分布式光纤动态应变传感基础研究

Aiming at the scientific and technical issues of narrow measuring range and slow responsing rate of the Brillouin type distributed fiber dynamic strain sensor technology, we focus on investigating influence mechanism of the amplitude, phase, polarization, frequency of the probe wave and pump wave on the Brillouin gain spectrum, and the coupling mechanism among the multiple Brillouin gain spectrums which are generated by multiple optical frequency. The complete theoretical model of the Brillouin gain splicing spectrum would be further established, which include the amplitude and phase information. Based on the theoretical research, we will solve the key techniques: obtain high frequency shift optical pulse with high extinction ratio, splice the multiple Brillouin gain spectrums, then we assemble and demonstrate the prototype of distributed optical fiber dynamic strain sensor based on Brillouin gain splicing spectrum, and launch related dynamic strain sensing application research. This research will further enlarge the strain measuring range and responsing rate, it has important theoretical guidance meaning and realistic application value for the actual dynamic strain system development.

针对布里渊型分布式光纤动态应变传感技术中存在的测量范围小和响应速度慢等基础科学和应用技术问题，着重研究受激布里渊非线性效应中探测光和泵浦光的幅度、相位、偏振、频率等因素对布里渊增益谱的影响机制，以及多光频产生的多布里渊增益谱之间的耦合作用机理，建立包含幅度和相位信息的布里渊增益剪裁谱的完整理论模型。在此理论研究基础上，解决高消光比的高频移频光脉冲的产生和多布里渊增益谱的剪裁拼接等关键技术，搭建基于布里渊增益剪裁谱的分布式光纤大范围动态应变传感原型装置，并开展相关的动态应变传感应用研究。本项目的研究将从本质上扩展分布式光纤动态应变传感系统的测量范围和兼顾高响应速度，对传感系统的开发具有重要的理论指导意义和实际应用价值。

本项目按计划开展分布式光纤动态应变传感技术研究，着重研究了布里渊非线性效应、相干瑞利散射效应，研制了超窄线宽光纤激光器、线宽可调谐光纤激光器和高阶模式光纤激光器用于分布式光纤传感，研究了探测光和泵浦光的幅度、相位、偏振、频率等因素对布里渊散射和瑞利散射的影响机制，建立了包含幅度和相位信息的分布式光纤动态应变感知的完整理论模型。在此理论研究基础上，解决了高消光比的高频移频光脉冲的产生和多布里渊增益谱的剪裁拼接等关键技术，搭建实现了分布式光纤大范围动态应变传感原型装置，并开展了相关的动态应变传感应用研究。