双频太赫兹圆极化吸波与异常反射手性超表面  

Dual-Band Terahertz Chiral Metasurface with Circularly Polarized Absorbing and Anomalous Reflecting

作　　者：张航[1,2,3] 董琳 汤鹏程[1,2] 张庆乐 孙厚军 司黎明[1,2,3] ZHANG Hang;DONG Lin;TANG Peng-cheng;ZHANG Qing-le;SUN Hou-jun;SI Li-ming(School of Integrated Circuits and Electronics,Beijing Institute of Technology,Beijing 100081,China;Beijing Key Laboratory of Millimeter Wave and Terahertz Technology,Beijing 100081,China;Yangtze Delta Region Academy,Beijing Institute of Technology,Jiaxing,Zhejiang 314019,China;State Key Laboratory of Terahertz and Millimeter Waves,City University of Hong Kong,Hong Kong 999077,China)

机构地区：[1]北京理工大学集成电路与电子学院,北京100081 [2]毫米波与太赫兹技术北京市重点实验室,北京100081 [3]北京理工大学长三角研究院,浙江嘉兴314019 [4]香港城市大学太赫兹及毫米波国家重点实验室,中国香港999077

出　　处：《电子学报》2023年第10期2690-2699,共10页Acta Electronica Sinica

基　　金：国家重点研发计划(No.2022YFF0604801);国家自然科学基金(No.62271056,No.61527805);北京市自然科学基金-海淀原始创新联合基金(No.L222042)。

摘　　要：本文提出了一种工作在太赫兹频段的双频圆极化手性吸波和异常反射手性超表面,通过合理组合两种手性结构,实现在两个频段相互独立的圆极化手性吸收和异常角度的圆极化转换功能.该双频太赫兹手性超表面在2.53 THz处对左旋圆极化波的吸收率为96.3%,对右旋圆极化波实现同极化的反射;在3.43 THz处对右旋圆极化波的吸收率为90.9%,而对左旋圆极化波表现为同极化反射功能.本文进一步通过连续旋转单元图案引入几何相位,实现了2π反射相位全覆盖.组阵后的手性超表面在两个工作频点各自吸收特定旋向的圆极化波,而对正交极化的圆极化波分别发生约±20°的保手性异常反射.这种基于手性超表面的双频太赫兹多功能器件有望应用于电磁能量收集、极化转换器、手性传感等领域.Based on the theory of Jones matrix and the principle of Pancharatnam-Berry phase,a dual-band terahertz circularly-polarized(CP)absorbing and anomalous reflecting chiral metasurface is proposed in this paper.The CP chiral ab⁃sorption and conversion function with anomalous reflection angles are realized independently in the two frequency bands.The metasurface unit consists of a combination of two chiral structures,which has an absorption rate of 96.3%for the inci⁃dent left-hand circularly polarized(LHCP)waves,and realizes co-polarized reflection for the incident right-handed circular⁃ly polarized(RHCP)waves at a low frequency of 2.53 THz;meanwhile,the co-polarized reflection will be achieved for the LHCP waves at a high frequency of 3.43 THz,and the absorption rate of the RHCP waves is 90.9%.According to the prin⁃ciple of Pancharatnam-Berry phase,the full coverage of the 360°reflection phase can be realized by rotating the chiral meta⁃surface unit.This chiral metasurface array can absorb the incident CP waves with specific handedness at two operating fre⁃quencies(low frequency 2.53 THz and high frequency 3.43 THz),and generate the handedness-preserving anomalous reflec⁃tions with−26°and+19°angles for the corresponding orthogonal CP waves,respectively.This terahertz multi-function beam control device based on the chiral metasurface has numerous potential in electromagnetic energy harvesting,polariza⁃tion converters,chiral sensing,radar and other fields.

关 键 词：太赫兹 手性超表面 圆二色性 超材料吸波器 异常反射 

分 类 号：TN8[电子电信—信息与通信工程]