title: Plasmonic channel waveguides in random arrays of metallic nanoparticles.
abstract: We report detailed characterization of surface plasmon-polariton guiding along 1-, 1.5- and 2-μm-wide channels in high-density (~75 μm-2) random arrays of gold 70-nm-high and 50-nm-wide nanoparticles fabricated on a 70-nm-thin gold film supported by a 170-μm-thick silica substrate. The mode propagation losses, effective index dispersion, and scattering parameters are characterized using leakage-radiation microscopy, in direct and Fourier planes, in the wavelength range of 740-840 nm. It is found that the mode supported by 2-μm-wide channels propagates over > 10 μm in straight waveguides, with the corresponding S-bends and Y-splitters functioning reasonably well. The results show that the SPP waves can efficiently be guided by narrow scattering-free channels cut through randomly corrugated surface regions. The potential of this waveguiding mechanism is yet to be fully explored by tuning the scattering mean-free path and localization length via the density and size of random nanoparticles. Nevertheless, the results obtained are encouraging and promising diverse applications of these waveguide components in plasmonic circuitry.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Pisano
authors.forename: Victor
authors.initials: V
authors.lastname: Coello
authors.forename: Cesar E
authors.initials: CE
authors.lastname: Garcia-Ortiz
authors.forename: Yiting
authors.initials: Y
authors.lastname: Chen
authors.forename: Jonas
authors.initials: J
authors.lastname: Beermann
authors.forename: Sergey I
authors.initials: SI
authors.lastname: Bozhevolnyi