Experimental realization of underwater optical communication based on single photon detector

Abstract

In recent years, underwater wireless optical communication (UWOC) has attracted more and more attention owing to its high bandwidth and high speed. The blue-green band is a transmission window due to its relatively low loss in the underwater channel. However, UWOC is still limited to about 300 meters subjecting to the large channel loss and the mediocre sensitivity of the avalanche photo-diode (APD). In this paper, we propose and experimentally realize an underwater optical communication scheme based on single-photon detection and non-return-to-zero on-off keying (NRZ-OOK) modulation. The key rate of 200 kbps was achieved with a bit error rate (BER) of 1×10⁻⁴ below the forward error correction (FEC) limit of 3.8×10⁻³ with 7% overhead when the power of the light source is 0.02 mW and total channel loss is 67 dB. The relatively good result shows that a system adopting an NRZ-OOK modulation scheme and single-photon detection is promising for high bandwidth and long-distance underwater optical communication.