Optical study of GeO2-PbO-PbF2 oxyfluoride glass singly doped with Pr3+, Nd3+, Sm3+ and Eu3+

Glasses with composition 50GeO(2)-(50 - x)PbO-5PbF(2)-xLnF(3) (Ln = Pr3+, Nd3+, Sm3+, Eu3+) were synthesised in the bulk form. The content of PbF2 was constant and amounted to 5 mol% whereas, the concentration of luminescent ions was 0.2 and 2 mol%. Spectroscopic properties (absorption, emission) of optically active ions were studied at room temperature. Oscillator strengths have been used to calculate phenomenological intensity parameters Omega(2,4,6). Radiative transition probabilities as well as branching ratios and radiative lifetimes of luminescent levels were estimated. Lifetimes and the fluorescence dynamics were studied as a function of concentration. The Judd-Ofelt analysis and the Inokuti-Hirayama model for energy transfer between activator ions provided information on radiative processes and non-radiative relaxation of excited states. (c) 2005 Elsevier B.V. All rights reserved.