含石墨烯的金属-分布式布拉格反射镜-金属结构中光学Tamm态的研究  

Optical Tamm States in Metal-Distributed Bragg Reflection-Metal Structure with Graphene

作　　者：杨书丹 李培丽 张若羽 Yang Shudan;Li Peili;Zhang Ruoyu(College of Electronic and Optical Engineering&College of Microelectronics,Nanjing University of Posts&Telecommunications,Nanjing,Jiangsu 210023,China)

机构地区：[1]南京邮电大学电子与光学工程学院、微电子学院,江苏南京210023

出　　处：《中国激光》2021年第16期205-214,共10页Chinese Journal of Lasers

基　　金：国家自然科学基金(60707006)。

摘　　要：基于光学Tamm态(OTS)的局域场增强特性和石墨烯的电控特性,提出一种含石墨烯的金属-分布式布拉格反射镜-金属(M-DBR-M)复合结构。考虑石墨烯层对介质界面连续性的影响,基于修正的传输矩阵法建立完善的理论模型,并研究结构参数以及驱动电压对OTS特性的影响。结果表明,随着驱动电压的增大,两个OTS的本征波长均发生蓝移,当驱动电压大于石墨烯的突变电压时,本征波长发生蓝移且趋于稳定,说明可以通过电控石墨烯来实现OTS的本征波长在一定范围内动态可调;增大DBR周期数,两个OTS的本征波长分别发生红移和蓝移,说明吸收率对周期数的波动具有鲁棒性;入射端的金属层厚度在25~35 nm之间,能够实现完美吸收;出射端的金属层厚度则在70 nm处有吸收率的极大值。Objective Optical Tamm state(OTS)is a new type of surface-localized state,which can be excited at the interfaces between metal and distributed Bragg reflection(M-DBR)or between two photonic crystals.The electric fields of OTSs are localized at the interfaces and intensity of the electric fields decays because it is away from the interfaces.Compared with the traditional surface states,OTS has a high-intensity local mode and perfect absorption of incident electromagnetic wave and has a narrower linewidth,which can be excited by transverse electric(TE)and transverse magnetic(TM)polarized waves at a wide-angle range incidence.Researchers have conducted several studies on OTS,but the structural parameters are fixed.Besides,they do not have the tunability and cannot expand the application field.Thus,the emergence of tunable structures is an inevitable tendency.Graphene is a new type of two-dimensional(2 D)carbon atom material with special optical and electrical properties,which can interact with incident electromagnetic waves.By changing the chemical potential(ν),the conductivity can be adjusted to achieve tunable absorption.In this study,we propose a metal-DBR-metal(M-DBR-M)structure with graphene based on the local characteristics of OTS and the electronic control characteristics of graphene.Tuning intrinsic wavelength by adjusting the driving voltage.The proposed structure can provide references for the research and design of photonic devices,such as sensors,absorbers,narrow-band selective filters,and optical detectors based on OTS.Methods In this paper,the dielectric constant of the metal layer is modeled using the Drude-Lorentz dispersion model.The influence of the graphene layer on dielectric interface continuity is considered.Thus,the modified transfer matrix method is used instead of the traditional transfer matrix method.The proposed structure is simulated using the COMSOL multiphysics software.The influence of material dispersion is neglected.We assume that the structure is in the air,and light incident into

关 键 词：光谱学 石墨烯 光学Tamm态 金属-分布式布拉格反射镜 吸收率 

分 类 号：O436[机械工程—光学工程]