基于级联长周期光纤光栅的光纤布拉格光栅解调系统  

FBG Demodulation System Based on Cascaded Long-Period Fiber Grating

作　　者：邹红波[1,2] 梁大开[1] 曾捷[1] 李堃[1] 周怡妃[1] 

机构地区：[1]南京航空航天大学航空宇航学院,南京210016 [2]三峡大学电气与新能源学院,宜昌443002

出　　处：《南京航空航天大学学报》2011年第6期723-727,共5页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：国家自然科学基金(60907038)资助项目;江苏省自然科学基金(BK2009370)资助项目;中国博士后科学基金(20090461116)资助项目;江苏省博士后科研资助计划(1001010B)资助项目;611航空科研基金资助项目

摘　　要：提出了一种基于级联长周期光纤光栅的光纤布拉格光栅解调系统。级联长周期光纤光栅作为边沿滤波器,利用它的一个线性区监测单个光纤布拉格光栅传感信号。该系统具有结构简单、价格低等优点,但易受光源抖动及系统其他不稳定因素等带来的系统噪声的影响。为消除系统噪声带来的不利影响,对该系统进行了改进。改进系统利用级联长周期光纤光栅的两个线性区同时监测两个光纤布拉格光栅传感信号。分别用原系统及其改进系统对温度进行监测,实验的温度测量范围为-70～-115°C。原系统的灵敏度为0.49 mV/°C,温度分辨率为0.5°C;改进系统的灵敏度为0.86 mV/°C,温度分辨率为0.3°C。实验结果表明改进系统能有效消除系统噪声,提高系统的精度。A demodulation system of fiber Bragg grating（FBG） based on a cascaded long-period fiber grating（CLPG） is presented.A key interrogating component of this system is CLPG which acts as an edge filter converting wavelength variation into optical power measurement,thus realizing a FBG sensing signal monitoring by one linear region of CLPG.This system has some advantages such as a simple structure and low cost.However,it is inevitably influenced by system noise such as broadband optical source fluctuations,power fluctuations and so on.In order to eliminate the adverse effect of system noise,an improved demodulation system is proposed.The improved system simultaneously monitors two FBG sensing signals by two linear regions of CLPG.Using the original system and the improved system to monitor temperature,the experimental measurement range of temperature is -70--115°C.The sensitivity of original system is 0.49 mV/°C and its temperature resolution is 0.5°C.In contrast with original system,the sensitivity of improved system is 0.86 mV/°C and its temperature resolution is 0.3°C.Experimental results show that the improved system can effectively eliminate system noise,thus improving the accuracy of the system.

关 键 词：级联长周期光纤光栅 光纤布拉格光栅 解调 边沿滤波器 

分 类 号：TN253[电子电信—物理电子学]