Temperature rise induced by a cw laser beam revisited

Abstract

The problem of spatial distribution of the temperature rise due to a cw laser beam focused on the surface of an absorbing material is reexamined. The effect of temperature dependence of the absorption and reflection coefficients is incorporated in the calculations in a self‐consistent way. A Green’s function has been developed for the heat diffusion equation in the axially symmetric case and a general steady‐state solution is obtained for an arbitrary source function. Compared with previous results, our calculations predict melting at lower laser power densities and changes in the spatial temperature distribution. In the limit of large absorption constants these differences are small. However, they become increasingly significant as the absorption constant is decreased.