title: Influence of plasmon destructive interferences on optical properties of gold planar quadrumers.
abstract: Arrays of planar symmetric gold quadrumers consisting of a central nano-disc surrounded by three similar nano-discs belonging to the D(3h) point group were designed and fabricated. Since the geometrical configuration of quadrumers is the same as planar trigonal molecules, nano-discs can play the roles of artificial atoms to study the coupling trends among them. The plasmonic properties of the nano-disc structures are investigated by reflection spectrum measurement and finite-difference time-domain calculation with good agreement. Plasmon interaction among the nano-discs is also studied via a mass-spring coupled oscillator model. A pronounced Fano resonance (FR) is observed for the fabricated nano-discs with inter-disk gaps of around 18 nm during light irradiation at normal incidence. Although the obtained FR is independent of the excitation polarization, the near-field energy spatial distribution can be flexibly tuned by the polarization direction. This has potential applications in nano-lithography, optical switching and nonlinear spectroscopy.
authors.affiliation: Data Storage Institute, (A*STAR) Agency for Science, Technology and Research, Singapore.
authors.forename: M
authors.initials: M
authors.lastname: Rahmani
authors.forename: T
authors.initials: T
authors.lastname: Tahmasebi
authors.forename: Y
authors.initials: Y
authors.lastname: Lin
authors.forename: B
authors.initials: B
authors.lastname: Lukiyanchuk
authors.forename: T Y F
authors.initials: TY
authors.lastname: Liew
authors.forename: M H
authors.initials: MH
authors.lastname: Hong