The structural aspects of the solubility of Pr3+ ions in GeS2-based glasses

Low solubility of rare-earth ions in covalently-bonded network forming sulphide glasses is one of the major obstacles in fabricating an efficient 1.3 mu m optical fibre amplifier. In the present investigation, a structural approach has been adopted for enhancing the solubility of rare-earth ions in a network-forming sulphide glass hosts. The relationship between the residual concentrations of OH- ions, measured by infrared spectrophotometric technique, in various glasses after drying of starting powders prior to melting and the solubility of Pr3+ ions (2000 ppm by weight, ppmw) dissolved in the glass matrix is drawn and discussed by making reference to the glass structure. The solubility of Pr ions has been investigated by measuring the (1)G(4) lifetimes and by analysing the emission and absorption spectra. The effect of structural modification on the tendency to resist devitrification and on related physical properties is also examined.