Abstract
This paper reports on the Judd–Ofelt analysis of 2×1020ions/cm3 Er3+-doped aluminosilicate glasses. Mainly BaO, MgO and CaO have been used as network modifier oxides. The five studied compositions were prepared by using the conventional melt-quenching method. From the UV–vis–NIR absorption spectra, the Judd–Ofelt parameters, Ωk (k=2, 4, 6) of Er3+ were evaluated and discussed in detail. From the systematic variations of the Ω2 parameter, structural changes in the glasses are deduced: higher barium concentrations result in an increasing symmetry at the Er3+-sites. This finding also correlates with higher calculated fluorescence lifetime values. Ω6 is related to the optical basicity of the glass composition, while Ω4 seems to represent a mixture of Ω2 and Ω6. This finding is strengthened by comparison with data of previous publications.
The radiative transition probabilities A, radiative lifetimes τrad and fluorescence branching ratios β were calculated. The calcium aluminosilicate glass shows the highest Er3+ absorption cross sections.