变周期亚波长介质光栅多层膜的双重Fano共振特性  

Double Fano Resonance Characteristics Based on Variable Period Subwavelength Dielectric Gratings Multilayer Films

作　　者：肖春艳[1] 杨晨 周鑫德 XIAO Chun-yan;YANG Chen;ZHOU Xin-de(Institute of Resources and Environment,Henan Polytechnic University,Jiaozuo 454003,China;Hebei Province Key Laboratory of Test/Measurement Technology and Instrument,School of Electrical Engineering,Yanshan University,Qinhuangdao 066004,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454003 [2]燕山大学电气工程学院,河北省测试计量技术及仪器重点实验室,河北秦皇岛066004

出　　处：《光谱学与光谱分析》2024年第3期681-687,共7页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2016YFC1400601-3);国家自然科学基金项目(42007175)资助。

摘　　要：现在众多传感结构模型只能对单变量待测样本折射率进行传感检测,为实现不同待测样本的高通量检测并降低环境因素的干扰,提出了一种基于波长调制的变周期亚波长介质光栅多层膜复合结构。以双周期为例进行分析,变周期光栅层由两个具有不同光栅周期的介质光栅A和B组成,通过有限元法对传输特性进行分析,TE偏振入射光以垂直于光栅层表面的方式入射至介质光栅表面,当在介质光栅区域A和B内分别满足相位匹配条件时,变周期亚波长介质光栅会形成GMR,提供两个具有单一窄带的双离散态共振缺陷峰;由于类F-P腔中含有周期性光子晶体,光波传播到光子晶体会产生光子禁带,提供一个较宽频带的连续态。在满足相位匹配条件时,变周期亚波长波导结构中形成的双离散态共振缺陷峰与周期性光子晶体多层介质薄膜构成的类F-P腔中形成的连续态发生耦合,实现双重Fano共振。然后通过探究波导层厚度dw和光子晶体周期数N对传感特性的影响,选择dw=97 nm和N=3,使其达到FOM值最大。最终因变周期介质光栅层是由两种具有不同介质折射率的材料构成,在介质光栅区域A和B的光栅凹槽部分可设置两个传感检测单元,建立基于波长调制的双重Fano共振全电介质传感模型,设置不同的传感检测区域,发现双重Fano光谱曲线在不同传感检测区域内都能随着ns1和ns2变化,间接实现了对待测样本折射率的动态检测,因而可在同一传感结构模型中实现对不同待测样本折射率区间的多变量检测。结果表明,在传感检测单元A内,FR1和FR2的FOM值分别为631.53和463.7 RIU^(-1);在传感检测单元B内,FOM值分别为480.67和834.04 RIU^(-1)。所设计的传感结构模型通过结构参数优化,实现了传感结构的高反射率、高FOM值和较宽的检测范围,对双重Fano共振提供了理论参考,对待测样本折射率的多变量检测具有一定的研�Currently,many sensing structure models can only sense the refractive index of single variable samples to be measured.In order to achieve high-throughput detection of different samples to be measured and reduce the interference of environmental factors,a variable period subwavelength dielectric grating multilayer composite structure based on wavelength modulation is proposed.Take the double period as an example for analysis.The variable period grating layer is composed of two dielectric gratings,A and B,with different grating periods.The transmission characteristics are analyzed by the finite element method.The TE polarized incident light is incident on the surface of the dielectric grating in a manner perpendicular to the surface of the grating layer.When the phase matching conditions are met in the dielectric grating areas A and B,the variable period subwavelength dielectric grating will form GMR,Providing two double discrete resonance defect peaks with a single narrow band.Because the F-P-like cavity contains a periodic photonic crystal,the photonic band gap will be generated when the light wave propagates to the photonic crystal,providing a wide band continuous state.Under the condition that the phase matching condition is satisfied,the double discrete state resonance defect peak formed in the variable period subwavelength waveguide structure is coupled with the continuous state formed in the F-P-like cavity composed of the periodic photonic crystal multilayer dielectric film,and the double Fano resonance is realized.Then,by exploring the influence of waveguide layer thickness d w and photonic crystal cycle number N on the sensing characteristics,we choose d w=97 nm and N=3 to maximize the FOM value.Finally,the variable period dielectric grating layer is composed of two materials with different dielectric refractive indices,two sensing and detection units can be set in the grating groove part of the dielectric grating areas A and B,and a dual Fano resonance all-dielectric sensing model based on wavelength mod

关 键 词：传感器 双重Fano共振 变周期亚波长光栅 导模共振 周期性光子晶体多层膜 

分 类 号：O436[机械工程—光学工程]