Controlling high-<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>Q</mml:mi></mml:math> trapped modes in polarization-insensitive all-dielectric metasurfaces

Abstract

We reveal peculiarities of the trapped (dark) mode excitation in a polarization-insensitive all-dielectric metasurface, whose unit supercell is constructed by particularly arranging four cylindrical dielectric particles. Involving group-theoretical description we discuss in detail the effect of different orientations of particles within the supercell on characteristics of the trapped mode. The theoretical predictions are confirmed by numerical simulations and experimental investigations. Since the metasurface is realized from simple dielectric particles without the use of any metallic components, they are feasibly scalable to both $\ensuremath{\mu}\text{m-}$ and nanometer-size structures, and they can be employed in flat-optics platforms for realizing efficient light-matter interaction for multiple hot-spot light localization, optical sensing, and highly efficient light trapping.