Optimization of the parameters of dynamically stable resonators of continuously pumped solid-state lasers

A modified Magni procedure is used in a numerical analysis of dynamically stable resonators with an internal focusing element. Calculations are reported of the dependences of the maximum volume occupied by the TEM₀₀ mode in the active element, of the width of the stability zone, and of the geometric parameters of the resonator ensuring the maximum volume of the fundamental mode on the focal length (divided by the resonator length) of an induced thermal lens in the middle of the stability zone. An experimental procedure for constructing dynamically stable resonators allowing for real sources of instabilities in continuously pumped laser systems is proposed and the results of experimental tests are reported. These tests show that resonators with the stability zone width considerably greater than the astigmatism of the induced thermal lens can ensure both a spatially homogeneous profile and a minimum instability of the laser radiation, which in practice does not exceed the initial instability of the pump radiation.