针对布里渊光时域分析分布式传感原理和受激布里渊散射的特点,应用微波电光调制分布反馈式半导体激光器产生频移可调的探测光,和传感光纤中相反方向传输的脉冲激励光进行受激布里渊散射作用,当探测光和激励光的频率差在布里渊频移附近时,频移探测光和激励光产生受激布里渊散射,通过改变探测光的频移值,检测探测光功率信号,可得到沿光纤各处的布里渊频移,再利用布里渊频移和应变(或温度)的关系,计算得到沿光纤分布的传感量。设计了基于微波电光调制的布里渊光时域分析传感器实验系统,实现了25 km的分布式温度传感,达到5 m的空间分辨力和3 ℃的温度分辨力。

The technique of Brillouin optical time domain analysis distributed optical fiber sensing has been presented and demonstrated experimentally, which is based on electrooptic modulation. Microwave electrooptic modulation is adopted to produce frequency-adjustable probe light, which is interacted with pulsed pump light via stimulated Brillouin scattering, when the optical frequency difference between probe and pump light is near the fiber's Brillouin frequency shift. The detecting signal of probe light is processed by digital BOXCAR and computer, then the fiber's Brillouin frequency shift could be obtained, and the distributing temperature or stress of the fiber could be calculated. The experimental procedures and results are presented. A laboratory system of 25 km distributed Brillouin optical time domain analysis temperature sensor is achieved, with 3 ℃ in temperature resolution, and 5 m in spatial resolution.