Composite vortex patterns formed by component light beams with non-integral topological charge

Abstract

We present a study of composite vortices in light beams using component beams with no integral topological charge. We observed the same general features that are seen in when the component beams have an integral topological charge [E.J. Galvez, N. Smiley, and N. Fernandes, Composite optical vortices formed by collinear Laguerre-Gauss Proc. SPIE 6131, pp. 19-26, 2006.]. These are: (1) that new vortices appear at distances from the beam that depend on the ratio of the intensity of the component beams, and (2) that the angular location of the vortices depends on the phase difference between them. We also observed that some of the vortices associated with fractional charge that did not follow the same dynamics.