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

Abstract

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 (Ωλ), spontaneous emission probability (AR), branching ratios (βR) and radiative lifetimes (τR) 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 G5/2 state to the lower lying states 6H5/2, 6H7/2, 6H9/2 and 6H11/2 upon exciting the sample with a 488 nm line of an argon ion laser. The stimulated emission cross-sections (σe) and branching ratios (βmeas) were estimated from the emission spectra for all emission transitions and decay curve analysis for the 4G5/2 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.