Behavior of Phase in Tightly Focused Optical Vortex

In this study, we analyze the phase and local wave vector dynamics in a tightly focused linearly polarized optical vortex. Unlike the case of a scalar vortex, several vortex centers are formed in the studied system, which leads to the appearance of several zones with a giant wave vector. The spatial arrangement of these centers is determined by the topological charge of the incident beam. A single topological charge leads to a single vortex center located on the optical axis. For a topological charge of two, pair of vortices each with a single charge is formed off-axis in the focal plane. For topological charges greater than two, a triplet of vortices is formed, in which two vortices with a single charge are shifted from the axis.