Enhanced third harmonic generation from sinusoidal graphene gratings

Abstract

We investigate the nonlinear optical third harmonic generation of sinusoidal curved graphene which is placed on the dielectric substrate. Under transverse magnetic polarization, the third harmonic generation (THG) from graphene is dramatically enhanced at fundamental-mode and several higher-order modes of surface plasmon of graphene. The enhancement factor of THG is up to106 compared to that from graphene on a planar dielectric. We study in detail THG intensity affected by the Fermi level of graphene, grating period and amplitude, and the angle of incidence of light. The tunable and enhanced THG response at multiple wavelengths show that the sinusoidal-shaped graphene grating has potential applications for graphene based broadband nonlinear photonics.