Mechanisms of formation of periodic structures under the action of radiation on absorbing condensed media

A theoretical analysis is made of the relative importance of the various mechanisms of formation of a periodic microrelief on the surface of an absorbing medium subjected to pulsed high-intensity monochromatic radiation. A linear approximation in respect of the amplitude of a surface perturbation is used to find the depth of spatial modulation of the absorbed intensity as a function of the optical parameters of the medium. It is shown that hydrodynamic effects in a molten layer on an irradiated surface may play an important role in the formation of a surface relief.