偏振光时域反射技术对多点扰动检测的研究进展

光波在光纤中传输时，其偏振态对光纤外界的变化十分敏感。基于偏振效应的光时域反射技术可以实现对光纤沿线挤压、弯曲、振动等事件的分布式传感。然而，由于光波偏振态的前后关联性，光纤中最靠前的扰动往往会掩盖其后续扰动对偏振态造成的影响，使得光时域反射技术对多点扰动的检测存在困难。文章综述了该技术在多点扰动分布式传感检测方面的研究进展，对频谱分析法、解析本地双折射矢量法和基于特殊光纤的传感方法等技术手段进行了对比和分析。

The Research Progress of Detecting Multi-Disturbing Events forPolarization Optical Time Domain Reflectometer

The state of polarization (SOP) of optical lightwave in fiber is very sensitive to the external events. Based on this phenomenon, the polarization time domain reflectometer (POTDR) can be used as a distributed sensing means for the detection of fiber pressing, bending, and vibration, etc. However, SOP of optical lightwave at a specific position is dependent to its previous status. That means the first disturbance nearest to the input end is usually fused with subsequent disturbances, which makes the POTDR method difficult to detect multi-disturbances. In this paper, research progress of multi-disturbances detection by POTDR was reviewed. Existing POTDR techniques like analyzing spectrum method, resolving local birefringence method and special sensing fiber method were introduced and analyzed.