Terahertz multi-band absorber and dual-bandwidth polarization converter based on VO2 and graphene

• DOI: 10.1016/j.rinp.2023.107006
• Publication Date: 2023-09-22T16:29:18Z
• Authors: Yang Jia; Guan Wang; Xin Zhang; Meichen Li; Fengjuan Miao; Yachen Gao
• Keywords: Metamaterials; Physics; QC1-999; Vanadium dioxide; Graphene; Multiple functions; 7. Clean energy; Polarization converter

A terahertz metamaterial with multiple functions is proposed based on patterned graphene, concentric gold rings and gold columns, and vanadium dioxide (VO2). By adjusting the temperature of VO2, it can be in metal state or insulator state, correspondingly the metamaterial can work as a dual-bandwidth polarization converter or an multi-bandwidth absorber. When the metamaterial acts as a polarization converter, by adjusting the Fermi level of graphene, the converter can realize simultaneously x-polarized wave to y-polarized wave polarization conversion (CPC) and line-to-circular (LTC) polarization conversion (PC). In addition, by adjusting the Fermi level of graphene, the operating frequency and operating efficiency of the absorber and polarization converter can be dynamically tuned. By studying the electric field distribution and the surface current of the metamaterial, the physical mechanism of efficient absorption and dual-bandwidth polarization is explored. Moreover, the proposed multifunctional metamaterial is highly robust to incidence angle. It has potential applications in communication, spectroscopy, sensors, and physical detection.