Effects of an absorptive coating on the dynamics of underwater laser-induced shock process

Dynamical Visualization of Laser-Induced Shock Phenomena in Liquid

“…Figure 6 (b) shows photoelastic images at corresponding energies for ablation under bulk-liquid, where a conÞ ning effect was fully realized. 19 For pulse energies of 5 mJ, the image obtained under 0.6 mm liquid parafÞ n showed the same number of fringes as that observed in the ablation under bulk liquid. This suggests that a 0.6 mm thick liquid overlay is adequate to get the full confining effect of liquid overlays.…”

Bubble dynamics in metal nanoparticle formation by laser ablation in liquid studied through high-speed laser stroboscopic videography

“…When a short, high-powered laser pulse is irradiated onto a solid surface in water, a very high level of stress is induced by the confinement effect of the surrounding water on the plasma. We have directly observed and reported this effect using a high-speed camera and a high-speed video camera [13][14][15]. In order to visualize this process, we have developed a custom-designed high-speed videography system designated "high-speed laser stroboscopic videography".…”

“…The behavior of laser-induced bubbles on a metal plate was studied [19]. Our previous results have revealed various aspects of the dynamic phenomena that occur during laser ablation on solid targets in liquid, as well as inside the solid itself [13][14][15].…”

Cavity formation and surface modeling of laser milling process under a thin-flowing water layer

“…Based on Eq. (22), the percentage of laser energy absorbed by workpiece was found to range from 2.5 to 4% for 30-kHz pulse frequency and 1.5-2% for 250 kHz depending on water flow velocity and laser power as shown in Fig. 15.…”

“…A reason for this feature is relevant to the interaction between laser, water and plasma plume. In general, the laser ablation in water encounters the formation of vapor bubble and plasma at the laser-irradiated area, in which shock wave and stress wave radially propagate in water and work material [22]. In addition, when the workpiece undergoes the rapid vaporization, a cavitation bubble is generated and grows to its maximum before collapsing and releasing shockwave.…”