Coupling of multiple LSP and SPP resonances: interactions between an elongated nanoparticle and a thin metallic film.

We study the coupling interactions between a progressively elongated silver nanoparticle and a silver film on a glass substrate. Specifically, we investigate how the coupling between localized surface plasmons (LSPs) and propagating surface plasmon polaritons (SPPs) is influenced by nanoparticle length. Although the multiple resonances supported by the nanoparticle are effectively standing wave surface plasmons, their interaction with the SPP continuum of the underlying Ag film indicates that their spectral response is still localized in nature.

Compound resonance-induced coupling effects in composite plasmonic metamaterials.

We study a compound plasmonic system composed of a periodic Au grating array placed close to a thin Au film. The study is not limited to normal incidence and dispersion diagrams are computed for a broad variety of parameters. In addition to identifying localized and propagating modes and the coupling/hybridization interactions between them, we go further and identify modes of compound nature, i.

Plasmon delocalization onset in finite sized nanostructures.

The transition from localized to delocalized plasmons (i.e. the transition from a situation where the decay length of a travelling surface plasma wave is greater than its propagation distance to a situation where it is smaller) and hence the onset of plasmon delocalization is studied in a single 2D silver nanoparticle of increasing length.