一种适用于湿度传感的表面等离子微环传感器  

A Surface Plasmon Micro-Ring Sensor Suitable for Humidity Sensing

作　　者：李志全[1] 安东阳[1] 张鑫[1] 赵玲玲[1] 沙晓鹏[1] 郭士亮[1] 李文超[2] 

机构地区：[1]燕山大学电气工程学院,河北秦皇岛066004 [2]东北大学秦皇岛分校控制工程学院,河北秦皇岛066004

出　　处：《光谱学与光谱分析》2015年第9期2660-2664,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(61172044;61107039);河北省自然科学基金项目(F2012203204;F2014501150)资助

摘　　要：提出了一种适用于湿度传感的表面等离子微环传感器。该传感器纵向上采用表面等离子多层波导结构,横向上采用U型微环结构,以聚酰亚胺（polyimide,PI）为感湿材料。根据传输矩阵法推导表面等离子微环传感器结构的传递函数,外界环境的相对湿度变化引起聚酰亚胺的折射率变化,从而多层波导结构的有效折射率发生改变,导致传感器的输出光谱发生漂移。重点分析讨论了多层波导结构的传输特性以及感湿部位折射率的变化对输出光谱的影响。根据计算和仿真得出：当U型波导的两个耦合点间的距离为微环周长的整数倍时,传感器的输出光谱水平漂移量较大,自由光谱范围（FSR）加倍,达到128nm,当外界环境相对湿度从10%RH变化到100%RH时,漂移量Δλm在0.005~0.038μm之间变化,相比于其他湿度传感器,灵敏度提高了10~50倍,高达0.0005μm/%RH,并且传输稳定。结果表明：设计的表面等离子微环传感器,灵敏度较好,性能稳定,可以应用于湿度测量,并且实现了在高灵敏度感湿的同时兼顾大范围的滤波选频,为微型光学器件的制备提供了理论基础。Temperature is a very important parameter in scientific research,production and life.Almost all the properties of ma-terials are related to temperature.The precise measurement of the temperature is a very important task,so the temperature sen-sor is widely used as a core part in the temperature measuring instrument.A novel surface plasmon micro-ring sensor suitable for humidity sensing is presented in this paper.The sensor uses a multi-layered surface plasmon waveguide structure and choosing Polyimide （Polyimide,PI）as the moisture material.We get the transfer function of surface plasmon micro-ring sensor by using transfer matrix method.Refractive indexes of Polyimide and the multilayer waveguide structure change as environment relative humidity changes,thus leading to an obvious peak drift of output spectrum.The paper mainly discusses the influence of the changes of the refractive index of humidity-sensing parts on the output spectrum,and the transmission characteristics of multi-layer waveguide structure.Through the finite element method and the theoretical simulation of Matlab,We can draw：When the length between the two coupling points of the U-shaped waveguide is an integer multiple of circumference of the micro-ring,an obvious drift in the horizontal direction appears,the free spectral range （FSR）doubled and the sensitivity is 0.000 5 μm/%RH;When the external environment relative humidity RH changes from 10% to 100% RH,scatter is change between including （in-cluding 0.005 m to 0.005 m,compared to other humidity sensor,the Sensitivity of sensor improves 10~50 times and the trans-mission is very stable.Results show that the design of surface plasma micro ring sensors has better sensitivity,stable perform-ance and can be used in the humidity measurement,achieving a high sensitivity in the sense of humidity when the wide range of filter frequency selection is taken into account,and providing a theoretical basis for the preparation of micro-optics.

关 键 词：表面等离子微环传感器 多层波导结构 传输矩阵法 灵敏度 

分 类 号：TN256[电子电信—物理电子学]