Isochronal chaos synchronization of a chain mutually coupled semiconductor lasers

In this paper, a chaotic synchronization system model of a chain mutually coupled semiconductor lasers is established by adding a relay laser between the mutually coupled semiconductor lasers with cavity. The isochronal chaos synchronization condition is theoretically analysed. The influences of injection current, mutual coupling strength and feedback strength on isochronal chaos synchronization are numerically studied. The distributions of synchronous quality in the two-dimensional parameter space for mutual coupling strength and feedback strength are revealed. We show that when the injection current is big enough and the mutual coupling conditions and feedback conditions are completely the same, the stable isochronal chaos synchronization with high quality can be obtained among all the lasers. Stable isochronal chaos synchronization between central laser and side laser is distributed in the area when both mutual coupling strength and feedback strength are small or similar. Two side lasers can easily achieve the stable isochronal chaos synchronization with high quality, because they receive the same injection from central laser at the same time. The system model can be further expanded into the realizing of remote two-way isochronal chaos synchronization or the isochronal chaos synchronization of the arrayed semiconductor laser system.