基于双开缝环结构的半反射和半透射超宽带超薄双偏振太赫兹超表面  

Double-split-ring structure based ultra-broadband and ultra-thin dual-polarization terahertz metasurface with half-reflection and half-transmission

作　　者：杨东如 程用志[1,3] 罗辉 陈浮 李享成 Yang Dong-Ru;Cheng Yong-Zhi;Luo Hui;Chen Fu;Li Xiang-Cheng(School of Information Science and Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;State Key Laboratory of Refractory Materials and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Longzhong Laboratory,Xiangyang 441000,China)

机构地区：[1]武汉科技大学信息科学与工程学院,武汉430081 [2]武汉科技大学耐火材料与冶金国家重点实验室,武汉430081 [3]湖北隆中实验室,襄阳441000

出　　处：《物理学报》2023年第15期280-292,共13页Acta Physica Sinica

基　　金：湖北省自然科学基金创新群体项目(批准号:2020CFA038);湖北省重点研发项目(批准号:2020BAA028)资助的课题.

摘　　要：提出了一种基于双开缝环结构的半反射和半透射双偏振超宽带太赫兹超表面,能实现光束偏折和生成涡旋光束.该超表面单元结构仅由附着在超薄介质层上的金属双开缝环构成,在超宽频带范围内同时调控反射和透射太赫兹圆偏振(circular polarization,CP)波和线偏振(linear polarization,LP)波.基于传输相位和几何相位理论,改变开缝环的大小和旋转方向,在0.3—1.2 THz范围内可以实现透射和反射的正交LP波和CP波在0—2π相移全覆盖,对应的正交LP波和CP波平均幅值为0.45的相对带宽分别达到86%和120%.本文特别设计了全空间超表面模型,实现了LP波和CP波光束偏折与生成涡旋光束.这些研究有助于全空间多功能太赫兹超表面器件的实现和实际应用.In this paper,we propose a dual-polarization ultra-wideband metasurface with half-reflection and halftransmission based on a double-split-ring(DSR)structure operating in a terahertz(THz)frequency range.The designed metasurface can simultaneously control the circularly polarized(CP)wave and linearly polarized(LP)wave in reflection mode and transmission mode,covering an extensive THz frequency range.The unit-cell architecture of the metasurface consists of a periodic arrangement of the DSR structure made of metal,which is affixed to an ultra-thin dielectric substrate.By manipulating the size and rotation direction of the DSR structure,we achieve full phase coverage of 0–2πof the orthogonally polarized LP wave and CP wave across a frequency span of 0.3–1.2 THz,encompassing transmission and reflection scenarios.The relative bandwidths of the corresponding orthogonal LP wave and CP wave with an average amplitude of 0.45 reach 86%and 120%,respectively.Specifically,through numerical simulations,we demonstrate that the designed metasurface has the ability to achieve THz beam deflection and vortex beam generation while reflecting and transmitting LP wave and CP wave.The proposed dual-polarization ultra-wideband metasurface holds great promise for various applications in the terahertz frequency range.These findings pave the way for the development of flexible and versatile THz devices with expanded functionality,thereby opening up new possibilities for wavefront manipulation in metasurfaces.

关 键 词：太赫兹 超表面 圆偏振 线偏振 光束偏折 涡旋光束 

分 类 号：O441.4[理学—电磁学]