Superdirective all-dielectric nanoantennas: Theory and experiment

Abstract

We introduce a novel concept of superdirective nanoantennas based on the generation of higherorder optically-induced magnetic multipoles. Such an all-dielectric nanoantenna can be realized as an optically small spherical dielectric nanoparticle with a notch excited by a point source located in the notch. We also confirm the predicted superdirectivity effect experimentally through scaling to the microwave frequency range.