  Lasers are becoming a more and more important tool in cutting and shaping
materials. Improving precision and effectivity is an ongoing demand in science
and industry. One possibility are double pulses. Here we study laser ablation
of aluminum by the two-temperature model. There the laser is modeled as a
source in a continuum heat conduction equation for the electrons, whose
temperature then is transferred to a molecular dynamics particle model by an
electron-phonon coupling term. The melting and ablation effectivity is
investigated depending on the relative intensity and the time delay between two
Gaussian shaped laser pulses. It turns out that at least for aluminum the
optimal pulse shapes are standard Gaussian pulses. For double pulses with delay
times up to 200 ps we find a behavior as observed in experiment: the ablation
depth decreases beyond a delay of 10 ps even if one does not account for the
weakening at the second pulse due to laser-plasma interaction.
