Depth-Dependent Channel Characterization for Visible Light in Underwater Optical Wireless Links

We provide a detailed description of depth-dependent effects that affect the propagation of light in underwater optical wireless links. We consider different wavelengths in the visible spectrum, corresponding to practically feasible laser sources, and compare them in terms of attenuation and losses as a function of depth. Absorption and scattering properties of water for different wavelengths are evaluated for realistic chlorophyll profiles versus depth. Results show which visible wavelength is the most suitable to reduce the light propagation losses in a specific water condition. The developed model is useful to describe the channel characteristics and to evaluate the performance of vertical links in underwater optical wireless communications.