Generation of white-light optical vortices through four-wave mixing

In this work, we report on the first study of the n on-phase-matched degenerate FWM of type ω
_s
=2ω
₁
-ω
₂
involving pump beams carrying two-dimensional spatial phase dislocations in the form of single-charged OVs. Our model is based on a set often coupled nonlinear partial differential Schrδdinger-type equations for the ten equally-spaced frequency components ω} (j= 1,...,10), which take into account two-dimensional beam diffraction, FWM effect, as well as self-phase modulation (SPM) and cross-phase modulation (XPM) effects.