# Hot electrons modulation of third harmonic generation in graphene

## TL;DR

This paper investigates how hot electrons influence third harmonic generation in graphene, revealing deviations from expected behavior that impact the performance of graphene-based nonlinear photonic devices.

## Contribution

It demonstrates the effect of hot electrons on third harmonic generation in graphene and highlights implications for device performance under varying electronic temperatures.

## Key findings

- Deviation from cubic power-law in third harmonic generation due to hot electrons
- Electronic temperature affects nonlinear optical response of graphene
- Implications for graphene-based photonic device performance

## Abstract

Hot electrons dominate the ultrafast ($\sim$fs-ps) optical and electronic properties of metals and semiconductors and they are exploited in a variety of applications including photovoltaics and photodetection. We perform power-dependent third harmonic generation measurements on gated single-layer graphene and detect a significant deviation from the cubic power-law expected for a third harmonic generation process. We assign this to the presence of hot electrons. Our results indicate that the performance of nonlinear photonics devices based on graphene, such as optical modulators and frequency converters, can be affected by changes in the electronic temperature, which might occur due to increase of absorbed optical power or Joule heating.