基于布里渊散射光时域分析的温度传感技术研究

Research of Temperature Sensing Technology Based on Brillouin Scattering Optical Time Domain Analysis

为提高布里渊时域分析的传感精度,探寻一种相同条件下传感更为稳定、精确的传感光纤,通过实验得到一种布里渊频移与温度拟合线性度约为1的传感光纤。理论上分析了布里渊散射谱线宽度对温度传感测量精度的影响机制,在布里渊时域分析系统实验中分别以普通单模光纤与非零色散位移光纤(G.655)为传感光纤,测出在一定温度变化范围内标定点的布里渊散射谱线宽度和频移值。实验结果表明,非零色散位移光纤的布里渊散射谱线宽度随温度变化比较稳定,具有较高的传感精度。因此以G.655光纤为传感光纤更利于长距离监测场传感精度的提高。

For improving the sensing accuracy of BOTDA,a kind of sensing fiber is found in which the fitting linearity of Brillouin frequency shift with temperature is about 1.Theoretically,the mechanism that the Brillouin linewidth affected on the temperature sensing accuracy is analyzed.In this experiment of BOTDA system,the ordinary single-mode optical fiber and the non-zero dispersion shifted single mode optical fiber are respectively used as sensing fiber,and the linewidth of Brillouin scattering and Brillouin frequency shifted have been measured in a certain temperature range.Through analying the experiment data,the results show that it is more favorable to improving sensing accuracy in a long distance monitoring field by using non-zero dispersion shifted mode optical fiber as the sensing fiber.