Resonant Fully dielectric metasurfaces for ultrafast Terahertz pulse generation

TL;DR

This paper introduces a fully dielectric semiconductor metasurface that significantly enhances terahertz pulse generation efficiency, offering a scalable and tunable approach for advanced electromagnetic wave control.

Contribution

It presents a novel dielectric metasurface design exploiting morphology-mediated resonances for efficient terahertz emission, surpassing traditional metal or semiconductor-based metasurfaces.

Findings

40-fold efficiency enhancement at optimized wavelength

Demonstrates potential for scalable terahertz emitter design

Exploits quadratic nonlinear response of dielectric material

Abstract

Metasurfaces represent a new frontier in materials science paving for unprecedented methods of controlling electromagnetic waves, with a range of applications spanning from sensing to imaging and communications. For pulsed terahertz generation, metasurfaces offer a gateway to tuneable thin emitters that can be utilised for large-area imaging, microscopy and spectroscopy. In literature THz-emitting metasurfaces generally exhibit high absorption, being based either on metals or on semiconductors excited in highly resonant regimes. Here we propose the use of a fully dielectric semiconductor exploiting morphology-mediated resonances and inherent quadratic nonlinear response. Our system exhibits a remarkable 40-fold efficiency enhancement compared to the unpatterned at the peak of the optimised wavelength range, demonstrating its potential as scalable emitter design.