Optical Interaction Effects in Nanoplasmonic Antennas at Visible Wavelengths

In this article we study the effects of nanoelements' optical interactions on the properties and response of the nanoplasmonic antennas. Here, we report on some simple, ultra directive, and compact optical antenna designs working based on a hybridized plasmon mode. By enhancing the electromagnetic (EM) coupling between the nanoparticles, we achieve new optimum designs. Using two, three, or four closed nanoelements, the nano-antenna shows high directionality and gives us the opportunity to have a compact, color-switched, and spectrally-tunable optical nanoantenna. Such design are experimentally realized by HCL – a bottom-up nanofabrication based on colloidal self-assembly. Finally, in order to design a highly directive nanoantenna we present a new highly directive and packed Yagi-Uda (P-YU) nano-antenna. (paper)