共查询到17条相似文献,搜索用时 156 毫秒
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周期三阶色散对色散管理孤子传输的影响 总被引:1,自引:0,他引:1
建立了含有三阶色散的色散管理系统模型,研究了周期三阶色散对色散管理孤子传输的影响.结果表明,三阶色散独立于其它效应,它导致色散管理孤子出现显著的线性延时和轻度崩塌,而且它对色散管理孤子的影响在传输距离上可平均.若周期性地改变光纤的三阶色散系数,可有效避免它对色散管理孤子传输的影响. 相似文献
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基于光纤拉曼放大器(FRA)的非线性偏微分耦合方程,采用时分复用(TDM)方式抽运,研究了多波长抽运源反向抽运时信号光在光纤中的传输特性.利用分布傅里叶变换方法数值模拟了TDM反向抽运光纤拉曼放大器的色散特性.分析了光纤的色散系数、抽运光的占空比,以及抽运源的数量变化等对光纤拉曼放大器色散的影响,研究结果为TDM抽运光纤拉曼放大器色散的进一步研究提供了参考. 相似文献
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文中提出了一种基于光纤色散真时延技术的光控相控阵雷达多波束接收网络。该网络制作原理是根据光纤的色散特性,主要由密集波分复用器(DWDM)和光纤延时模块构成。DWDM 实现对多通道光合成,多个光开关和光纤延时环组成的光纤延时模块实现对合成的多路光载波进行延时量调节,从而实现波束扫描。依据原理方案,研制了一套16通道光接收、双波束形成网络,实现从-40°到+45°的16个不同波束指向扫描,切换速度≤30us。暗室测试证明了其波束形成能力。 相似文献
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针对光纤传输中的偏振模色散(PMD)问题,研究和比较了现有PMD的光域补偿方法.利用等效啁啾技术,提出了一种基于啁啾光纤光栅的光域补偿方案,用具有光敏性质的保偏光纤制成啁啾光纤光栅,将其作为PMD补偿器中的时延线,实现了PMD的自适应反馈补偿.实验结果显示,该方案能有效补偿光纤传输中的PMD问题,提高光信号的传输质量. 相似文献
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Haiyun Xia Jianping Yao 《Lightwave Technology, Journal of》2009,27(22):5029-5037
In the complete reconstruction of ultrashort optical pulses based on temporal interferometry, the chromatic dispersion and the optical time delay are two key factors, which determine the measurement accuracy. Due to the higher order dispersion, the wavelength-to-time mapping becomes nonlinear, leading to a nonuniformly spaced interference pattern and a decreased fringe visibility in the time domain, even though the input pulse is transform limited. On the other hand, an estimation of the time delay difference with a minor deviation from the true value will result in an artificial linear chirp in the reconstructed phase of the pulse under test. In this paper, a rigorous mathematical analysis on the nonlinear frequency-to-time mapping is performed, with which the phenomena of a nonuniformly spaced interference pattern and a decreased fringe visibility are explained. A frequency-to-time mapping function including higher order dispersion is developed. With a general mapping function, using a transform-limited pulse as the reference signal, we propose a method for real-time tracking of the system parameters, including the chromatic dispersion corresponding to all the optical devices incorporated in the system and the time delay introduced by the interferometer. Finally, a complete reconstruction of a 237 fs optical pulse is demonstrated experimentally with an average angular error of 0.18 rad ranging from 190.65 to 193.85 THz. 相似文献
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提出一种新型的基于宽谱光源和色散器件结合的光控波束形成网络(OCBFN)方案,与利用独立激光器的方案进行了比较,给出了该方案的工作原理和延时链路理论分析,并通过实验验证了该方案实现光控延时的可行性。实验中利用掺铒光纤放大器(EDFA)作为宽谱光源,10 km单模光纤(SMF)作为色散器件实现光路延时,可调谐光滤波器选择光路的工作波长,利用矢量网络分析仪产生微波信号并测量信号延时特性,在9.25~10.25 GHz微波频段中,实验测得的系统延时范围、延时精度及真延时特性(延时大小与微波信号频率无关)验证了基于宽谱光源的可调谐光控微波延时方案的可行性。 相似文献
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The error floor of minimum shift keying (MSK) signal transmission over a mobile radio channel with small time dispersion is analyzed. In contrast to previous investigations, no restrictive assumptions about the impulse response of the channel and/or sampling time are made, and closed-form analytical expressions for the error floor and optimum sampling time are derived. It is found that, generally, the error probability depends on the variance of relative delay (which conforms to the conventional RMS delay spread) as well as on the product of mean relative delays of echoes advancing and succeeding the chosen sampling time, weighted by corresponding mean powers. This implies that (elsewhere widely accepted) simple determination of the error floor by RMS delay spread only can now be seen as a special case when sampling is at mean delay and distribution of the delay profile's power around it is balanced. Furthermore, it is shown that the novel formula reflects the impact of delay profile shape on the error performance (that has been usually neglected, although not always justifiably), and that in general case, the optimum sampling instant is not at the mean delay. The theoretical results are verified by comparison with Monte Carlo (MC) simulations' results; achieved agreement lies within the accuracy of the simulations 相似文献
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大气折射会对无线电波造成射线弯曲和时延色散。对工作在微波频段的LEO-SAR而言,弯曲效应会导致雷达图像在距离上的偏移,而色散效应导致的二次相位误差会对接收信号造成脉冲展宽,使雷达图像分辨率降低,产生畸变。通过对这两种传播效应进行建模分析,选择电离层、对流层环境折射效应均较强的三亚地区进行折射指数剖面建模,仿真计算了该大气环境下,不同频段和轨道高度上LEO-SAR目标成像的距离向漂移和分辨率的变化,分析了大气折射引起的射线弯曲和时延色散特性对LEO-SAR成像质量的影响,为不同类型的LEO-SAR提供准确合理的折射误差修正补偿。 相似文献
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为了提高一种3bit可变光纤延迟线的延时精度,提出一种采用可调谐激光器作为系统光源的技术,利用光纤的材料色散特性即光纤的折射率随传输波长变化而改变的特点,来改变延时光纤中信号存储的时间,从而达到提高光纤延迟线延时精度的目的。仿真结果表明,采用该种技术的光纤延迟线系统,平均延时误差从4.1ps下降到了1.3ps,延时精度得到了显著提高。 相似文献