Enhanced Light Emission by Magnetic and Electric Resonances in Dielectric Metasurfaces. Issue 16 (18th May 2020) - Murai, Shunsuke
Abstract: An enhanced emission of high quantum yield molecules coupled to dielectric metasurfaces formed by periodic arrays of polycrystalline silicon nanoparticles is demonstrated. Radiative coupling of the nanoparticles, mediated by in‐plane diffraction, leads to the formation of collective Mie scattering resonances or Mie surface lattice resonances (M‐SLRs), with remarkable narrow line widths. These narrow line widths and the intrinsic electric and magnetic dipole moments of the individual Si nanoparticles allow resolving electric and magnetic M‐SLRs. Incidence angle‐ and polarization‐dependent extinction measurements and high‐accuracy surface integral simulations show unambiguously that magnetic M‐SLRs arise from in‐ and out‐of‐plane magnetic dipoles, while electric M‐SLRs are due to in‐plane electric dipoles. Pronounced changes in the emission spectrum of the molecules are observed, with almost a 20‐fold enhancement of the emission in defined directions of molecules coupled to electric M‐SLRs, and a fivefold enhancement of the emission of molecules coupled to magnetic M‐SLRs. These measurements demonstrate the potential of dielectric metasurfaces for emission control and enhancement, and open new opportunities to induce asymmetric scattering and emission using collective electric and magnetic resonances. Abstract : Magnetic and electric Mie surface lattice resonances (M‐SLRs) are excited via the enhanced radiative coupling between Mie resonators by in‐plane diffraction on a square array of poly‐crystalline silicon nanoparticles. A significant and directionally enhanced photoluminescence is demonstrated from an emitter layer coupled to M‐SLRs. The results open new opportunities for fundamental studies of light–matter interaction with dielectric metasurfaces.