Circular slot with square split ring resonators (SRRs) based metasurface absorber for terahertz applications

A graphene metamaterial-based absorber that can be tuned to three distinct frequencies and is not affected by any polarization angle has been proposed for THz applications. The design of the polarization-insensitive metamaterial absorber includes two split ring resonators and a circular slot with minus shaped strip on the graphene material. Simulation findings using the finite element method demonstrate that the developed absorber has absorption efficiencies greater than 90%. Graphene’s surface plasmon resonances confine the field, resulting in three ideal narrow absorption peaks at 7.07, 7.57, and 9.49 THz with efficiencies of 91.08%, 99.15%, and 99.85%, respectively. Moreover, it has been shown that the absorber’s performance can be enhanced and the resonance frequencies shifted by altering the chemical potential of the graphene sheet. The suggested THz absorber’s response is the same for both transverse (TE) and transverse (TM) polarizations, and it is also angularly stable (up to 90 degrees).