Microscopic and Macroscopic Simulation of Ultra-Short-Pulse Laser Processing by CIP Method

Abstract

We performed 1.5-dimensional simulation of the Fokker-Planck equation using the CIP method to investigate femto-second-laser heating processes. We found that the heat flux in the solid part approaches a classical thermal conduction theory like the Spitzer-Härm theory on quite a short time scale ω _pt < 100, while the heat flux on the vacuum side becomes free streams that don't depend on the temperature gradient. On the basis of this result, we performed a hydrodynamic simulation using the CIP method with classical thermal conduction. The experimental ablation depth was replicated very well, showing that even fs pulse laser processing can be satisfactorily described by classical heat conduction.