Cavity Formation and Material Ablation for Single-Pulse Laser-Ablated Solids Immersed in Water at High Pressure

Abstract

The effects of hydrostatic pressure on cavity formation and material ablation have been investigated for a brass plate immersed in water irradiated by a single laser pulse of duration <10 ns. Shadowgraph imaging and volumetric measurements of the ablated material demonstrate that the density of the material inside the cavity does not vary significantly for hydrostatic pressures between 0.1 and 30 MPa (300 atm) during the early stages, <600 ns after laser irradiation, indicating that the pressures induced by focusing a high-power laser in the confined medium dominate the transient pressure regime over this period.