Numerical Modeling of Diode-End-Pumped High-Power ${\hbox {Er}}^{3+}$ :YAG Lasers

A theoretical model is presented describing continuous-wave operation of diode-end-pumped Er³⁺ :YAG lasers. Implemented as a numerical computer model it takes into account the full spectral information of the pump and laser transitions as well as all important ionic levels, their Stark splitting, decay schemes, up-conversion processes, excited-state absorption and especially the thermal dependencies of these important parameters. The model is compared to experimental results with good agreement and predicts highly efficient operation of Er:YAG lasers even at high temperatures.