title: Acousto-plasmonic and surface-enhanced Raman scattering properties of coupled gold nanospheres/nanodisk trimers.
abstract: This work is devoted to the fundamental understanding of the interaction between acoustic vibrations and surface plasmons in metallic nano-objects. The acoustoplasmonic properties of coupled spherical gold nanoparticles and nanodisk trimers are investigated experimentally by optical transmission measurements and resonant Raman scattering experiments. For excitation close to resonance with the localized surface plasmons of the nanodisk trimers, we are able to detect several intense Raman bands generated by the spherical gold nanoparticles. On the basis of both vibrational dynamics calculations and Raman selection rules, the measured Raman bands are assigned to fundamental and overtones of the quadrupolar and breathing vibration modes of the spherical gold nanoparticles. Simulations of the electric near-field intensity maps performed at the Raman probe wavelengths showed strong localization of the optical energy in the vicinity of the nanodisk trimers, thus corroborating the role of the interaction between the acoustic vibrations of the spherical nanoparticles and the surface plasmons of the nanodisk trimers. Acoustic phonons surface enhanced Raman scattering is here demonstrated for the first time for such coupled plasmonic systems. This work paves the way to surface plasmon engineering for sensing the vibrational properties of nanoparticles.
authors.affiliation: Institute of Material Research and Engineering, A*STAR, Singapore. tripathy-sudhiranjan@imre.a-star.edu.sg
authors.forename: Sudhiranjan
authors.initials: S
authors.lastname: Tripathy
authors.forename: Renaud
authors.initials: R
authors.lastname: Marty
authors.forename: Vivian Kaixin
authors.initials: VK
authors.lastname: Lin
authors.forename: Siew Lang
authors.initials: SL
authors.lastname: Teo
authors.forename: Enyi
authors.initials: E
authors.lastname: Ye
authors.forename: Arnaud
authors.initials: A
authors.lastname: Arbouet
authors.forename: Lucien
authors.initials: L
authors.lastname: Saviot
authors.forename: Christian
authors.initials: C
authors.lastname: Girard
authors.forename: Ming Yong
authors.initials: MY
authors.lastname: Han
authors.forename: Adnen
authors.initials: A
authors.lastname: Mlayah
mesh_terms: D000162:Acoustics; D003198:Computer Simulation; D006046:Gold / Q000737:chemistry*; D008027:Light; D008422:Materials Testing; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D006046:Gold