基于非线性滤波器的FBG解调系统的研究  

An FBG demodulation system based on nonlinear filters

作　　者：庞启[1] 王喜昌[1] 杨尚明[1] 王中训[1] 

机构地区：[1]烟台大学光电信息学院,山东烟台264005

出　　处：《光电子．激光》2013年第11期2096-2101,共6页Journal of Optoelectronics·Laser

基　　金：山东省省级重点攻关计划(WL10K28)资助项目

摘　　要：传统的光纤Bragg光栅(FBG)滤波解调系统解调精度较低,且线性滤波器的滤波曲线不是严格的线性。从理论推导了基于线性滤波器的解调系统中滤波光和直接探测光光功率的比值和滤波器的透过率函数成正比。而传统的线性滤波解调方法过于理想化,为了修正这一问题,根据理论推导对波长和比值的关系按非线性滤波解调处理。实验结果表明,非线性解调系统的温度解调精度高于线性解调系统,一定程度上提高了解调系统的精度。而且线性滤波器的FBG解调系统中几乎全部采用实际波长进行解调,本文在非线性滤波解调系统中引入虚拟波长的概念,对基于线性滤波系统或非线性滤波系统的FBG系统进行解调,从而可以不用对实际波长的变化进行标定而直接解调出FBG所处环境温度的变化。The traditional filter demodulation sy stem has lower demodulation accuracy and the filter′s curve is not strictly linear.This paper deduces theoretically that the ratio of the filtered light which exists in the linear filter system and the direct probe light′s optical power is proportional to the filter′s transmittance function.In order to overcome the problem with t raditional demodulation method of linear filter the nonlinear demodulation processing in accordance with the relationship between wavelength and ratio has greatly improved the performance of present li near filter dem odulation system.The experimental results show that temperature demodulation accuracy of the nonlinear demodulation system is h igher than that of the linear demodulation system.What′s more,this paper i ntroduces the concept of virtual wavelength to the nonlinear filter demodulation system,which succeeds in directly demodulating the environmental temperature changes without calibrating the chan ges of concrete wavelength.

关 键 词：光纤Bragg光栅(FBG) 温度解调 线性滤波 多项式拟合 

分 类 号：O436[机械工程—光学工程]