title: Enhancement of second-harmonic generation from metal nanoparticles by passive elements.
abstract: We prepare arrays of gold nanoparticles that include both noncentrosymmetric particles with a second-order nonlinear optical response (active particles) and centrosymmetric particles with no second-order response (passive particles). The plasmon resonances of the active and passive particles are at distinct wavelengths, yet the passive particles modify the electromagnetic modes of the structure in such a way that second-harmonic generation from the active particles is enhanced. Our results provide a completely new concept for optimizing the nonlinear responses of metamaterials.
authors.affiliation: Optics Laboratory, Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland. robert.czaplicki@tut.fi
authors.forename: Robert
authors.initials: R
authors.lastname: Czaplicki
authors.forename: Hannu
authors.initials: H
authors.lastname: Husu
authors.forename: Roope
authors.initials: R
authors.lastname: Siikanen
authors.forename: Jouni
authors.initials: J
authors.lastname: Mäkitalo
authors.forename: Martti
authors.initials: M
authors.lastname: Kauranen
authors.forename: Janne
authors.initials: J
authors.lastname: Laukkanen
authors.forename: Joonas
authors.initials: J
authors.lastname: Lehtolahti
authors.forename: Markku
authors.initials: M
authors.lastname: Kuittinen