Formation of Axially Asymmetric Optical Vortices from Gaussian Beams behind a Spiral Phase Plate.

We study numerically the statistics of the formation of local intensity maxima in the focal plane of a collecting lens after a Gaussian beam passes through a spiral phase transparency in the presence of amplitude‒phase noise in the beam. It is shown that when the amplitude of field fluctuations is about 15%, two hot spots are most likely to be formed on the annular profile of an optical vortex with a topological charge m = 1. Moreover, in more than half of the implementations, these hot spots are located diametrically opposite to the phase dislocation region. In an elliptical beam, regions of increased intensity in the cross section of the optical vortex are located predominantly along the shorter axis. [ABSTRACT FROM AUTHOR]