title: Breakdown of the slowly varying envelope approximation in the self-focusing of ultrashort pulses.
abstract: We show theoretically and experimentally that with ultrashort pulses much longer than a single optical cycle, the effects of self-steepening and space-time focusing are important for describing the nonlinear dynamics of self-focusing. Asymmetric temporal splitting of the pulse envelope is observed in which the relative magnitudes of the peaks are reversed as the input power is increased.
authors: J K
authors: JK
authors: Ranka
authors: A L
authors: AL
authors: Gaeta