Observation of maximal intrinsic chirality empowered by dual quasi-bound states in the continuum in a planar metasurface  

作　　者：XIN QI JIAJU WU FENG WU SONG ZHAO CHAO WU YUEYANG MIN MINA REN YUFEI WANG HAITAO JIANG YUNHUI LI ZHIWEI GUO YAPING YANG WANHUA ZHENG HONG CHEN YONG SUN 

机构地区：[1]MOE Key Laboratory of Advanced Micro-Structured Materials,School of Physics Science and Engineering,Tongji University,Shanghai 200092,China [2]School of Optoelectronic Engineering,Guangdong Polytechnic Normal University,Guangzhou 510665,China [3]l3 Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology,School of Physics Science and Engineering,Tongji University,Shanghai 200092,China [4]Department of Electrical Engineering,Tongji University,Shanghai 201804,China [5]State Key Laboratory on Integrated Optoelectronics,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China

出　　处：《Photonics Research》2024年第2期244-252,共9页光子学研究（英文版）

基　　金：National Key Research and Development Program of China(2021YFA1400602);National Natural Science Foundation of China(11974261,62075213,12104105,12274325,11874286,61621001,91850206)。

摘　　要：Metasurfaces with spin-selective transmission play an increasingly critical role in realizing optical chiral responses,especially for strong intrinsic chirality,which is limited to complex three-dimensional geometry.In this paper,we propose a planar metasurface capable of generating maximal intrinsic chirality and achieving dual-band spinselective transmission utilizing dual quasi-bound states in the continuum(quasi-BICs)caused by the structural symmetry breaking.Interestingly,the value of circular dichroism(CD)and the transmittance of two kinds of circular polarization states can be arbitrarily controlled by tuning the asymmetry parameter.Remarkable CD approaching unity with the maximum transmittance up to 0.95 is experimentally achieved in the dual band.Furthermore,assisted by chiral BICs,the application in polarization multiplexed near-field image display is also exhibited.Our work provides a new avenue to flexibly control intrinsic chirality in planar structure and offers an alternative strategy to develop chiral sensing,multiband spin-selective transmission,and high-performance circularly polarized wave detection.The basic principle and design method of our experiments in the microwave regime can be extended to other bands,such as the terahertz and infrared wavelengths.

关 键 词：PLANAR INTRINSIC QUASI 

分 类 号：O43[机械工程—光学工程]