The influence of F -ion doping on the fluorescence (~4I_(13/2)→~4I_(15/2)) line shape broadening in Er~(3+)-doped oxyfluoride silicate glasses

摘要

The doping of fluorine in silicate glasses is of particular interest for enhancing the spectroscopic properties of rare-earth ion doped devices currently used in telecommunication networks. This glass host combines the structural properties of both silicate and fluoride glasses by providing a range of structural sites for Er-ions, which are essential for designing planar and fibre amplifiers with high Er-ion solubility. In this investigation a series of fluorine modified silicate glasses are reported and their measured spectroscopic and physical properties are compared. On the basis of structural models of silicates known in the literature, the effects of the incorporation of F~-, Al~(3+) ions and network formers such as GeO_2, P_2O_5, and B_2O_3 on the broadening of emission line shape for the ~4I_(13/2) →~4I_(15/2) transition of Er-ion are analysed. Structural aspects of large solubility for Er-ions in the oxyfluoride silicate hosts are also discussed by making comparison with the data available in the literature. We also report an unusual concentration quenching characteristics in oxyfluoride silicate glasses, which is important for amplifier and laser design and are not known in the literature. Based on the spectroscopic properties of oxyfluoride glasses, the figures-of-merit (FOM) for amplifier design are compared and the relationships with the F/O ratio in the glass and spectroscopic properties of the device are also discussed.