Interaction of two optical vortices propagating through turbulent atmosphere

Optical vortices are associated with orbital angular momentum (OAM) and play a significant role in optical communications. During propagation through turbulent atmosphere, optical vortices are subject to atmospheric turbulence, which induces effects such as vortex annihilation. This paper investigates the interaction of two optical vortices during their propagation through turbulent atmosphere. The results show that when the topological charge magnitudes of the two optical vortices are m and n, they evolve into m+n optical vortices, each with a topological charge magnitude of 1. As the propagation distance increases: when the topological charges of the two optical vortices have equal magnitudes but opposite signs, the wavefront exhibits either no optical vortex or a pair of optical vortices with topological charges of \pm 1 after sufficiently long propagation; when the topological charges have unequal magnitudes and opposite signs, the wavefront contains m+n, m+n-2, or |m-n| optical vortices after sufficiently long propagation. These findings can provide theoretical guidance for the control of optical vortex propagation.