一种新型的双向长距离光纤混沌保密 通信系统性能研究

基于两个在驱动混沌信号注入下的响应半导体激光器之间的混沌同步, 提出了一种新型的可实现信息双向、长距离保密传输的系统, 并建立了相应的理论模型. 利用该理论模型, 研究了系统的双向传输性能、 安全性能以及系统性能随传输距离的变化. 结果表明: 两个响应激光器在受到发自同一驱动混沌激光器的混沌光注入下, 其混沌输出虽然与注入混沌信号相差很大, 但两个响应激光器的混沌输出却能实现非常好的无时间延迟的等时同步; 对窃听者可能获取信息的各个途径进行了考察, 结果显示该系统具有很好的安全性; 采用普通单模光纤作为传输信道, 信息经过50 km传输后, 解调信息Q因子可达到6以上; 采用色散位移光纤, 信息经过200 km的传输, 解调信息Q因子还可达6以上.

A new type of bidirectional long distance optical fiber chaotic secure communication system

Based on the chaotic synchronization of two response semiconductor lasers (RLs) under the injection from a common chaotic signal of a drive laser (DL), a new type of secure communication system, which allows bidirectional and long-distance information transmissions, is proposed. A corresponding theoretical model is established to study the bidirectional transmission performance, security performance and the system performance under different transmission distances. The results show that when two RLs receive chaotic light injected from a DL, the chaotic outputs of two RLs achieve a fairly good isochronal synchronization without any time delay, while there is a big difference between the signals of RLs and the signal of DL; the system owns high security level after having analyzed the various ways from which eavesdropper may obtain message; if the ordinary single mode optical fiber is used as a transmission channel, the Q factor of decoded message can reach more than 6 after a propagation over 50km; if the dispersion-shifted fiber is employed, the Q factor of decoded message can still reach more than 6 after a propagation over 200km.