Formation of amplitude-phase envelopes of intense short pulses in waveguides

The critical amplitudes are found for the lowest and higher modes of various envelopes of TE-polarized pulses in a graded-index fiber waveguide. The spatial and energy characteristics of subcritical and supercritical evolution regimes are considered. A study is made of the special features of resonance doubling of the pump wave frequency associated with the discrete nature of the spectra of the interacting modes.