A low-loss fiber accessible plasmon photonic crystal waveguide for planar energy guiding and sensing

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.