Harmonic generation by metal nanostructures optically coupled to 2D transition metal dichalcogenide

TL;DR

This paper investigates how strong coupling between 2D transition metal dichalcogenides and metal nanostructures influences high harmonic generation, revealing complex dynamics and significant enhancement effects through simulations and analytical models.

Contribution

It introduces a detailed analysis of nonlinear optical interactions between 2D materials and plasmonic structures, highlighting the impact on harmonic generation and providing new insights into coupled nanostructure behavior.

Findings

Strong coupling affects even harmonic generation in metal nanostructures.

Coupling with 2D WS2 significantly enhances second harmonic generation.

Complex dynamics depend on physical parameters of the coupled system.

Abstract

Rigorous electrodynamical simulations based on the nonlinear Drude model are performed to investigate the influence of strong coupling on high harmonic generation by periodic metal gratings. It is shown that a thin dispersive material with a third order nonlinearity strongly coupled to surface plasmon-polaritons significantly affects even harmonics generated solely by the metal. The physical nature of this effect is explained using a simple analytical model and further supported by numerical simulations. Furthermore, the behavior of the second and third harmonics is investigated as a function of various physical parameters of the model material system, revealing highly complex dynamics. The nonlinear optical response of 2D few-layer WS2 with both second and third order susceptibilities coupled to a periodic plasmonic grating is shown to have a significant effect on the second harmonic generation of the metal.