Free-space propagation properties of Gaussian vortex and Bessel-Gaussian vortex beams having fractional topological charges in turbulent medium

Abstract Optical information processing has received a lot of interest in recent years because of its benefits, such as low energy usage and parallel data handling capability. However, atmospheric turbulence caused due to uneven heating of the air, poses challenges for free-space transmission. The fluctuations distort light waves and cause errors in data transfer. Structured light-based information encoding is emerging as a possible approach which not only overcomes such error but provides encoding capability. Its distinct properties, such as intensity control, self-healing capability, and configurable phase and polarization distributions, increase versatility for efficient data encoding. In this study, we investigate the efficacy of free space data communication in presence of turbulent condition using Gaussian vortex and Bessel-Gaussian vortex beam having fractional topological charge. In this regard, we obtain various statistical parameters like scintillations index, peak signal-to-noise ratio, and mean square error of both Bessel-Gaussian vortex beam and Gaussian vortex beam corresponding to different level of turbulence. Additionally, we have studied the beam divergence of both types of beam within a turbulent medium. To introduce the effect of turbulence experimentally we used a Kolmogorov-type turbulence simulator with a pseudo-random phase plate.