Graphene-Based Couplers: A Brief Review

Graphene is an interesting debated topic between scientists because of its unique properties such as tunable conductivity. Graphene conductivity can be varied by either electrostatic or magnetostatic gating or via chemical doping, which leads to the design of various photonic and electronic devices. Among various graphene-based structures, plasmonic graphene couplers have attracted the attention of many researchers because of their fascinating applications in the THz frequencies. There are four main types of graphene couplers proposed in the literature, which are: 1- directional, 2- non-reciprocal, 3- dielectric, and 4- nano-ribbon couplers. This paper aims to study and investigate the various types of graphene-based couplers published in the literature.