High Speed Underwater Wireless Optical Communication with High Receiver Sensitivity and Large Dynamic Range

Photomultiplier tube (PMT) detector, with extreme sensitivity, has been applied as a part of optical receiver in underwater wireless optical communication (UWOC) research in recent years. However, it suffers low dynamic power range, which significantly restricts the increase of optical receiver performance. In this paper, an adaptive optical power control (AOPC) system based on liquid crystal light valve (LCLV) and photomultiplier tube (PMT) gain controlling is proposed and demonstrate to increase the optical dynamic range for high sensitive UWOC links. Experimental results show under the transmission rate of 100 Mbps, the optical signal dynamic ranges of receiver module after loading the adaptive receiver-side optical power control function expands 68dB.