Synchronization in multiple time delay chaotic laser diodes subject to incoherent optical feedbacks and incoherent optical injection

We present the first report of the synchronization regimes in both unidirectionally and bidirectionally coupled multiple time delay chaotic laser diodes subject to incoherent optical feedbacks and incoherent optical injection. We derive the existence conditions and numerically study the stability for lag, complete, and anticipating synchronization regimes and cascaded synchronization. We also study in detail the effect of parameter mismatches and noise on the synchronization quality. It is emphasized that sensitivity of the synchronization quality to parameter mismatches can lead to a high level of security due to the difficulty in replicating the receiver laser. We show that the injection current and feedback delay times are highly important parameters from this point of view. (C) 2011 Elsevier Ltd. All rights reserved.