共查询到17条相似文献,搜索用时 156 毫秒
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新型三激光器结构的混沌同步特性 总被引:1,自引:1,他引:0
设计了一种新型的闭环双向三激光器混沌保密通信系统,驱动激光器基于延时外光反馈,两个参数完全相同的响应激光器在自身延时反馈和驱动激光器的驱动下实现混沌同步。建立了相应的理论模型,研究了系统的分岔特性、同步性以及内部参数失配对其同步性能的影响,并与不含自身光反馈的开环系统进行了比较。研究结果表明,当系统参数满足一定条件时,两个响应激光器的关联极值接近于1,而驱动激光器和响应激光器的相关性很小。与开环系统相比,该系统的载波带宽拓宽了约1.99GHz,对参数失配比较敏感并具有更好的保密性能。 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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提出一种基于对称相移键控混沌同步的高速密钥安全分发方案:混沌驱动信号对称地经过两个非平衡马赫-曾德尔干涉仪驱动无外腔反馈的响应激光器,并通过随机键控马赫-曾德尔干涉仪中的相位调制器实现相移键控混沌同步。通信双方对相移键控混沌同步时序进行双阈值量化产生随机密钥,然后交换、对比键控参数并筛选出参数相同(即键控相位相同)时的随机密钥作为一致密钥,实现密钥分发。本方案中,混沌驱动信号经过非平衡马赫-曾德尔干涉仪产生了基于延时自干涉的非线性变换,降低了驱动信号与响应信号之间的相关性(~0.25),提高了密钥分发的安全性。此外,利用共驱无外腔反馈响应激光器构成开环同步结构,缩短混沌同步恢复时间至~1.8 ns,提高了密钥分发速率。数值仿真结果表明,在误码率为3.8×10-3的条件下,可实现1.28 Gbit/s的高速密钥安全分发。 相似文献
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通过改变两个耦合混沌激光器反馈相位,实现了两激光器之间信号的双向同步传输。两个激光器之间的部分透光的平面镜可以诱导延时和混沌动力学。数值模拟考虑延迟的激光器速率方程,证明了两个激光器可以达到高质量同步。编解码的过程从信号改变两个激光器的反馈相位开始,检测两个激光器中混沌载波光功率的差,并与本地信号进行对比,最终恢复发送者传输的数字信息。根据恢复出来信号的眼图,可以看出该系统具有很高的传输质量。本方案中,窃听者即使可以得到传输信号的差值,也无法得知本地信号,因此,无法解调出发送者的信息,系统的安全传输性能得以保障。 相似文献
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双环掺铒光纤激光器混沌键控保密通信系统理论模型和数值模拟 总被引:1,自引:0,他引:1
提出双环掺铒光纤激光器激光混沌键控保密通信系统及理论模型,通过调制泵浦光参数以实现混沌键控保密通信;分析了通过参数调试补偿克服系统参数失配以减小同步误差的方法:模拟了两个单环掺铒光纤激光器激光和一个双环掺铒光纤激光器激光分别在0码和1码上的混沌同步及其解码,该系统在相空间,在时域和频域都具有很好的保密性能和反破译能力。 相似文献
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Shibasaki N. Uchida A. Yoshimori S. Davis P. 《Quantum Electronics, IEEE Journal of》2006,42(3):342-350
We numerically investigate the detailed characteristics of chaos synchronization in semiconductor lasers subject to polarization-rotated optical feedback. The emission of the dominant TE mode of a drive laser is rotated 90 deg and fed back to the laser with time delay. The polarization-rotated TE mode is also injected with time delay into the TM mode of a second laser. Two types of synchronization with different time-lags are found, as in the case for synchronization in semiconductor lasers with nonrotated optical feedback. However, a significant difference to the nonrotated optical feedback case is that neither of the two types of synchronization requires matching of optical carrier frequency between the two lasers. 相似文献
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We propose and demonstrate a scheme for generating synchronized chaotic mode hopping in two wavelength-tunable lasers. Chaotic mode hopping resulting in large hops in wavelength is induced by delayed feedback of an electrical signal proportional to the intensity of the laser output which passes through an optical filter. Mode hopping among up to 11 modes was experimentally observed and optical signals in each wavelength band show a different on-off modulation time series. Analysis of the time series indicates high dimensionality. By using a unidirectional coupling method that injects part of the output of one laser into another, we can synchronize the chaotic mode hopping of two separate lasers and obtain synchronized chaotic on-off modulation patterns in multiple corresponding wavelength bands. The robustness of the synchronization with respect to the parameter mismatch and the effects of the coupling strength are investigated. The chaotic mode hopping dynamics and synchronization are well described with a numerical model that includes the characteristics of the laser tuning and the filter transmission. A multiplexed data transmission scheme using chaotic carriers is proposed and experiments demonstrate that multiple messages can be simultaneously recovered when chaos synchronization is achieved 相似文献
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Anticipating synchronization based on optical injection-locking in chaotic semiconductor lasers 总被引:3,自引:0,他引:3
Numerical studies for anticipating chaos synchronization in semiconductor lasers with optical feedback are presented. Anticipating chaos synchronization in a delay-differential system is believed to occur when all chaos parameters between the two systems are perfectly coincident with each other. However, we find new schemes of anticipating chaos synchronization when the parameters between the two systems have mismatches. Under these conditions, the time lag between the two laser outputs is equal to that of anticipating chaos synchronization, but the physical origin of the phenomenon comes from optical injection-locking or amplification in laser systems. We show the evidence of such chaotic synchronization using trajectories in the phase space of the phase difference and the carrier density in the laser oscillations. 相似文献
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《Quantum Electronics, IEEE Journal of》2010,46(2):258-264
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Demultiplexing chaos from multimode semiconductor lasers 总被引:3,自引:0,他引:3
We show numerically that the injection of two chaotic modes of a multimode semiconductor laser with optical feedback into two single-mode stand-alone semiconductor lasers leads to chaotic synchronization between the respective intensities. The effect of parameter mismatch between the transmitter and receiver lasers is examined, and it is concluded that the observed synchronization is a consequence of injection locking. Under these conditions, the possibility of using this demultiplexing scheme for message transmission is examined. 相似文献
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Synchronized chaotic optical communications at high bit rates 总被引:7,自引:0,他引:7
Jia-ming Liu How-foo Chen Shuo Tang 《Quantum Electronics, IEEE Journal of》2002,38(9):1184-1196
Basic issues regarding synchronized chaotic optical communications at high bit rates using semiconductor lasers are considered. Recent experimental results on broadband, high-frequency, phase-locked chaos synchronization, and message encoding-decoding at 2.5 Gb/s are presented. System performance at a bit rate of 10 Gb/s is numerically studied for the application of three encryption schemes, namely chaos shift keying, chaos masking, and additive chaos modulation, to three chaotic semiconductor laser systems, namely the optical injection system, the optical feedback system, and the optoelectronic feedback system. By causing synchronization error in the forms of synchronization deviation and desynchronization bursts, the channel noise and the laser noise both have significant effects on the system performance at high bit rates. Among the three laser systems, the optoelectronic feedback system has the best performance while the optical feedback system has the worst. Among the three encryption schemes, only the performance of additive chaos modulation with low-noise lasers is acceptable at high bit rates. 相似文献
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Chaos synchronization and chaotic signal masking in semiconductor lasers with optical feedback 总被引:7,自引:0,他引:7
Theoretical and experimental investigations of chaos synchronization and its application to chaotic data transmissions in semiconductor lasers with optical feedback are presented. Two schemes of chaos synchronization-complete and generalized synchronization-are discussed in the delay differential systems. The conditions for chaos synchronization in the systems and the robustness for the parameter mismatches are studied. The possibility of secure communications based on the chaos masking technique in semiconductor lasers with optical feedback is also discussed, and message transmission of a 1.5-GHz sinusoidal signal is demonstrated. The method of bandwidth enhancement of chaotic carriers is proposed for broad-band chaos communications. 相似文献