# Plasmon-induced nonlinearity enhancement and homogenization of graphene metasurfaces

## TL;DR

This paper shows that patterning graphene into metasurfaces significantly boosts its third-order nonlinear susceptibility, and introduces a new homogenization method to accurately quantify this enhancement, opening avenues for advanced nonlinear optics.

## Contribution

A novel homogenization technique is developed to accurately characterize nonlinear susceptibility in graphene metasurfaces, revealing over two orders of magnitude enhancement.

## Key findings

- Nonlinear susceptibility of graphene can be enhanced by patterning into metasurfaces.
- The proposed homogenization method accurately predicts nonlinear properties.
- Enhanced nonlinearity may enable new nonlinear optical applications.

## Abstract

We demonstrate that the effective third-order nonlinear susceptibility of a graphene sheet can be enhanced by more than two orders of magnitude by patterning it into a graphene metasurface. In addition, in order to gain deeper physical insights into this phenomenon, we introduce a novel homogenization method, which is subsequently used to characterize quantitatively this nonlinearity enhancement effect by calculating the effective linear and nonlinear susceptibility of graphene metasurfaces. The accuracy of the proposed homogenization method is demonstrated by comparing its predictions with those obtained from the Kramers-Kronig relations. This work may open up new opportunities to explore novel physics pertaining to nonlinear optical interactions in graphene metasurfaces.