Dynamics of laser ablation of biological tissues

Abstract

We have developed a subnanosecond time resolution ultrafast photographic setup that can be used both as shadowgraph and Schlieren apparatus. With this setup a detailed study of the time history of the plume ejection and shock wave propagation have been preformed. We have shown that the shock wave fronts follow the behaviour predicted by shock wave theories, and that the planar shock wave fronts travel always perpendicular to the ablated surface. In addition to the earlier known hemispherical shock wave a new, head‐wave type wave front was found that is presumably caused by a bunch of very fast particles preceding the formation of the main ablation plume. We have shown that the dynamics of short pulse Nd laser induced cavitation bubbles is considerably different in water and bovine cornea.