Numerical study of laser ablation on aluminum for shock-wave applications: development of a suitable model by comparison with recent experiments

In order to control laser-induced shock processes, two main points of interest must be fully understood: the laser–matter interaction generating a pressure loading from a given laser intensity profile and the propagation of induced shock waves within the target. This work aims to build a predictive model for laser shock-wave experiments with two grades of aluminum at low to middle intensities (50 to 500  GW/cm 2 500  GW/cm2 ) using the hydrodynamic Esther code. This one-dimensional Lagrangian code manages both laser–matter interaction and shocks propagation. The numerical results are compared to recent experiments conducted on the transportable laser shocks generator facility. The results of this work motivate a discussion on the shock behavior dependence to elastoplasticity and fracturation models. Numerical results of the rear surface velocity show a good agreement with the experimental results, and it appears that the response of the material to the propagating shock is well predicted. The Esther code associated to this developed model can therefore be considered as a reliable predictive code for laser ablation and shock-wave experiments with pure aluminum and 6061 aluminum in the mentioned range of parameters. The pressure–intensity relationship generated by the Esther code is compared to previously established relationships

Simulation of laser-driven cratering experiments on aluminum

After a brief description of the physical principles involved in the cratering process, the authors present a specific methodology to simulate laser-driven cratering experiments performed with a long pulse duration (100 ns) and a small focal spot diameter (220 μ m). This methodology can be divided into two steps. First, the 2D-axisymmetrical pressure field generated by the laser on the target is determined from laser parameters. Second, this pressure is applied on the surface of the target in a Eulerian simulation. In order to validate this methodology, the authors simulate a laser shot on a thin aluminum target whose rear surface velocity is recorded by a VISAR (Velocity Interferometer System for Any Reflector). Once validated, they use the methodology to simulate laser-driven cratering experiments on semi-infinite aluminum targets. Numerical results are compared to experimental measurements of the craters. Although slight differences are pointed out and discussed, the proposed methodology is well adapted to simulate craterization laser shots

Investigation of stress induced by CO2 laser processing of fused silica optics for laser damage growth mitigation

International audienc

Birefringence and residual stress induced by CO2 laser mitigation of damage growth in fused silica

International audienc

Effect of laser irradiation on silica substrate contaminated by aluminium particles

International audienc

High power CW laser heating of graphite at high temperature and applications in material studies and laser processing’

International audienc

High power CW laser heating of graphite at high temperature and applications in material studies and laser processing’

International audienc

Heat treatment of fused silica optics repaired by CO2 laser

International audienc

Influence of artificial metallic defects size on the surface cleaning process

International audienc