Thermo-modulational interband susceptibility and ultrafast temporal dynamics in nonlinear gold-based plasmonic devices

TL;DR

This paper models the nonlinear temporal dynamics of gold-based plasmonic devices caused by heating, revealing a thermo-modulational nonlinearity that affects surface plasmon polariton propagation and induces a spectral red-shift.

Contribution

It introduces the first theoretical model of thermo-modulational effects on plasmonic device dynamics, including a novel nonlinear Schrödinger-like equation for pulse propagation.

Findings

Thermo-modulational nonlinearity significantly influences plasmonic propagation.

Predicted intense spectral red-shift due to thermal effects.

First theoretical description of heat-induced nonlinear dynamics in gold nanowires.

Abstract

Starting from first principles, we theoretically model the nonlinear temporal dynamics of gold-based plasmonic devices resulting from the heating of their metallic components. At optical frequencies, the gold susceptibility is determined by the interband transitions around the X,L points in the first Brillouin zone and thermo-modulational effects ensue from Fermi smearing of the electronic energy distribution in the conduction band. As a consequence of light-induced heating of the conduction electrons, the optical susceptibility becomes nonlinear. In this paper we describe, for the first time to our knowledge, the effects of the thermo-modulational nonlinearity of gold on the propagation of surface plasmon polaritons guided on gold nanowires. We introduce a novel nonlinear Schroedinger-like equation to describe pulse propagation in such nanowires, and we predict the appearance an intense spectral red-shift caused by the delayed thermal response.