Graphene-Based Active Tunable Metasurfaces for Dynamic Terahertz Absorption and Polarization Conversion

Simultaneous broadband absorption and polarization conversion are crucial in many practical applications, especially terahertz communications. Thus, actively tunable metamaterial systems can exploit the graphene-based nanomaterials derived from renewable resources because of flexible surface conductivity selective permeability at frequencies. In this paper, we propose a active bifunctional metasurface for dynamic conversion. The graphene ring presents certain opening angle (A) along diagonal xoy plane. When A = 0°, proposed behaves as absorber. Numerical results show feasibility achieving polarization-insensitive absorber with nearly 100% absorptance, bandwidth its 90% absorptance is 1.22 THz under normal incidence. Alternatively, when 40° after optimization, serves convertor, resulting robust ratio (PCR) curves surpassing 0.5 reflection spectrum. To tune PCR response or broad spectrum graphene, change Fermi energy dynamically 0 to 0.9 eV. Furthermore, both linear spectra exhibit insensitivity incident angle, allowing large angles within high-performance operating conditions. demonstrate physical process, present impedance matching theory measure electric field distributions. This architecture frequency range has several such modulators, sensors, stealth, optoelectronic switches. wave beam steering also have application prospects intelligent systems.