Competition between phase-matching and stationarity in Kerr-driven optical pulse filamentation.

Experiments show that the spatiotemporal spectral broadening of an intense pump pulse in a Kerr medium in the presence of strong higher-order dispersion does not lead to symmetric profiles, and hence cannot be interpreted as standard modulational instability of a plane and monochromatic nonlinear eigenmode. The highly asymmetric features of the generated (K perpendicular,Omega) spectrum are due to odd-order dispersion terms and are interpreted in terms of spontaneous formation of stationary conical waves.