Abstract

Nanometric silver particles show anomalous absorption in the visible spectral region due to the resonant excitation of localised surface plasmons (SP). The resonance frequencies are mainly determined by the shape of the particle. Particle samples are produced by thermal evaporation in high vacuum, leading to a particle shape being described in a good approximation as a rotational ellipsoid. Uniformity in the shape of the particles on a macroscopic sample can be gained by using a mask produced by electron-beam lithography for the evaporation process.

© 1996 Optical Society of America