FEM simulation of periodical local heating caused by Laser Interference Metallurgy

Interfering laser beams of a high power pulse laser give the opportunity to apply a direct lateral interaction with metals based on mechanisms of photo-thermal interaction of features with a well-defined long-range order in the scale of typical microstructures (i.e., from the sub micrometer level up to micrometers). This study reports laser interference irradiation experiments on one- and two-layer thin metallic films. Depending on the energy of the laser beams different topographical regimes were observed and explained using thermal simulations. The transition of the topographical regimes could be explained due to local and periodical melting or vaporization of the layers. Measurements of the time-resolved electrical resistance of the films during laser irradiation were carried out and compared to the thermal simulations corroborating the experimental observations.