基于时分复用和窄波长扫描激光的长距离光纤布喇格光栅传感系统  

Long-distance Fiber Bragg Grating Sensor System Based on Time Division Multiplexing and Narrow Wavelength Swept Laser

作　　者：刘川[1] 饶云江[1,2] 冉曾令[1] 封莎[1] 

机构地区：[1]电子科技大学光纤传感与通信教育部重点实验室,成都610054 [2]重庆大学光电技术与系统教育部重点实验室,重庆400044

出　　处：《光子学报》2010年第11期2004-2007,共4页Acta Photonica Sinica

基　　金：国家自然科学基金重点项目(60537040)资助

摘　　要：提出了一种通过提高长距离光纤布喇格光栅传感系统容量,从而实现多传感点参量测量的新方法.采用时分复用、窄波长范围扫描激光方式,将多个中心波长相近的低反射率光纤布喇格光栅放置于系统的不同位置,构成准分布式光纤传感系统,实现了多个传感点参量的同时测量.同时提出了采用掺铒光纤和喇曼混合放大方法来延长传感距离.在系统的中间加入一个喇曼泵浦进行喇曼放大以此补偿光纤布喇格光栅反射的信号,系统末端的掺铒光纤利用前面喇曼泵浦剩余的泵浦功率产生自发辐射光并放大传感信号,使得整个系统的传感距离延长.实验证实:将三只中心波长均在1580nm附近,反射率均小于4%的光纤布喇格光栅,分别放置在系统的不同位置,在200km处获得了15dB的信噪比,反射信号明显;并且在200km处的静态应变和温度实验中,线性度均达到了0.999以上.A novel low-reflectivity Fiber Bragg Grating sensor system with a combination of time division multiplexing mode,a narrow wavelength swept laser is proposed and demonstrated for achieving multiple sensing points,long-distance,quasi-distributed measurement.Time division multiplexing mode and the low reflectivity Fiber Bragg Gratings which have the close center wavelength are used to monitor multiple points simultaneously.And,Er-doped fiber and Raman amplification method is proposed to extend the sensing distance.The middle of the system involves a Raman pump for amplifying FBG reflected signal,and the Erbium-doped fiber uses the remaining Raman pump power to generate amplification of spontaneous emission and amplify sensing signal.Experimental results show that an excellent optical SNR of 15 dB has been achieved for 200 km transmission distance.In the static strain and temperature experiments at the distance of 200 km,the linearities achieve more than 0.999.

关 键 词：光纤传感器 低反射率光纤布喇格光栅 时分复用 窄波长扫描激光 喇曼放大 

分 类 号：TP212.14[自动化与计算机技术—检测技术与自动化装置]