Near-field-induced tunability of surface plasmon polaritons in composite metallic nanostructures.
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.
Christ
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Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology Lausanne, EPFL-STI-NAM, ELG Station 11, CH-1015 Lausanne, Switzerland. andre.christ@epfl.ch
Lévêque
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Martin
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Zentgraf
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Kuhl
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Bauer
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Giessen
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Tikhodeev
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