Luminescent properties of Tb3+- doped TeO2-WO3-GeO2 glasses for green laser applications.

Different concentrations of Tb 3+ -doped oxyfluoro tellurite (TWGTb) glasses were prepared by conventional melt quenching technique and characterized for green laser applications. The Judd-Ofelt theory was applied to evaluate various spectroscopic and radiative parameters. The TWGTb glasses exhibit 5 D 3 → 7 F 5-3 and 5 D 4 → 7 F 6-0 transitions when excited at 316 nm radiation. The variation of intensity of 5 D 4 → 7 F 5 (Green) and 5 D 3 → 7 F 4 (Blue) transitions and the green to blue (I G /I B ) intensity ratios were studied as a function of Tb 3+ ions concentration. The laser characteristic parameters such as effective bandwidth (Δλ eff ), stimulated emission cross-section (σ e ), gain bandwidth (σ e  × Δλ eff ) and optical gain (σ e  × τ R ) were determined using the three phenomenological Judd-Ofelt intensity parameters. The fluorescence decay profiles of 5 D 4 metastable level exhibit single-exponential nature for all the samples. Based on the experimental results we suggest that the 1.0 mol% of Tb 3+ -doped TWGTb glass could be a suitable laser host material to emit intense green luminescence at 545 nm. [ABSTRACT FROM AUTHOR]