Analyzing the Characteristics of Underwater Wireless Optical Channel based on Turbulence

Underwater Wireless Optical Communication (UWOC) is a transformative technology that leverages the propagation of light through water to enable high-speed data transmission in submerged environments. Turbulence, caused by factors such as water currents, temperature gradients, and other hydrodynamic phenomena, poses significant challenges to optical signal propagation. This work examines an UWOC channel model, taking into account the effects of various water mediums, absorption, scattering, and refractive index. First, the impact of air bubbles and the refractive index (air and water medium) on received power levels in relation to connection length has been examined. A noticeable decrease (66%) in received optical power has been observed (at d=50 meters) upon switching from air to water as the transmission medium. Similarly, even taking into account the impact of air bubbles in the aqueous medium, no discernible difference in received power was seen. On the other hand, when there were no air bubbles, the received power was significantly lower. When the transmitted power was decreased by 66%, a 71.42% reduction in optical power has been observed (at λ=460). The impacts of salinity, turbidity, temperature change, and air bubbles caused the received power levels to reach zero at λ=530 nm. The received power level decreased by 60.74% at a distance of 10 meters when the water medium changed from pure sea to clear ocean, and by 91.07% when the water medium moved from pure sea to coastal ocean. The transition from clear sea to turbid harbor in the water medium did not result in any substantial received power. This is because turbid harbor water has higher attenuation values than clean seawater.