  A metal nanoparticle plasmon waveguide for electromagnetic energy transport
utilizing dispersion engineering to dramatically increase lateral energy
confinement via a two-dimensional pattern of Au dots on an optically thin Si
membrane is described. Using finite-difference time-domain simulations and
coupled-mode theory, we show that phase-matched evanescent excitation from
conventional fiber tapers is possible with efficiencies > 90 % for realistic
geometries. Energy loss in this waveguide is mainly due to material absorption,
allowing for 1/e energy decay distances of about 2 mm for excitation at
telecommunication frequencies. This concept can be extended to the visible
regime and promises applications in optical energy guiding, optical sensing,
and switching.
