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

Abstract

The relaxation time of nonlinear optical response has been obtained by femtosecond pump–probe measurements for borate glasses containing gold nanoparticles prepared by conventional melt-quenching and heat treatment techniques. Size effects of gold nanoparticles on the relaxation process were investigated. 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 relaxation processes. In addition, the tail component is very small and is not affected by the pump intensity. This shows that the borate glass matrix has superior properties in the slow relaxation process.