Nonlinear Interaction of Terahertz Waves with Nanostructured Graphene in Resonance Multilayer Plasmon Structures

A numerical–analytical method is developed for mathematical simulation of nonlinear effects in multilayer plasmonic structures (PSs) based on nanostructured graphene. A nonlinear effect of the third-harmonic generation in multilayer PSs based on 2D periodic lattices of rectangular graphene microribbons on dielectric layers is numerically simulated in the terahertz frequency range. It is shown that the efficiency of nonlinear interaction (third-harmonic generation) in multilayer graphene PSs increases by several orders of magnitude at the resonance frequencies of the fundamental and higher modes of surface plasmon polaritons and can be increased in comparison with single-layer PSs due to an increase in the number of layers and packing density of the lattices of graphene microribbons, as well as application of multilayer substrates (dielectric mirrors). A decrease in the chemical potential leads to a decrease in the plasmon resonance frequency whereas the amplitude of the generated third harmonic significantly increases.