Monolithic 40-GHz Mode-Locked MQW DBR Lasers for High-Speed Optical Communication Systems

The state-of-the-art of the development and fabrication of advanced 1.55-mum/40-GHz pulse laser modules with a monolithic InP-based mode-locked distributed Bragg reflector (DBR) MQW laser chip inside is reported, with respect to the future applications in high-speed optical communications. We emphasize the latest improvements for hybrid mode-locked devices, which integrate a saturable absorber or an electroabsorption modulator. We further illustrate different technical approaches that enable meeting predetermined frequencies and wavelengths, and which are at the same time promising with respect to high fabrication yields     

40 Gb/s Field-Modulated Wavelength Converters for All-Optical Packet Switching

We present a high-functionality photonic integrated circuit that performs field-modulated wavelength conversion. This device incorporates an on-chip sampled grating distributed Bragg reflector laser for wide tunability. Wavelength conversion is accomplished using a preamplified semiconductor optical amplifier photodiode receiver interconnected with a traveling-wave modulator to form a high-speed optical gate. This paper discusses the design and performance of this device, as well as its potential for optical packet switching applications. Error-free wavelength conversion is demonstrated at 40 Gb/s with 1–3 dB power penalty compared with back-to-back transmission over 22 nm of input and output tuning. Output extinction in all cases is greater than 9 dB, and conversion efficiency ranges from $-$2 to $-$ 6 dB over the tuning range. This device additionally demonstrates the capability for external 10 Gb/s modulation, which can be used for optical label encoding.      

三相变流器的模糊PI神经网络控制研究

提出了一种神经网络电流内环控制加混合模糊PI电压外环控制的双环控制结构.对三机电压型可逆就流器系统而言,神经网络电流内环控制使系统具有更强的鲁棒性,混合模糊PI电压外环控制加快了系统的响应速度.为了增强系统的抗扰性能还引入了电流前馈控制.最后通过仿真及试验验证了控制方案的正确性与可行性.     

Technologies for Quantum Key Distribution Networks Integrated With Optical Communication Networks

Secure networks composed of optical networks and quantum key distribution (QKD) are considered in this paper. A network layer structure is defined to focus on issues important with respect to the QKD network layer that controls QKD links and supplies a secure key for message transmission. A multiple-user QKD network layer can be constructed with timing synchronization, secure key sharing between indirectly connected nodes with switched QKD systems and key relays, and key management to control the volume of key generation and supply in response to the demand from optical network nodes.      

Polarization-Insensitive Monolithic 40-Gbps SOA–MZI Wavelength Converter With Narrow Active Waveguides

A polarization-insensitive monolithic 40-Gbps semiconductor optical amplifier (SOA)-Mach-Zehnder interferometer wavelength converter has been developed. Based on the photon-electron rate equation, we optimized the dimensions of the waveguide structure to maximize the field confinement in the active layer. An InGaAsP active layer with narrow SOA waveguide effectively enables polarization-insensitive high-speed wavelength conversion. High-precision wafer processing technique enabled the fabrication of submicrometer-wide active waveguides with low current leakage. Input waveguide arrays were fabricated at intervals of 25 mum and mounted in a module with two-lens aspherical lens optics. The 40-Gbps nonreturn-to-zero wavelength conversion experiment demonstrates a clear eye opening over full C-band operation     

基于GMPLS的电力通信光网络光多播连接建立机制

通用多协议标签交换技术(GMPLS)推动着电力通信光网络向智能化方向发展,同时,云计算、高清视频分发等新业务的发展使得点到多点的光多播在电力通信光网络中得到越来越多的应用。文章基于GMPSL信令协议RSVP-TE提出了一种新的光多播连接信令机制,它避免了原机制中可能的预留冲突问题,且能够提高网络中波长转换器的利用效率,从而提高了多播连接建立的成功概率。     

两种加辅助网络的全桥变换器的损耗对比分析

在传统移相全桥变换器拓扑上加入由电容和电感组成的无源辅助网络,可以在宽输入电压和整个负载范围内实现原边开关管的零电压开关(zero voltage switching,ZVS)。通过精确的损耗计算,可以寻找降低损耗的方法,优化电路结构以进一步提高变换器的效率。针对加辅助网络的全桥变换器进行深入完整的损耗分析,提出一种新颖的简化损耗分析模型及其详细计算公式,并以采用型辅助网络和采用Y型辅助网络的两种变换器为对象,进行详细的损耗分析和对比。最后通过实验验证本文理论分析的正确性。该文对于深入研究全桥直流变换器具有一定的参考价值。     

Ultrafast All-Optical Serial-to-Parallel Converters Based on Spin-Polarized Surface-Normal Optical Switches

We describe our recent work on all-optical serial-to-parallel converters (SPCs), from the all-optical switches employed in the SPCs to the application of the SPCs for packet processing. The ability to handle ultrafast optical signals is enabled by types of surface-normal optical switches employing different switching mechanisms: one is based on rapid electron trapping in low-temperature-grown Be-doped quantum wells, and the other is based on differential spin-excitation. With these switches, 1:16 SPCs are demonstrated for 40-Gbit/s, 100-Gbit/s, and 1-Tbit/s optical packets. In addition, the SPC is compact, low power, polarization insensitive, exhibits extremely high on/off ratios, and generates a simultaneous parallel output, and thus, provides a promising interface device allowing the processing of ultrafast, asynchronous optical packets in a highly functional complementary metal-oxide-semiconductor (CMOS) processor. As an application, an optical label swapper that integrates the SPC with a CMOS processor is also demonstrated for 40-Gbit/s asynchronous optical packets     

High-Speed OTDM and WDM Networks Using Traveling-Wave Electroabsorption Modulators

We describe the design and performance of a number of elements based on traveling-wave electroabsorption modulators (TW-EAMs) in optical time-division-multiplexing (OTDM) and wavelength-division-multiplexing (WDM) networks. The incorporation of traveling-wave (TW) electrode design into electroabsorption modulators (EAMs) relieves the resistance-capacitance (RC ) bandwidth limitation common to lumped components, enabling higher operation speed without shortening the device. As a result, high-speed operation can be combined with essential modulator characteristics such as modulation efficiency and extinction ratio. While significant modulation bandwidth has been achieved, a lesser known aspect is that the TW electrode also provides an extra dimension for improving and enabling functionalities beyond broadband modulation. This new dimension originates from the distributed effect of the TW design and its interactions with distinctive EAM properties. This paper reviews such developments in recent years with specific applications for optical signal processing in OTDM and WDM networks. The covered functionalities include various optical gating operations for OTDM, regenerative wavelength conversions for WDM, and clock recovery     

电力骨干光传输网络的动态波道均衡路由波长分配算法

提出一种电力光传输网络中基于业务的路由波长分配(RWA)算法。算法设计旨在解决复杂电力光传输网络拓扑下,多业务等级请求路由波长分配问题。首先根据复杂网络拓扑情况与业务请求状况,完成业务请求合并与对跨域业务的路由选择;其次依据域内与域间优先级设定策略,完成业务请求优先级设定,并按照优先级顺序,采用分组波长分配算法完成波长分配。仿真结果表明,算法在处理大规模复杂网络拓扑、多业务等级路由波长分配问题上,有效降低了网络请求阻塞率,提高了光传输网络资源利用率。     

用于配电网故障消弧的级联H桥多电平变换器设计及仿真

将级联H桥多电平变换器用于配电网单相接地故障的消弧,不仅能够满足配电网高电压大功率的要求,同时其良好的输出波形特性能够满足故障电流全补偿的要求。本文对该变换器进行设计,确定主电路参数,选择合适的控制策略并对其进行建模,同时采用悬浮电容为级联H桥多电平变换器提供直流电压,因此设计直流侧电容电压稳定电路,最后通过PSCAD/EMTDC对设计结果进行仿真验证。     

区域光传输通信网络的融合

随着电力网架的不断发展和“三集五大”体系建设的推进,通信站点不断增多,光通信网络结构越来越复杂,面对提升集约化、扁平化、专业化管理的需求,承载的业务越来越多。通过对台州、临海二级区域通信网络现状及存在问题的分析,提出了地、县区域内通信网络融合方案,优化了通信系统网络结构,传输网自愈保护能力得到增强,智能化水平明显提升,区域通信网络的安全可靠性能大幅提高。     

A New Light-Path Setup Scheme for Dynamic Traffic in Ring-based Optical Networks

A simple and fast ring management token (RMT) wavelength reservation method for dynamic traffic in multi-ring wavelength-routed networks is proposed. The RMT is an agent that can control and manage the used wavelength in the network efficiently. We show that the proposed scheme achieves a high performance in terms of setup delay and loss probability. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

多变换器模块化串并联组合系统

多变换器串并联组合系统在很多场合都有广阔的应用前景。以输入并联输出并联组合系统为基础,提出适合其他三种组合(输入并联输出串联、输入串联输出并联以及输入串联输出串联)的多变换器模块化串并联组合系统。其特点是不但单个变换器模块可以正常独立工作,而且还可以将多个变换器模块仅通过母线联接的方式进行串并联组合,不需要外加任何电路,就可以组成新的变换器系统,真正实现组合系统的模块化结构。同时,针对多变换器串并联组合系统中模块可能出现故障的问题,进一步提出了具有容错功能的模块化结构,即当某个模块出现故障时,系统仍然能够维持正常工作。仿真和实验结果验证了该结构的有效性。     

变频器直流电路的设计

交-直-交电压型变频器主电路的原理图上元器件少,且分布直观。但在实际的电路搭建过程中如果任意组合或考虑不周,那么这样的系统是存有安全隐患的。     

变频器应用中常见问题分析

间接变频将工频电流通过整流器变成直流,然后再经过逆变器将直流变换成可控频率的交流。直接变频器则将工频交流变换成可控频率的交流,没有中间环节。     

Converters for Supplying Pulsed Power Loads

There is a growing need for supplying repetitive pulsed power loads of increasing magnitudes up to several hundred megawatts or more in areas of radar, lasers, high-energy physics experiments and thermonuclear fusion. The nature of such loads can be expected to be as diverse as their applications. The pulsed power demands and corresponding reactive volt-amperes requirements are undesirable from the frequency and voltage fluctuation standpoint, even for the large utility power systems. Techniques for supplying large dc-pulsed loads from a relatively small size ac generator by means of inductive storage and the capacitor commutated converters are presented. A theoretical basis is provided for analyzing the converters which serve to minimize the effects of pulsed power and corresponding reactive volt-amperes. Energy transfer between the storage inductor and the pulsed load is permitted with minimal loss, at a readily controllable rate including the reversibility of power in case of inductive loads. Use of a simple control scheme is shown to provide a precise load voltage regulation which may be a requirement for certain applications. The greatest use of these circuits would be in supplying loads with pulse durations of a few milliseconds to many seconds or minutes.     

准滑模控制开关DC-DC变换器分析

准滑模控制的滑模系数和边界层的选取因缺乏明确的关系式而难以确定,该文以相变量系统模型为基础,详细分析了准滑模控制方法的特性和在Buck变换器控制中的应用;研究了准滑模控制的边界层、滑模系数、准滑动模态区相互之间的定量数学关系,所获得的研究结果可以指导我们有效的选取滑模系数和边界层厚度。计算机仿真和实验结果表明准滑模控制器可以获得更加平滑的占空比,有利于减小输出电压的纹波,抑制系统抖振。     

电力光纤通信网络的最佳路径选择

为解决电力光纤通信网分期分批建设导致的网络资源利用率偏低、网络结构不尽合理等问题,文章综合考虑电力通信网的业务特点、通信组网所需的纤芯数以及网络成本最优等因素,对架设于不同电压等级输电线路上光缆可靠性赋予不同的权值.以此为约束条件改进了Floyd算法并开发了计算软件,用于寻找电力通信网最佳路径,进行组网设计.福州市区东南部的应用表明,文章提出的算法与实际情况相吻合.     

电力光传输网中基于主动监测业务的多链路故障定位算法

根据实际运行中电力光传输网的复杂性,针对随机并发多链路故障场景,在传统主动定位算法的基础上,提出一种基于主动监测业务的故障定位算法,即主动融合算法。该算法首先预处理业务的告警信息,简化告警表;然后利用主动监测器,发送检测业务,最终精确定位多链路故障的位置。与传统的被动定位算法相比,主动融合算法可以提高定位准确率10%以上;与传统的主动算法相比,主动融合算法可以进行多链路故障的定位。仿真结果表明,主动融合算法定位时长在9 ms以内,定位准确率达到70%以上,能够满足电力光传输网的正常运行需求。