Spectroscopic properties and Judd-Ofelt analysis of Sm3+ doped lead-germanate-tellurite glasses

Spectroscopic properties of Sm3+ (1 mol%) ions in 49 PbO-30 GeO2-20 TeO2 glass have been characterized through optical absorption and temperature dependent fluorescence. The spectroscopic parameters such as oscillator strengths (f), Judd-Ofelt (J-O) intensity parameters (Omega(lambda)), spontaneous emission probability (A(R)), branching ratios (beta(R)) and radiative lifetimes (tau(R)) of various excited levels have been determined from the absorption spectrum by using J-O analysis. From the fluorescence spectra, four emission transitions have been observed from the (4)G(5/2) state to the lower lying states H-6(5/2), H-6(7/2), H-6(9/2) and H-6(11/2) upon exciting the sample with a 488 nm line of an argon ion laser. The stimulated emission cross-sections (sigma(e)) and branching ratios (beta(meas)) were estimated from the emission spectra for all emission transitions and decay curve analysis for the (4)G(5/2) level has also been carried out for different concentrations. Based on these results, the utility of Sm3+ doped lead-germanate-tellurite glasses as laser active materials in the visible region is discussed.