Self-channeling and pulse shortening of femtosecond pulses in multiphotonionized dielectric solids

Summary form only given.We present a numerical study of the spatio-temporal evolution of femtosecond pulses in dielectric solids. In solids the role of the group-velocity dispersion (GVD) is more dominant, and the characteristic parameters for the optical Kerr effect as well as for the multiphoton ionization differ by some orders of magnitude in comparison to those in gases. Despite these distinct physical conditions, the results of our numerical investigation show the possibility of self-channeling of high-peak power femtosecond pulses with powers somewhat above the critical power of self-focusing. We consider the case that multiphoton ionization dominates compared with the tunneling ionization and where the avalanche ionization plays no significant role because of the shortness of the pulses.