Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia



Advanced Search

Atmospheric and Oceanic Optics

2023 year, number 8

Deformation and wander of vortex beams in artificial convective turbulence

A.V. Falits, V.V. Kuskov, V.A. Banakh, L.O. Gerasimova, R.Sh. Tsvyk, A.N. Shesternin
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: vortex beam, turbulence, beam wander, convection, laboratory experiment, digital holography

Abstract

The results of experiments on the propagation of vortex optical beams in an artificial convective turbulent medium along a path 12 m long are presented. An artificial turbulent medium is created at a laboratory bench, where laser beams are generated with different values of the topological charge of the orbital angular momentum of the vortex optical field. The characteristics of the path and the parameters of the propagating radiation in the experiment correspond to the propagation conditions, which can be described in terms of geometric optics. It has been established that during the propagation of an optical beam, in the near diffraction zone, as the optical turbulence increases, the instantaneous distributions of the intensity of vortex beams become speckled, the original ring structure of the beam is distorted and disappears. In the averaged intensity distributions, the ring structure is gradually blurring with strengthening the refractive turbulence and becomes close to that of a Gaussian beam with the intensity maximum at the center. The random wandering of vortex beams, whose initial transverse size increases with the topological charge, and beams, whose initial transverse size remains unchanged with a change of the topological charge, is compared. It is shown that the amplitude of random displacements of a vortex beam energy centroid is independent of the topological charge.