Plasmonic sectoral horn nanoantennas.

In this Letter, plasmonic sectoral horn nanoantennas working at near-infrared wavelength (1550 nm) have been investigated. We demonstrate that, although there are certain differences between the plasmonic and classical radiofrequency (RF) sectoral horn antennas, the plasmonic horns still possess a number of attractive features, like their RF counterparts, such as tunable high directivities, simplicity in fabrication, and ease of coupling to waveguides. As a specific application, we further show how to exploit these findings to optimize an optical wireless nanolink using the proposed horn nanoantennas, and obtain a 60-fold increase in the received power compared with the situation of matched dipole nanoantennas.