Analytical solution of the laser-induced temperature distribution across internal material interfaces

The paper presents an analytical solution of the heat conduction equation with constant coefficients for laser irradiation at the interface of two materials by applying Laplace transformation. Special attention is put on liquid–solid interfaces. The model considers the laser absorption in only one material as well as at the interface. The temperature distribution and the thermal flow across the materials interface as well as the energy efficiency to heat the solid material were studied in dependence on selected material properties, the laser beam absorption, and the length of the laser pulse. High solid surface temperatures can be achieved with high absorption liquids, sufficient interface absorption, and at short laser pulses. The comparison with numerical results shows a good congruence.