Enhancing Air-Water Optical Communication: Achieved 6.7 Photons/bit Through TCPA

Underwater wireless optical communication (UWOC) faces substantial challenges in optical signal detection and processing, particularly when traversing the boundary between air and water. To address this issue, this study introduces and validates a method known as time-correlation photon accumulation (TCPA). In addition, the study also analyzed the relative performance of different error-correcting codes. An experimental system for 256-PPM photon-counting communication (PCC) has been developed, demonstrating that the system can achieve a communication sensitivity of 6.7 photons/bit with an accumulation number of 2 when utilizing SCPPM (5006, 5040) and TCPA technology.