Abstract:
Analytic expressions are derived for one-dimensional distributions of temperature and thermoelastic stresses in an active element (AE) upon stationary multipass pumping equal to or exceeding the threshold. Three events caused by the AE heating are considered, each of the events damaging the laser: a decrease in the efficiency due to the change in the spectral and luminescent properties of the active media, violation of the normal regime of the AE cooling, and destruction of the AE due to the increase in the thermo-mechanical stresses. The domains of the parameters (such as the AE absorption coefficient, the AE thickness, etc.) are determined at which one of the above events first occurs as the pump intensity and correspondingly the AE temperature are increased. Expressions for estimating the limiting pump intensities for each set of the parameters are obtained.