Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 35: Poster Session II

MM 35.39: Poster

Mittwoch, 25. März 2009, 16:30–18:30, P4

Crater Formation in Metals Induced by Femtosecond Laser Pulses — •Steffen Sonntag, Johannes Roth, and Hans-Rainer Trebin — Institut für Theoretische und Angewandte Physik, Universität Stuttgart, 70550 Stuttgart, Deutschland

We investigate femtosecond laser ablation of metals using a hybrid simulation scheme. Two coupled equations are solved simultaneously: a generalized transport equation for the electronic system which accounts for laser energy absorption and electronic part of the heat conduction, the other for the dynamics of the lattice where the ablation process takes place. For the electron temperature the generalized heat-conduction equation is solved by applying a finite difference scheme. For the lattice properties, e.g. pressure, density or temperature, we use common molecular dynamics. Energy transfer between the subsystems is allowed by introducing an electron-phonon coupling term. This combined treatment of the electronic and atomic systems is an extension of the well known two-temperature model [1].

Atomic scale images of the ablation process are shown. We discuss the crater formation induced by Gaussian beam profiles, i.e. by TEM00 modes. Ablation and melting thresholds for different metals will be presented.

[1] S.I. Anisimov, B.L. Kapeliovich and T.L. Perel’man: Sov. Phys. JETP 39, 375(1974)