Color image information transmission in plasma sheath turbulence based on orbital angular momentum mode

This study numerically investigates the transmission of color images through a 0.4 m plasma sheath turbulence (PST) channel, based on the anisotropic power spectrum of the refractive-index fuctuation in the PST. A simulation model for the encoding and decoding of image pixels is proposed by utilizing the orbital angular momentum (OAM) mode of Gaussian vortex beams. The impacts of refractive index fluctuation variance, outer scale, and anisotropy parameters on the peak signal-to-noise ratio (PSNR) of the received image and the bit error rate (BER) in free-space optical (FSO) communication are analyzed. The results indicate that as the variance of refractive index fluctuation increases, the outer scale decreases, and the anisotropy parameters decrease, the PSNR progressively decreases while the BER increases. Furthermore, under weak turbulence conditions, the BER is 1.25 × 10^-4, and even under strong turbulence, the BER is as low as 0.447. The successful transmission of a 256 × 256-pixel color image demonstrates the feasibility of the proposed encoding and decoding scheme.