Giant Stokes fields on semicontinuous metal films

摘要

The local electric fields on a semicontinuous metal film are shown to experience giant fluctuations in the visible and infrared spectral ranges when the dissipation in metallic grains is small. The field fluctuations result in strongly enhanced Raman scattering. The scattered local fields at the Stakes frequency are concentrated in sharp well-separated peaks and are enhanced up to giant values, similar to 10(14), that exceed by many orders of magnitude the average enhancement, similar to 10(6). This opens a fascinating possibility for Raman scattering spectroscopy of single molecules on a semicontinuous metal film. A developed scaling theory for surface-enhanced Raman scattering from a semicontinuous film successfully explains the experimental observations. (C) 1998 Optical Society of America. [References: 35]