超长光纤布拉格光栅及分布式传感应用

超长光纤布拉格光栅（FBG）在分布式传感方面具有巨大的研究价值和应用前景，是当前国际上光纤传感领域的研究热点。然而，超长FBG及其分布式传感应用的研究在国内目前还基本处于空白。本项目拟在深圳大学双光束干涉在线写制FBG技术的前期研究基础之上，开展超长光纤布拉格光栅及分布式传感应用的研究，包括：搭建超长FBG的写制系统，即紫外双光束干涉条纹同步写入装置；研究超长FBG的设计、制作和测试；研究超长FBG的光频域反射（OFDR）解调技术；实验研究基于超长FBG的分布式应变和温度传感。最终研制出光栅长度1 m、带宽< 5 pm的高质量超长FBG样品和空间分辨率< 1 mm的OFDR分布式波长解调系统样机。本项目的研究有利于填补相关领域的空白，最终实现一种新颖的、并具有实用化前景的超长光纤布拉格光栅及相应的分布式应变和温度传感系统。

Ultra-long fiber Bragg gratings (FBGs) have great research values and application prospects in the area of distributed sensing, and they are currently hot topics in the research field of fiber-optic sensing at abroad. However, nearly no research was carried out in China on the topics of ultra-long FBGs or their applications on distributed sensing. Therefore, in this project, we intend to study the ultra-long fiber Bragg gratings and their applications on distributed sensing, based on the preliminary study of the dual-beam interferometric FBG online writing system at Shenzhen University. The research contents include: building the writing-system for fabricating ultra-long FBGs, i.e. dual-UV-beam interferometric synchronous writing apparatus; design, fabrication, and testing of ultra-long FBG; research on the distributed wavelength demodulation technique for ultra-long FBGs, i.e. optical frequency domain reflectometry (OFDR) demodulation technique; experimental studies on distributed strain and temperature sensing based on the ultra-long FBGs. Finally, we expect to obtain high-quality ultra-long FBG samples with grating lengths of 1 m, and bandwidths of < 5 pm, and an OFDR distributed wavelength demodulation prototype with a spatial resolution of < 1 mm. This project is conducive to fill the gaps in the field of ultra-long FBGs and their applications on distributed sensing, and ultimately provides a kind of novel and applicable ultra-long fiber Bragg gratings and the corresponding distributed strain and temperature sensing systems.