Nonequilibrium heating in metal films: An analytical and numerical analysis

Ultrashort pulsed laser heating of metals at room temperature is commonly s tudied using the parabolic two step (PTS) model. An analytical solution of the PTS is presented and compared to numerical results. The analytical solu tion assumes constant thermophysical properties, which Is appropriate for a pplications such as nondestructive testing using low laser fluences. The as sumption of constant thermophysical properties is discussed, and appropriat e regimes are established. Numerical and analytical solutions of the PTS mo del are compared to experimental data in order to demonstrate the utility o f these solutions for determining the thermal diffusivity of thin films.