We study theoretically the non-phase-matched degenerate four-wave mixing of type ωs = 2ω1 ωω2, involving beams carrying two-dimensional spatial phase dislocations in the form of singly-charged optical vortices (OVs). Accompanying third-order nonlinear processes in the non-resonant nonlinear medium (NLM), which are accounted for, are self- and cross-phase modulation. In the case of pump OV beams with identical topological charges the model predicts the generation of signal beams carrying OVs of the same charge. If the pump beams carry OVs with opposite charges, the generated signals are predicted to carry triply charged vortices which, in the case of a non-negligible initial free-space propagation from the plane of vortex generation to the NLM, decay inside the NLM into three singly-charged vortices with highly overlapping cores.
|Journal||Proceedings of SPIE - The International Society for Optical Engineering|
|Publication status||Published - 18 Jan 2011|
|Event||16th International School on Quantum Electronics: Laser Physics and Applications, September 20, 2010 - September 24, 2010 - Nessebar, Bulgaria|
Duration: 1 Jan 2011 → …