Characteristics of Tantalum Ablation under the Impact of a Femtosecond Laser

We have studied tantalum ablation under a single impact by 80-fs laser pulses using interference microscopy with a temporal resolution and scanning electron microscopy. The ablation plume structure and the crater morphology reveal different mechanisms of substance removal, which depend on the laser pulse energy density. We have measured the thresholds of the spall and fragmentation ablation types and determined the nonmonotonous dependence of the crater depth on the energy density.