Digital Image Transmission Over FSO System with OAM Beams: Quality Assessment

This paper presents a new high-speed black and white image transmission across Free Space Optics (FSO) system utilizing Orbital Angular Momentum (OAM) multiplexing. The system is designed to simultaneously transmit four distinct black and white images (trees, cameraman, lighthouse, and peppers), each modulated onto a separate OAM beam (LG00, LG015, LG045, and LG075) at a rate of 10 Gbps, demonstrating the feasibility of parallel transmission of digital images. The system performance is evaluated over different weather conditions including Clear Air (CA), different fog levels, and real-world meteorological data from Riyadh city, Kingdom of Saudi Arabia (KSA). A median filtering technique is applied to improve image quality, leading to notable enhancements in Signal-to-Noise Ratio (SNR), Peak Signal-to-Noise Ratio (PSNR), and Structural Similarity Index (SSIM). The system successfully supports the transmission over a 16 km in CA weather and 10 km link under Riyadh weather conditions. At these ranges, SNR, PSNR, and SSIM are greater than 6.05 dB, 11.54 dB, and 0.56, respectively. This study underscores the potential of using OAM-based FSO systems for high-speed, real-time remote monitoring, particularly in adverse atmospheric environments.