Polarization-controlled selective excitation of Mie resonances in a dielectric nanoparticle on a coated substrate

Abstract

Spherical high-index nanoparticles with low material losses support sharp high-$Q$ electric and magnetic resonances and exhibit a number of interesting optical phenomena. Developments in fabrication techniques have enabled further study of their properties and the investigation of related optical effects. After deposition on a substrate, the optical properties of a particle change dramatically due to mutual interaction. Here, we consider a silicon spherical nanoparticle on a dielectric one-layered substrate. At normal incidence of light, the layer thickness controls the contribution of the nanoparticle's electric and magnetic multipoles to the subsequent optical response. We show that changing the polarization of incident light at a specific excitation angle and layer thickness leads to switching between the multipoles. We further observe a related polarization-driven control over the direction of the scattered radiation.