Excitation and relaxation dynamics in dielectrics irradiated by an intense ultrashort laser pulse

When transparent dielectrics are irradiated by an intense, ultrashort laser pulse, the electron density in the conduction band is increased tremendously. Simultaneously, valence band states become unoccupied and the electron–phonon coupling strength is increased. In this paper, we present our work on modeling the ultrafast nonequilibrium dynamics of laser-excited transparent dielectrics with Boltzmann collision integrals. We track the distribution function of conduction and valence band electrons and discuss the effects of Auger recombination in relation to impact ionization and multiphoton/tunnel ionization on the femtosecond timescale. Finally, we investigate the electron–phonon coupling strength in highly excited dielectrics and calculate the electron–phonon coupling parameter for silicon dioxide-like material.