Thermal lens study of the OH~ influence on the fluorescence efficiency of Yb~(3+)-doped phosphate glasses

摘要

In this work, the thermal lens (TL) technique is used to determine the fluorescence quantum efficiency (η) of Yb~(3+)-doped phosphate glasses. The role of nonradiative processes such as energy migration among Yb ions and the interaction with OH~- radicals are presented and discussed. Two sets of samples with the same Yb concentrations were prepared, one at ambient conditions (set A) and the other in N_2 atmosphere (set N). The TL technique was shown to be very sensitive to the amount of OH radicals. Moreover, the η values obtained from the TL method are in good agreement with the calculate ones (based on lifetime measurements). The results indicate that TL can be a valuable technique to evaluate the quantum efficiency and nonradiative rates in ion-doped materials.