基于大功率超窄线宽单模光纤激光器的ф-光时域反射计光纤分布式传感系统  

Distributed Optical Fiber Sensing System Based of Rayleigh Scattering Light ф-OTDR Using Single-Mode Fiber Laser with High Power and Narrow Linewidth

作　　者：谢孔利[1] 饶云江[1] 冉曾令[1] 

机构地区：[1]电子科技大学宽带光纤传输和通信网技术教育部重点实验室,四川成都610054

出　　处：《光学学报》2008年第3期569-572,共4页Acta Optica Sinica

基　　金：教育部博士点基金(A0901010120060614017)资助课题

摘　　要：提出了一种基于大功率超窄线宽单模光纤激光器的ф-光时域反射计光纤分布式传感系统。传感光缆采用普通单模光纤制成的直径3 mm的细光缆,并埋设于室外。入侵者走在光缆上面或附近产生的压力(振动)导致光纤中瑞利散射光相位发生变化,由于干涉作用,光相位变化将引起光强度的变化,通过实时将当前时刻的-光时域反射计后向瑞利散射信号与其前一时刻(时间间隔0.1 s)的后向瑞利散射信号连续相减检测这种干涉效应来定位入侵位置。经适当的数据处理后,该传感系统定位精度可达到50 m(为目前报道的-光时域反射计传感系统最高定位精度),定位范围可达到14 km,信噪比约为12 dB,且灵敏度较高。该系统可望能广泛用于军事基地、国界、核设施及监狱等重要场所的安全防范。A phase-sensitive optical-time-domain-reflectometer （φ-OTDR） using a fiber laser with high power and narrow linewidth is described. The sensing element is a single-mode telecommunication fiber cable with a 3 mm diameter buried outdoors. The phase changes of Rayleigh scattering light resulting from the pressure （vibration） of the intruder on the ground immediately above or near the buried fiber. By subtracting a present φ-OTDR trace signal from an earlier one with a time difference of 0. 1 s, the system can locate the intrusion point where the optical intensity will change for the reason of interference. By processing the returned signal properly, a distance range of 14 km can be reached, with the best spatial resolution of ～50 m reported to date, and a signal-to-noise ratio of ～12 dB, to the best of our knowledge. Such a distributed sensing system is anticipated to be used widely in safety monitoring of military bases, national boarders, nuclear facilities, electrical power generation stations, jails, et al..

关 键 词：光纤光学 光纤分布式传感 光时域反射计 相位敏感光时域反射计 入侵检测 

分 类 号：TP212.14[自动化与计算机技术—检测技术与自动化装置]