Argia txiki egiten denean

Abstract

A brief historical perspective on the concept of light is introduced, focusing on some of the aspects derived from its ondulatory nature, which determines many of the properties of light-matter interaction within the electrodynamical theory. The ondulatory nature of light sets up a diffraction limit, which  prevents standard localization of light below half a micrometer. The use of metallic nanoparticles, and the excitations of their conduction electrons with the generation of electronic surface charge density waves, so-called plasmons, allows for bringing the energy and momentum of light down to sub-diffraction dimensions. Metallic nanostructures are shown to act as effective optical nanoantennas which capture and emit light, opening photonics to the realm of the nanoscale. Examples of technological application of optical nanoantennas in the fields of optical nanoscopy, surface-enhanced molecular spectroscopy, oncological therapy, energy havesting, metamaterials and information technologies are discussed.