Ultra-High Normalized Bandwidth TE and TM Polarization Insensitive Terahertz Absorber with Graphene Disks Configuration

In this paper, we have proposed ultra-broadband terahertz absorber with three layers of periodic graphene disks arrays (PGDAs). A gold layer was utilized as backside reflector and TOPAS as dielectric spacers. Circuit model of PGDAs and the developed Transmission Line Model (TLM) for the absorber is utilized to design the structure using impedance matching concept. The validity of the results of the device was confirmed by Finite Element Method (FEM). The structure absorbs both TE and TM polarizations. Furthermore, the obtained normalized absorption bandwidth is 148% with a bandwidth of 2.64 THz in 1.78 THz central frequency which is to best of our knowledge the best report in two-dimensional graphene-based structures.