Published Paper Details:

This study proposes a novel underwater optical wireless communication (UOWC) system employing orbital angular momentum (OAM) multiplexing with pulse amplitude modulation (PAM4) for high-speed data transmission. The system consists of four distinct Laguerre-Gaussian (LG) modes (LG0,0, LG0,15, LG0,35, LG0,70), each carrying 20 Gb/s data streams using a green laser operating at 532 nm. To evaluate the robustness and adaptability of the system in diverse marine environments, simulations were conducted across five different water types: Pure Sea (PS), Clear Ocean (CO), Coastal Sea (CS), Harbor I (HI), and Harbor II (HII). Simulation results demonstrate that the system achieves reliable data transmission over distances up to 10.8 meters in the clearest waters, with performance gracefully degrading to shorter ranges of around 2.8 meters in highly turbid harbor conditions, confirming its adaptability to varied underwater environments. This work emphasizes the scalability and spectral efficiency of OAM-PAM4 systems and highlights their potential in applications such as deep-sea exploration, marine sensor networks, and real-time surveillance.