Analysis and direct calculation of the energy migration interaction parameter in high concentration Nd3+ doped YAG laser crystal

The energy migration interaction parameter C-DD in high concentration Nd3+ doped YAG laser crystal was estimated using the Yokota-Tanimoto (Y-T) model and the spectral overlap model (SOM) of Kushida, respectively. Firstly, the experimental luminescence decay curves of F-4(3/2) state of Nd3+ ions in YAG laser crystal at room temperature for 2.0at.% and 3.0at.% Nd3+ concentrations reported by Mao were fitted successfully using the Y-T model, and the parameter C-DD was obtained to be 1.50x10(-39) cm(6)/s. Secondly, the parameter C-DD was directly calculated using the spectral overlap model (SOM) of Kushida; C-DD was calculated to be 2.73x10(-39) cm(6)/s. By comparing the energy migration interaction parameter C-DD with the energy transfer interaction parameter C-DA (1.794x10(-40) cm(6)/s), it was concluded that the energy migration rate between Nd3+ ions in YAG laser crystal was about 11 times larger than the energy transfer rate, and that energy migration played a very important role in high concentration Nd3+-doped YAG laser crystal.