Abstract

Rare earth ions can easily be incorporated into fluoride glasses in moderate to large concentrations, and, due to their low phonon energy, these glasses appear to have many advantages over oxide glasses as hosts for rare earth ions used in optical amplifiers and lasers. We have therefore investigated the luminescence and radiative lifetimes of Pr³⁺, Pr³⁺/Yb³⁺ and Pr³⁺/Yb³⁺/Lu³⁺ doped bulk AlF₃-based glass samples as a function of rare earth ion concentration. Initial results show a lifetime of about 150 µs for the ¹G₄ → ³H₄ state and a 20% decrease with the addition of Yb³⁺. In addition we find that the addition of 2 wt% of Yb increases the fluorescence of Pr³⁺ at 1.32 microns by a factor of 7 when excited with 488 nm radiation. The effect of Yb³⁺ and Lu³⁺ on the ¹G₄ → ³H₅, ¹D₂ → ³F₄ and ¹D₂ → ¹G₄ transitions of praseodymium would be presented.

© 1994 Optical Society of America