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

摘要:

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1km长光纤上实现了4.5m的空间分辨率、6.29℃的温度测量精度。

Abstract:

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.