Waveguide engineering of graphene's nonlinearity

TL;DR

This paper demonstrates how waveguide engineering, including hybrid plasmonic design and Fermi level tuning, significantly enhances graphene's nonlinear optical properties, enabling low-power nonlinear devices.

Contribution

It introduces a novel waveguide design that amplifies graphene's nonlinearity and reduces required switching power through Fermi level manipulation.

Findings

Nonlinear parameter is dramatically increased.

Switching optical power is reduced to sub-watt levels.

Design enables practical nonlinear optical devices using graphene.

Abstract

Graphene has recently been shown to possess giant nonlinearity; however, the utility of this nonlinearity is limited due to high losses and small interaction volume. We show that by performing waveguide engineering to graphene's nonlinearity, we are able to dramatically increase the nonlinear parameter and decrease the switching optical power to sub-watt levels. Our design makes use of the hybrid plasmonic waveguide and careful manipulation of graphene's refractive index by tuning its Fermi level. The ability to tailor the nonlinear parameter in graphene based waveguides via the Fermi level provides a paradigm of nonlinear optics devices to be realized.