Enhancement of Bovine Bone Ablation Assisted by a Transparent Liquid Layer on a Target Surface

The purpose of this study was to investigate the laser-induced ablation of bovine bone assisted by a transparent liquid layer on top of the target surface. A Q-switched Nd:YAG laser was used to ablate bovine tibia at various energy levels. Distilled water was applied to the sample surface in order to examine the role of a transparent liquid layer during the ablation. Plasma generation and transient acoustic waves were monitored to identify dominant mechanisms involved in the ablation process. Ablation efficiency was measured from the cross-sectional tomography acquired by optical coherence tomography (OCT). Ablation with a liquid layer lowered the damage threshold and enhanced both the laser-induced acoustic excitation and the ablation efficiency, which saturated at higher radiant exposures. The enhanced ablation of the liquid-assisted process is primarily due to photomechanical effects associated with explosive vaporization and plasma confinement. The saturation of the pressure amplitude and ablation efficiency was attributed to increased plasma shielding