Aspects of oceanic optical comms: From air to sea

Optical communications, with its promise of two-way links at relatively high date-rates between submerged and above water parties, continues to intrigue. However, such optical comm as well as laser-line scanning systems are impacted not just by the atmosphere-sea interface, but also artificial water/air interfaces, with applicability to some UUV or sensor networks. In addition, in situ scatter (from various hydrosols and bubbles) also has a detrimental impact. Fortunately, despite the inherent challenges of this channel, potential mitigation approaches exist or have been proposed. These range from hardware solutions in both beamforming and agility to data handling and modulation techniques.