Phase distortions due to temperature rise of optics irradiated by periodically repeated short pulses

Temperature variation and wave front distortions due to temperature rise and thermal stress, in rotationally symmetric and isotropic optical elements irradiated by periodically repeated short pulses, have been calculated. The analytical expressions of the periodically varying temperature distributions have been obtained by making full use of the periodicity of the pulsed laser system. For the case where the diameter of optical element is considerably larger than the thickness and the temperature variation along the thickness direction is negligibly small, the plain approximation has been used to estimate phase distortions. The results have shown that the polarization-independent phase distributions due to thermal deformations of the optical element may be of concern, especially if one considers the fact that the phase distortions of the light wave may be accumulated after passing through several optics.