium-doped optical fiber amplifier, a polarization mode scrambler, an optical fiber narrowband reflection filter, an optical fiber Raman pump laser, a single-mode sensing optical fiber, an optical fiber filter, a photoelectric reception amplifier module, two digital signal processors, a photoelectric heterodyne reception amplifier module and a computer, wherein the optical fiber Brillouin frequency shifter is formed by connecting the circulators, the single-mode optical fiber and the optical fiber Fabry-Perot (F-P) filter in turn. The sensor has a simple structure, low price and high measuring accuracy and stability.

Description

technical field [0001] The invention relates to a distributed optical fiber Brillouin sensor, in particular to a distributed optical fiber Brillouin sensor fused with an optical fiber Brillouin frequency shifter. Background technique [0002] In the field of optical fiber Brillouin optical time domain analyzer, Zhang Zaixuan proposed a new type of "Fiber Brillouin optical time domain analyzer" (Chinese patent: ZL200810063711.8), which uses the broadband nonlinear optical amplification effect of optical fiber and the distribution of coherent amplification. The optical fiber Brillouin optical time domain analyzer made of the strain, temperature effect and optical time domain analysis principle of Liouin scattered light solves the problem of narrowband detection laser and narrowband optical time domain analyzer invented by T.Horiguchi et al. Difficulties in frequency locking of pump lasers. In order to improve the measurement accuracy of Brillouin Optical Time Domain Analyzer ...

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Problems solved by technology

However, electronic detection in the microwave band (11GHz) is difficult and expensive; Chen Fang and Wan Shengpeng proposed the "Sensing System for Dual-Fiber Coherent Heterodyne Detection of Brillouin Frequency Shift" (Sensors and Microsystems, 2006 , 47(8):18-23), using the same batch of optical fiber as the sensing fiber, with the same parameters of 10.3km as the reference fiber to achieve coherent detection, omitting the optical frequency shift adjustment link, simplifying the optical path and filtering , which reduces the frequency stabilization requirements of the light source, but it is unrealistic to use an optical fiber with the same parameters as the sensing optical fiber as a reference optical fiber in a long-range Brillouin time-domain reflectometer, which lacks practicability, and is only used for medium-range 10km transmission. sensory system

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