Transverse-electric Brewster effect enabled by nonmagnetic two-dimensional materials

Abstract

Discovered in the 19th century, the Brewster effect is known to occur for transverse-magnetic waves in regular optical dielectrics; however, it is believed to arise for transverse-electric (TE) waves only in systems with magnetic responses, i.e., nonunity effective relative permeability. This paper introduces a scheme to realize the TE Brewster effect in a homogeneous dielectric interface without magnetic responses, by adding ultrathin two-dimensional (2D) materials such as graphene. In particular, the effect remains even for waves approaching normal incidence, spanning from terahertz to visible frequencies. In contrast to the conventional Brewster effect, the graphene-assisted TE Brewster effect is asymmetric, and can be achieved only when the incidence is from the higher-refractive-index side. Moreover, graphene layers can tailor a total-internal-reflection dielectric interface into zero reflection, accompanied by perfect absorption. This control over TE waves enabled by ultrathin 2D materials may lead to a variety of applications, such as atomically thin absorbers, polarizers, and antireflection coating.