attributed to self-channeling, were investigated by use of gigawatt pulses from a Ti: sapphire
chirped-pulse-amplification laser system. A filament contained only a small fraction of the
pulse energy and always ended at the diffraction length of the beam (∼ 100 m),
independently of the pulse energy. These features are explained by the moving-focus
model, which is presented as an alternative to the self-channeling model. Computer …