共查询到19条相似文献,搜索用时 62 毫秒
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光交叉连接(OXC)是未来波分复用光传送网实现交换与选路功能的核心部件.目前,OXC节点的物理结构得到深入研究,已经提出了一些采用不同光子器件的OXC实现方案.本文从描述光交叉连接功能的角度出发,给出一种分析OXC节点功能结构的模型,并比较各种OXC方案在功能结构上的差异。 相似文献
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光交叉连接(OXC)是波分复用(WDM)全光网的核心节点技术,其结构直接决定了其性能,严格无阻塞是最根本的要求.对于已经提出的多种多样的OXC结构,本文归纳出四种最基本的无阻塞结构,在此基础上具体推演分析其它OXC结构,这样便清晰地论证了OXC结构的阻塞性.对部分阻塞结构提出了消除阻塞的修正方法. 相似文献
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提出了一种低串扰无损耗的光开关矩阵.该结构是在扩展Benes(DB)结构的基础上通过改进得到的称为改进的扩展Benes(IDB)结构,并通过进一步的改进得到各级改进的扩展Benes(GIDB)结构.理论分析了IDB结构和GIDB结构中串扰产生的机理和对信号的影响,比较了几种结构的信噪比和光交换容量之间的关系.发现随着光交换规模的扩大,GIDB结构相对于DB结构信噪比明显提高.实验研究了4×4的IDB、GIDB结构中串扰引起的误码率降低以及眼图的恶化情况.结果表明GIDB结构能有效减少串扰的影响. 相似文献
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组播业务的迅速增长对现有光网络的光路分配提出了更高的挑战.针对在大规模的光网络中,由于光组播路径中光信噪比过低导致传输层光链路无法正常工作,并由此带来"假性信令成功"的问题,提出了一种光信噪比受限的光组播路径分配机制.该机制充分利用光网络节点中光信噪比监测功能,在信令消息中携带光信噪比性能参量,并在光组播路径分配的信令过程中将光信噪比作为光波长分配的重要依据.通过该机制,控制平面在信令过程中充分考虑光信噪比因素,确保传输层的光组播路径得以顺利建立并正常工作.仿真结果表明,所提出的基于光信噪比感知的组播光路分配机制能够解决"假性信令成功"的问题,并有效降低光组播路径的阻塞率. 相似文献
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调制不稳定性对级联放大光纤传输系统信噪比的影响 总被引:1,自引:0,他引:1
在考虑光纤损耗和级联放大器的情况下,推导了调制不稳定性的产生条件和增益的普适解析表达式,分析了调制不稳定性对信噪比的影响,给出了一个新的计算信噪比的表达式。 相似文献
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衍射光学元件衍射效率的测量 总被引:2,自引:0,他引:2
根据衍射光学元件衍射效率的测量原理,建立衍射光学元件衍射效率测量的双光路装置,简要介绍了双光路测量的优点。针对衍射光学元件衍射效率的测量装置,讨论了影响衍射效率测量精度的因素,合理地选择测量装置中的针孔光阑,即可以让主衍射级次的光全部通过被探测器接收,又可以滤掉次级衍射光,保证测量结果的准确度。针对所设计研制的一个折衍射混合成像光学系统,测量了可见光波段3个激光波长的衍射效率,并对测量结果进行了模拟和分析。在473~632.8nm波段范围内任意一个波长处,衍射效率的测量结果同理论值的偏差均小于5.0%。实验证明,双光路测量装置可以用于测量衍射光学元件的衍射效率。 相似文献
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We developed a system to measure disk noise as a function of both radial and angular position. In order to obtain an accurate disk noise measurement, crosstalk and intersymbol interference were avoided by recording regularly repeating pit patterns and the influence of electronic and laser noise was removed by averaging techniques. We found the system’s mapping ability and its high sensitivity to be very useful in investigating disk noise phenomena in the mastering process. We used the system to assess the accuracy and reproducibility of the photopolymerization replication and Al vapor deposition processes. Also, we investigated the choice of photoresist and found that photoresists with the combination of the narrowest molecular weight distribution and the highest photo-active compound content resulted in the lowest disk noise levels. Our system can, in principle, be adapted to evaluate magneto-optical and phase change disks. 相似文献
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卫星内无线光网络通信技术及其实现 总被引:1,自引:8,他引:1
卫星内无线光网络通信的基础在于卫星内无线光通信链路. 为保障链路质量, 必须解决适合卫星内环境的抗噪和抗多径损害等技术问题, 以及相关设备的适当重量、体积和功耗等实现问题. 其关键是结合载波和卫星环境的特性, 并配合其它卫星技术研究无线光网络通信技术. 实验表明, 在卫星内实现适应编码调制和脉冲波形技术, 无线光噪声复合消除技术、后验均衡技术和有序捆绑解调解码技术等, 点对点和点对多点高速光链路误码率达到了正常通信要求. 为进一步利用无线光属性组建高服务质量(QoS)网络, 获得高的整体通信效率奠定坚实根基. 相似文献
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The following article describes an advanced dense wavelength division multiplexing (DWDM) Optical Network developed by L-3 Photonics. The network, configured as an amplified optical bus, carries traffic simultaneously in both directions, using multiple wavelengths. As a result, data distribution is of the form peer-to-multi-peer, it is protocol independent, and it is scalable. The network leverages the rapid growth in commercial optical technologies, including wavelength division multiplexing (WDM), and when applied to military and commercial platforms such as aircraft, ships, unmanned and other vehicles, provides a cost-effective, low-weight, high-speed, and high noise-immune data distribution system. 相似文献
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The following article describes an advanced dense wavelength division multiplexing (DWDM) Optical Network developed by L-3 Photonics. The network, configured as an amplified optical bus, carries traffic simultaneously in both directions, using multiple wavelengths. As a result, data distribution is of the form peer-to-multi-peer, it is protocol independent, and it is scalable. The network leverages the rapid growth in commercial optical technologies, including wavelength division multiplexing (WDM), and when applied to military and commercial platforms such as aircraft, ships, unmanned and other vehicles, provides a cost-effective, low-weight, high-speed, and high noise-immune data distribution system. 相似文献
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A simple method to evaluate the performance of transparent optical networks (TON) that takes into account the incoherent homodyne crosstalk, signal distortion, inter-symbol interference (ISI), amplified spontaneous emission (ASE) noise, and arbitrary optical and electrical filters is proposed. This method combines the effect of the incoherent homodyne crosstalk with an exhaustive Gaussian approximation for the influence of ASE noise, signal distortion, and ISI. It is shown that the incoherent homodyne crosstalk penalty depends on the ASE noise accumulated in the TON, ISI, and extinction ratio. The proposed method estimates are compared with experimental results published by other authors. Good agreement is observed for one, two, and four incoherent homodyne crosstalk signals, revealing that the proposed method provides accurate estimates even when the methods based on a Gaussian approximation for the incoherent homodyne crosstalk fail. The proposed method is used to assess the performance of a TON composed by optical add-drop multiplexers based on arrayed waveguide gratings. Results reveal that incoherent homodyne crosstalk, ASE noise, and ISI impair the TON performance and, therefore, none can be neglected in the TON design. 相似文献
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Abstract A simple method to evaluate the performance of transparent optical networks (TON) that takes into account the incoherent homodyne crosstalk, signal distortion, inter-symbol interference (ISI), amplified spontaneous emission (ASE) noise, and arbitrary optical and electrical filters is proposed. This method combines the effect of the incoherent homodyne crosstalk with an exhaustive Gaussian approximation for the influence of ASE noise, signal distortion, and ISI. It is shown that the incoherent homodyne crosstalk penalty depends on the ASE noise accumulated in the TON, ISI, and extinction ratio. The proposed method estimates are compared with experimental results published by other authors. Good agreement is observed for one, two, and four incoherent homodyne crosstalk signals, revealing that the proposed method provides accurate estimates even when the methods based on a Gaussian approximation for the incoherent homodyne crosstalk fail. The proposed method is used to assess the performance of a TON composed by optical add-drop multiplexers based on arrayed waveguide gratings. Results reveal that incoherent homodyne crosstalk, ASE noise, and ISI impair the TON performance and, therefore, none can be neglected in the TON design. 相似文献