title: Optimization of a nanotip on a surface for the ultrafast probing of propagating surface plasmons.
abstract: We theoretically analyze a method for characterizing propagating surface plasmon polaritons (SPPs) on a thin gold film. The SPPs are excited by few-cycle near-infrared pulses using Kretschmann coupling, and a nanotip is used as a local field sensor. This geometry removes the influence of the incident excitation laser from the near fields, and enhances the plasmon electric field strength. Using finite-difference-time-domain studies we show that the geometry can be used to measure SPP waveforms as a function of propagation distance. The effects of the nanotip shape and material on the field enhancement and plasmonic response are discussed.
authors.forename: B
authors.initials: B
authors.lastname: Ahn
authors.forename: J
authors.initials: J
authors.lastname: Schötz
authors.forename: W A
authors.initials: WA
authors.lastname: Okell
authors.forename: F
authors.initials: F
authors.lastname: Süßmann
authors.forename: B
authors.initials: B
authors.lastname: Förg
authors.forename: S C
authors.initials: SC
authors.lastname: Kim
authors.forename: M F
authors.initials: MF
authors.lastname: Kling
authors.forename: D
authors.initials: D
authors.lastname: Kim