Wædegaard, Kristian Juncher4; Sandkamm, Ditte Både4; Haahr-Lillevang, Lasse4; Bay, Kathrine Glerup5; Balling, Peter4
1 Department of Physics and Astronomy, Science and Technology, Aarhus University2 Interdisciplinary Nanoscience Center - INANO-Fysik, Ny Munkegade, Interdisciplinary Nanoscience Center, Science and Technology, Aarhus University3 Department of Chemistry, Science and Technology, Aarhus University4 Department of Physics and Astronomy, Science and Technology, Aarhus University5 Department of Chemistry, Science and Technology, Aarhus University
A theoretical description of ultrashort-pulse laser excitation of dielectric materials based on strong-field excitation in the Keldysh picture combined with a multiple-rateequation model for the electronic excitation including collisional processes is presented. The model includes light attenuation in a self-consistent manner and changing optical properties described in a Drude picture. The model can be used to calculate the electronic excitation as a function of time and depth, and from these quantities the time-dependent optical parameters as well as the ablation depth can be derived. The simulations provide insight into the excitation and propagation dynamics of short-pulse excitation and show that at increasing fluence the excitation becomes localized near the material surface and gives rise to strongmodifications of the optical properties of the material.