脉冲编码瑞利布里渊光时域分析温度传感技术  

Temperature Sensing Technology Based on Rayleigh Brillouin Optical Time Domain Analysis with Pulse Coding

作　　者：张立欣[1] 李永倩[1] 安琪[1] 李晓娟[1] 

机构地区：[1]华北电力大学电子与通信工程系,河北保定071003

出　　处：《光学学报》2017年第11期60-67,共8页Acta Optica Sinica

基　　金：国家自然科学基金(61377088);国家自然科学基金青年基金(51407074;51607066);河北省自然科学基金(F2014502098);中央高校基本科研业务费专项基金(2016XS104)

摘　　要：瑞利布里渊光时域分析系统(BOTDA)存在信号小、噪声大的问题,会导致系统空间分辨率与信噪比难以同时提高。将脉冲编码技术引入瑞利BOTDA系统,可在不降低空间分辨率的前提下有效地提高系统信噪比和布里渊频移测量精度。分析了瑞利BOTDA温度传感系统的原理,介绍了Golay互补序列的特性,并给出了单脉冲和编码脉冲系统的信噪比表达式;搭建了单脉冲和脉冲编码瑞利BOTDA温度传感系统,测量了单脉冲瑞利BOTDA系统的温度传感特性及脉冲编码瑞利BOTDA系统的空间分辨率和温度测量精度。实验结果表明,由瑞利BOTDA系统获得的布里渊频移与温度呈良好的线性关系,温度系数为(1.109±0.010)MHz·℃-1;当采用10ns脉冲宽度、64bit格雷编码时,在1.77km光纤的加温段上实现了空间分辨率为1m、温度测量精度为1.39℃的传感测量。Spatial resolution and signal-to-noise ratio are difficult to be improved at the same time due to the small signal and big noise in Rayleigh Brillouin optical time domain analysis （BOTDA） system. A technique of pulse coding is introduced into Rayleigh BOTDA system, and then the signal-to-noise ratio and Brillouin frequency shift measurement accuracy of the system can be improved effectively without decreasing spatial resolution. The principle of the temperature sensing system based on Rayleigh BOTDA is analyzed. The characteristic of Golay complementary sequence is introduced and the expressions of the signal-to-noise ratio between single pulse system and coded pulse system are achieved. Rayleigh BOTDA temperature sensing systems of single pulse and coded pulse are constructed. The temperature sensing characteristic of single pulse system and the spatial resolution and the accuracy of temperature measurement of coded pulse system are measured. The experimental results show that the Brillouin frequency shift obtained by the Rayleigh BOTDA system has a linear relationship with temperature, and the temperature coefficient is （1.109±0.010） MHz·℃^-1 The spatial resolution of 1 m and temperature accuracy of 1.39℃ are obtained on the heated section of 1.77 km fiber when Golay code is 64 bit and the pulse width is 10 ns.

关 键 词：光纤光学 布里渊光时域分析 单端结构 瑞利散射 脉冲编码 格雷互补序列 

分 类 号：TN247[电子电信—物理电子学]