Enhanced third harmonic generation from the epsilon-near-zero modes of ultrathin films

TL;DR

This paper demonstrates efficient third harmonic generation using epsilon-near-zero modes in ultrathin ITO films, achieving high conversion efficiency through field enhancement, with potential applications in nanoscale frequency conversion.

Contribution

The study introduces a novel nanoscale frequency conversion technique utilizing ENZ modes in ultrathin films, achieving significant efficiency improvements.

Findings

Achieved 3.3x10^-6 conversion efficiency

Field enhancement factor of 200

Demonstrated applicability to other materials

Abstract

We experimentally demonstrate efficient third harmonic generation from an indium tin oxide (ITO) nanofilm (lambda/42 thick) on a glass substrate for a pump wavelength of 1.4 um. A conversion efficiency of 3.3x10^-6 is achieved by exploiting the field enhancement properties of the epsilon-near-zero (ENZ) mode with an enhancement factor of 200. This nanoscale frequency conversion method is applicable to other plasmonic materials and reststrahlen materials in proximity of the longitudinal optical phonon frequencies.