Electronic excitation in femtosecond laser interactions with wide-band-gap materials

Effects of the ultrashort laser excitations of wide-band-gap materials are investigated. Single-, double-, and multiple-shot cases are considered with a particular focus on the control over the transient reflectivity changes and the energy deposition rate. We show that the history of laser excitations affects not only the ionization process and the final number of the conduction-band electrons, but also determines the reflectivity time evolution and the rate of laser energy deposition into the target. Based on the obtained calculation results, both thermal effects and structural modifications can be better controlled.