Graphene-Integrated Plasmonics Metasurface for Active Controlling Artificial Second Harmonic Generation

Plasmonics has developed tremendously in recent years owing to its significant performance in enhanced nonlinear optical emission. However, plasmonic structures have predefined geometry, lacking flexibility for active control of the artificial nonlinear signal. In this paper, we numerically investigate active control of second harmonic generation (SHG) from plasmonic metasurface based on magnetic Lorentz force. The unit element of designed plasmonic metasurface consists of a gold split ring resonator and a bismuth bar, and integrated with graphene layer. By varying the Fermi energy of graphene from 0.2 eV to 1.0 eV, we achieve a 17.2 THz shift of the second harmonic frequency. In addition, it is demonstrated that the range of SHG frequency shift can be further enlarged by increasing the number of graphene layer. Our results pave the way for applications in generation of continuous laser source, optical communications and signal processing.