为了达到布里渊光时域分析(BOTDA)系统双通道激光源的布里渊频移要求,设计了一个光纤布里渊频移器,放置在其探测脉冲通道,使探测光与另一通道的扫频光具有布里渊频移差(约11.2GHz)。通过分析频移器的输出光谱线宽窄化原理,利用光纤中激发的布里渊增益谱结合一定的环形腔结构形成窄线宽的布里渊斯托克斯光谱输出,且分析了环形腔频移器的受激布里渊散射阈值和光-光转换效率两个性能指标及其影响因素。采用1551nm窄线宽光源,对实际搭建的9km单模光纤布里渊频移器进行了实验验证,结果表明:频移器的受激布里渊散射阈值为2.3mW,布里渊频移对应的波长改变约为0.1nm,此时的定向耦合器耦合比为0.4,光-光转换效率为49%。所设计的光纤布里渊频移器能达到布里渊光时域分析系统光源的技术指标,降低了系统的复杂性和成本。 In order to meet the requirement of Brillouin frequency shift of BOTDA system, a fiber Brillouin frequency shifter was designed and placed in the probe pulse channel to make the probe light communicate with another channel The swept frequency light has a Brillouin frequency shift difference (about 11.2 GHz). By analyzing the narrow bandwidth principle of the output spectrum of the frequency shifter, a Brillouin Stokes spectral output with a narrow linewidth is formed by utilizing the Brillouin gain spectrum excited in the optical fiber and a certain ring cavity structure, and the ring cavity frequency Shock absorber stimulated Brillouin scattering threshold and optical - optical conversion efficiency of the two performance indicators and its influencing factors. The 1551nm narrow linewidth light source is used to verify the 9km single mode fiber Brillouin frequency shifter actually constructed. The results show that the threshold of the stimulated Brillouin scattering of the shifter is 2.3mW, and the Brillouin frequency shift corresponds to Wavelength change of about 0.1nm, at this time the directional coupler coupling ratio of 0.4, optical - optical conversion efficiency of 49%. The designed fiber Brillouin frequency shifter can achieve the technical indicator of the light source of Brillouin optical time-domain analysis system, reducing the system complexity and cost.