Optical forces on interacting plasmonic nanoparticles in a focused Gaussian beam
Artikel i vetenskaplig tidskrift, 2008

We theoretically analyze optical forces on aggregates of metal nanoparticles in a focused Gaussian beam by extending the generalized Mie theory, which includes higher order multipoles and retardation effects. For two interacting metallic particles, an attractive gradient force, mainly caused by multipole plasmon excitation, exists at short interparticle distances, while induced dipolar fields dominate for separations of the order of the particle radius R or larger. The long-range force component can be either attractive or repulsive depending on the phase of the induced dipoles, as determined by the illumination wavelength and the collective dipolar plasmon resonance. In particular, the repulsive force that occurs for illumination near the plasmon resonance wavelength can be so large that it overcomes the optical trapping effect of the Gaussian beam.

DIELECTRIC SPHERE

LIGHT-SCATTERING

LOCALIZED APPROXIMATION

ENHANCED RAMAN-SCATTERING

RIGOROUS JUSTIFICATION

METAL NANOPARTICLES

SHAPE COEFFICIENTS

AXIS BEAMS

LORENZ-MIE THEORY

ELECTROMAGNETIC-FIELD

Författare

Z. P. Li

Institute of Physics Chinese Academy of Sciences

Mikael Käll

Chalmers, Teknisk fysik, Bionanofotonik

H. Xu

Institute of Physics Chinese Academy of Sciences

Lunds Universitet

Physical Review B - Condensed Matter and Materials Physics

1098-0121 (ISSN)

Vol. 77 6- 085412

Ämneskategorier

Annan teknik

DOI

10.1103/PhysRevB.77.085412