Distance-dependent plasmon resonant coupling between a gold nanoparticle and gold film.
We present an experimental analysis of the plasmonic scattering properties of gold nanoparticles controllably placed nanometers away from a gold metal film. We show that the spectral response of this system results from the interplay between the localized plasmon resonance of the nanoparticle and the surface plasmon polaritons of the gold film, as previously predicted by theoretical studies. In addition, we report that the metal film induces a polarization to the single nanoparticle light scattering, resulting in a doughnut-shaped point spread function when imaged in the far-field. Both the spectral response and the polarization effects are highly sensitive to the nanoparticle-film separation distance. Such a system shows promise in potential biometrology and diagnostic devices.
Mock
Jack J
JJ
Center for Metamaterials and Integrated Plasmonics, Department of Electrical and Computer Engineering, Duke University, Box 90291, Durham, North Carolina 27708, USA.
Hill
Ryan T
RT
Degiron
Aloyse
A
Zauscher
Stefan
S
Chilkoti
Ashutosh
A
Smith
David R
DR