The Impact of Water Density and Chlorophyll in Underwater Wireless Optical Communication

A 450 nm blue-light laser diode underwater wireless optical communication (UWOC) system with 155 Mbps, 622 Mbps, and 1.25 Gbps is tested in a various water density. In a 1.03 g/cm³ density, the UWOC communication can transmit information up to 3 meters. The optical power attenuation is increased in higher seawater density and longer distances. The seawater density contributes to the UWOC system absorption and scattering, which degrades the signal. Different modulation speeds can also increase the BER value in different water densities. Moreover, the UWOC system was tested with chlorophyll-containing water at different turbidity levels. Adding more chlorophyll to the water increased light absorption, which caused the deterioration of the UOWC results.