Cascaded and adaptive chaos synchronization in multiple time-delay laser systems

This paper provides the report of cascaded and adaptive chaos synchronization in multiple time-delay semiconductor lasers. We demonstrate that provided the feedback and light’s travel times are equal, regardless the communication distance between the transmitter and receiver lasers identical synchronization takes place, i.e. the light’s travel time is not a fundamental restriction on the communicating system performance. We also show that when the parameters of the systems to be synchronized are not available online parameter estimation can be applied to estimate them. The results are important for chaos-based long-haul communication systems.