title: Directional surface enhanced Raman scattering on gold nano-gratings.
abstract: Directional plasmon excitation and surface enhanced Raman scattering (SERS) emission were demonstrated for 1D and 2D gold nanostructure arrays deposited on a flat gold layer. The extinction spectrum of both arrays exhibits intense resonance bands that are redshifted when the incident angle is increased. Systematic extinction analysis of different grating periods revealed that this band can be assigned to a propagated surface plasmon of the flat gold surface that fulfills the Bragg condition of the arrays (Bragg mode). Directional SERS measurements demonstrated that the SERS intensity can be improved by one order of magnitude when the Bragg mode positions are matched with either the excitation or the Raman wavelengths. Hybridized numerical calculations with the finite element method and Fourier modal method also proved the presence of the Bragg mode plasmon and illustrated that the enhanced electric field of the Bragg mode is particularly localized on the nanostructures regardless of their size.
authors.affiliation: Université Paris 13, Sorbonne Paris Cité, Laboratoire CSPBAT, CNRS, (UMR 7244), 74 rue Marcel Cachin, F-93017 Bobigny, France. HORIBA Jobin Yvon S.A.S. Villeneuve d'Ascq, 231 rue de Lille 59650 Lille, France.
authors.forename: Raymond
authors.initials: R
authors.lastname: Gillibert
authors.forename: Mitradeep
authors.initials: M
authors.lastname: Sarkar
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Bryche
authors.forename: Ryohei
authors.initials: R
authors.lastname: Yasukuni
authors.forename: Julien
authors.initials: J
authors.lastname: Moreau
authors.forename: Mondher
authors.initials: M
authors.lastname: Besbes
authors.forename: Grégory
authors.initials: G
authors.lastname: Barbillon
authors.forename: Bernard
authors.initials: B
authors.lastname: Bartenlian
authors.forename: Michael
authors.initials: M
authors.lastname: Canva
authors.forename: Marc Lamy
authors.initials: ML
authors.lastname: de la Chapelle