P. Hansinger, G. Maleshkov, I. L. Garanovich, D. Skryabin, D. N. Neshev, A. Dreischuh, and G. G. Paulus
Experiments performed with different vortex pump beams show for the first time the algebra of the vortex topological charge cascade, that evolves in the process of nonlinear wave mixing of optical vortex beams in Kerr media due to competition of four-wave mixing with self- and cross-phase modulation. This leads to the coherent generation of complex singular beams within a spectral bandwidth larger than 200nm. Our experimental results are in good agreement with frequency-domain
numerical calculations that describe the newly generated spectral satellites.
Keywords: Nonlinear optics; Nonlinear optics, four-wave mixing; Optical vortex; Topological charge.