Tailoring the nanoantenna geometry to improve efficiency and bandwidth

Following our recent results on plasmonic nanoantennas of different geometry and shape, here we explore how geometry, size and loading techniques may affect and improve efficiency, bandwidth and sensitivity of various optical nanoantennas. We show how it may be possible to operate various nanoantenna geometries as efficient optical nanoradiators, and how their tuning and matching properties may be tailored with large degrees of freedom by designing suitable nanoloads placed at their gap. In this way, we successfully apply nanocircuit concepts to model the loading nanoparticles and in matching them to suitable optical lines. High levels of optical radiation efficiency may be achieved, even considering the realistic absorption of optical metals, by properly selecting specific geometries, size and design.