THE INFLUENCE OF REACTIVE ATMOSPHERE PROCESSING ON THE CRYSTALLIZATION KINETICS OF GAF3 INF3 BASED GLASSES/

Gallium-indium fluoride based glasses are one of the lowest phonon ene rgy hosts for Pr-ion doped fibre amplifiers. However, to date the fabr ication of low background loss fibres have been proved difficult. In t he present investigation, GaF3/InF3 based glasses are prepared under t he controlled reactive atmosphere of SF6, HF and N-2 gas mixture. The devitrification characteristics of glass samples prepared in a range o f reactive-atmospheres (RA) have been studied using differential scann ing calorimetry. From the isothermal data, the time-temperature-transf ormation curves have been compared for various reactive-atmosphere pro cessing (RAP) conditions and, the influence of RAP conditions on the g lass stability is discussed. Loss in multimode fibres (similar to 135 mu m) drawn from the glass rods processed under RAP conditions are com pared as a function of processing conditions. The measured loss values are reported in 0.5 to 2.0 mu m wavelength regime.