Relaxation of excited states of Tm~(3+) and Tm~(3+)-Eu~(3+) energy transfer in YVO_4 crystal

摘要

Tm~(3+)-Eu~(3+) energy transfer processes and relaxation dynamics of the ~3H_4 and ~3F_4 excited states of Tm~(3+) ions in 1 at. % Tm~(3+), 5 at. % Eu~(3+):YVO_4 single crystal were studied. Contribution of Tm~(3+)-Eu~(3+) energy transfer reduces effectively the lifetime of terminal level in a potential ~3H_4-~3F_4 laser transition at around 1.48 μm. Adverse quenching of the ~3H_4 emission by Eu~(3+) ions is found to be less efficient than that reported for Tm~(3+) + Tb~(3+) system in YVO_4. The classical Inokuti-Hirayama model accounts well for an experimental decay curve of the ~3H_4 emission recorded for co-doped crystal. Stimulated emission cross section for ~3H_4-~3F_4 transition of Tm~(3+) at around 1.48 μm was analyzed taking into account the anisotropy of YVO_4 crystal.