Spectroscopic properties and concentration effects on luminescence behavior of Nd~(3+) doped Zinc-Boro-Bismuthate glasses

摘要

A detail investigation on laser spectroscopic properties as a function of Nd~(3+) ions concentration in a new heavy metal oxide based Zinc-Boro-Bismuthate glasses is reported. The Judd-Ofelt analysis indicated an enhancement in Nd-0 bond covalency as well as the local asymmetry of active ions on increase in dopant concentration from 0.1 to 1.5 mol%. Based on the Judd-Ofelt intensity parameters, several radiative properties such as transition probability, radiative lifetime, branching ratio and stimulated emission cross-section of Nd~(3+) ions have been derived. The luminescence intensity has showed a strong increase up to 0.5 mol% Nd_2O_3, which then attains maximum at 1 mol% and falls down for further increase in dopant concentration. The luminescence quenching behavior at higher dopant concentration . has been attributed to the hopping migration assisted energy transfer mechanism leading to the cross-relaxation among active ions. The energy transfer micro-parameters for cross-relaxation (C_(DA)) and donor energy migration (C_(DD)) have been derived from the luminescence decay analysis as well as spectral overlap function respectively. The high stimulated emission cross-section and smaller cross-relaxation micro-parameters along with high quantum yield from the present glasses suggests their potential for compact infrared lasers and waveguide applications.