Plasmonic nanophotonics: manipulating light and sensing molecules

We show that plamonic nanomaterials allow the localization and guiding light, with high efficiency, and molecule sensing, with unsurpassed sensitivity. Two types of palsmonic naomaterials are considered: metal nanowires and fractal colloid aggregates. The electromagnetic field distribution for thin metal nanowires is found, by using the discrete dipole approximation. The plasmon polariton modes in wires are numerically simulated. These modes are found to be dependent on the incident light wavelength and direction of propagation. The existence of localized plasmon modes and strong local field enhancement in percolation nanowire composites is demonstrated. Novel left-handed materials in the near-infrared and visible are proposed based on nanowire composites. Dramatic enhancement in fractal colloid aggregates and, especially, in fractal-microcavity composites are discussed along with new potential applications of these plasmonic materials.