UOWC transmission system based on OAM beams: performance evaluation

This paper proposes a novel 4 x 10 Gb/s underwater optical wireless communication system based on orbital angular momentum (OAM) multiplexed beams. The proposed transmission uses four OAM beams based on Laguerre-Gaussian profiles, each transporting data at 10 Gb/s at 532 nm operating wavelength. The system performance is evaluated for five different types of water environments, i.e., pure sea (PS), clear ocean (CO), coastal ocean (CS), harbor I (HI), and harbor II (HII) by measuring the received optical power (ROP), underwater transmission distance, bit error rate, beam divergence angle, eye-diagrams, and receiver aperture diameter. The obtained results show that the PS has the longest underwater propagation distance of 10 m, while HII has the shortest range of 2.62 m due to high attenuation at ROP of approximately -18 dBm. The underwater span achieved at the same ROP value for CO, CS, and HI are 8 m, 6.1 m, and 3.85 m, respectively.