Racemic dielectric metasurfaces for arbitrary terahertz polarization rotation and wavefront manipulation  

作　　者：Jie Li Xueguang Lu Hui Li Chunyu Song Qi Tan Yu He Jingyu Liu Li Luo Tingting Tang Tingting Liu Hang Xu Shuyuan Xiao Wanxia Huang Yun Shen Yan Zhang Yating Zhang Jianquan Yao 

机构地区：[1]College of Optoelectronic Engineering,Chengdu University of Information Technology,Chengdu 610225,China [2]School of Precision Instruments and Opto-Electronics Engineering,Tianjin University,Tianjin 300072,China [3]College of Materials Science and Engineering,Sichuan University,Chengdu 610065,China [4]School of Information Engineering,Nanchang University,Nanchang 330031,China [5]Department of Physics,School of Physics and Materials Science,Nanchang University,Nanchang 330031,China [6]Key Laboratory of Terahertz Optoelectronics,Ministry of Education,Department of Physics,Capital Normal University,Beijing 100048,China.

出　　处：《Opto-Electronic Advances》2024年第10期41-50,共10页光电进展（英文）

基　　金：supported by the Scientific Research Foundation of Chengdu University of Information Technology(No.KYTZ202245);Information Materials and Device Applications Key Laboratory of Sichuan Provincial Universities(No.2023XXCL002);the Key Research and Development Project of Sichuan Province:Research on Development and Application Technology of VO2 Nano powder/Slurry with Intelligent Temperature Control(Subproject No.2022Z091);Sichuan Science and Technology Program(No.2023ZYD0020);National Natural Science Foundation of China(No.62201378,12364045,12304420);Natural Science Foundation of Jiangxi Province(No.20232BAB211025 and 20232BAB201040);Young Elite Scientists Sponsorship Program by JXAST(No.2023QT11).

摘　　要：Dielectric chiral metasurface is a new type of planar and efficient chiral optical device that shows strong circular dichroism or optical activity,which has important application potential in optical sensing and display.However,the two types of chiral optical responses in conventional chiral metasurfaces are often interdependent,as their modulation of the amplitudes and phases of orthogonal circularly polarized components is correlated,which limits the further progress of chiral meta-devices.Here we propose a new scheme for independently designing the circular dichroism and optical activity of chiral metasurfaces to further control the polarization and wavefront of transmitted waves.Inspired by mixtures of chiral molecular isomers,we use the dielectric isomer resonators to form“super-units”instead of single meta-atoms for chiral responses in terahertz band,which is called racemic metasurface.By introducing two levels of Pancharatnam-Berry phases between meta-atoms and“super-units”,the polarization rotation angle and wavefront of the beam can be designed without the far-field circular dichroism.We demonstrate the strong control ability on terahertz waves of this scheme through simulation and experiments.In addition,this new type of device with near-field chirality but no far-field circular dichroism may also have important value in optical sensing and other technologies.

关 键 词：RACEMIC dielectric metasurfaces terahertz waves CHIRALITY 

分 类 号：O43[机械工程—光学工程] O441.4[理学—光学]