一种消除偏振衰落的干涉型光纤传感器  

Interference fiber-optic sensor eliminating polarization- induced fading

作　　者：吴媛[1] 卞庞[1] 赵江[1] 艾鑫[1] 

机构地区：[1]复旦大学光纤研究中心,上海200433

出　　处：《仪器仪表学报》2014年第4期889-893,共5页Chinese Journal of Scientific Instrument

基　　金：国家973计划(2010CB327805);科技支撑计划(2011BAF06B01);国家重大科学仪器设备开发专项(2012YQ150213)资助项目

摘　　要：针对干涉型光纤传感器中使用单模光纤作为传感器件时,传输光偏振态在双折射影响下所带来的干涉信号"偏振诱导衰落"问题,提出了稳定相干的保偏光路结构。该结构采用单模感应光纤与法拉第旋转镜组合,消除感应光纤偏振特性变化对干涉的影响。同时,通过干涉模块(IU)中使用保偏光纤并以π/2的方式焊接,使光路结构的其他部分均工作在保偏状态,获得稳定相干的保偏光路结构。实验结果表明,该方法能很好地消除偏振态在双折射影响下所带来的干涉信号"偏振诱导衰落",使系统达到偏振稳定,干涉条纹可见度可达40%。Aiming at the problem that in interference fiber optic sensor,when single mode fiber is used as the sensor device,the transmission light polarization state brings ＂polarization-induced fading＂ of the interference signal under the influence of double refraction,a polarization maintaining light path structure with stable interference is proposed.The structure employs the combination of single mode sensing fiber and Faraday rotating mirror （FRM） to eliminate the effect of the polarization characteristic variation of the sensing fiber on interference.Meanwhile,the polarization-maintaining fiber and polarization-maintaining fiber components are used to form a polarization-immune interfere unit （IU）,which includes a key port connecting to the polarization-maintaining fiber with a polarization axis offset of π/2,which makes the other parts of the light path work in polarization-maintaining state.The Faraday rotating mirror is connected at the end of the sensing fiber to completely eliminate the polarization-induced signal fading in the sensing fiber.Theoretical analysis and experiment results in support of the statements are presented.The experiment results indicate that the proposed method can eliminate the polarization-induced fading of the interference signal brought by the polarization state under the influence of double refraction,which makes the system reach stable polarization,and the interference fringe visibility reaches 40％.

关 键 词：干涉型光纤传感器 偏振诱导衰落 琼斯矩阵 干涉条纹可见度 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置] TH74[自动化与计算机技术—控制科学与工程]