Designing and Analysis of Underwater Optical Wireless communication system

Underwater wireless communications, have more attention day after day, due to their wide applications in the military, and in the scientific community. It is also useful in vehicles and devices that are deployed underwater which are difficult to connect with wires. Acoustic communications mostly used underwater technology nowadays, this technology suffers from limited bandwidth and capacity, and for this reason, a complementary technology like underwater wireless optical communication (UOWC) is to be in the field. In this paper, we simulated the UOWC system with Optisystem software to measure the maximum distances in different underwater mediums. In this simulation, three types of seawater are used: pure seawater, Coastal Ocean, and turbid harbor. The intensity modulation for the message signal was performed using a Mach-Zehnder Modulator and Laser Diode as the light source. Results were compared between the wavelength at the beginning of the visual light spectrum and the wavelengths that have the minimum attenuation in the same visual spectrum, in terms of the transmitting distance and the transmitting power. A signal was sent for more than 100 m in clear ocean water with 1 mW, while the same type of water signal was sent for the same distance with 0.35 mW (65% saving) using different operating wavelengths.