基于偏振依赖损耗特性分析的光纤光栅扭转传感器研究

项目名称： 基于偏振依赖损耗特性分析的光纤光栅扭转传感器研究

项目编号： No.61307108

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 汪弋平

作者单位： 南京师范大学

项目金额： 25万元

中文摘要： 扭转的直接测量是光纤布拉格光栅(FBG)传感器的一项技术难题，其主要瓶颈在于普通FBG的光谱对扭转的变化极不敏感。然而,本课题组前期的研究表明,扭转能对FBG产生显著的偏振效应，其中，偏振依赖损耗(PDL)特性对扭转的响应尤其敏感，比FBG传统的光谱分析更适用于扭转测量。本项目拟采用FBG的PDL特性分析来实现扭转的测量，具体内容包括：研究扭转作用下FBG的PDL参数的响应机制，建立基于FBG的PDL特性分析的扭转传感理论模型；研究FBG的主要参数对这种传感器的性能影响，优化传感器的参数设计；通过对温度、应变以及扭转方向对FBG的PDL特性变化的研究，提出对温度和应变不敏感，能同时测量扭转角大小和方向的传感方法，并设计低成本的传感解调方案。本项目旨在揭示扭转作用下普通FBG的PDL参数的响应机制，为利用普通FBG实现扭转的直接测量提供新的理论和方法，在结构安全监测领域具有广阔的应用前景。

中文关键词： 光纤光栅；扭转测量；偏振依赖损耗；双折射；

英文摘要： Twist direct measurement is one of the technical chanllenges for the normal fiber Bragg grating (FBG) sensors. The main bottleneck is the extremely low sensitivity of the normal FBG spectrum to the twist variation. However,the preceding work of our project group has shown that the twist will introduce obvious polarization effects to the FBG. Among of them, the polarization dependent loss (PDL) properties is especially sensitive to the twist and thus more suitable for mesuring twist than the conventional spectral analysis of FBG sensors. The project prepares to realize the twist measurement by exploiting the PDL properties of the normal FBG. The main contents include studying the response mechanism of the PDL parameters of the FBG versus the twist and developing theoretical models of the twist sensor based on analysis of the PDL properties; The project also deal with optimizing the design parameters by analyzing the influence of the main FBG parameters on their sensing performance. By studying the evolution of the PDL response of the FBG with respect to the temperature、strain and twist direction, a temperature and strain insensitive method which can measure twist angle and twist direction simultaneously will be proposed and a low cost sensing demodulation scheme will also be developed. The project aims to reveal

英文关键词： fiber Bragg grating；twist sensing；polarization dependent loss；birefringence；