Enhanced High-Harmonic Generation from an All-Dielectric Metasurface

TL;DR

This paper demonstrates significant enhancement of high-harmonic generation using a silicon dielectric metasurface with a sharp Fano resonance, enabling advanced control of high-field processes at the nanoscale.

Contribution

It introduces a novel all-dielectric metasurface that significantly boosts high-harmonic emission through a resonant Fano feature, advancing nanophotonic control of high-field phenomena.

Findings

Harmonic emission is enhanced by over 100 times compared to unpatterned samples.

Harmonics are highly anisotropic and polarization-dependent.

The enhancement is wavelength-selective due to the Fano resonance.

Abstract

The recent observation of high-harmonic generation from solids creates a new possibility for engineering fundamental strong-field processes by patterning the solid target with subwavelength nanostructures. All-dielectric metasurfaces exhibit high damage thresholds and strong enhancement of the driving field, making them attractive platforms to control high-harmonics and other high-field processes at nanoscales. Here we report enhanced non-perturbative high-harmonic emission from a Si metasurface that possesses a sharp Fano resonance resulting from a classical analogue of electromagnetically induced transparency. Harmonic emission is enhanced by more than two orders of magnitude compared to unpatterned samples. The enhanced high harmonics are highly anisotropic with excitation polarization and are selective to excitation wavelength due to its resonant feature. By combining nanofabrication technology and ultrafast strong-field physics, our work paves the way for designing new compact ultrafast photonic devices that operate under high intensities and short wavelengths.