一种基于暗脉冲光布里渊时域分析仪的延长传感距离的方法

基于暗脉冲的布里渊时域分析仪系统中泵浦光和探测光的功率较高,相互作用强烈,严重限制了系统的有效传感距离。而现有的系统众多采用利用多段具有不同布里渊散射频率的光纤相互连接延长传感距离的方法,降低每段光纤上的受激布里渊散射效应,延长有效传感距离,但这种方案会增加的系统的复杂度,影响实际应用.本文提出一种简单的暗脉冲光布里渊时域分析仪的结构,可在满足高空间分辨率的条件下,有效的延长系统的传感距离,取代通常的利用多段具有不同布里渊散射频率的光纤相互连接延长传感距离的方法.利用基于光抑制载波的技术,产生具有两个边带的斯托克斯光.斯托克斯光的两个边带和泵浦光相互作用,同时激发布里渊散射增益和衰减效应,在接收端利用两者接收信号的差,可抵消原有暗脉冲泵浦信号中准连续光对传感距离的影响,从而有效地延长系统的传感距离,并利用数值仿真的方法验证了此方法的有效性.

Dark-Pulse Brillouin Optical Time Domain Analyzer for km-Range Detection with Only One Fiber Section

 In dark-pulse Brillouin optical time domain analyzer (DP-BOTDA) DP-BOTDA the effective sensing length is greatly limited by the severe interaction between the Quasi-CW pump light and pump light.A simple DP-BOTDA was proposed to prolong the total sensing length without using multi-section fibers.To mitigate the impact of the high power Quasi-CW pump light,both Brillouin gain and loss effect along fiber were measured simultaneously in this scheme,yielding the Brillouin signal by subtracting the two side bands of the optical carrier suppressed (OCS) Stokes light.Based on this proposal,the total sensing length in DP-BOTDA could be increased.Simulations and discussions were conducted to validate the proposal,and the results are useful for designing high spatial resolution distributed Brillouin fiber sensor.