Effect of annealing and dopants concentration on the optical properties of Nd3+:Al3+ co-doped sol-gel silica glass

Nd3+ in SiO2 glass samples co-doped with aluminum at different concentrations have been synthesized by a sol-gel method. The effect of annealing temperature and concentration of dopants on the optical properties of the samples were investigated. Red-shift in absorption peaks was observed with annealing. Judd-Ofelt analysis shows the change in local environment of the Nd3+ ions with heat treatment. The fluorescence intensity of peaks at 880 nm and 1060 nm which result from the 4F3/2 →4I9/2 and 4I11/2 states increased significantly with increase in annealing temperature as well as aluminum concentration.