Improved Pr{sup 3+}-doped heavy metal fluoride glasses and fibers

Praseodymium doped heavy metal fluoride glass preforms were fabricated via a modified suction casting method. A subsequent redraw process was employed to obtain high quality single mode fluoride fiber. Modifications of the ZBLAN composition, including the incorporation of In{sup 3+}, Y{sup 3+} and Cs{sup +}, were undertaken in an attempt to improve optical properties while maintaining the inherent drawability of ZBLAN. Thermal analysis to determine the various draw parameters was conducted using Differential Scanning Calorimetry, while optical characterization included spectral absorption, fluorescence, and fluorescent lifetime measurements for all specimens. The modifications in composition resulted in an increase in the fluorescent lifetime of Pr{sup 3+} at 1.3{mu}m.