光纤双折射导致的偏振相关问题是限制光纤通信及光纤传感系统性能指标提升的主要瓶颈之一。由于光纤中的双折射随时空随机变化，目前还没有理想的分布式监测方式。本项目旨在探索光纤双折射的分布式测量方法，力求为进一步研究光纤通信、光纤传感等领域的偏振相关问题并抑制其影响提供依据和手段。本项目从理论、实验及应用三个层面研究基于布里渊散射的光纤双折射分布式测量方法：首先研究布里渊散射谱增益、频移及线宽与光纤双折射的定量关系。结合光纤双折射的分布式数学模型，通过理论仿真提出应用布里渊散射谱各参数进行双折射分布式测量的原理及步骤，并估算其应用在不同种光纤时的测量误差；在实验室环境下设计并搭建基于上述测量原理的光纤双折射分布式测量系统，并利用各类通信及传感光纤测试系统性能；在上述研究基础上，研究将光纤双折射分布式测量方法整合到现有光纤通信系统及分布式传感系统的方法。

Fiber birefringence is one of the factors that limits the performance of optical communication and optical fiber sensing system. Due to the randomness of fiber birefringence both in time and spatial domain, currently it is difficult to distributed monitor fiber birerfringence in general single mode fibers. In this project, the technology of distributed fiber birefringence measurement is investigated based on Brillouin scattering in optical fibers. This tachnology can be further used to develop the methods for inhibitting effects of fiber birefringence in fiber communication and sensing systems. The technology is investigated from three aspects: from the aspect of theory, the mathmatical relations between fiber birefringence and Brillouin gain, peak frequency and linewidth are studied, then combined with the model of random fiber birefringence, the principles and procedures of the birefringence measurement methods using Brillouin gain, peak frequency and linewidth are developed seperately, also the measurment errors on different types of fibers are estimated based on theoretical simulations; from the aspect of experiment, the setup of distributed birefringence measurement system is designed and built in lab enviroment, and system performances are tested using several types of communication and sensing fibers; from the aspect of application, the methods of integrating the distributed birefringence measurement system into the existing fiber communication and sensing systems are studied.