Optical nanorod antennas as dispersive one-dimensional Fabry-Peacuterot resonators for surface plasmons

Resonant optical nanoantennas exhibit a different length scaling due to the surface plasmons compared to their radio frequency counterparts. In this letter, we address this difference by calculating the wavelength-dependent effective mode index n(eff) for a cylindrical one-dimensional gold nanowire waveguide. Our results show that nanorod optical antennas act as dispersive and lossy Fabry-Peacuterot resonators for surface plasmons.