Optical antennas are nanostructures designed as a device designed to efficiently convert free-propagating optical radiation to localized energy and vice versa. They are based on metal nanoparticles (NPs) and the interaction between light and metal NPs, which is dominated by localized surface Plasmon resonances (LSPRs). The excitation of LSPRs can lead to large near field enhancements and to an increase of the effective extinction cross section (scattering +
absorption) up to several times the physical cross section of the nanoparticle. These properties can be used to increase the interaction of any object located in their vicinity with free space radiation. In this talk, I will give a brief general introduction and discuss important experimental factors that generally control the optical antennas properties as well as exploring different physical systems where optical nanoantennas locally interact with carbon nanotubes, nanoemmiters, graphene and dielectric waveguides. Finally, I will talk about my research work at the LPL, where we are trying to explore the possibilities of incorporate these metallic nanostructures to increase the internal and external efficiency of organic light emitting diodes.