Light-induced polishing of an evaporating surface

A theoretical model is proposed of the process of polishing of the surfaces of diamond films by graphitization and evaporation from the solid phase by XeCl excimer laser pulses. The model predicts that the Fourier harmonics of the surface irregularities with periods exceeding 0.7–4.1 μm are smoothed out and this accounts fully for the observed surface polishing effect. Ways of smoothing out the harmonics of surface irregularities of even shorter periods are discussed. The proposed theoretical model is applicable also to nonlaser radiation sources as well as to the process of thermochemical etching by radiation characterized, by analogy with evaporation, by the Arrhenius dependence of the etching front velocity on the surface temperature.