Quantum-efficiency measurements in oxygen-containing gallium lanthanum sulphide glasses and fibers doped with Pr(3+)

The production of competitive fiber amplifiers in the 1.3-mum region requires both good quantum efficiency in the lasing ion and the capability to produce low-loss fibers. Oxygen-doped gallium lanthanum sulphide (GLS) doped with Pr(3 ) may provide a route to both, We describe measurements of the quantum efficiency of Pr(3 ) emission at 1.3 mum from the (1)G(4)-(3)H (5) transition in GLS glass and fiber containing varying quantities of lanthanum oxide. We show that oxide-containing GLS glasses, which are known to have considerably better thermal and glass-forming properties than pure GLS, can show quantum efficiencies of up to 84% of that of pure GLS, No degradation of quantum efficiency is seen when oxide-containing GLS glass is pulled into fiber form