The time-development of a laser irradiated surface in the case of a high ablation rate is given by the local energy balance. The analytical solution is found by the method of characteristics. The macroscopic shape of the metal decays into a selfsimilar surface shape. The ablation rate depends on the amplitude and the spatial period of the surface such that the contour is smoothed out in the course of time. Linear polarization of the laser beam induces an anisotropy of the irradiated surface.
