The low phonon-energy of GeS 2 glass ( 350 cm −) makes it an ideal host for designing Pr-doped glasses for 1300 nm fibre amplifier. In the present investigation, a number of chalcohalide and chalcogenide glasses based on GeS 2 as a major constituent were studied. The effect of the removal of OH − ions from the starting powders by vacuum drying on prolonging the 1G 4 lifetimes and on increasing the 1G 4 absorption intensity in Pr-doped GeS 2-based glasses is discussed. The structural role of network modifiers in improving the spectroscopic ( 1G 4) and thermal characteristics is also reported. The longest measured metastable lifetime is 200 μs in a 2000 ppm by weight (ppmw) Pr-ion doped glass. In the light of the Johnson-Mehl-Avrami transformation kinetics equation, the computed critical cooling rate for glass formation has been compared with the measured cooling rate from the melt homogenization temperature.