Enhanced chaos synchronization and communication in cascade-coupled semiconductor ring lasers

We numerically investigate the properties of chaos synchronization in a master–slave configuration consisting of a master semiconductor ring laser (SRL) with self-feedback or cross-feedback and a solitary SRL (slave). Different coupling schemes related to global injection and mode-selective injection are proposed and explored in our simulations. The numerical results demonstrate that among the studied coupling motifs the synchronization performance between the modes of the two chaotic SRLs is better when global injection scheme is employed. Furthermore, enhanced chaos synchronization and communication in three cascade-coupled SRLs via global injection are reported, where the time delay signature cannot be identified from the outputs of the three SRLs due to the proper selection of cross-feedback parameters of the master SRL.     

Amplitude synchronization in a system of two coupled semiconductor lasers

We consider a system of ordinary differential equations used to describe the dynamics of two coupled single-mode semiconductor lasers. In particular, we study solutions corresponding to the amplitude synchronization. It is shown that the set of these solutions forms a three-dimensional invariant manifold in the phase space. We study the stability of trajectories on this manifold both in the tangential direction and in the transverse direction. We establish conditions for the existence of globally asymptotically stable solutions of equations on the manifold synchronized with respect to the amplitude. __________ Translated from Ukrains’kyi Matematychnyi Zhurnal, Vol. 60, No. 3, pp. 426–435, March, 2008.     

Adaptive synchronization of two nonlinearly coupled complex dynamical networks with delayed coupling

This paper investigates the adaptive synchronization between two nonlinearly delay-coupled complex networks with the bidirectional actions and nonidentical topological structures. Based on LaSalle’s invariance principle, some criteria for the synchronization between two coupled complex networks are achieved via adaptive control. To validate the proposed methods, the unified chaotic system as the nodes of the networks are analyzed in detail, and numerical simulations are given to illustrate the theoretical results.     

Adaptive backstepping sliding mode control for chaos synchronization of two coupled neurons in the external electrical stimulation

In this paper, a robust control system combining backstepping and sliding mode control techniques is used to realize the synchronization of two gap junction coupled chaotic FitzHugh-Nagumo (FHN) neurons in the external electrical stimulation. A backstepping sliding mode approach is applied firstly to compensate the uncertainty which occur in the control system. However, the bound of uncertainty is necessary in the design of the backstepping sliding mode controller. To relax the requirement for the bound of uncertainty, an adaptive backstepping sliding mode controller with a simple adaptive law to adapt the uncertainty in real time is designed. The adaptive backstepping sliding mode control system is robust for time-varying external disturbances. The simulation results demonstrate the effectiveness of the control scheme.