基于银/高纯铟复合膜的表面等离子体共振折射率传感器  

Surface Plasmon Resonance Refractive Index Sensor Based on Silver/High-Purity Indium Composite Film

作　　者：王一晴 齐跃峰[1,2] 曹子尧 魏林特 郭星辰 陈斯琦 刘燕燕 Wang Yiqing;Qi Yuefeng;Cao Ziyao;Wei Linte;Guo Xingchen;Chen Siqi;Liu Yanyan(School of Information Science and Engineering,Yanshan University,Qinhuangdao 066004,Hebei,China;Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province,Qinhuangdao 066004,Hebei,China)

机构地区：[1]燕山大学信息科学与工程学院,河北秦皇岛066004 [2]河北省特种光纤和光纤传感器重点实验室,河北秦皇岛066004

出　　处：《光学学报》2023年第3期220-227,共8页Acta Optica Sinica

基　　金：国家自然科学基金重点项目(61735011);河北省科技研发重点项目(19251703D);中央引导地方科技发展专项(19941708G)。

摘　　要：为了解决单一金属膜结构的光纤表面等离子体共振(SPR)盐度传感器结构不稳定且灵敏度较低的问题,设计了一种高灵敏度的锥形三芯光纤结构的SPR盐度传感器。以银膜为激发表面等离子体共振的金属层,在其表面涂覆高纯铟以增强其稳定性。通过Kretschmann四层结构模型对传感器进行理论分析,结果表明,在光纤锥区纤芯模和包层模之间会出现强烈的模式耦合,在覆膜区会激发明显的等离子体共振。对涂覆银膜和高纯铟膜的SPR传感器进行折射率性能测试,在1.4%~3.6%的盐度变化范围内,涂覆银膜和高纯铟膜的SPR传感器灵敏度高达4989.34 nm/RIU,对应的盐度灵敏度为9.1 nm/%,比仅涂覆银膜的SPR传感器灵敏度提高了44%。Objective As people tend to pay much attention to the ecological environment,the detection of liquid salinity in hydrological environments has gradually become an indispensable part of research fields such as agricultural planting,aquaculture,and monitoring of the marine environment.Surface plasmon resonance(SPR)technology has unique advantages in liquid salinity detection due to its fast response speed and high precision.The optical fiber SPR sensor combines optical fiber and plasma technology to overcome the limitations of prismtype SPR sensors.It not only has the advantages of simple structure and water resistance of optical fiber sensors but also has a wide detection range and high detection sensitivity of surface plasmon technology and convenient operation.However,traditional optical fiber SPR sensors based on multimode or singlemode single metal film structures generally face many problems.Specifically,the metal film is easy to fall off,and the detection sensitivity is low.In addition,the stability is poor.Indium has excellent electrical properties and positive flexibility.Therefore,it is an important optoelectronic material and is easy to form a firm coated on a metal surface.Furthermore,it is not easy to react with alkaline solutions and has good corrosion resistance.Therefore,this paper uses the strong coupling characteristics of a threecore fiber and the principle of SPR to design a tapered fiber SPR sensor based on a silver film and a highpurity indium film,which can improve the sensitivity and corrosion resistance of the sensor.Methods This thesis is based on the theory of an optical fiber SPR sensor,and the propagation law of light in a tapered fiber is studied.The total reflection coefficient of the sensor is obtained by using the Fresnel formula,and the influence of the diameter of the cone waist region,the length of the sensing region,and the thickness of the metal film on the sensor is analyzed by numerical calculation,and the optimal parameters are determined.The sensor is fabricated according t

关 键 词：传感器 表面等离子体共振 三芯光纤 折射率传感器 高纯铟 

分 类 号：O439[机械工程—光学工程]