Enhanced coherent amplification and nonlinear effects using tunable THz hyperbolic metamaterials based on active and passive graphene

Graphene is a two-dimensional (2D) material that is very appealing for terahertz (THz) applications given that its plasma frequency is located exactly in this frequency band, as well as its extremely large third-order nonlinear parameters [1] - [3] . In addition, its linear and nonlinear properties are both highly tunable via electrical bias or chemical doping. As a result, graphene based devices ...