Abstract: We study experimentally the nonlinear dynamics of two-color optical vortex beams in the presence of second-harmonic generation combined with the effects of photoand thermal refraction, as well as self- and induced-phase modulation. We use an iron-doped lithium niobate crystal as a nonlinear medium for the vortex propagation and observe experimentally, depending on the laser wavelength, a decay of a double-charge vortex, splitting and reshaping of background beam, pattern formation, and controllable nonlinear rotation of a vortex pair.

Keywords: photorefractive spatial solitons; orbital angular-momentum; self-frequency shift; 2nd-harmonic generation; wave-guides; vortex solitons; propagation dynamics; phase modulation; laser-pulses; beams

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