Simulation of ultrashort double-pulse laser ablation

In this paper, we study the mechanisms of femtosecond double-pulse laser ablation of metals. It was previously shown experimentally that the crater depth monotonically drops when the delay between two successive pulses increases. For delays longer than the time of electron-ion relaxation the crater depth can be even smaller than that produced by a single pulse. The results of the performed hydrodynamic simulation show that the ablation can be suppressed due to the formation of the second shock wave. The modeling results of the double-pulse ablation obtained for different delays correlate with the experimental findings.

Research highlights▶ Double-pulse crater depth depends on the delay between pulses. ▶ Two pulses can produce the crater less than a single one. ▶ Ablation process can be suppressed by the second pulse. ▶ The longer delay the higher atomization and smaller clusterization. ▶The deeper thermodynamic trajectory enters into metastable liquid region the shorter lifetime of this state.