Multi band square-shaped polarization-insensitive graphene-based perfect absorber

In this manuscript, an original graphene-based metamaterial perfect absorber (MPA) was suggested and investigated with substituting aluminum with graphene. The proposed structure consists of a gold substrate as a conductive layer, a silicon substrate as a middle insulated layer and the patterned graphene layer as a resonator. The suggested structure, with only one metamaterial layer, has a lot of advantages such as simple implementation, cost-effectiveness, simple design and frequency tunability. The results of the proposed absorber, demonstrate that the absorber can provide absorption close to 100% at the frequencies of 0.56, 0.79, 1.02 and 1.25 THz by 0.9 eV graphene chemical potential (μc). With increasing the thickness of the silicone insulating layer, the absorption peaks number can be increased up to XIII bands. Also, changing the Fermi level can cause an absorption frequency shift. Furthermore, this structure is polarization insensitive and it is tolerating incident angles up to 45°. The recommended absorber is an appropriate candidate for filtering, spectroscopy, imaging and sensing application.