Wideband tunable and polarization insensitive THz absorber using graphene metamaterial based triple split ring with plus structure

Abstract Terahertz (THz) broadband metamaterial absorbers with tunable absorption characteristics have garnered significant interest because of their high demand and application in cutting-edge optical systems. On top of that, the resurgence of graphene has presented researchers with new opportunities to advance high-performance metamaterial devices, particularly in the realm of absorption applications. This paper unveils a neoteric design for a broadband tunable graphene metamaterial absorber incorporating glass patterned on graphene in triple rectangular split ring and plus fashion. Systematically performing numerical simulations, our proposed metamaterial absorber (MMA) has been found to exhibit an absorption bandwidth of 4.26 THz, ranging from 0.69 THz to 4.96 THz, with absorptivity exceeding 90%. Through the manipulation of the chemical potential of graphene within the range of 0.1 eV to 0.7 eV, along with the adjustment of the dimensions of the structure and polarization angles, it becomes feasible to dynamically modify and improve the maximum absorption. A transmission line equivalent circuit model is used to calculate the impedance components of all layers, which is crucial for determining impedance. The optimized design configuration, relative bandwidth, and tunable capability of this absorber offer a promising avenue for the development of high-speed optical switches and there are numerous applications in the field of terahertz technology such as solar energy harvesting, stealth technology, imaging, and cloaking.