基于二氧化钒的多功能可切换超材料器件研究  

Multifunctional Switchable Metamaterial Devices Based on Vanadium Dioxide

作　　者：陈玲英 曹莹珏 李向军 章乐[1,2] 李吉宁 严德贤[1,2] Chen Lingying;Cao Yingjue;Li Xiangjun;Zhang Le;Li Jining;Yan Dexian(Key Laboratory of Electromagnetic Wave Information Technology and Metrology of Zhejiang Province,College of Information Engineering,China Jiliang University,Hangzhou 310018,Zhejiang,China;Center for THz Research,China Jiliang University,Hangzhou 310018,Zhejiang,China;School of Precision Instrument and Opto-Electronics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]中国计量大学信息工程学院浙江省电磁波信息技术与计量检测重点实验室,浙江杭州310018 [2]中国计量大学太赫兹研究所,浙江杭州310018 [3]天津大学精密仪器与光电子工程学院,天津300072

出　　处：《光学学报》2025年第1期256-264,共9页Acta Optica Sinica

基　　金：国家级大学生创新训练计划项目(202410356050);国家自然科学基金(62175223)。

摘　　要：提出一种基于加号单元结构阵列的可切换太赫兹超材料器件,通过引入二氧化钒(VO_(2))材料,可以在不同的太赫兹频段实现交叉极化转换、线-圆极化转换和宽带吸收,具有多功能的特性。当VO_(2)处于绝缘态时,该结构在多个频段内可实现线-圆极化转换和交叉极化转换;当VO_(2)从绝缘态转变到金属态时,在1.610~4.010 THz频段内吸收率超过90%,具有宽频带和高效率等优点。此外,还对太赫兹波入射角度和极化角度对器件的极化转换特性和吸收特性的影响进行研究,证明该结构具有极化不敏感和入射角度稳定性高的特点。研究结果表明:所提器件独特的多层堆叠结构不仅展现出卓越的吸收性能,还能够在多种极化状态下快速转换,在太赫兹成像、通信和安全检测等领域有很大的应用潜力。Objective We design a switchable terahertz metamaterial device based on an array of cross-shaped unit cell structures.By introducing vanadium dioxide(VO_2),we achieve cross-polarization conversion,linear-to-circular polarization conversion,and broadband absorption across different terahertz frequency bands,demonstrating multifunctionality.Methods We conduct electromagnetic simulations using CST MICROWAVE STUDIO software to analyze the device's performance.The VO_2-based metamaterial consists of six layers:a VO_(2) cross-shaped patch array,a polyimide(PI,εPI=3.5) layer,an elliptical metal strip,a VO_(2) thin film,another PI layer,and a bottom metal layer.Geometrical dimensions are optimized through numerical calculations,resulting in a unit structure period P=70 μm,surface cross patch dimensions a=15 μm,b=4 μm,and dielectric layer thickness h=13 μm.The major and minor axes of the elliptical metal patch are m=44.8 μm and n=12 μm.The VO_(2) thin film,elliptical metal strip,and bottom metal(σAu=4.56×10~7 S/m) have a thickness of t=0.1 μm.The phase transition of VO_(2) between its insulating and metallic states is triggered by external stimuli,such as temperature,electromagnetic fields,and optical fields.We assume conductivities of 2×10~5 S/m and 20 S/m to represent the metallic and insulating states of VO_2,respectively.By changing the conductivity,the device can switch between absorption and polarization conversion functionalities.Results and Discussions We design a multifunctional terahertz metamaterial structure based on the phase transition characteristics of VO_2,which achieves broadband absorption,cross-polarization conversion,and linear-to-circular polarization conversion simultaneously.The structure has the following features:First,it adopts a symmetric design,making the metasurface absorber polarization-insensitive.Second,in terms of performance,when VO_(2) is in its insulating state,the structure enables linear-to-circular polarization conversion and linear-to-linear cross-polarization conversion

关 键 词：光学器件 太赫兹超材料 多功能器件 极化转换 吸收 

分 类 号：O441[理学—电磁学]