A wide-range model for simulation of pump-probe experiments with metal
Résumé
Pump-probe experiments give information about the substance in states out of equilibrium. A wide-range numerical model is used for the description of material response on ultrashort laser action. The amplitude and phase of the complex reflection coefficient have been measured in experiment. The intense p-polarized pump pulse of 1240 nm length creates the plasma on the surface of a metallic target. A weak s-polarized probe pulse with 620 nm is used for diagnostics of the plasma by means of femtosecond interference microscopy. A theoretical model is developed for simulation of laser-mater interaction on the basis of two-temperature hydrodynamics with heat transport phenomenon, ionization, plasma expansion, electron-ion collisions and two-temperature equation of state for an irradiated substance. A comparison of the experimental findings with the results of modeling for Al and Ag targets shows that the model is suitable up to intensities of 10^15 W/cm^2