Design and investigation on polarization insensitive dual band graphene based tunable absorber for THz applications

Abstract

In this communication, a metal-free graphene-based Absorber is designed and examined in the THz regime. The graphene layer is coated over the SiO2 substrate, while the silver layer is used on the other side of the substrate. The designed absorber works in two frequency bands i.e. 2.2–2.91 THz (11–14 μm) and 4.85–5.83 THz (51–62 μm), having more than 90% absorption. Peak absorption is obtained 2.55 THz and 5.05 THz with 97.78% and 99.71% absorption. With the help of circular sectoring, the designed absorber shows wide polarization and wide incident angle (up to 60°) insensitivity for both TE and TM modes. Change in chemical potential of graphene provides the tunable characteristics in the designed absorber. All these outcomes confirm that the designed metal-free graphene-based metamaterial absorber works efficiently in THz regime and can be used in different applications such as, sensing and imaging.