Transformation of the optical vortex dipole by an astigmatic lens

Abstract

The transformation of the optical vortex dipole (OVD) by an astigmatic lens is studied. The explicit propagation expression of the OVD nested in a Gaussian beam is derived and used to analytically determine the position of the OVD after the passage through the astigmatic lens. The transformation by an aberration-free lens is treated as a special case. It is shown that, depending on the propagation distance, waist width, off-axis distance and astigmatic coefficient, the motion, annihilation and revival of the OVD and the inversion of the topological charge may take place. Specifically, the creation of two OVDs may appear under certain conditions. The results are illustrated by numerical examples.