基于FBG和光频域反射技术的混合式光纤传感网研究

Research of hybrid fiber sensing network based on FBG and optical frequency domain reflectometry

基于光纤Bragg光栅技术和光频域反射(OFDR)技术,构建了一个具有分立式传感子层和分布式传感器子层的双层结构混合式光纤传感网络。在分立式传感子层中,FBG用于实现温度参量的传感;在分布式传感子层中,采用OFDR方法解调光纤中的瑞利散射信息从而获得分布式的应变参量。整个传感网络共用同一个宽光谱可调谐激光光源,分立式子层和分布式子层两者协同工作,实现应变和温度两个参量的高精度测量,其中应变分辨率达到0.75με,温度分辨率达到±1℃。本文构建的传感网络为构建大容量、大规模、多参量、高空间分辨率和高测量精度的光纤传感网络提供了一种有益探索。

We present a bilayer structure of hybrid fiber sensing network based on fiber Bragg grating （FBG） and optical frequency domain refIectometry （OFDR）,which consists of a discrete sensing layer and a distributed sensing layer. In discrete sensing layer, temperature is measured By FBG. In the distrib- uted sensing layer, distributed strain is demodulated from the information of Rayleigh-scattering in the fi- ber by OFDR. The whole network using one tunable laser source with wide optical spectrum could a- chieve the cooperative work between the discrete sensing layer and the distributed sensing layer. The sensing network can accurately measure strain and temperature,in which the strain sensitivity is 0.75με and the temperature sensitivity is ±1℃. This sensing network by proposed method provides a good ex- ploration for a sensing network with large capacity,multiple parameters, high spatial resolution and high measurement accuracy.