title: Cascaded optical field enhancement in composite plasmonic nanostructures.
abstract: We present composite plasmonic nanostructures designed to achieve cascaded enhancement of electromagnetic fields at optical frequencies. Our structures were made with the help of electron-beam lithography and comprise a set of metallic nanodisks placed one above another. The optical properties of reproducible arrays of these structures were studied by using scanning confocal Raman spectroscopy. We show that our composite nanostructures robustly demonstrate dramatic enhancement of the Raman signals when compared to those measured from constituent elements.
authors.affiliation: School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.
authors.forename: V G
authors.initials: VG
authors.lastname: Kravets
authors.forename: G
authors.initials: G
authors.lastname: Zoriniants
authors.forename: C P
authors.initials: CP
authors.lastname: Burrows
authors.forename: F
authors.initials: F
authors.lastname: Schedin
authors.forename: C
authors.initials: C
authors.lastname: Casiraghi
authors.forename: P
authors.initials: P
authors.lastname: Klar
authors.forename: A K
authors.initials: AK
authors.lastname: Geim
authors.forename: W L
authors.initials: WL
authors.lastname: Barnes
authors.forename: A N
authors.initials: AN
authors.lastname: Grigorenko