Hybrid metasurface-photonic crystal-based platform for nonlinear optical applications

We design and experimentally demonstrate nonlinear, periodically stacked, all-dielectric metasurfaces, enabling an efficient third harmonic generation not only in the transparent but also in the absorptive wavelength range of the constituent materials. Mie resonance-based silicon metasurfaces were vertically integrated, using the spin-on-glass as the spacer, to generate and control the photonic bandgap formed due to stacking. We developed and optimized the planarization and alignment processes to achieve the predicted performance in laboratory experiments. This work offers a simple and reliable theoretical and experimental approach for three-dimensional integration relying on the synergy of the unique properties of metamaterials and photonic crystals.