倾斜光纤光栅表面等离子共振氢敏调控及其在气液两相环境下的高灵敏氢气传感

Based on the requirements of the national important practical applications of hydrogen energy security monitoring and some fundamental problems such as the low sensitivity, zero-point shifting and multi-circumstances applications finding from previous studies by other researchers and ourselves, this project is proposed to study the regulations of the surface Plasmon resonance on the surface of the Au/Pd-coated tilted fiber Bragg grating (TFBG), as well as their applications in hydrogen monitoring. Based on the optical fiber coupled-mode theory analysis, the molecular dynamics simulations of the Au/Pd-H system and the experimental studies, on one hand, we want to discover the action mechanism its regulation of the surface Plasmon resonance excited by the Au/Pd film to the cladding modes of the TFBG, and the mechanism of solution-diffusion of the hydrogen for the Au/Pd-coated TFBG, and achieve the theoretical analysis mode and improve the sensitivity of the hydrogen sensor. On the other hand, we want to study and optimize the lower order cladding modes and fiber core mode to realize the self-calibration of the zero shift problem and solve the problem of the cross section of the temperature. Furthermore, to apply the proposed hydrogen sensor in the gas and liquid circumstances successfully, the effective index models of the Au/Pd film in the gas and liquid circumstances will be built and their the regulations of the surface Plasmon resonance will be studied. And Finally, a high performance (high integration, high sensitivity, self-calibration of the zero shift, insensitive to temperature and applicable in gas and liquid circumstances) Au/Pd-coated TFBG-based surface Plasmon resonance hydrogen sensor, together with its demodulation, multiplexing and network monitoring technologies, are proposed to study. It will be designed by combining the advanced TFBG fabrication technology, fiber coating technology, networking and temperature compensation by the Bragg wavelength of the TFBG. This new hydrogen sensing technology is expected to be in a state of international leading level.

本项目针对氢能源安全监测的国家重大应用需求以及当前氢气传感器存在的如灵敏度低、零点漂移及无法多场合应用等共性基础性问题，提出研究倾斜光纤光栅（TFBG）SPR氢敏调控及其氢气传感应用。一方面基于光纤耦合模理论分析和Au/Pd-H分子动力学模拟并结合具体实验研究，获得TFBG表面Au/Pd膜对氢气的溶解-扩散机制及其对SPR的调控规律，大幅提高氢气传感器的灵敏度。另一方面通过优化TFBG低阶包层模和纤芯基模实现氢气传感的零点漂移自标定和温度不敏感。在此基础之上，分别构建气液两相环境下Au/Pd复合膜有效折射率模型，研究TFBG的SPR分别在气相和液相环境中的氢敏性能调控，实现气液两相环境下的高灵敏氢气检测。最后，结合先进的TFBG制备、光纤镀膜及复用技术，研制出具有高灵敏度、零点漂移自标定、温度不敏感和气液两相可用的TFBG氢气传感器及其解调、复用和阵列化传感技术，达到国际领先技术水平。

本项目按计划从氢气敏感材料和光纤传感结构设计两方面出发，通过深入的光纤光栅耦合模理论分析和数值模拟，结合具体的氢气及其相关的传感实验，实现了高性能倾斜光纤光栅结构的设计、制备；研究了倾斜光纤光栅包层模激发的表面等离子共振（SPR）氢敏调控技术，揭示了倾斜光纤光栅包层模激发SPR的作用和调控机理及其吸放氢气过程中包层模有效折射率变化关系，以及其与SPR的相互作用规律，实现了系列高灵敏度、响应快、低检测下限的多种光纤氢气传感器；研究并获得了多种氢敏感材料与氢气的相互作用规律（包括金/钯合金、三氧化钨、金属有机框架多孔氢敏材料等），在此基础之上，掌握了这些氢敏材料与倾斜光纤光栅的镀膜技术和耦合规律；开展了气液两相环境下的倾斜光纤光栅表面功能化及其分布式传感技术研究，实现了气液两相光纤氢气传感器的自标定技术，大大提高了光纤氢气传感器的稳定性，开发了分布式光纤氢气泄露监测系统，实现了对氢气的高灵敏、高精度的检测。并进一步拓展和开发了辅助氢气传感所需要的应力、温度、压力等多种光纤传感器。相关研究成果在国际重要学术期刊上发表高水平学术论文32篇（其中SCI文章29篇），授权瑞士发明专利1项，申请中国发明专利5项，授权3项；参加国内外学术交流12人次，邀请海内外学者学术交流13人次，培养研究生/本科生15人。