title: Comparison of femtosecond laser ablation of aluminum in water and in air by time-resolved optical diagnosis.
abstract: The dynamic process of material ejection and shock wave evolution during one single femtosecond laser pulse ablation of aluminum target in water and air is experimentally investigated by employing pump-probe technique. Shadowgraphs and digital holograms with high temporal resolution are recorded, which intuitively reveal the characteristics of femtosecond laser ablation in the water-confined environment. The experimental result indicates that the liquid significantly restrict the diffusion of the ejected material, and it has a considerable effect on the attenuation of the shock wave. In addition, the expansion Mach wave generated by the ultrasonic expansion of the shock wave is observed.
authors.forename: Haofeng
authors.initials: H
authors.lastname: Hu
authors.forename: Tiegen
authors.initials: T
authors.lastname: Liu
authors.forename: Hongchen
authors.initials: H
authors.lastname: Zhai