Chaos And Chaos Synchronization Of Semiconductor Lasers And Its Applications In Secure Communication

In recent years, chaos synchronization and secure communication based on semiconductor lasers (SLs) have abstracted considerable attention. A semiconductor laser, when subjected to perturbation such as optical feedback, optical injection, optoelectronic feedback, can display chaotic output. When two SLs can realize good chaos synchronization, messages masked in the chaotic carrier can be extracted at the receiver. Relative to the incoherent optical feedback, the incoherent optical feedback is less sensitive to frequency detuning, so it can deduce requirements of system to working conditions. And relative to the optoelectronic feedback, bandwidth limitation is not existed for the incoherent optical feedback. So the incoherent optical feedback synchronization system is presented by some scholars.In this paper, we numerically study the synchronization of incoherent optical feedback semiconductor laser under closed-loop and open-loop schemes. The results show that, even though this optimal condition (k1=σ+k2 for closed-loop and k1=σfor the open-loop scheme) is satisfied, the synchronization quality is related to the value of the coupling coefficient. Under both open-loop and closed-loop schemes, the minimum necessary coupling coefficient to reach a correlation coefficient of 0.9, increase with the increase of the feedback strength of transmitter laser. Compared with the open-loop scheme, the closed-loop scheme is more sensitive to parameters mismatch.Finally, we compare communication performances under these two schemes with CSK. The results show that, message can be hided effectively under both schemes, where open-loop scheme shows better performance than closed-loop scheme. This result is in disagreement with the case of coherent optical feedback...