Scattering focusing and localized surface plasmons in a single Ag nanoring

摘要

We investigate the far-field scattering property of a single Ag nanoring. Under oblique excitation,ntwo-focus scatterings with distinct intensities were observed.We show that the two-focus scatteringsnresult from the interference of far-field scattering light from the ring circumference, and the localnfield enhancement effect of surface plasmons plays the key role in the focus intensity. By finitendifference time domain and numerical integer methods, we calculated far-field scattering andnsurface plasmons’ distributions, and the results are in good agreement with the experiment. © 2010nAmerican Institute of Physics. u0004doi:10.1063/1.3532113