Design and analysis of a laser communication link between an underwater body and an air platform

Laser based free space underwater optical communication is useful in a variety of fields. Underwater sensor networks, for example, are a network of sensors or underwater observatories that collect oceanographic data over an interval of time and send them to the outside world periodically for processing. Current methods, such as acoustic communication are limited in bandwidth; the use of cables such as fiber optic is expensive and not practical for autonomous vehicles and radio frequency waves suffer severe attenuation in water. Communication between submerged bodies and space platform is another interesting example. In this paper the design and development of an optical communication link based on 635 nm Laser diode and Silicon photo detector has been discussed. The aim of the work is to study experimentally the performance of the communication between an underwater body and a space platform in the laboratory.