基于二氧化钒的太赫兹超材料动态可调宽带吸收器  

Dynamically Tunable Broadband Terahertz Metamaterial Absorber Based on Vanadium Dioxide

作　　者：龚江 宗容[1] 李辉 段韬 Gong Jiang;Zong Rong;Li Hui;Duan Tao(School of Information,Yunnan University,Kunming,Yunnan 650500,China)

机构地区：[1]云南大学信息学院,云南昆明650500

出　　处：《激光与光电子学进展》2021年第3期252-258,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61162004)。

摘　　要：在硅平面上设计了一种基于二氧化钒(VO_(2))超材料的可调谐太赫兹(THz)宽带吸收器,该吸收器由VO_(2)谐振层和被SiO_(2)介质隔开的金属反射层组成。数值仿真结果表明,具有高电导率(30000 S/m)的VO 2表现为金属相,其吸收率大于90%时吸收带宽达到了2 THz,并且分别在4.5 THz和5.8 THz处实现了吸收率为99.3%和99.6%的完美吸收。具有低电导率(100 S/m)的VO_(2)则表现为绝缘相,其在相应的宽频吸收带内的峰值吸收率仅为8%。因此,通过改变吸收器结构中VO 2材料的电导率,可以实现宽频带内吸收率的动态调谐以及吸收和反射功能的切换。此外,由于结构的对称性,所提出的吸收器在垂直入射条件下具有偏振不敏感特性,并且在大入射角度范围内保持着良好的吸收性能。In this paper,a vanadium dioxide(VO_(2))based tunable broadband terahertz(THz)absorber is designed on the silicon plane,which is composed of a VO_(2) resonator and a metal layer,separated by a thin silicon dioxide(SiO_(2))dielectric layer.Numerical simulation results show that VO_(2) with high conductivity(30000 S/m)is at its metal phase,and when its absorptivity is greater than 90%,the 2.0 THz absorption bandwidth can be obtained.In addition,the perfect absorption is realized with absorptivity of 99.3%and 99.6%at 4.5THz and 5.8THz,respectively.In contrast,VO_(2) with low conductivity(100 S/m)is at its insulation phase,and the peak absorptivity in the corresponding broad absorption band is only 8%.Therefore,by altering the conductivity of VO_(2) in the absorber,one can switch between absorption and reflection and realize the dynamic tuning of absorptivity in a broad frequency band.In addition,the proposed absorber is polarization-insensitive under vertical incidence due to its structural symmetry.Moreover,the absorber maintains an excellent absorption performance over a wide incident angle range.

关 键 词：材料 超材料 太赫兹 可调谐吸收器 二氧化钒 

分 类 号：O436[机械工程—光学工程]