Numerical simulation of femtosecond pulse propagation in air undergoing self-focusing and ionization

Summary form only given. Intense, ultrashort laser pulse propagation in gases is of considerable current interest. Recently, self-channelling of femtosecond pulses in air over 20 m in distance has been demonstrated. To better study the propagation characteristics of such pulses, we have developed a numerical code based on the paraxial wave equation.