The Numerical Simulation of Reflectivity of Aluminum Alloy Irradiated by Laser Beam

Based on the free electron model－the Drude/Fresnel theory, the variation of reflectivity of the aluminium surface under intense laser interaction is analyzed in this paper. From the numerical simulation of the relation of the aluminium conductivity with temperature, the instantaneous variations of the reflectivity at the aluminium surface in the solid, liquid and vapor states are conducted. The results are in accord with the experiments. When the laser power density is in the range from 1011~1015 W/cm-2, the numerical simulation results of the reflectivity with temperature are obtained according to the plasma model and the assumption of local thermal equilibrium (LTE). The results are approximate to the experimental results from abroad.