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

Glasses with the composition of 30B(2)O(3)-40GeO(2)-(30-x)Gd2O3-xSm(2)O(3) (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 (Omega(lambda), lambda = 2,4,6) obtained from the absorption spectrum follow the trend Omega(4) > Omega(2) > Omega(6). Photoluminescence spectra revealed a dominant emission band at 597 nm which was attributed to (4)G(5/2) -> H-6(7/2) transition. From the emission spectra and JuddOfelt intensity parameters radiative properties including transition probabilities (A), radiative decay times (tau(R)), branching ratio (beta(R)) and stimulated emission cross-section (sigma(E)(rho)) were calculated. The decay curves of (4)G(5/2) level exhibited non-exponential behavior and well fitted to Inokuti-Hirayama model for S = 6. The analyzed spectroscopic properties viz. A, beta(R), sigma(E)(rho) and CIE chromaticity coordinates demonstrate the suitability of BGGS1.00 glass for visible reddish-orange laser applications among the prepared glasses.