| Institution: | 1. Information Materials and Device Applications Key Laboratory of Sichuan Provincial Universities, Chengdu University of Information Technology, Chengdu, 610225 China;2. Sichuan Changhong Electric Co., Ltd., 35 East Mianxing Road, High-tech Park, Mianyang, Sichuan, 621000 China;3. Key Laboratory of Optoelectronics Information Technology (Tianjin University), Ministry of Education, Institute of Laser & Opto-electronics, School of Precision Instruments and Opto-electronics Engineering, Tianjin University, Tianjin, 300072 China;4. State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, No. 58, Renmin Avenue, Haikou, Hainan, 570228 China
Dongguan ROE Technology Co.,Ltd., Dongguan, 523000 China;5. State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, No. 58, Renmin Avenue, Haikou, Hainan, 570228 China |
| Abstract: | In the field of optoelectronics, circular dichroism (CD) has caused great research interest because it is widely used in imaging and biosensing. A new method for dynamically controlling terahertz (THz) CD in metamaterials is proposed. By introducing chirality and graphene to metamaterials, a pair of chiral structures with completely opposite responses to left-handed circularly polarized (LCP) waves and right-handed circularly polarized (RCP) waves are designed. The influencing factors of CD are explored, including the gap of the structure, the linewidth of graphene, and the Fermi level of graphene. The largest CD (ΔR) is 77%. The CD can be actively modulated in a modulation range of 39–77% and the modulation depth is up to 38%. In addition, two-channel and four-channel chiral metasurfaces for near-field imaging are designed in this way. Good imaging effects and on (“1”) or off (“0”) effects of the multichannel metasurface are demonstrated. This work provides new ideas for the design of tunable metasurfaces and promotes the application of metasurfaces in THz dynamic imaging. |
