布里渊光时域反射计检测信号较微弱的自发布里渊散射光,其布里渊频移只有11 GHz左右。相干检测是一较好的方法,但其接收信号是一宽带的幅度调制信号,难以直接解调。采用实时小波变换对传感信号进行处理,设计了布里渊光时域反射计传感器实验系统,实现了25 km的分布式温度传感,在5 m的空间分辨率和1 min的响应时间下,达到40 με的 应变分辨率。

In Brillouin optical time domain reflectometer,the detected spontaneous Brillouin scattering light is very weak,and the Brillouin frequency shift is only about 11 GHz. The coherent detect is a good method,but the detected signal is a wideband amplitude-modulated signal,which is hard to demodulate. The real-time Morlet wavelet transform is adopted to overcome this problem. The experimental procedures and results are presented in the text. A laboratorial system of 25 km distributed Brillouin optical time domain refractor is achieved,with the stress resolution of 40 με,the spatial resolution of 5m and the system response time of 1 minute.