Adaptive Receiver Control for Reliable High-Speed Underwater Wireless Optical Communication With Photomultiplier Tube Receiver

Photomultiplier tube (PMT) receiver is a promising solution for long-distance underwater wireless optical communication (UWOC) due to its characteristics of high gain, low noise, and large receiver area. However, the complex underwater environment leads to the dynamic change of the received optical intensity and impacts the stability and reliability of UWOC system using PMT. In this work, the bandwidth limitation and performance degradation of UWOC system caused by PMT saturation is experimentally observed and characterized for various optical intensity and PMT gain. A low-cost, high-integrated, and small-volume receiver control system and relevant adaptive control strategy are proposed to improve the stability and reliability of UWOC system by dynamically adjusting the received optical power and PMT gain according to the detected optical signal. The experiment results show that the dynamic range of UWOC received optical power can be extended to 68 dB (−63 dBm∼5 dBm) for 100 Mbit/s OOK modulation based UWOC system.