title: Near-field-induced tunability of surface plasmon polaritons in composite metallic nanostructures.
abstract: We numerically study near-field-induced coupling effects in metal nanowire-based composite nanostructures. Our multi-layer system is composed of individual gold nanowires supporting localized particle plasmons at optical wavelengths, and a spatially separated homogeneous silver slab supporting delocalized surface plasmons. We show that the localized plasmon modes of the composite structure, forming so-called magnetic atoms, can be controlled over a large spectral range by changing the thickness of the nearby metal slab. The optical response of single-wire and array-based metallic structures are compared. Spectral shifts due to wire-mirror interaction as well as the coupling between localized and delocalized surface plasmon modes in a magnetic photonic crystal are demonstrated. The presented effects are important for the optimization of metal-based nanodevices and may lead to the realization of metamaterials with novel plasmonic functionalities.
authors.affiliation: Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology Lausanne, EPFL-STI-NAM, ELG Station 11, CH-1015 Lausanne, Switzerland. andre.christ@epfl.ch
authors.forename: A
authors.initials: A
authors.lastname: Christ
authors.forename: G
authors.initials: G
authors.lastname: Lévêque
authors.forename: O J F
authors.initials: OJ
authors.lastname: Martin
authors.forename: T
authors.initials: T
authors.lastname: Zentgraf
authors.forename: J
authors.initials: J
authors.lastname: Kuhl
authors.forename: C
authors.initials: C
authors.lastname: Bauer
authors.forename: H
authors.initials: H
authors.lastname: Giessen
authors.forename: S G
authors.initials: SG
authors.lastname: Tikhodeev