共查询到18条相似文献,搜索用时 140 毫秒
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为了研究单向耦合垂直腔面发射激光器系统的混沌动力学及其在通信中的应用,采用数值仿真的方法,理论研究了两个单向耦合的垂直腔面发射激光器偏振模的同步特性,并通过对发射激光器偏振态相位的调制实现了该系统的编码。结果表明,主激光器和从激光器相应模式间可以获得高性能的同步,而且存在两个明显的同步区域——完全同步和注入锁定同步。加载的数字信息也可以在从激光器每个偏振分量中还原,这表明可以利用单模或多横模垂直腔面发射激光器进行多信道混沌通信。 相似文献
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多变量耦合实现双环掺铒光纤激光器混沌同步 总被引:5,自引:1,他引:4
根据双环掺铒光纤激光器的理论模型,提出多变量单向耦合法实现混沌同步,对主从系统模型进行数学推导,研究不同参数条件下双环掺铒光纤激光器的混沌同步,得到实现混沌同步的条件,并在Simulink平台下动态仿真。结果表明,衰减系数不同的两个双环掺铒光纤激光器,主激光器通过定向耦合器驱动从激光器,主从系统可以实现精确混沌同步,且随着反馈强度的增大,实现系统混沌同步的时间越短,反馈强度的取值范围由衰减系数和耦合系数确定;选取不同的系统初值,主从系统可实现混沌同步,系统初值对达到混沌同步时间的影响可忽略不计;在主从系统中引入随机高斯噪声,主从系统仍可实现较好的混沌同步。 相似文献
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研究了偏振选择互注入条件下半导体激光器的同步和混沌滤波效应。将单模互注入速率方程扩展为包含两个偏振态的理论模型,并选择X偏振态作为互注入形式,不仅为激光器产生混沌和实现同步提供了条件,还可以完全抑制Y偏振光,实现了纯偏振模式同步。通过频率失调的引入,保持了激光器主从地位的稳定。研究结果表明,主从激光器实现了时差等于注入延时的混沌同步,输出功率表现出高频振荡并伴随有对称性破坏现象。对主激光器进行调制时,同步系统表现出与单向注入相似的混沌滤波效应;对从激光器进行调制时,系统的混沌滤波效应并不明显。 相似文献
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基于双区半导体激光器的速率方程,研究了双区半导体激光器的超混沌现象,给出了双区半导体激光器产生超混沌的条件;利用驱动-响应法实现了双区半导体激光器的超混沌同步,通过计算激光系统最大条件李亚谱诺夫指数随注入强度的变化,得到实现超混沌同步的注入参量的取值范围. 相似文献
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为了在光纤通信中实现多模同步传输以提高通信容量,构建了一个光注入多模半导体激光器开环混沌通信系统,并利用MATLAB数值仿真了系统的同步性能。结果表明,选取合适的系统参量,多模半导体激光器混沌通信系统能够实现完全同步;发射激光器和接收激光器对应模式可以实现完全同步,而且系统对内部参量失配具有较好的容忍性。 相似文献
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We numerically study the synchronization or entrainment of two unidirectional coupled single-mode semiconductor lasers in a master-slave configuration. The emitter laser is an external-cavity laser subject to optical feedback that operates in a chaotic regime. The receiver can either operate at a chaotic regime similar to the emitter (closed-loop configuration) or without optical feedback and consequently under continuous-wave conditions when it is uncoupled (open-loop configuration). We compute the degree of synchronization of the two lasers as a function of the emitter-receiver coupling constant, the feedback rate of the receiver, and the detuning. We find that the closed-loop scheme has, in general, a larger region of synchronization when compared with the open loop. We also study the possibility of message encoding and decoding in both open and closed loops and their robustness against parameter mismatch. Finally, we compute the time it takes the system to recover the synchronization or entrainment state when the coupling between the two subsystems is lost. We find that this time is much larger in the closed loop than in the open one. 相似文献
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Experimental synchronization of mutually coupled semiconductor lasers with optoelectronic feedback 总被引:1,自引:0,他引:1
Anticipated or retarded synchronization of a mutually coupled nonlinear system is experimentally studied through a mutually coupled semiconductor laser system subject to optoelectronic feedback. These two types of synchronization are found to arise from a predictable relation between feedback/coupling delay times under particular feedback/coupling strength combinations. A comparison between the experimental results and the theoretical predictions is completed. The experimental results mostly agree with theoretical predictions. System limitations are also discussed. 相似文献
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A. A. Koronovskii R. A. Filatov A. E. Hramov 《Journal of Communications Technology and Electronics》2007,52(3):343-351
Chaotic synchronization is found to arise in coupled beam-plasma systems with supercritical current. It is shown that, with increasingly stronger coupling, such systems pass from asynchronous behavior via phase synchronization to complete synchronization. Chaotic synchronization is studied according to a method based on the introduction of a continuous set of phases of the chaotic signal. In the case of unidirectional coupling, a generalized chaotic synchronization mode is observed. The mechanism of its emergence in the beam-plasma systems is investigated via the modified-system method. 相似文献
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In this paper, it is proposed that a hybrid global adaptive coupling synchronization scheme among Lorenz chaotic dynamical nodes to realize the secure communication system between base station and multi-unmanned aerial vehicle (UAV) formation. The specific method is that the feedback drive–response synchronization is utilized for first two nodes of base station and the leader of multi-UAV formation, and the nodes of all UAVs are coupled by unidirectional adaptive coupling synchronization according to a directed link in ad hoc network of multi-UAV formation. It is demonstrated that the asymptotic stability of the proposed hybrid adaptive coupled synchronization by constructing the Lyapunov function. In this way, the encrypted information formed by plaintext information masked into the chaotic sequence generated by the chaotic dynamical node of base station; meanwhile, it is fed back into the base station node as the drive system. On the other hand, encrypted information is forwarded to the leader node as the response system for decryption. The feedback driver–response synchronization is used to realize secure communication between the base station and the leader of multi-UAV formation. Meanwhile, secure communication among its leader and followers is achieved through the unidirectional adaptive coupling synchronization in the network. This strategy ensures the multi-UAV formation decrypting encrypted information synchronously and effectively improves the security, consistency, and overall performance of their commands. 相似文献
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JIANG Guo-ping 《中国邮电高校学报(英文版)》2002,9(4)
1 IntroductionToday ,muchattentionhasbeenpaidtochaossynchronization[1 ,2 ] .Chaossynchronizationcanmainlybeclassifiedintotwotypescalledmutualsynchronizationandmaster slavesynchronizationac cordingtothecouplingconfiguration[3,8] .Thefor meriswithbi directionalco… 相似文献
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将主动-被动同步法改进后,用于对长延迟状态下电光双稳态系统进行混沌控制和同步研究,分别采用单向驱动方法和驱动-耦合方法研究电光双稳态系统的混沌控制和同步。数值模拟表明,在适当参数条件下应用单向驱动方法,驱动系统可以将响应系统控制到各周期状态,且驱动系统的状态决定了响应系统的状态;适当选取耦合系数和驱动强度,两种方案都可以实现驱动系统与响应系统之间的混沌同步。从同步效果上来看,驱动-耦合方法所需耦合系数更小,可控的耦合系数范围比较广,同步效果更好。 相似文献
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Peters-Flynn S. Spencer P.S. Sivaprakasam S. Pierce I. Shore K.A. 《Quantum Electronics, IEEE Journal of》2006,42(4):427-434
It is shown that the optimum correlation for chaos synchronization of master-slave semiconductor lasers occurs at a delay time that is sensitive to both the injection strength and the frequency detuning of the driving field. This effect may be overlooked if the correlation function is not evaluated globally. The correlation function has been used as the de facto method for quantitatively determining the degree of synchronization achieved between unidirectional coupled chaotic semiconductor lasers, see for example . The correlation function is a continuous function of the delay time but is normally evaluated at only two delay times. It is shown that this approach can cause a misidentification of the dominant synchronization process and can also mask important temporal fluctuations in the nature and quality of the chaos synchronization. In essence, two factors contribute to the potential for misidentification, the first is the inherent small time shift required to obtain the optimum correlation and the second is the quasi-periodicity that is present in certain chaotic regimes. This paper shows that a reevaluation of some of the published numerical studies of chaos synchronization is necessary. 相似文献
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《Quantum Electronics, IEEE Journal of》2010,46(3):279-284