基于Fabry-Perot模型设计亚波长金属狭缝阵列光学异常透射折射率传感器  

Design of extraordinary-optical-transimission refractive-index sensor of subwavelength metallic slit array based on a Fabry-Perot model

作　　者：曾志文[1] 刘海涛[1] 张斯文[1] 

机构地区：[1]南开大学信息技术科学学院现代光学研究所,光学信息技术科学教育部重点实验室,天津300071

出　　处：《物理学报》2012年第20期170-178,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10804057);教育部高等学校科技创新工程重大项目培育资金(批准号:708021);教育部新世纪优秀人才支持计划(批准号:NCET-08-0289);国家重点基础研究发展计划(批准号:2007CB307001);天津市应用基础及前沿技术研究计划(批准号:1 1JCZDJC15400)资助的课题~~

摘　　要：研究了在水溶液环境中亚波长金属狭缝阵列光学异常透射的折射率传感特性.采用严格的全矢量方法计算了狭缝阵列的透过率谱.建立了Fabry-Perot半解析模型,能够精确预言全矢量方法的计算结果.基于该模型给出的共振条件,提出并解释了当透射峰精确位于瑞利异常位置时,透射峰能达到最尖锐的状态,给出了设计狭缝阵列达到该状态的方法.设计得到的透过率谱峰值半高宽δλ可达0.01 nm,对应的溶液折射率测量不确定度δn_s达到2×10^(-6)RIU.系统地给出了阵列周期、狭缝宽度、入射角等参数对设计得到的传感灵敏度,δλ,δn_s,峰值透过率等的影响.The refractive index sensing properties of a period array of subwavelength metallic slits in water environment are investigated. The transmission spectra of the slit array are calculated with a rigorous fully-vectorial method. A simple semi-analytical Fabry-Perot model that can accurately reproduce the rigorous fully-vectorial data is built up. We find that the transmission peak becomes sharpest as it is exactly located at the Rayleigh anomaly position, which is explained based on the resonance condition derived from the model. The method to design the slit array to achieve this sharpest transmission peak is presented. The full width at half-maximum （SA） of the designed transmission peak can be as low as 0.01 nm, which corresponds to a refractive-index measurement uncertainty （δns） of 2 × 10^-6 RIU. The influences of array period, slit width and incident angle on the designed sensitivity, δλ, δns and peak transmittance of the sensor are systematically provided.

关 键 词：折射率传感器 亚波长金属狭缝阵列 Fabry-Perot模型 光学异常透射 

分 类 号：TP212.14[自动化与计算机技术—检测技术与自动化装置]