Excited-state absorption ofNi2+inMgF2and MgO

We report an analysis of the excited-state dynamics, fluorescence, as well as excited-state absorption, in the ${\mathrm{Ni}}^{2+}$-doped vibronic laser systems MgO:${\mathrm{Ni}}^{2+}$ and ${\mathrm{MgF}}_2$:${\mathrm{Ni}}^{2+}$. Use is made of this analysis to show the ability and the limitations of the single-configuration-coordinate model and the Struck and Fonger theory to describe or predict the gross features of the ground-state and the excited-state absorption and emission data.