In situ growth of optically active erbium doped Al2O3 thin films by pulsed laser deposition

Thin Al2O3 films are grown and in situ doped with erbium by pulsed laser deposition in a single step process, by alternate ablation from Al2O3 and Er targets. The as-deposited films have an Er step dopant profile throughout the film thickness, whose concentration depends on the number of pulses at the Er target. The as-grown films are optically active, as evidenced by the photoluminescence spectrum centered at 1.533 mu m, corresponding to intra-4f transitions in Er3+. The photoluminescence intensity increases upon annealing due to an increase of the luminescence lifetime. This is most likely a result of a decrease in the nonradiative decay channels, related to annealing of defects in the Al2O3 film. (C) 1996 American Institute of Physics.