Optical and luminescence characteristics of Sm3+ doped B2O3-GeO2-Gd2O3 glasses

Glasses with the composition of 30B2O340GeO2-(30-x)Gd2O3-xSm2O3 (x = 0.25, 0.5, 1 and 1.5 mol%) have been prepared by melt quenching technique. Their optical and luminescence properties were analyzed via absorption, photoluminescence and decay time measurements. Judd-Ofelt intensity parameters (Ωλ, λ = 2,4,6) obtained from the absorption spectrum follow the trend Ω4 > Ω2 > Ω6. Photoluminescence spectra revealed a dominant emission band at 597 nm which was attributed to 4G5/2 → 6H7/2 transition. From the emission spectra and Judd-Ofelt intensity parameters radiative properties including transition probabilities (A), radiative decay times (τR), branching ratio (βR) and stimulated emission cross-section (σpE) were calculated. The decay curves of 4G5/2 level exhibited non-exponential behavior and well fitted to Inokuti-Hirayama model for S = 6. The analyzed spectroscopic properties viz. A, βR, σpE and CIE chromaticity coordinates demonstrate the suitability of BGGS1.00 glass for visible reddish-orange laser applications among the prepared glasses.