基于弱光栅的高速高复用分布式温度传感网络

High-Speed High-Multiplexing Distributed Temperature Sensor Network Based on Weak-Reflection Fiber Gratings

提出一种基于弱光栅的新型高速高复用分布式温度传感网络。通过自制可调谐多波长光源代替可调谐激光器以解决其存在的监测时间长、系统实时性差的问题。在一根光纤上刻制3个中心波长分别为1529.488、1545.202、1557.100nm的高反射低带宽的光纤布拉格光栅(FBG),再刻制3组反射率为3%,中心波长分别为1529.488、1545.202、1557.100nm的9个FBG,并将其等距连接。以高反射FBG的反射光作为系统光源,以弱光栅作为监测光栅,结合光波分复用技术与光时域反射技术,进行温度实验。实验结果表明,在5℃～80℃的温度范围内,各个弱反射FBG的中心波长随温度呈良好的线性变化,温度测量的误差为±0.5℃,空间分辨率为10m。

High-speed high-multiplexing distributed temperature sensor network based on weak-reflection fiber gratings is proposed. In order to solve problems such as long monitoring time and poor real-time performance of the system, a multiple-wavelength light source is used instead of tunable laser. Three fiber Bragg gratings （FBG） with high reflectivity and low bandwidth are carved on a single fiber and their central wavelengths are 1529. 488, 1545.202 and 1557. 100 nm, respectively. Another three groups of nine FBG whose central wavelengths are 1529. 488, 1545. 202 and 1557. 100 nm with 3 % reflectivity are carved equidistantly on the same fiber. Light from the high-reflection FBG is used as the light source of the system and the weak gratings are used as the monitoring gratings. The experimental results show that, in the temperature range of 5℃-80℃, the central wavelength of each weak-reflection FBG changes linearly as the temperature changes, and the error of temperature measurement is ±0.5 E and spatial resolving power is 10 m.