Magnetic Toroidal Dipole Resonances for Efficient THz Generation in Dielectric Metasurfaces

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Authors: Davide Rocco, Olga N. Sergaeva, Luca Carletti, Andrea Tognazzi, Paolo Franceschini, Alfonso Carmelo Cino, Andrea Locatelli, Costantino De Angelis
Cited by: 1
References: 49

Abstract

Nonlinear dielectric metasurfaces represent a rapidly advancing family of optical devices characterized by high nonlinear conversion efficiency with an ultrathin form factor. Here, we report on terahertz (THz) emission through difference-frequency generation (DFG) in an Aluminum Gallium Arsenide (AlGaAs) metasurface supporting magnetic toroidal dipolar resonances at the two pump wavelengths, which nonlinearly interact with each other. The simultaneous excitation of these high-Q resonances, together with the dispersive behavior of the nonlinear susceptibility, enables an exceptionally strong DFG response. Conversion efficiencies around 8 THz exceed those of an unstructured AlGaAs slab of the same thickness by over nine orders of magnitude. These results highlight the potential of DFG metasurfaces as compact and highly efficient platforms for THz generation.

Fields of Study & Subjects

Metamaterials and Metasurfaces Applications Plasmonic and Surface Plasmon Research Terahertz technology and applications

Publication details

Journal / source
IEEE photonics journal
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Volume
18
Issue
2
Pages
1–7
Publication date
10 February 2026
Language
EN