Transient electron excitation and nonthermal electron-phonon coupling in dielectrics irradiated by ultrashort laser pulses

Abstract

We calculate nonequilibrium electron distributions created by the absorption of an intense, ultrashort laser pulse in a transparent model-dielectric using a Boltzmann-type collision approach. We compare electron energy and particle density, as well as electron-phonon energy transfer of a full nonequilibrium simulation with values of a simulation enforcing instant thermalization, testing the inherent assumption of temperature-based models. Finally, we calculate electron-phonon coupling parameters of nonequilibrium distributions and compare these with those of thermalized distributions of the same particle and energy density. We find that the strength as well as the relaxation of the electron-phonon coupling depends considerably on the excitation parameters.