Ionization-induced leaking-mode channeling of intense short laser pulses in gases

We demonstrate that short laser pulse self-guiding over distances of many R ayleigh lengths can be achieved in the absence of any focusing nonlinearity as a result of trapping of a leaking wave in a plasma channel produced by field-induced ionization in the saturation regime. A detailed computational study of the new self-guiding effect in both cases of comparatively long l aser pulses, when the traditional approximation of the slowly varying compl ex amplitude is valid, and of high intense ultrashort laser pulses comprisi ng only few field cycles have been performed.