Multifunctional analysis and verification of lightning-type electromagnetic metasurfaces
Jie Xu, Jian Tang, Yu Cheng, Ming Chen, Hexuan Wang, Jianfeng Xiong, Tianrang Wang, Shuaizhao Wang, Youdan Zhang, Wen Hui, Shiliang Qu, Libo Yuan
Abstract
Aiming at the problems that most of the existing electromagnetic metasurfaces have single function and narrow application scope, a highly integrated lightning-type metasurface is proposed in this study. It can realize the functions of circular dichroism (CD), absorption of electromagnetic waves, broadband x-to-y cross polarization conversion (CPC) function, linear-to-circular polarization conversion (LTC-PC) function and asymmetric transmission (AT), and its functions are also analyzed and verified. The designed metasurface consists of the bottom grating structure, the lower SiO 2 , the middle lightning-type graphene, the upper SiO 2 , the top graphene and photosensitive silicon. Through numerical calculations, the CD of design can reach more than 85% at 4.22 THz. The function of bimodal absorption is achieved at 4.09 and 8.69 THz. At 7.41∼8.21 THz, the polarization conversion ratio (PCR) of the metasurface reaches more than 99%. Simultaneously, the function of LTC-PC can be formed when PCR is 50%. Finally, when the designed metasurface is in the transmissive state, the AT of design is close to 60% at 7.84 THz. This design provides a new design idea and method for biomedical detection, image processing, modulators, smart switches, optical diodes and other fields.