Propagation of Riemann–Silberstein vortices through an astigmatic lens

Abstract

The propagation of Riemann-Silberstein (RS) vortices for Gaussian vortex beams with topological charges m=+1 through a lens is studied. It is shown that if there is an ideal lens, a RS vortex and a circular edge dislocation appear for Gaussian on-axis vortex beams, while only RS vortices take place for Gaussian off-axis vortex beams. In the presence of an astigmatic lens, there exist RS vortices but no edge dislocations for both Gaussian on-axis and off-axis beams. By varying the astigmatic coefficient, the off-axis parameter, and the propagation distance, the motion, creation, and annihilation of vortices may take place, and in the process, the total topological charge of RS vortices remains unchanged.

Propagation property of the non-paraxial vector Lissajous singularity beams in free space

“…Since Kessler and Freund studied polarization singularities in polychromatic vector wave fields, much interest has been exhibited in the singular phenomena of polychromatic vector beams [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. The Lissajous singularities can be created by second-hormonic generation with commensurate frequencies or can emerge from the incoherent addition of two incommensurate vector beams [1,4,[10][11][12].…”