Simulation of third-harmonic and supercontinuum generation for femtosecond pulses in air

Numerical simulations of third-harmonic and supercontinuum generation for femtosecond pulses propagating in air are presented which, for the first time to the best of our knowledge, do not rely on the decomposition of the total field into slowly-varying fields centered around the fundamental and third-harmonic. The simulation results are interpreted using an effective three-wave mixing approach, and together they provide new insights into the relation between third-harmonic and supercontinuum radiation.