Dynamics of pulsed laser ablation

Summary form only given. Above a certain fluence threshold, laser light incident on a target induces a rapid removal of material, a process called ablation. A survey of results from the literature shows that, if the laser energy deposition time is short compared with the time required to accelerate matter, the ablation threshold energy is an order of magnitude lower than the energy required to evaporate matter. Theory reveals that very large transient tensile stresses are generated at the surface. I postulate that when these stresses exceed the tensile strength of the material, ablation occurs. To verify the theory I built a Michaelson interferometer capable of measuring surface motion with a resolution of a few nanometers at time intervals of a few nanoseconds.