Color-tuning and switching optical transport through CdS hybrid plasmonic waveguide

We report the color-tuning and switching optical transport characters of CdS hybrid plasmonic waveguide by using near-field optical microscopy. The guided photoluminescence spectra under various waveguide lengths demonstrate a spectroscopic red-shift for the part of CdS nanoribbon placed on the sapphire substrate and an energy compensation at Ag film. Surface plasmon polariton leakage and radiation are explored by near-field characterizations. Finite difference time domain simulations have good agreement with the experimental observations of subwavelength confinement and propagation. With a strong end facet emission, the suggested hybrid plasmonic waveguide can serve as a color-changeable optical nanosource in integrated photonic devices. (C) 2009 Optical Society of America