Interfacial Mode Interactions of Surface Plasmon Polaritons on Gold Nanodome Films

Hollow metallic nanodome structures were fabricated using anodized aluminum oxide (AAO) nanopores as deposition and sacrificial templates. Individual Au nanodomes inherit the unique shapes of the well-defined AAO membranes whose pedestal cells become square or hexagonal lattices with hemispheres in close proximity. Minimal contact between the hollow nanodomes and the glass substrate provide an identical dielectric medium across the film. The nanodome Au films support surface plasmon polaritons (SPPs) of strong air-Au and weak Au-glass modes in the light transmission dispersions. The mode crossings of distinct SPPs exhibit characteristic energy gaps, which depend on the periodic geometries of the nanostructures.