基于微纳光纤波导耦合效应的微型瞬态磁场传感机理与技术的研究

As for the the problems of the present fiber magnetic field sensor technologies including limited measurement range, narrow responding bandwidth and susceptible to thermal variations, the project proposes an all-fiber magnetic fied sensor technology based on Micro/Nano fiber waveguide coupling effects by combining the optical properties of the micro/nano fiber and the magneto-optic properties of the magnetic-optic crystal. The project will delve into the fundamental theory and key technologies involved in the proposed sensor,which include: ① investigating the intrinsic mechanism of periodic wavelength coupling formed in the micro/nano fiber waveguide coupler and grasping the rules of coupler spectrum changing with the applied magnetic field; ② Mastering the temperature characteristics of micro/nano fiber coupler's component marterials, and exploring a kind of temperaure insensitive optical magnetic field sensor by optimizing the coupler configurations; ③ investigating the demodulation method for the coupler spectrum with wide measurement range and high speed. The project is expected to lay theoretical and experimental foundations for realizing an all-fiber magnetic field sensor that has compact size, wide responding bandwidth,and be insensitive to the environmental temperature. The achievements from our research works are very important for enhancing the the present magnetic field sensing technical level and further expanding the micro/nano fiber waveguide coupling theories.

针对当前光纤磁场传感技术中存在的动态测量范围及频率响应范围窄、难以消除环境温度影响等问题，项目将微纳光纤技术和磁光晶体的磁、光性能有机地结合在一起，提出一种基于微纳光纤-磁光晶体耦合结构的全光纤磁场检测技术，并围绕其基础理论和关键技术展开研究：①研究波导耦合形成的内在物理过程，及其耦合光谱特征随被测磁场信号的变化机理；②研究耦合结构各组成部分的热敏特性以及环境温度对耦合结构输出光谱特征的影响规律，探索通过优化传感器的结构实现温度不敏感的磁场传感技术；③研究传感器输出周期性耦合光谱的大量程、快速解调技术，实现宽动态测量范围及宽频带响应范围的光纤磁场传感技术。项目旨在为实现微型、瞬态、宽频且对环境温度不敏感的全光纤磁场检测奠定理论和试验研究基础，对提高当前光纤磁场检测技术水平、丰富微纳光纤波导耦合理论具有重要意义。

项目提出了一种基于微纳光纤波导耦合效应的全光纤磁场检测技术，旨在解决传统光纤磁场传感技术存在的动态测量范围小、频率响应范围窄等瓶颈问题，探索一种环境温度本质不敏感的微型宽带光纤磁场传感技术。围绕这一研究目标，项目主要完成了以下四个方面的研究工作：①研究了微纳光纤-磁光晶体波导耦合结构对磁场敏感机理，建立磁场传感方程；②明确了耦合结构中各部分材料（包括光纤、磁光晶体、封装材料等）的结构参数与热敏特性参数与耦合波长之间的数学定量关系，提出满足环境温度不敏感的耦合结构参数的设计及选取原则；③研究了耦合光谱的大量程、快速解调技术，实现了宽动态测量范围及宽频带响应范围的光纤磁场传感技术；④确定了合理的传感器制备和封装技术。项目突破解决了当前光纤磁场传感检测中关键技术问题，同时对于丰富微纳光纤波导耦合理论具有重要意义。