Luminescence quenching by OH-groups in highly Er-doped phosphate glasses for waveguide amplifiers

Highly (?4 mol %) Er-doped phosphate bulk glasses were prepd. by common glass melting techniques. A special heat-treatment was conducted with the as-melted samples. The luminescent lifetime of Er ions at 1500 nm increases substantially, typically from 3 ms up to 7.2 ms for a sample doped with 2 mol% Er2O3, due to the controlled heat-treatment. The increase of the lifetime is ascribed to a decrease in concn. of hydroxyl groups incorporated in the glass, which is confirmed by IR absorption spectroscopic measurements. Based on elec. dipole - dipole interaction theory, the luminescence concn. quenching mechanism by hydroxyl groups is modeled. The model predicts that more than half of the hydroxyl groups in the glass is coupled to Er ions. Preliminary results on planar waveguide formation using optimized phosphate glasses by thin film techniques are presented. [on SciFinder (R)]