Chaotic Synchronization Characteristics Of VCSEL Networks And Its Application In Multi-target Chaotic Radar Ranging

Vertical cavity surface-emitting laser(VCSEL)is a typical representative of micro semiconductor laser.It has many advantages such as low threshold current,single-longitudinal mode output,circular beam output to couple with optical fiber readily,easy integration to form laser array or laser network.In addition,it can generate two mutually orthogonal chaotic polarization modes with large bandwidth under certain conditions.Using these unique advantages,chaotic synchronization of VCSEL network can be generalized to many fields such as chaotic secure communication,generation of high-speed and wide-bandwidth random codes,logical calculation of optical chaotic signal and so on.In particular,synchronized chaotic radars in VCSEL network provide potential applications for multi-target ranging.However,for VCSEL network,owing to the diversity of topology module,the existence of different coupling delay times in the network,and complex nonlinear dynamic behaviors and unique polarization conversion characteristics of VCSEL,the chaotic synchronization mechanism of VCSEL network and the key technologies about its application in multi-target chaotic radar ranging need to be explored in depth.Therefore,the innovative contents of this thesis are as follows.(1)For diverse three-node VCSEL networks with uniform time-delayed coupling,we propose a new criterion of the globally complete chaos synchronization(GCCS)among all node lasers by using the mater stability function(MSF).Here,the MSF can be obtained by calculating the maximum Lyapunov exponent(MLE)and the MLE,as a function of the constant row sum and the eigenvalue of the outer-coupling matrix,is calculated from the modified master stability equation.It is worth noting that the outer-coupling matrices have a nonzero row sum(nondiffusive coupling)and the inner-coupling is a function of the self-node and delay connection node.It is found that GCCS can be achieved for an arbitrarily given three-node VCSEL network when two points determined by constant row sum and two transversal eigenvalues fall into the region of stability where MLE is negative and the MLE as a function of constant row sum and the eigenvalue associated to perturbations within the synchronization manifold is positive.The criterion can be generalized to multi-node VCSEL network.Based on the theoretical criterion and synchronization error theory,we further explore the synchronization properties in three-node VCSEL network with the ring topology andthat with the bus topology.As a result,the theoretical criterion is in excellent agreement with our numerical results,which indicate that the theoretical criterion is valid and feasible.Moreover,for the three-node VCSEL network with the ring topology,the influences of the key parameters(row sum and delay-time)on the GCCS quality are explored and the robustness of the GCCS quality to row sum mismatch is discussed.See chapter 3 for the contents of this work.(2)We propose a novel scheme of the real-time ranging for the six orientational targets based on the VCSEL network with three nodes.In the scheme,we explore a method to realize the GCCS of the network with different channel delays.Under the GCCS,we use the six chaotic polarization radars for the ranging of the six orientational targets based on Hilbert transform theory.It is found that the ranging of the six orientational targets has good performance,such as real-time stability and high accuracy,and the absolute errors of the ranging reach millimeter magnitude.Moreover,all relative errors are small and less than 11%.See chapter 4 for the contents of this study.In summary,the chaotic synchronization characteristics of three-node VCSEL networks and its application in real-time ranging for the six orientational targets are studied in this thesis.Based on MSF,this paper explores the complete chaotic synchronization characteristics of three-node VCSEL networks with nondiffusive and uniform delay coupling,and proposes a new criterion of the GCCS for diverse network topologies.On this basis,we further investigate a method to realize the GCCS of three-node ring VCSEL network with different channel delays,and utilize the synchronized chaotic polarization radars in three-node VCSEL network to measure the distances of the six orientational targets.