Q-switched laser ablation of tissue: plume dynamics and the effect of tissue mechanical properties

A Q-switched Er:YAG laser was used to ablate skin, liver, and agar gel. The materials were chosen for their varying degrees of stiffness. It was seen that the varying mechanical properties effected the dynamics of the ablation process. The lower stiffness materials demonstrated a lower velocity of the ablated material and a longer post-pulse ablation duration. The effects were mediated by high ablation pressures causing elastic expansion of the crater during and after the pulse.