Enhanced Nonlinear Harmonic Signal Emission by an Electromagnetically Induced Transparency Resonant All-Dielectric Metasurface

Artificially engineered all-dielectric configurations have received growing attention in the past decades owing to their unique properties in facilitating low-loss and efficient manipulation of electromagnetic radiations. Using the concept of all-dielectric metamaterials, in this study, we demonstrate that a metasurface consisting of all-dielectric unit cells based on a combination of bar and ring resonators efficiently augments the emission of nonlinear harmonics through the use of the optically driven electromagnetically induced transparency (EIT) mode. Initially, we discuss and present the spectral response of the system in the linear regime to judiciously tailor the geometrics of the proposed meta-atom. By taking advantage of the effective third-order nonlinear susceptibility tensors of the entire dielectric metasurface, as well as the resonant EIT feature in the near-infrared wavelengths, we showed that the designed platform facilitates the emission of visible light. The formation of robust near-field enhancements within the unit cell enabled the emission of the third harmonic beam with a high conversion efficiency of 1.75 × 10
⁻⁴
%. Compared to the analogous studies based on nonlinear dielectric meta-optics (i.e., Mie resonators), the proposed configuration facilitates substantially high conversion efficiency and low loss operation. We envision that this understanding paves the way toward the use of asymmetric lineshapes and all-dielectric metasurfaces in the development of coherent light sources and intense lasers.