Investigation and Design of Laser Diode based Diver-to-Diver Optical Communication System

Divers need proper communication techniques as sound waves cannot propagate through water. Research fraternity has designed several underwater communication systems to overcome this intriguing factor of communication. Researchers have opted several approaches for audio signal communication through water. Designed communication systems vary in complex circuitry, audio signal quality, system components and cost. In this present study, we seek to experimentally demonstrate the feasibility of laser diodes and solar cell receiver for audio signal transmission through water. Audio signals were transmitted through water by imposing over blue, green and red LDs. We have examined light scattering and our findings validate laser diode with shorter wavelength gives less scattering. This paper also outlines an approach for out-of-sight communication. In our experimental trials, the maximum propagation distance is 62 cm by using 450 nm blue laser diode. This study also includes discussion of collimating lens effect on audio signal transmission.