Mathematical modeling of energy processes in YAG:Er3+ lasers

A comparison of theoretical and experimental results shows that a suitable selection of the spectroscopic parameters of YAG:Er³⁺ crystals can ensure a qualitative agreement between calculations and experiments (within the limits of the relevant errors). Calculations demonstrate a considerable contribution of direct pumping of the upper active level by flashlamp excitation. The maximum theoretical value of the differential efficiency for the best laser head is 2.7%.