a State Key Laboratory of Precision Spectroscopy, School of Physics and Electronic Science, East China Normal niversity,Shanghai 200241, China
b Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
c Collaborative Innovation Center of Light Manipulations and Applications, Shandong Normal University, Jinan 250358, China
Funds:
This work was partly supported by the National Natural Science Foundation of China (91850202, 92150301, 12074121,
62105101, 62175066, 11727810, 12034008) and the Science
and Technology Commission of Shanghai Municipality
(21XD1400900, 20ZR1417100, 21JM0010700).
Femtosecond laser ablation (FLA) has been playing a prominent role in precision fabrication of material because of its circumvention of thermal effect and extremely high spatial resolution. Molecular dynamics modeling, as a powerful tool to study the mechanism of femtosecond laser ablation, still lacks the connection between its simulation results and experimental observations at present. Here we combine a single-shot chirped spectral mapping ultrafast photography (CSMUP) technique in experiment and a three-dimensional two-temperature model-based molecular dynamics (3D TTM-MD) method in theory to jointly investigate the FLA process of bulky gold. Our experimental and simulated results show quite high consistency in time-resolved morphologic dynamics. According to the highly accurate simulations, the FLA process of gold at the high laser fluence is dominated by the phase explosion, which shows drastic vaporized cluster eruption and pressure dynamics,while the FLA process at the low laser fluence mainly results from the photomechanical spallation, which shows moderate temperature and pressure dynamics. This study reveals the ultrafast dynamics of gold with different ablation schemes,which has a guiding significance for the applications of FLA on various kinds of materials.