Experimental and theoretical spectroscopic study of erbium doped aluminosilicate glasses

This paper reports on the Judd-Ofelt analysis of 2 x 10(20) ions/cm(3) 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, Omega(k) (k=2, 4, 6) of Er3+ were evaluated and discussed in detail. From the systematic variations of the Omega(2) 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. Omega(6) is related to the optical basicity of the glass composition, while Omega(4) seems to represent a mixture of Omega(2) and Omega(6). This finding is strengthened by comparison with data of previous publications. The radiative transition probabilities A, radiative lifetimes tau(rad) and fluorescence branching ratios beta were calculated. The calcium aluminosilicate glass shows the highest Er3+ absorption cross sections. (C) 2016 Elsevier B.V. All rights reserved.