High-Q collective Mie resonances in monocrystalline silicon nanoantenna arrays for the visible light.

Dielectric optical antennas have emerged as a promising nanophotonic architecture for manipulating the propagation and localization of light. However, the optically induced Mie resonances in an isolated nanoantenna are normally with broad spectra and poor -factors, limiting their performances in sensing, lasing, and nonlinear optics. Here, we dramatically enhance the -factors of Mie resonances in silicon (Si) nanoparticles across the optical band by arranging the nanoparticles in a periodic lattice. We select monocrystalline Si with negligible material losses and develop a unique method to fabricate nanoparticle arrays on a quartz substrate. By extinction dispersion measurements and electromagnetic analysis, we can identify three types of collective Mie resonances with -factors 500 in the same nanocylinder arrays, including surface lattice resonances, bound states in the continuum, and quasi-guided modes. Our work paves the way for fundamental research in strong light-matter interactions and the design of highly efficient light-emitting metasurfaces.