Effects of non-radiative processes on the infrared luminescence of Yb3+ doped glasses

This study is focused on the contribution of radiative and non radiative processes on the infrared emission of Yb doped phosphate glasses. The effects of energy migration and interaction with impurities, particularly OH− radicals, are discussed based on Yb3+ luminescence and lifetime measurements. Two sets of samples with the same composition were used: one prepared at ambient conditions (set A), and the other in a dry box under N2 atmosphere (set N). Infrared spectra have shown that OH− radicals are strongly reduced in the samples prepared in N2 atmosphere. The Yb3+ infrared luminescence is more intense in samples of set N by a factor 2 and small quenching is observed at least at Yb concentrations of 13%. On the other hand, the infrared emission of samples of set A is strongly quenched for Yb concentrations higher than 10%. The measured lifetimes also corroborate the conclusion that OH radicals reduce significantly the Yb3+ fluorescence quantum efficiency.