Tunable and multi-band plasmon resonance gratings using spheroidal nanoparticles

In recent years, there has been immense interest in two-dimensional metallic gratings based on plasmonic nanoparticles. The enhanced fields in these structures due to the plasmonic resonance of nano-particles, makes them ideal candidates for a variety of applications. Many of these studies have utilized spherical nano-particles which have a well-known localized surface plasmon resonance condition that is independent of wavelength. In this paper, we propose plasmonic arrays based on spheroidal nano-particles. We demonstrate that, unlike spheres, the localized surface plasmon resonance in these particles can be tuned. Additionally, we show that by using multi-layer arrays, we can obtain multiple plasmonic resonances.