非对称分布反馈光纤激光传感器复用特性及机理研究

Distributed feedback fiber laser (DFB-FL) sensor is a new type of active fiber optic sensor with high sensitivity, large dynamic range, easy to wavelength division multiplexing, small size,light weight,etc. It has unparalleled advantages in weak vibration signal and underwater acoustic signal detection, and has broad application prospects.However, in the application of DFB-FL sensor, there are many key technical issues yet to be resolved, such as multiplexing noise suppression, large-scale multiplexing, remote transmission. For the existing stagnant status of symmetric DFB-FL sensors multiplexing, the project carries out the research of asymmetric DFB-FL sensor multiplexing features and mechanism for the first time. Based on the analysis of asymmetric DFB-FL features and the optical feedback influence mechanism, we study optimization designs of asymmetric DFB-FL and adopt the combined optical fiber isolation devices, distributed Raman fiber amplification methods. We focus on solving the phase shift grating sidelobe suppression, remote transmission fiber Rayleigh scattering suppression and DFB-FL signal optical amplification, the array optical power balance and single-fiber dense multiplexing. And we can explore the methods of multiplexing noise suppression and single-fiber dense wavelength division multiplexing through theoretical and experimental studies. Then we could provide theory and technical supports for reducing DFB-FL sensor array noise, and increasing the abilities of remote transmission and large-scale networking.

分布反馈光纤激光（DFB-FL）传感器是一种新型有源光纤传感器，具有灵敏度高、动态范围大、易于波分复用、体积小重量轻等优点，在微弱水声、震动信号探测方面有着不可比拟的优势，具有广阔应用前景。但目前DFB-FL传感器在走向应用方面尚有诸多瓶颈问题未解决，如复用噪声抑制、大规模复用、远程传输等。本课题针对现有对称DFB-FL传感器复用性能停滞不前的现状，首次开展非对称DFB-FL传感器复用特性与机理研究。在分析非对称DFB-FL特性和光反馈影响机理的基础上，通过对非对称DFB-FL进行优化设计，结合组合隔离结构、分布式拉曼光纤放大等方法，重点解决相移光栅旁瓣抑制、远程传输中光纤瑞利散射抑制和信号光放大、阵列功率均衡和单纤密集复用的问题，从理论和实验上探讨出抑制复用噪声的方法和提升单纤密集复用性能的技术途径，为降低DFB-FL传感器阵列噪声、增大远程传输能力和实现大规模组网提供理论和技术支撑。

分布反馈光纤激光（DFB-FL）传感器是一种新型有源光纤传感器，具有灵敏度高、动态范围大、易于波分复用、体积小重量轻等优点，在微弱水声、震动信号探测方面有着不可比拟的优势，具有广阔应用前景。但目前DFB-FL传感器在走向应用方面尚有诸多瓶颈问题未解决，如复用噪声抑制、大规模复用、远程传输等。本课题针对现有对称DFB-FL传感器复用性能停滞不前的现状，首次开展非对称DFB-FL传感器复用特性与机理研究。. 在分析非对称DFB-FL特性和光反馈影响机理的基础上，通过对相移光栅进行优化设计，抑制了相移光栅旁瓣；结合WDM、耦合器、隔离器等组合光路结构实现了长距离单纤多级DFB-FL复用，有效抑制了长距离传输光纤的瑞利散射的影响，解决了光纤激光传感器长距离复用技术瓶颈。采用分布式拉曼光纤放大方法实现了信号光远程分布式放大；通过低阈值、低损耗非对称DFB-FL的设计提高了阵列功率均衡和单纤密集复用能力。从理论和实验上探讨出抑制复用噪声的方法和提升单纤密集复用性能的技术途径，为降低DFB-FL传感器阵列噪声、增大远程传输能力和实现大规模组网提供理论和技术支撑。. 项目实施期间，项目研究成果获得了2015年山东省科技进步奖一等奖。在国际、国内有影响力的期刊会议上发表论文共15 篇，其中被SCI/EI 检索8篇，申请专利7 项，其中发明专利5项，授权专利4 项，其中授权发明专利2 项。. 通过和中石化地球物理公司合作，先后组织开展了2次较大规模的行业实验室对比试验， 2次大规模的野外炸药对比试验，1次井下对比试验，进行了2次生产作业地震数据采集，首次在国内利用光纤检波器获得高清晰地震剖面图，体现出非对称光纤激光传感器灵敏度高、频带宽高频响应好、地层分辨率高的优势，这些优势对于微地震监测至关重要，将在非常规油气水力压裂微地震监测领域具有广阔的应用潜力和前景。