Active control of terahertz quasi-BIC and asymmetric transmission in a liquid-crystalintegrated metasurface  

作　　者：SHI-TONG XU JUNXING FAN ZHANQIANG XUE TONG SUN GUOMING LI JIANDI LI DAN LU LONGQING CONG 

机构地区：[1]Shandong Provincial Key Laboratory of Laser Polarization and Information Technology,School of Physics and Engineering,Qufu Normal University,Qufu 273165,China [2]Department of Electrical and Electronic Engineering,Southern University of Science and Technology,Shenzhen 518055,China

出　　处：《Photonics Research》2024年第10期2207-2213,共7页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(62005143,62175099,62335011);Basic and Applied Basic Research Foundation of Guangdong Province(2023A1515011085);Shenzhen Science and Technology Innovation Program(20220815151149004,20230807093617036,JSGGKQTD20221101115656030);Regular Undergraduate University Teacher Visiting and Training Funding of Shandong Province。

摘　　要：Quasi-bound states in the continuum(quasi-BICs)offer an excellent platform for the flexible and efficient control of light-matter interactions by breaking the structural symmetry.The active quasi-BIC device has great application potential in fields such as optical sensing,nonlinear optics,and filters.Herein,we experimentally demonstrate an active terahertz(THz)quasi-BIC device induced by the polarization conversion in a liquid crystal(LC)-integrated metasurface,which consists of a symmetrically broken double-gap split ring resonator(DSRR),an LC layer,and double graphite electrodes.In the process of LC orientation control under the external field,the device realizes the active control from the OFF state to the ON state.In the OFF state,the LC has no polarization conversion effect,and the device behaves in a non-resonant state;but for the ON state,the device exhibits obvious quasi-BIC resonance.Furthermore,we achieve asymmetric transmission based on polarization-induced quasiBIC modulation precisely at the quasi-BIC resonance position,and its isolation can be controlled by the external field.The study on dynamic quasi-BIC by the LC-integrated metasurface introduces a very promising route for active THz devices,which guarantees potential applications for THz communications,switching,and sensing systems.

关 键 词：FIELD QUASI ASYMMETRIC 

分 类 号：O753.2[理学—晶体学] O441.4