共查询到20条相似文献,搜索用时 62 毫秒
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码型转换是实现非归零(NRZ)信号全光时钟恢复的关键技术.提出了一种基于折叠式超快非线性干涉仪的全光NRZ到伪归零(PRZ)信号转换的新型方案.基于半导体光放大器的分段模型和超快非线性干涉仪的传输函数,建立了该方案的理论分析模型,数值模拟了不同速率下的码型转换过程.实验实现了稳定的10,20和40 Gbit/s的NRZ到PRZ信号的码型转换,分析了影响码型转换输出特性的因素,理论分析结果与实验结果基本符合.
关键词:
超快非线性干涉仪
半导体光放大器
全光码型转换 相似文献
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基于SOA全光偏振调制的双信道光传输系统的仿真与分析 总被引:1,自引:0,他引:1
仿真并分析了基于半导体光放大器全光偏振调制的双信道光传输系统模型.该系统分别利用两级半导体光放大器的交叉偏振调制效应(XPolM),将两路独立的强度调制的抽运光变换到一路探测光的两个正交的偏振态上,实现双通道偏振复用的全光数据传输.首先对单个半导体光放大器的动力学过程进行了理论分析,数值计算了具有不同抽运光功率的半导体光放大器对探测光偏振态的影响,进而对双半导体光放大器偏振复用系统的调制/解调原理进行了分析,模拟仿真了双半导体光放大器的双通路偏振复用的调制及解调过程,仿真结果与实验结果相符. 相似文献
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通过引入场传输模型对在对向传输方案下的半导体光放大器中增益、相位及啁啾的超快动态特性进行了数值分析.讨论了半导体光放大器中带内效应光谱烧孔与载流子加热,以及带间效应载流子消耗对动态特性的影响.同时分析了半导体光放大器的有源区长度对增益动态特性的影响.结果显示:对向传输下同样可应用蓝移失谐滤波器提高半导体光放大器的工作速率,但与同向传输方案不同的是,在对向传输方案下利用短有源区长度的半导体光放大器更利于实现高速的全光波长变换.理论分析结果可为基于半导体光放大器的超快全光信号处理提供理论指导. 相似文献
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Ugeda MM Fernández-Torre D Brihuega I Pou P Martínez-Galera AJ Pérez R Gómez-Rodríguez JM 《Physical review letters》2011,107(11):116803
Understanding the coupling of graphene with its local environment is critical to be able to integrate it in tomorrow's electronic devices. Here we show how the presence of a metallic substrate affects the properties of an atomically tailored graphene layer. We have deliberately introduced single carbon vacancies on a graphene monolayer grown on a Pt(111) surface and investigated its impact in the electronic, structural, and magnetic properties of the graphene layer. Our low temperature scanning tunneling microscopy studies, complemented by density functional theory, show the existence of a broad electronic resonance above the Fermi energy associated with the vacancies. Vacancy sites become reactive leading to an increase of the coupling between the graphene layer and the metal substrate at these points; this gives rise to a rapid decay of the localized state and the quenching of the magnetic moment associated with carbon vacancies in freestanding graphene layers. 相似文献
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A. H. Taub 《General Relativity and Gravitation》1979,10(12):1009-1009
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In this note we use some of the results of [3] to derive a general duality theorem for the cohomologies of foliated structures on a manifold. The result is applied to the special case of a symplectic manifold M on which the foliation is given by a complex polarization F in the sense of geometric quantization. We obtain, for example, a rigorous proof of the fact that for a smooth function ƒ on M whose Hamiltonian vector field leaves F invariant, the spectrum of the corresponding prequantization operator v(ƒ) coincides with the spectrum of its transpose, under the above duality. This latter result was obtained by Simms in [12] under certain hypotheses. Proofs of the validity of those hypotheses are now available in the literature; cf. [3] and [7]. 相似文献
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Valfells A. Verboncoeur J.P. Lau Y.Y. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2000,28(3):529-536
Analyzes the effects of space charge shielding on the steady state of a multipactor discharge on a dielectric. Analytic methods are used to obtain an exact function for the potential in the discharge, assuming a Maxwellian distribution of emitted electrons. An equation for the amount of power deposited on the dielectric by the multipactoring electrons, for a given saturation level, is given. A simple method for obtaining the saturation level, for a given material, is obtained 相似文献
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We study the relation between the centro-affine geometry of star-shaped planar curves and the projective geometry of parametrized maps into RP1. We show that projectivization induces a map between differential invariants and a bi-Poisson map between Hamiltonian structures. We also show that a Hamiltonian evolution equation for closed star-shaped planar curves, discovered by Pinkall, has the Schwarzian KdV equation as its projectivization. (For both flows, the curvature evolves by the KdV equation.) Using algebro-geometric methods and the relation of group-based moving frames to AKNS-type representations, we construct examples of closed solutions of Pinkall’s flow associated with periodic finite-gap KdV potentials. 相似文献