基于少模光纤的单端BOTDA温度传感研究

Research on Single-Ended BOTDA Temperature Sensing System Based on Few-Mode Fiber

提出了一种基于少模光纤的分布式温度传感系统,理论分析了少模光纤的布里渊散射谱和温度传感特性,将光纤末端产生的菲涅尔反射光作为探测光,搭建单端结构的布里渊光时域分析(BOTDA)系统,实现阶跃折射率两模光纤的温度传感测量。实验结果表明,阶跃两模光纤的布里渊频移与温度呈良好的线性关系,并在1 km长光纤上实现了4.5 m的空间分辨率、6.29℃的温度测量精度。

A distributed temperature sensing system based on few-mode fiber is proposed.The Brillouin scattering spectrum and temperature sensing characteristics of few-mode fiber were theoretically analyzed.A single-ended Brillouin optical time-domain analysis system was constructed by taking the Fresnel reflected light generated at the end of the fiber as the probe light,and the temperature sensing measurement of step index two-mode fiber were realized.The experimental results show that the Brillouin frequency shift of step index two-mode fiber has a good linear relationship with temperature.And a spatial resolution of 4.5m and a temperature measurement accuracy of 6.29℃are achieved on a 1km fiber.