The thermal lensing effect in the crystal influences the stability of solid-state lasers. The deformation of the end faces of the crystal and the temperature dependence of the refraction index causes this effect. The photoelastic effect produced by thermal induced stress in the crystal has also an influence. For high power lasers and for lasers with a radially polarized laser beam the analysis of the photoelastic effect is important. We use FE model to calculate the deformation, heat and stress distribution in the laser crystal with high accuracy in this work. Using the calculated stress distribution we also simulated the refraction index anisotropy with respect to the crystal orientation. We can study stability of laser resonators for both radially and azimuthally polarized laser beam, as a result of our simulation. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)