One-Temperature Analytical Model for Femto-/Atto-Second Laser-Metals Drilling: A Novel Approach

Materials (Basel). 2022 Jul 19;15(14):5010. doi: 10.3390/ma15145010.

Abstract

Recently, ultrafast lasers have been developed and potentially become a point of interest worldwide, as their interaction with matter is yet unknown and can be mediated by new physical mechanisms. Real-time experimentation requires enormous costs, and there is therefore a need to develop computational models for this domain. By keeping in view this idea, a non-Fourier heat equation has solved the case of ultrafast laser-material interaction. Initial and boundary conditions were considered, and a one-dimensional mathematical model was presented. The simulations were compared with the experimental results for ultrashort laser-metallic sample interaction, and a close correlation was proven. It was found that the coupling of electron-phonon becomes "zero" due to short laser-material interaction time. The propagation of thermal waves was identified due to non-Fourier heat implementation. When the pulse duration increases, the variation in the thermal distribution becomes trivial due to an inverse correlation between the pulse duration and total energy within the pulse. When the laser-material interaction time decreases from fs to as, the generation of thermal waves increases and the powerful laser intensity acts as a shock wave during laser-material interaction, which causes a higher intensity of the thermal wave.

Keywords: metals; modelling; non-Fourier heat equation; thermal waves; ultrashort laser pulses.