耦合器衰减实现的两种全光波长变换

在以往对全光波长变换的研究中,都是利用变换光实现波长变换,而利用闲频光的全光波长变换还没有相关报道.文章通过模拟耦合器衰减对全光波长变换的影响,发现在不同的泵浦光与信号光功率条件下,调节耦合器衰减可分别实现利用变换光的全光波长变换和利用闲频光的全光波长变换.     

波分复用的应用和发展

介绍了当前国际上的高速率光通信技术,波分复用的应用现状,讨论了波分复用光传送网的组网和保护问题,以WDM技术为基础形成全光传送网的技术要求,预测了WDM网络的发趋势和全光通信网的形成。     

波分复用全光通信网络

一、引言 目前,波分复用(WDM)全光通信网的关键技术:光纤高速传输技术、波分复用传输技术、光分插复用器(OADM)技术和光交叉连接(OXC)技术日趋成熟,为全光通信网奠定了技术基础。随着电信业务量的迅猛发展,为了解决目前通信网络的电子“瓶颈”效应,欧美发达国家对WDM全光通信网进行了大量的研究,先后建立了许多WDM全光通信网的试验网。本文将以斯德哥尔摩的METON试验网为例,对WDM全光通信网进行简单的介绍。 二、网络结构 全光通信网络的结构分为服务层(Service layer)和传送层(Transport layer),网络传送层分为SDH层、ATM层和光传送层。光传送层由OADM和OXC组成。在光传送层,通     

全光波长转换技术

文章简要介绍了全光波长转换技术在WDM全光通信网中的作用；介绍了以半导体光放大器（SOA）为核心器件的几种全光波长的转换技术——利用SOA的交叉增益调制效应、交叉相位调制效应或SOA中的四波混频效应实现波长转换，分析了工作原理并介绍了研究进展情况。     

华为在美国光纤通信展览会展示光突发传送网样机

华为近日在美国光纤通信展览会（OFC／NFOEC2011）上发布光突发传送网样机。该样机采用OBTN（光突发传送网）技术,实现了光层的分组调度,支持任意拓扑组网。该样机的成功研制大幅加速了全光交换技术的应用进程。     

利用闲频光实现全光波长变换的研究

文章用OptiSystem模拟出了利用闲频光实现的全光波长变换.通过调整半导体光放大器(SOA)注入电流、SOA腔长、泵浦光与信号波的频率差、偏振、耦合器信号衰减与泵浦衰减等参数的值,获得了12 dB的变换效率.研究发现,利用闲频光实现的全光波长变换比利用变换光实现的全光波长变换有更好的稳定性.     

对于OTN与PTN联合组网技术分析

随着网络通信技术的不断发展,光传输网在接入层、汇聚层、核心层的发展渐渐转变为PTN(分组传送网)与OTN(光传送网)技术。采用分组传送网与光传送网完成网络部署,具备很多优越性。若业务疏导容量较大,则可使用光传送网技术,如果需要精细化管理客户与业务,便能够使用PTN技术。分组传送网的主要特征为分组交换内核,它可将SDH技术取代,对WDM技术中存在的不足进行弥补,促使网络传送能力与光缆资源利用率大大提升,使网络通信变得全光化、IP化与智能化。文章主要分析OTN与PTN联合组网技术,并对其特点进行研究。     

光突发传送网样机华为

华为近日在全球最大的光通信展会——美国光纤通信展览会（OFC／NFOEC 2011）上发布业界首款光突发传送网样机。该样机采用OBTN（光突发传送网）技术,实现了光层的分组调度,支持任意拓扑组网。该样机的成功研制大幅加速了全光交换技术的应用进程。     

全光网关键技术

详细介绍全光网的关键技术，重点介绍了全光交换／路由技术、DWDM复用技术、EDFA光放大技术和各种新型光纤。     

自动交换光网络中全光波长转换器的应用和实现

作为自动交换光网络中的核心器件,全光波长转换器在网络中发挥着重要作用.总结了全光波长变换的实现方法,并重点介绍基于半导体光放大器交叉相位调制和利用可调谐光纤光栅外腔半导体激光器实现全光波长变换的最新进展、工作原理,最后简单介绍本实验室目前所做工作以及取得的成果.     

DWDM全光网络中波长转换技术的比较

波长转换技术是 DWDM全光网络中一项重要的基础技术。介绍了波长转换技术的基本原理 ,并对现有主要的几种波长转换技术进行比较 ,最后指出基于四波混频技术的波长转换技术是未来的研究方向     

Wavelength Conversion Technologies

This paper reports a review of the different technologies used for wavelength conversion in wavelength-division multiplexed networks. The strengths and the weaknesses of the competing technologies, including optoelectronic wavelength conversion, four-wave mixing, difference frequency generation, cross-gain and cross-phase modulation in semiconductor optical amplifiers, are stressed with regard to conversion speed, transparency and regeneration of the converted signal.     

On Multicast Routing for Wavelength-Routed WDM Networks with Dynamic Membership

Future broadband networks must support integrated services and offer flexible bandwidth usage. In our previous work in [1], we explored the optical link control (OLC) layer on the top of optical layer that enables the possibility of bandwidth on-demand (BoD) service directly over wavelength division multiplexed (WDM) networks. Today, more and more applications and services such as video-conferencing software and Virtual LAN service require multicast support over the underlying networks. Currently, it is difficult to provide wavelength multicast over optical switches without optical/electronic conversions although the conversion takes extra cost. In this paper, based on the proposed wavelength router architecture (equipped with ATM switches to offer O/E and E/O conversions when necessary), a dynamic multicast routing algorithm is proposed to furnish multicast services over WDM networks. The goal is to join a new group member into the multicast tree so that the cost, including the link cost and the optical/electronic conversion cost, is kept as low as possible. The same algorithm can be applied to other wavelength routing architectures with redefinition of electronic copy cost. The effectiveness of the proposed wavelength router architecture as well as the dynamic multicast algorithm is evaluated by simulation.     

混合光波长转换在波分复用光网络中的应用

在全光网络中，如何合理利用波长转换来降低光网络的阻塞率是一个非常关键的问题。研究了最新的波长转换体系结构和波长转换手段，提出一种全新的混合波长转换方法，在减少网络中波长转换器个数的同时，维持拥塞概率类似于全波长转换。提出了5种不同的波长转换器使用策略，并利用数值模拟的方法，比较了这5种不同的波长转换器使用策略，分析结果，得出了最小化光网络的阻塞概率的波长转换使用策略。结合混合波长转换和波长转换器使用策略，进一步提出了光网络中优化波长转换器配置的遗传算法，通过对14个节点的美国自然科学基金网(NSF Net)的数值模拟，结果表明它是十分有效的，在减少光网络中波长转换器数量，且不增加光网络波长数量的情况下，基本保持原有网络性能。     

WDM光网络中波长转换技术的研究

波长转换是ＷＤＭ 光网络中一项重要的基础技术。在大型光网络中,它通过波长重用,可以降低网络中因波长竞争而导致的阻塞,提高网络管理、控制和维护的灵活性。文中系统地论述了波长转换技术,首先介绍了ＷＤＭ 光网络中波长转换的必要性,随后分析各种不同的波长转换技术原理,讨论其主要性能及优缺点     

全光波长转换技术的改进和发展

全光波长转换技术(AOWC)对WDM光网络的发展有着重要的意义，在简单回顾传统AOWC的基础上，介绍了三种较新的波长转换技术，阐述了其工作原理，简要说明了其实检进展及优缺点；最后讨论了全光波长转换器的发展方向。     

全光归零(RZ)到非归零(NRZ)码型转换技术研究进展

随着多媒体网络服务业务类型的不断出现,人们对因特网带宽需求日益增长,未来的超高速大容量光子网络很可能是波分复用与时分复用相结合的智能网络。全光归零(RZ)到非归零(NRZ)的码型转换技术,是构建这种网络的关键技术之一,它能避免电子学器件的速率瓶颈,将时分复用(OTDM)与波分复用(WDM)有机结合,在光域内实现不同调制格式的数据在网络的不同部分之间自由传输,已经引起了越来越多人们的兴趣。介绍了当前全光归零到非归零码型转换技术的最新研究进展,分析了其工作原理,优缺点及性能参数,指出了目前存在的技术难点问题,最后对其发展前景进行了展望。     

Wavelength conversion technologies for WDM network applications

WDM networks make a very effective utilization of the fiber bandwidth and offer flexible interconnections based on wavelength routing. In high capacity, dynamic WDM networks, blocking due to wavelength contention can he reduced by wavelength conversion. Wavelength conversion addresses a number of key issues in WDM networks including transparency, interoperability, and network capacity. Strictly transparent networks offer seamless interconnections with full reconfigurability and interoperability. Wavelength conversion may be the first obstacle in realizing a transparent WDM network. Among numerous wavelength conversion techniques reported to date, only a few techniques offer strict transparency. Optoelectronic conversion (O/E-E/O) techniques achieve limited transparency, yet their mature technologies allow deployment in the near future. The majority of all-optical wavelength conversion techniques also offer limited transparency but they have a potential advantage over the optoelectronic counterpart in realizing lower packaging costs and crosstalk when multiple wavelength array configurations are considered. Wavelength conversion by difference-frequency generation offers a full range of transparency while adding no excess noise to the signal. Recent experiments showed promising results including a spectral inversion and a 90 nm conversion bandwidth. This paper reviews various wavelength conversion techniques, discusses the advantages and shortcomings of each technique, and addresses their implications for transparent networks     

DWDM光传送网中选路和波长分配

本文综述了密集波分复用（DWDM）光传送网中选路和波长分配（RAW）研究领域的最新研究成果。分析比较了固定路由和备用路由下不同RAW算法的性能,还讨论了不同情况下采用波长变换对网络性能的改善。     

Performance of fiber delay‐line buffers in asynchronous packet‐based optical switching networks with wavelength conversion

A major challenge in asynchronous packet‐based optical networks is packet contention, which occurs when two or more packets head to the same output at the same time. To resolve contention in the optical domain, two primary approaches are wavelength conversion and fiber delay line (FDL) buffering. In wavelength conversion, a contending packet can be converted from one wavelength to another in order to avoid conflict. In FDL buffering, contending packets can be delayed for a fixed amount of time. While the performance of wavelength conversion and FDL buffering has been evaluated extensively in synchronous networks with fixed‐sized packets, in this paper, we study the performance of FDL buffers in asynchronous packet‐based optical networks with wavelength conversion. An analytical model is proposed to evaluate the performance in terms of packet loss probability and average delay. Extensive simulation and analytical results show that, with appropriate settings, FDL buffers can perform much better in switches with wavelength conversion than in switches with no conversion. Copyright © 2014 John Wiley & Sons, Ltd.