50km长距离布里渊光时域分析分布式光纤传感器  

A 50 km Distributed Optical Fiber Sensor Based on Brillouin Optical Time-Domain Analyzer

作　　者：宋牟平[1] 励志成[1] 裘超[1] 

机构地区：[1]浙江大学信息与电子工程学系,浙江杭州310027

出　　处：《中国激光》2010年第6期1426-1429,共4页Chinese Journal of Lasers

摘　　要：普通单模光纤的布里渊散射光,其频移是温度或应变的函数,因此通过检测布里渊频移可得到沿光纤分布的温度或应变。长距离布里渊散射分布式光纤传感器有光时域分析和光时域反射计两种结构,虽然布里渊光时域反射计具有单端光信号处理的优点,但其传感长度受限于微弱的自发布里渊散射。而布里渊光时域分析采用的是较强的受激布里渊散射,更具有长距离传感能力。实现布里渊光时域分析的一个关键是产生传感所需的频移探测光。采用线宽小于1 MHz的光纤激光器作为单一光源,基于微波电光调制产生频移探测光,并采用正交偏振控制来抑制偏振相关信号衰弱。实现了50 km普通单模光纤的布里渊光时域分析,在10 m空间分辨率下达到约2℃的温度分辨率。For the standard single-mode optical fiber,the frequency shift of Brillouin scattering light is the function of the temperature or strain.The temperature or strain of the optical fiber can be obtained when Brillouin frequency shift is able to be detected.Long-distance sensing Brillouin scattering distributed optical fiber sensor（DOFS） has two structures of optical time-domain analyzer（OTDA） and optical time-domain reflectometer（OTDR）.Although Brillouin OTDR only process single end of the optical fiber,it suffers short sensing distance because of weak spontaneous Brillouin scattering.Brillouin OTDA possesses the merit of long-distance sensing for the relatively strong stimulated Brillouin scattering.One key point of achieving Brillouin OTDA is to produce the frequency-shifted probe light.Here,an optical fiber laser with linewidth less than 1 MHz is employed as the single optical source,a microwave electro-optical modulator is used to produce the frequency-shifted probe light,and a method of orthogonal polarization control is adopted to reduce the effect of the optical-polarization-related problem.A laboratorial system of 50 km distributed optical sensor is achieved with 2 ℃ in temperature resolution,and 10 m in spatial resolution.

关 键 词：传感器 布里渊光时域分析 电光调制 正交偏振控制 

分 类 号：TN247[电子电信—物理电子学] TP212.14[自动化与计算机技术—检测技术与自动化装置]