Abstract

Large enhancement of optical responses, selective photomodification and other fascinated effects have been observed in aggregated nanocomposites of noble metals.^1,2 The present concepts² connect high optical nonlinearities of the aggregated nanocomposites with a large local electric field enhancement, that takes place due to a strong dipole-dipole interaction between the nanoparticles. The present report is devoted to study the mechanisms responsible for cubic nonlinear optical response of the silver nanoaggregates in colloidal solution. We show that the light-induced movement of the metal nanoparticles could produce the optical nonlinearity of the aggregate.

© 2002 Optical Society of America