title: On the energy shift between near-field and far-field peak intensities in localized plasmon systems.
abstract: The localized plasmons of metallic nanoparticles and nanostructures are known to display an interesting and apparently universal phenomenon: upon optical excitation, the maximum near-field enhancements occur at lower energies than the maximum of the corresponding far-field spectrum. Here we present an explanation for this behavior, showing that it results directly from the physics of a driven and damped harmonic oscillator. We show that the magnitude of the shift between the near- and far-field peak intensities depends directly on the total damping of the system, whether it is intrinsic damping within the metal of the nanoparticle or radiative damping of the localized plasmon.
authors.affiliation: Laboratory for Nanophotonics, M.S. 61, Rice University , Houston, Texas 77005-1892, United States.
authors.forename: Jorge
authors.initials: J
authors.lastname: Zuloaga
authors.forename: Peter
authors.initials: P
authors.lastname: Nordlander