A graphene based broadband metasurface absorber in the terahertz region

Abstract

This article proposes the design of a graphene-based metasurface that can have a wide absorption bandwidth in the terahertz region. The unit segment of the proposed structure is composed of three parts stacked to each other. A graphene-based plus-shaped pattern is deposited on the top of an amorphous silicon dioxide (SiO2) dielectric substrate layer. Another square-shaped graphene pattern covers the backside of SiO2 completely. The top graphene geometry is an optimized one, which can achieve a wide absorption bandwidth of more than 90% absorptivity over a bandwidth of 12 THz ranging from 7 THz to 19 THz. The proposed metasurface achieves two closed absorption peaks at 9.55 THz and 12.5 within the above said spectral range. The design is ultrathin in nature and it is in the order of /30. The periodicity of the structure is approximately /7.5. The designed prototype is polarization independent in nature. This particular graphene-based metasurface works well upto 60ºof the incident angles of the incoming electromagnetic wave to the top surface of the structure under both TE and TM polarizations. © 2019 URSI. All rights reserved.