Investigating the Role of Spatiotemporal Optical Beam Profiles in Mixed Layer Oceanic Communication Channels

摘要

Underwater optical communication channels can provide access to GHz speed communications between assets located within a few hundred meters range of each other. However, channel phenomena such as turbulence, scattering layers, and propagation through density gradients (pycnoclines) even in the clearest of natural waters, can significantly degrade channel performance. Here, the role of the spatiotemporal structure of the optical resource is considered as a mechanism for improving performance of a surface-to-subsea downlink scenario through a typical pycnocline in clear, oceanic waters. A 3D+1 numerical solver was developed to incorporate experimentally collected CTD measurements of a pycnocline in the upper 80 m of the mixed layer in order to evaluate and compare the propagation of semi non-diffracting Bessel-Gauss beams and standard Gaussian beams through Jerlov Case 1 waters. In certain link environments with certain initial beam parameters, we find that utilizing nonstandard optical resources can provide system performance advantages.