Open AccessShape effects in the localized surface plasmon resonance of single nanoholes in thin metal films
Author(s) -
Borja Sepúlveda,
Yury Alaverdyan,
Joan Alegret,
Mikael Käll,
Peter Johansson
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.005609
Subject(s) - materials science , optics , polarization (electrochemistry) , surface plasmon resonance , plasmon , surface plasmon , scattering , discrete dipole approximation , dipole , thin film , aspect ratio (aeronautics) , surface plasmon polariton , localized surface plasmon , mie scattering , resonance (particle physics) , molecular physics , ellipsoid , light scattering , physics , optoelectronics , atomic physics , nanoparticle , nanotechnology , chemistry , quantum mechanics , astronomy
We report on the polarization-dependent optical response of elongated nanoholes in optically thin gold films. We measured elastic scattering spectra of spatially isolated ellipsoidal nanoholes with varying aspect ratio and compared the results to electrodynamic simulations. Both experiments and theory show that the plasmon mode that is polarized parallel to the short axis of the ellipsoidal hole red-shifts with increasing aspect ratio. This behavior is completely opposite to the case of elongated metal particles. We present a simple analytical model that qualitatively explains the observations in terms of the different orientations of the induced dipole moments in holes and particles.