基于表面等离子体共振的微位移光纤传感器  

Micro-Displacement Optical Fiber Sensor Based on Surface Plasmon Resonance

作　　者：魏勇[1] 苏于东 刘春兰[1] 刘璐 朱宗达 张永慧[3] Wei Yong;Su Yudong;Liu Chunlan;Liu Lu;Zhu Zongda;Zhang Yonghui(Key Laboratory of Intelligent Information Processing and Control, Chongqing Three Gorges University Chongqing 404100, China;Key Laboratory of In-Fiber Integrated Optics, Ministry of Education, Harbin Engineering University Harbin, Heilongjiang 150001, China;Basic Medicine Department, Chongqing Three Gorges Medical College, Chongqing 404100, China)

机构地区：[1]重庆三峡学院智能信息处理与控制重点实验室,重庆404100 [2]哈尔滨工程大学纤维集成光学教育部重点实验室,黑龙江哈尔滨150001 [3]重庆三峡医药高等专科学校基础医学部,重庆404100

出　　处：《激光与光电子学进展》2018年第4期85-91,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61705025);重庆市教委2017年度科学技术研究项目(KJ1710238;KJ1725391;KJ1710247);第三批重庆市高等学校青年骨干教师资助项目(20165339);重庆三峡学院2016年度重大培育科研项目(16PY13);重庆市高校创新团队计划(CXTDX201601034);重庆市高校市级重点实验室资助项目[(2017)3];重庆市发展和改革委员会资助项目[(2017)1007]

摘　　要：为实现对微小位移的精确测量,提高位移精度,提出了基于表面等离子体共振的微位移光纤传感器。利用渐变折射率多模光纤中光束的传播角度随入射光位置的变化而变化的特性,结合表面等离子体共振传感器的共振波长对共振角度变化具有很高灵敏度的特性,实现对微小位移的精确测量。为满足共振条件,将渐变折射率多模光纤研磨成具有合适角度的楔形,精确控制渐变折射率多模光纤的长度,并将光纤探针浸入到一定折射率的液体中。通过630nm单模光纤将白光光源从渐变折射率多模光纤的端面耦合到光纤探针中,搭建位移平台,精确控制单模光纤和渐变折射率多模光纤的径向相对位置,通过光谱仪检测共振波长随相对位置的变化规律。实验结果表明:当光纤研磨角度为12°,且液体折射率为1.350时,该传感器具有高达10.32nm·μm-1的灵敏度,位移分辨率高达1.9nm。In order to achieve accurate optical measurement method in micro-displacement and improve the accuracy of micro-displacement, we propose a novel micro-displacement optical fiber sensor based on surface plasmon resonance. In order to achieve precise measurement of micro-displacement, we use the characteristics that the propagation angle of the beam in the graded-index multimode fiber changes with the position of the incident light, and the resonant wavelength of the surface plasmon resonance sensor has the high sensitivity to the resonance angle variation. In order to achieve the resonance conditions, we polish the graded-index multimode fiber into a wedge with a suitable angle and precisely control the length of the graded-index multimode fiber. In addition, the fiber probe should be immersed into liquid such as water. A white light source is coupled from the end face of the graded- index multimode fiber to the fiber probe via a 630 nm single mode fiber, and an optical spectrum analyzer is employed to collect light beam and process the sensing signal. The fiber probe and single mode fiber are placed in a high precision displacement platform to control the radial relative position of the fibers. The experimental results show that when the fiber polishing angle is 12° and the liquid refractive index is 1. 350, the micro-displacement optical-fiber sensor has a maximum sensitivity of 10.32 nm·μm-1 and a minimum resolution of 1.9 nm.

关 键 词：光纤光学 微小位移测量 表面等离子体共振 渐变折射率多模光纤 光纤研磨技术 

分 类 号：TN253[电子电信—物理电子学] O434[机械工程—光学工程]