A graphene-based tunable polarization insensitive terahertz metasurface absorber for multi-band high-efficiency applications

Abstract

In this paper, we designed a novel tunable terahertz (THz) absorber that has unique properties of graphene integrated within a dual-layer metasurface structure. The proposed absorber demonstrates excellent performance by achieving eight distinct absorption peaks from 3.9 THz to 9.73 THz with an average absorption efficiency of 99.3%. This is achieved through the tunable surface conductivity of graphene which enables dynamic modulation of resonant frequencies via chemical potential adjustment. The design includes a gold base layer for total reflection, gallium arsenide (GaAs) dielectric spacers for optimum impedance matching and graphene patches to introduce multi-band absorption modes. Simulation results show the absorber's tunability, polarization insensitivity and angular stability which makes it highly adaptable for applications in medical diagnostics, material characterization, security screening and terahertz sensing. The proposed absorber's innovative architecture and simple design offers a versatile solution for the evolving demands of modern terahertz technologies.