Recent advances in high refractive index dielectric nanoantennas: Basics and applications

Nanoparticles made of High Refractive Index dielectric materials have been proposed as an alternative to metals driven by their low-losses and magnetic response. The coherent effects between the electric and magnetic resonances are responsible for their exceptional directionality properties that make them attractive in applications where enhancing light-matter interaction and controlling the radiation direction is extremely relevant. These nanoparticles, when used as unit-cells of more complex systems, such as metasurfaces, result to be essential in the design of novel optical devices. Their low-losses, strong confinement of electromagnetic energy and the outstanding scattering efficiencies show these nanoantennas as promising candidates for Surface Enhanced Spectroscopies, non-linear phenomena or sensing. Here, we describe and discuss the origins and recent advances in this rapidly developing field of dielectric nanophotonics, paying special attention to the main significant contributions we have done since its startup to boost its progress. In particular, light directivity, steering and switching of light, spectroscopy, sensing and non-linear phenomena, third harmonic generation are some of the applications that motivated this brief overview.