Nanooptics

Optical nanoantennas mediate near and far optical fields. Operating a directional nanoantenna in transmitting mode is challenging as the antenna needs to be driven by a nanosized optical-frequency generator, working at the antenna resonance frequency and attached precisely to the antenna feed with a correct orientation. Quantum emitters have been used as optical nano generators. However, their precise positioning relative to the nanoantenna is a technical barrier to the practical implementation. One unique source to drive nanoantenna is the photoluminescence of the antenna material as the operation frequency range corresponds to the electronic transitions in matter. Here, we exploit plasmon-modulated photoluminescence (PMPL) as an effective optical source to drive directional nanoantennas. We experimentally realize two technically challenging theoretical proposals, namely, optical nano-spectrometer based on Yagi-Uda nanoantennas and tunable broadband directional emission from log-periodic nanoantennas. Using photoluminescence from the nanoantenna as an optical source promotes practical implementation of transmitting optical nanoantennas.