基于光栅偏振参数的磁场传感方法研究  

Analysis of a New Magnetic-field Sensor Based on Polarized Parameters of Fiber Grating

作　　者：彭晖[1] 苏洋[1] 李玉权[1] 

机构地区：[1]解放军理工大学通信工程学院,南京210007

出　　处：《微波学报》2009年第5期88-91,96,共5页Journal of Microwaves

基　　金：国家自然科学基金资助项目(60871075)

摘　　要：给出了一种基于光纤光栅中法拉第效应与测量偏振相关参数的直接测量磁场的新方法。在外加磁场作用下,光纤光栅中的法拉第效应导致两个圆偏振光的传播常数发生改变,从而使色散与差分群时延发生改变。仿真结果表明,在外界弱磁场的情况下,磁致双折射与色散和差分群时延之间存在线性关系,利用这个关系可以通过测量光栅的色散和差分群时延来得到磁致双折射的大小,从而推测出外加磁场的大小。实验中得到该方案测量磁场的灵敏度为6.58522e-18m/Gs,利用现有精度为10-17的光矢量分析仪得到最小可测磁场为2Gs。实验与理论吻合较好。A New magnetic field measurement with fiber grating was analyzed in theory and experiment. When the magnetic field applied, the transmitted constants of two circularly polarized light in fiber grating will changed by the Farady effect. And so does the chromatic dispersion（CD） and differential group delay（DGD） of fiber grating. The simulation show that there are linear relationship between the magnetic circular birefraction and the ratio of the CD and DGD if the magnetic field is not strong. The value of magnetic circular birefraction can be derived from the measured value of CD and DGD using character, and the value of magnetic field can be derived. The measurement sensitivity is 6. 58522e^-18 m/Gs and the precision of this method is 2Gs using the optical vector analyzer with 10^-17 precision in experiment and those agree well with the theoretical analysis.

关 键 词：磁致双折射 色散 差分群时延 磁场测量 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]