Pulsed laser ablation of metals

We have developed a simple numerical model to describe the main physical processes involved in the laser heating and vapourisation of metal targets. Laser absorption and heating of the vapourised material, ionisation dynamics and re-radiation to the target surface are included. The model was used to calculate plasma absorption, the average ion energy and the ablation depth per pulse for an iron target irradiated with a 26 ns excimer laser pulse at 248 nm, and the results were compared with experiment. It is clear that absorption of the laser in the vapour plume has an important role in determining the dynamics of pulsed laser ablation. The absorption is much stronger than indicated by inverse bremsstrahlung, probably due to bound–bound and photoionisation processes. q1998 Elsevier Science B.V.