Red luminescence from Eu~(3+) -doped Te02-W03-Ge02 glasses for solid state lasers

摘要

Eu~(3+) -doped oxyfluoro tellurite (TWGEu) glasses were prepared by conventional melt quenching method. The optical band gap energy and covalence between Eu~(3+) and 0~(2-)/F~- ions were determined from optical absorption spectra. Using the ~5Do → ~7F~(1,2,4) emission transitions, the Ω_2 and Ω_4 intensity parameters were determined. These intensity parameters were used to evaluate the radiative parameters such as emission probability rate (Ar), luminescence branching ratio (β_r) and radiative life time (tr) of ~5D_0 → ~7F_J transitions. The laser characteristic parameters such as stimulated emission cross-section, gain bandwidth and quantum efficiency were determined. The luminescence decay profiles of ~5Do emission level were well fitted to single exponential function for all the concentrations. The experimental results show that the 0.5 mol% of Eu~(3+) -doped TWGEu glass could be the best choice to design red laser sources.