Thin 10-100 nm film in contact with substrate: Dynamics after femtosecond laser irradiation

Femtosecond laser irradiation of a thin gold film deposited on the thick glass substrate is considered. The thickness of a film has the order of a few microns and focal focal spot is small. Underlying physics of processes after irradiation is studied with combined approach of two-temperature hydrodynamic and MD simulations. Found are two adsorbed fluence thresholds F_s < F_a and three regimes of motion, in comparison with the freestanding film. There is oscillatory mode when the film oscillates remaining on substrate for 0 < F < F_s. For F_s < F < F_a the film breaks away from substrate because negative pressure overcomes the cohesion strength of the film-substrate contact. For F_a < F there is inner disruption of the film happened before the separation of metal from dielectric substrate.