Resonant Fully Dielectric Metasurfaces for Ultrafast Terahertz Pulse Generation
Luke Peters, Davide Rocco, Luana Olivieri, Unai Arregui Leon, Vittorio Cecconi, Luca Carletti, Carlo Gigli, Giuseppe Della Valle, Antonio Cutrona, Juan Sebastian Totero Gongora, Giuseppe Leo, Alessia Pasquazi, Costantino De Angelis, Marco Peccianti
Abstract
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 (THz) generation, metasurfaces offer a gateway to tuneable thin emitters that can be utilized 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, the use of a fully dielectric semiconductor exploiting morphology‐mediated resonances and inherent quadratic nonlinear response is proposed. This system exhibits a remarkable 40‐fold efficiency enhancement compared to the unpatterned at the peak of the optimized wavelength range, demonstrating its potential as a scalable emitter design.