Influence of oxygen pressure on structural and optical properties of Al2O3optical waveguides prepared by pulsed laser deposition

Pure and europium doped alumina waveguides have been prepared by Pulsed Las er Deposition using a KrF excimer laser at oxygen pressures in the range fr om 10(-7) to 0.1 mbar. The composition of the films and the doping ion conc entration were determined by Rutherford. Backscattering Spectroscopy. From X-ray diffraction measurements, a progressive growth of gamma-Al2O3 crystal lites is observed as the oxygen pressure decreases. After annealing treatme nt, the alumina films are constituted of alpha-Al2O3 crystallites while eur opium doped alumina films remain constituted of gamma-Al2O3 crystallites. T he films have optical waveguiding properties. The mean refractive index of the film increases as oxygen pressure decreases.