title: Directional excitation of surface plasmon polaritons via nanoslits under varied incidence observed using leakage radiation microscopy.
abstract: Surface Plasmon Polaritons (SPPs) are excited at the interface between a thin gold film and air via the illumination of nanoslits etched into the film. The coupling efficiency to the two propagation directions away from the slits is determined by leakage radiation microscopy, when the angle of incidence of the pump beam is changed from 0° to 20°. We find that preferential coupling of SPPs into one direction can be achieved for non-normal incidence in the case of single slits and slit pairs. The proportion of SPP excited into one direction can be in excess of 90%. We further provide a simple model of the process, and directly compare the performances of the two approaches.
authors.affiliation: Experimental Solid State Group, Physics Department, Imperial College London, London SW7 2AZ, UK. y.sonnefraud@imperial.ac.uk
authors.forename: Yannick
authors.initials: Y
authors.lastname: Sonnefraud
authors.forename: Sarp
authors.initials: S
authors.lastname: Kerman
authors.forename: Giuliana
authors.initials: G
authors.lastname: Di Martino
authors.forename: Dang Yuan
authors.initials: DY
authors.lastname: Lei
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Maier
mesh_terms: D006046:Gold / Q000737:chemistry*; D007368:Interferometry / Q000379:methods*; D008027:Light; D008422:Materials Testing; D008853:Microscopy / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010783:Photometry / Q000379:methods*; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold