一种对偏振敏感的光频域反射光纤布拉格光栅传感系统解调方案

为解决光纤光栅传感系统对横向应变的测量问题,提出了一种基于光频域反射技术的对偏振敏感的准分布式光纤布拉格光栅传感系统解调方案,该方案通过跟踪光纤光栅传感系统的偏振相关损耗为横向应变的测量提供信息.建立了系统的理论模型,分析了均匀光纤布拉格光栅在准分布式系统中的偏振特性以及偏振敏感的解调系统原理,讨论了该方案在测量横向应变的优越性,以光栅长度和双折射量值作为参数,对传感系统的偏振相关损耗变化规律进行研究.研究结果表明,本文提出的方案可以为在准分布光纤光栅传感系统中根据偏振相关损耗的变化实现对横向应变的准确测量提供理论依据.

A polarization sensitive demodulation scheme based on optical frequency domain reflectometry in Fiber Bragg Grating sensing system

In order to solve the problem of transverse strain measurement in the Fiber Bragg Grating sensing system,a polarization sensitive demodulation scheme based on optical frequency domain reflectometry technique in quasi-distributed Fiber Bragg Grating sensing system is proposed,the information of transverse strain can be provided by tracking the Polarization Dependent Loss of the sensing system.The polarization characteristics of the uniform Fiber Bragg Grating in a quasi-distributed manner and the principle of the polarization sensitive demodulation system are analyzed,and the superiority of the method in the measurement of transverse strain is discussed in this paper.The spectral evolution of polarization dependent loss of the sensing system as a function of grating length and the birefringence is studied.Simulation results show that the proposed scheme can provide theoretical basis for the accurate measurement of transverse strain in a quasi-distributed Fiber Bragg Grating sensing system.