title: Brillouin light scattering from surface acoustic waves in a subwavelength-diameter optical fibre.
abstract: Brillouin scattering in optical fibres is a fundamental interaction between light and sound with important implications ranging from optical sensors to slow and fast light. In usual optical fibres, light both excites and feels shear and longitudinal bulk elastic waves, giving rise to forward-guided acoustic wave Brillouin scattering and backward-stimulated Brillouin scattering. In a subwavelength-diameter optical fibre, the situation changes dramatically, as we here report with the first experimental observation of Brillouin light scattering from surface acoustic waves. These Rayleigh-type surface waves travel the wire surface at a specific velocity of 3,400 m s(-1) and backscatter the light with a Doppler shift of about 6 GHz. As these acoustic resonances are sensitive to surface defects or features, surface acoustic wave Brillouin scattering opens new opportunities for various sensing applications, but also in other domains such as microwave photonics and nonlinear plasmonics.
authors.affiliation: Institut FEMTO-ST, Université de Franche-Comté, CNRS, Besançon 25030, France.
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Beugnot
authors.affiliation: Laboratoire Charles Fabry, Institut d'Optique, Université Paris-Sud, CNRS, Palaiseau 91127, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Lebrun
authors.affiliation: Laboratoire Charles Fabry, Institut d'Optique, Université Paris-Sud, CNRS, Palaiseau 91127, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Pauliat
authors.affiliation: Institut FEMTO-ST, Université de Franche-Comté, CNRS, Besançon 25030, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Maillotte
authors.affiliation: Institut FEMTO-ST, Université de Franche-Comté, CNRS, Besançon 25030, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Laude
authors.affiliation: Institut FEMTO-ST, Université de Franche-Comté, CNRS, Besançon 25030, France.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Sylvestre