Optical spectroscopy of Sm3+ doped Na2O–ZnO–La2O3–TeO2 glasses

Abstract

Telluride glasses with the composition xSm2O3–(7−x)La2O3–3Na2O–25ZnO–65TeO2 (where x=0.1, 1, 2, 5 and 7mol%) were obtained by the melt quenching technique. Electronic absorption and fluorescence spectra as well as fluorescence dynamics of the Sm3+-doped title glasses are presented and analysed in detail. A Judd–Ofelt intensity analysis of the absorption spectrum at 300K has been applied for determination of Ωλ parameters (Ω2=3.10, Ω4=3.80, Ω6=1.61×10−20cm2) which in turn have been used for calculations of the radiative transition probabilities (AT), the natural (radiative) lifetimes (τR) of the 4G5/2 level of Sm3+, the fluorescence branching ratios (β) and the emission cross-sections (σem). The τR value of the 4G5/2 level amount to 1546μs and is slightly higher than the measured decay time of 1306μs. With the increasing of Sm2O3 concentration from 0.1 to 7.0mol% the experimental lifetime of the fluorescent level decreases from 1306 to 41μs. An analysis of the non-radiative decay was based on the cross-relaxation mechanisms. The optical achieved results indicate that the investigated glasses are potentially applicable as an orange and/or red laser host.