摘要
Optical chaos communication and key distribution have been extensively demonstrated with high-speed advantage but only within the metropolitan-area network range of which the transmission distance is restricted to around 300 km.For secure-transmission requirement of the backbone fiber link,the critical threshold is to realize long-reach chaos synchronization.Here,we propose and demonstrate a scheme of long-reach chaos synchronization using fiber relay transmission with hybrid amplification of an erbium-doped fiber amplifier(EDFA)and a distributed fiber Raman amplifier(DFRA).Experiments and simulations show that the hybrid amplification extends the chaos-fidelity transmission distance thanks to that the low-noise DFRA suppresses the amplified spontaneous emission noise and self-phase modulation.Optimizations of the hybrid-relay conditions are studied,including launching power,gain ratio of DFRA to EDFA,single-span fiber length,and number of fiber span.A 1040-km chaos synchronization with a synchronization coefficient beyond 0.90 is experimentally achieved,which underlies the backbone network-oriented optical chaos communication and key distribution.
基金
National Key Research and Development Program of China(2019YFB1803500)
National Natural Science Foundation of China(62035009,61731014)
Shanxia“1331 Project”Key Innovative Team
International Cooperation of Key R&D Program of Shanxi Province(201903D421012)
Development Fund in Science and Technology of Shanxi Province(YDZJSX2021A009)。
