Quantum size effects and nonlinear optical properties of ZnS and CdS semiconductor-doped silica glasses prepared by sol-gel process

Preparation of silica glasses doped with CdS and ZnS microcrystals is presented. The optical absorption spectra and the photoluminescence spectra show that the optical absorption edges and the photoluminescence peaks shift to the higher energy side with decreasing the size of the microcrystals, which exhibit the quantum size effect. The third order optical susceptibilities are measured by degenerate four wave mixing (DFWM) method. The third order optical nonlinearity of the nanocomposites prepared by the sol-gel process is largely enhanced.