基于双光反馈垂直腔面发射激光器的双信道混沌同步通信

利用双光反馈垂直腔面发射半导体激光器(VCSELs) 两个正交偏振模式输出的两个混沌信号作为混沌载波, 构建了一个双信道的混沌保密通信系统, 并对该系统的通信性能进行了数值仿真研究.研究结果表明: 通过合理的选取反馈参量, 双光反馈VCSELs两个偏振模式输出的混沌信号能很好地隐藏外腔反馈延时特性; 双光反馈VCSEL两个偏振模式输出的混沌信号通过偏振保持注入到接收VCSEL中, 在强注入锁定条件下可以实现很好的混沌同步, 同步性能对频率失谐的容忍性随着注入强度的增加而加强; 在附加混沌调制加密方式下, 500 Mbit/s的信号在传输过程中能够得到很好的隐藏, 同时在接收端可以成功解调; 随着通信速率的增加, Q因子呈现下降的趋势, 但对于 6 Gbit/s的信息, Q因子仍大于6. 关键词： 垂直腔面发射激光器 双光反馈 双信道 混沌通信

Dual-channel chaos synchronization and communication based on a vertical-cavity surface emitting laser with double optical feedback*

Using two orthogonal polarization mode outputs from a vertical-cavity surface emitting lasers (VCSEL) with double optical feedback as two chaotic carriers, a dual-channel chaos secure communication system is established, and the synchronization and communication performances of such a system are numerically investigated. The results show that under suitable operated condition, the time-delay signatures of two chaotic carriers originating from two linear polarization modes in the T-VCSLE with double optical feedback can be suppressed efficiently. Under the strong injection locking case, high-quality chaos synchronization between two corresponding modes of T-VCSEL and R-VCSEL can be realized by polarization-preserved optical injection from T-VCSEL to R-VCSEL. Moreover, the tolerance of the synchronization quality on the frequency detuning between T-VCSEL and R-VCSEL is enhanced with the increase of the injection strength. Adopting additive chaos modulation encryption scheme, two pieces of 500 Mbit/s encoded message can be hidden efficiently in the two chaotic carriers in the propagation process and can be successfully extracted at the receiver. Although Q factor decreases with the increase of message transmission rate, the values of Q factor for two channels are still larger than 6 for 6 Gbit/s message.
Keywords： vertical-cavity surface emitting lasers double optical feedback dual-channel chaos communication