Cascade Synchronization System Based On The Optoelectronic Negative Feedback Chaotic Lasers And Its Application In Secure Communication

The security of the information transmission has become more and more important with the development of modern communication technology. In recent years, chaos and chaos synchronization of semiconductor lasers (SLs) has attracted much attention for its potential applications in secure communications. The break-though of this technology will bring about revolutions in secure communications, especially in martial secure communications. At present, the deep physical insight into chaos synchronization of SLs and its applications in secure communications are not enough. Moreover in long-haul chaotic communications, the chaotic optical signal is degraded during transmission, and the degradation will be further enlarged with the increase of the distance. As a result, extraction of the message becomes difficult at the terminal receiver. In order to improve the performance of the chaotic communications systems, it needs to establish a chaotic optical message relay in the long-haul chaotic communications. In this paper, the cascade synchronization in optoelectronic negative feedback chaotic lasers and its applications in secure communications are studied theoretically in detail. The main works of this dissertation are listed as follows:A novel chaotic repeater system, based on the cascade synchronization in optoelectronic negative feedback chaotic lasers, is proposed. The synchronization characteristics and the influence of the parameters mismatch on the synchronization have been investigated. The results show that the complete synchronization can be realized under the suitable system parameters; the internal parameters mismatch of the lasers have influence on the synchronization quality, but the system behaves better robustness to parameters mismatch compared with the cascade synchronization based on the optical feedback.A cascade synchronization communication system based on optoelectronic negative feedback chaotic lasers is established. A 1-GHz message modulation and demodulation have been numerically studied. At the same time, the influence of the parameters mismatch on the decoding message has also been numerically studied. The results show that the sent message can be successfully extracted at both the mediator laser (ML) and the receiver laser (RL) parts; the internal parameters mismatch of the lasers have some influence on the decoding message, but the effect is not too violent.