Ablation Process of Femto Second Laser Pulses
Laser ablation is a technology which gains increasingly more importance for drilling, welding, structuring and marking of all kind of materials. For industrial usage, micro- and nanosecond pulses are typical. Due to the emerging melt and the incipient heat conduction of the electrons, materials will be heavily damaged close to the laser treated zone. Clogging of holes and lacking precision of the structuring are the consequences. The usage of shorter femtosecond laser pulses promises to improve the quality. Molecular dynamics simulations can contribute to new insight into the not completely comprehended ablation process with these short pulses. A team from the University of Stuttgart implemented a program package for the atomistic simulation of laser ablation on GCS supercomputers which can deal with the coupling of the laser light and the heat conduction by the electrons. Through these simulations, the researchers expect to get new insight into the composition of the melt (see figure) composed of gas and droplets. The latter should be avoided since they clog the drilling holes. The results are important for various industries for the manufacturing of better products. One such example is the medical field, where such shortpulse lasers are used for eye surgery.
PD Dr. Johannes Roth
Institute for Theoretical and Applied Physics, University of Stuttgart
Pfaffenwaldring 57, D-70550 Stuttgart