title: Discontinuity induced angular distribution of photon plasmon coupling.
abstract: Metal-dielectric transitions are important structures that can display a host of optical characteristics including excitation of plasmons. Metal-dielectric discontinuities can furthermore support plasmon excitation without a severe condition on the incident angle of the exciting photons. Using a semi-infinite thin gold film, we study surface plasmon (SP) excitation and the associated electromagnetic near-field distribution by recording the resulting plasmon interference patterns. In particular, we measure interference periods involving SPs at the scanable metal/air interface and the buried metal/glass one. Supported by optical near-field simulations and experiments, we demonstrate that the metal/glass surface plasmon is observable over a wide range of incident angles encompassing values above and below the critical incident angle. As a result, it is shown that scanning near-field microscopy can provide quantitative evaluation of the real part of the buried surface plasmon wavevector.
authors.affiliation: Groupe d'Optique de Champ Proche, LICB, UMR CNRS 5209, Université de Bourgogne, Dijon, France. damien.brissinger@u-bourgogne.fr
authors.forename: D
authors.initials: D
authors.lastname: Brissinger
authors.forename: A L
authors.initials: AL
authors.lastname: Lereu
authors.forename: L
authors.initials: L
authors.lastname: Salomon
authors.forename: T
authors.initials: T
authors.lastname: Charvolin
authors.forename: B
authors.initials: B
authors.lastname: Cluzel
authors.forename: C
authors.initials: C
authors.lastname: Dumas
authors.forename: A
authors.initials: A
authors.lastname: Passian
authors.forename: F
authors.initials: F
authors.lastname: de Fornel