title: Analysis of damping-induced phase flips of plasmonic nanowire modes.
abstract: We launch surface plasmons from one end of a silver nanowire by asymmetric illumination with white light and use plasmon-to-light scattering at the nanowire ends to probe spectroscopically the plasmonic Fabry-Perot wire modes. The spectral positions of the maxima and minima in the scattered intensity from both nanowire ends are found to be either in-phase or out-of-phase, depending on the nanowire length and the spectral range. This behavior can be explained by a generalized Fabry-Perot model. The turnover point between the two regimes is sensitive to the surface plasmon round trip losses and thus opens a new possibility for detecting changes of the optical absorption in the nanowire environment.
authors.affiliation: Institute of Physics, Karl-Franzens-University, Graz, Austria. andreas.hohenau@uni‑graz.at
authors.forename: Andreas
authors.initials: A
authors.lastname: Hohenau
authors.forename: Primoz
authors.initials: P
authors.lastname: Kusar
authors.forename: Christian
authors.initials: C
authors.lastname: Gruber
authors.forename: Joachim R
authors.initials: JR
authors.lastname: Krenn