Ultra-broadband and wide-angle reflective terahertz polarization conversion metasurface based on topological optimization  

作　　者：Ya-Jie Zhang Chao-Long Li Jia-Qi Luan Ming Zhao Ding-Shan Gao Pei-Li Li 张亚杰;李潮龙;栾迦淇;赵茗;郜定山;李培丽(Faculty of Electrical and Optical Engineering,Nanjing University of Posts and Communications,Nanjing 210023,China;Wuhan National Laboratory for Optoelectronics and School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]Faculty of Electrical and Optical Engineering,Nanjing University of Posts and Communications,Nanjing 210023,China [2]Wuhan National Laboratory for Optoelectronics and School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Chinese Physics B》2024年第10期287-294,共8页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China and the Open Project Program of Wuhan National Laboratory for Optoelectronics(Grant No.2022WNLOKF012).

摘　　要：Terahertz polarization conversion devices have significant potential applications in various fields such as terahertzimaging and spectroscopy.In this paper,we utilize genetic algorithms to topologically optimize the metasurface unit cellsand design a reflective linear polarization conversion metasurface with ultra-broadband and wide-angle characteristics.By partitioning the metallic pattern layer into quadrants,the encoding length is effectively reduced,resulting in a shorteroptimization time.The research results indicate that the converter possesses a polarization conversion efficiency ratio higherthan 90%and a relative bandwidth ratio of 125%in a range of 0.231-0.995 THz.Meanwhile,it can maintain excellentpolarization conversion properties when the incident angle of terahertz waves is less than 45°and the polarization angle isless than 15°,demonstrating excellent practicality.New insights are provided for the design of terahertz wide-angle ultrawidebandpolarization conversion devices,and the proposed metasurfce has potential applications in terahertz polarizationimaging,spectroscopy and communication fields.

关 键 词：metasurface polarization conversion topology optimization ULTRA-BROADBAND 

分 类 号：O441.4[理学—电磁学]