Spectroscopy of Pr3+ ions in lithium borate and lithium fluoroborate glasses

Optical absorption and emission spectra of 1 mol% Pr3+ doped lithium borate and lithium fluoroborate glasses have been recorded. The intensities of f-f transitions are parameterized in terms of Judd-Ofelt (JO) intensity parameters Omega (lambda) (lambda = 2, 4 and 6). The JO parameters obtained with modified JO theory have been used to predict radiative properties such as spontaneous emission probabilities (A), lifetimes ( tau (R)) and branching ratios (beta (R)) for all the 12 excited states of these Pr3+ doped glasses along with some of the reported Pr3+ :systems. The predicted beta (R) are compared with the experimental values for the emission from P-3(0) and P-3(1) levels. The stimulated emission cross-sections are also evaluated for all the observed emission transitions. The beta (R) values for the potential laser transitions including the (1)G(4) --> H-3(5) (1.3 mum) transition useful for fibre amplifier have been compared for 17 Pr3+ :systems. The effect of compositional changes of the glasses on the optical properties of Pr3+ ions have been discussed. (C) 2001 Elsevier Science B.V. All rights reserved.