Coupling dielectric waveguide modes to surface plasmon polaritons

Abstract

We study dielectric/metal thin film multilayers designed for the coupling of dielectric waveguide modes and surface plasmons. The coupling as identified in calculated dispersion relations for extended multilayers is confirmed by measured angle-resolved reflectance data. By lateral structuring of the multilayers the mutual coupling of dielectric and plasmonic modes is directly observed by fluorescence based microscopy. For a light wavelength of 514nm we find a coupling length of 15µm. Our results highlight the potential of hybrid dielectric/metal waveguides for integrating surface plasmon based photonic circuitry or sensing elements into conventional optical devices.