Tunability of the Brewster angle and dispersion type of the asymmetric graphene-based hyperbolic metamaterials

Abstract

In this paper, the reflection and transmission properties of the plane electromagnetic waves are investigated at the interface of an asymmetric graphene-based hyperbolic metamaterial composed of alternating stacks of graphene monolayers and dielectric layers. It is shown that the Brewster angle can be changed by tailoring the orientation of the optical axis of the considered structure as well as the chemical potential of the graphene. Furthermore, the propagation of the wave vectors and Poynting vectors are studied in the given structure. Such structures have singlet dispersion behavior for the transverse electric wave and triplet dispersion behavior for the transverse magnetic wave. These types of dispersion can be switched by modifying the orientation of the optical axis, the chemical potential of the graphene, and the frequency of the impinging wave. Such tunability characteristics of the graphene-based metamaterials may be practical to design optical devices such as hyperlenses and tunable optical filters.