The structure of an optical vortex formed in a partially coherent Laguerre–Gauss laser beam was considered. The main object of study was the recorded vector field of wavefront tilts that consisted of the vortical and potential components. It was found that the vortical motion weakened as the coherence decreased. Main regularities in the behavior of the vortical component can be described by the Scully vortex model of vortical liquid flow. In the spatial evolution, the potential component of tilts may alternate the sign, thus determining the direction of energy flow to the center or to the periphery of the vortex. Energy flow lines in the beam demonstrate the pattern of decay of an optical vortex similar to the pattern of decaying vortical motion in viscous liquid.
© 2012 Optical Society of America
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