title: Fano resonances in plasmonic nanoclusters: geometrical and chemical tunability.
abstract: Clusters of plasmonic nanoparticles and nanostructures support Fano resonances. Here we show that this spectral feature, produced by the interference between bright and dark modes of the nanoparticle cluster, is strongly dependent upon both geometry and local dielectric environment. This permits a highly sensitive tunability of the Fano dip in both wavelength and amplitude by varying cluster dimensions, geometry, and relative size of the individual nanocluster components. Plasmonic nanoclusters show an unprecedented sensitivity to dielectric environment with a local surface plasmon resonance figure of merit of 5.7, the highest yet reported for localized surface plasmon resonance sensing in a finite nanostructure.
authors.affiliation: Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA.
authors.forename: J Britt
authors.initials: JB
authors.lastname: Lassiter
authors.forename: Heidar
authors.initials: H
authors.lastname: Sobhani
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Fan
authors.forename: Janardan
authors.initials: J
authors.lastname: Kundu
authors.forename: Federico
authors.initials: F
authors.lastname: Capasso
authors.forename: Peter
authors.initials: P
authors.lastname: Nordlander
authors.forename: Naomi J
authors.initials: NJ
authors.lastname: Halas