PARAMETER EFFECTS ON TEMPERATURES IN THE THIN FILM IRRADIATED BY ULTRAFAST-PULSE LASER

Abstract

The effects of parameters on temperatures in thin metal films heated by ultrafast-pulse laser are investigated in this paper. The time scale in which energy transfers from the electrons to lattice is on the order of a picosecond for metals. Therefore when the duration of ultrafast-pulse laser heating metal films is on the order of or shorter than a picosecond, a substantial nonequilibrium can occur between the electron and lattice temperature and the metal lattices stay almost thermally undisturbed in this highly nonequilibrium regime. A parabolic two-temperature heating model is employed to investigate thermal transport in thin metal films irradiated by ultrafast-pulse laser. Using the Laplace transform and assuming the thermal properties to be independent of temperature, a closed form solution of temperature in the thin film is provided. The effects of laser parameters and material properties on temperatures are also discussed.