Relaxation behavior of nonlinear optical response in borate glasses containing gold nanoparticles

The relaxation time of nonlinear optical response has been obtained by femt osecond pump-probe measurements for borate glasses containing gold nanopart icles prepared by conventional melt-quenching and heat treatment techniques . Size effects of gold nanoparticles on the relaxation process were investi gated. The relaxation time of a fast relaxation component increases with a decrease of the particle radius. The tail of the decay curve due to a slow relaxation component increases with an increase of the particle size. These results indicate that the particle size is an important factor for relaxat ion processes. In addition, the tail component is very small and is not aff ected by the pump intensity. This shows that the borate glass matrix has su perior properties in the slow relaxation process. (C) 2001 American Institu te of Physics.