Long-distance duplexing underwater wireless optical communication with a dual-band photon-counting system

We proposed a long-distance duplexing UWOC with a dual-band single photon-counting system in a laboratory environment by using non-return to zero on-off keying modulation. The system successfully achieved a data rate of 1Mbps through a 20m swimming pool with attenuation coefficients of 1.3m-1@450nm and 0.96m-1@520nm. Based on the experimental attenuation coefficients of the swimming pool, the transmission performance was predicted to be 142m and 339m in the clean seawater and pure seawater, respectively. Compared with the APD, communication distances of the photon counting UOWC with SPAD was increased by 1.6 times and 1.57 times in the the clean seawater and pure seawater, respectively.