融合的高效能T比特光传送方案

在介绍下一代骨干网络要求的基础上,从全光网络技术、下一代T比特ODU交叉网络、OTN汇聚等方面介绍了融合的T比特传送网络基于零接触技术的可管理光传送平台.     

未雨绸缪 计划未来——北电全套光传输解决方案领跑未来“光”时代

随着光网络技术的深入发展和广泛应用,光传送网络已成为各运营商承载传送业务的核心平台,如何构建安全、高效、低成本和扩展性好的光传送网络,是目前业界普遍关注的问题。面临目前多种宽带业务的强势发展和3G网络的兴起,光传送网络要求具备超高速率、超大容量、超长距离、多业务处理和业务灵活配置等特点,北电网络《未雨绸缪计划未来》一文正是基于光网络的目前这种发展趋势,针对长途光传送网、城域光传送网和3G光传送网等不同光网络分析了网络特点、功能需求和建设模式等,在此基础上介绍了北电网络光传送网络产品DWDM(CPL)和MSTP(OME6500)的集成新技术和主要功能,这对于关注和研究光传送网络发展及构建的运营商、科研单位以及工程规划设计部门等都有一定的参考价值。     

分组交换技术在光传输网中的研究与设计

针对用电路交换技术传输OTN信号面临容量、速率受限的问题,研究了基于包结构的光传送网的优势并提出实现方案。文中首先介绍了分组交换网络和光传送网相结合的基本结构,以及OTN帧结构及混合网络中标准的包格式,最后描述了一个将OTN技术和数据包技术相融合的可实现结构。该结构能将光信道数据单元解复用为低阶形式,并将其切割为离散的数据包。切割好的数据包由标准包接口送往包交换芯片进行交换,交换后的数据包进入重组模块,将其重组为连续的数据流,再由复用模块将光信道数据单元复用到其高阶形态发送出去。     

ASON组网中的保护恢复机制

光传送网正逐步从单纯的传送平台演进为与上层业务网紧密结合的综合网.为使网络更有效快速地服务于最终用户,运营商需要构筑新一代的光传送网,通过ASON智能光网络技术将核心网和综合业务传送网结合在一起,提供全新端到端的业务服务和管理模式.     

LSON组网中的保护恢复机制

光传送网正逐步从单纯的传送平台演进为与上层业务网紧密结合的综合网。为使网络更有效快速地服务于最终用户，运营商需要构筑新一代的光传送网，通过ASON智能光网络技术将核心网和综合业务传送网结合在一起，提供全新端到端的业务服务和管理模式。     

智能光网络体系结构与服务功能的探讨

大容量、智能化、综合业务处理将成为传送网络未来的基本发展方向，本文着重对智能光网络的网络体系与结构、智能光网络拄制平面相关技术“硬智能光网络的网络服务功能进行探讨。     

全新的通信网—宽带综合业务数字网BISDN

当今的通信网以专用网为特征,这意味着对一种通信业务至少存在一种网络来传送这种业务。目前在国际上就存在着多种公用网与专用网,在公用网中,常见的就有: 电报网(Telex Network)传送电报信息,传送速率很低(最多为300比特/秒),字符或汉字以一种特殊的比特码(Baudot码)编码。     

4位5GS/s 0.18μm CMOS并行A/D转换器

基于0.18 μm CMOS工艺,设计了一种最大采样速率为5 GS/s的4位全并行模数转换器.设计中,为了提高模数转换器的采样速度,采用三种技术相结合:1)比较电路与解码电路都采用流水线的工作方式;2)在比较器中使用电感技术,提高比较器的转换速度;3)使模拟电路和数字电路都工作在低摆幅的工作状态,在提高速度的同时,降低了电路的功耗.为了提高电路的信噪比,采用全差分输入输出方式和低摆幅时钟控制,并在解码器中先将温度计码转换成格林码,再将格林码转换成二进制码,有效地抑制了由比较电路产生的亚稳定性.仿真结果表明,在输入信号为102.539 MHz、5 GS/s采样率下,设计的电路有效比特数达3.74位,积分非线性和微分非线性分别小于0.255 LSB和0.171 LSB,功耗小于65 mW.     

上海贝尔：睿智光网助推低成本传输

云计算业务的持续增长、新应用特别是视频业务的爆炸式发展,以及智能设备的日益普及,正推动光网络向T比特时代迈进。上海贝尔光网络能力中心负责人郭中华指出：“更高的速率、更大的带宽、智能化和高效运维是构建T比特光网络的四大驱动力。”     

光网络的进展研究

光传送网是指光信道接入点所定界的传送网络。光传送网络的物理层采用光纤作为传输媒介，光传送网为客户层信号在很大范围内提供包括传送、复用、路由、管理、抗故障等功能。光传输技术经历了PDH、SDH到WDM的发展过程。在90年代，SONET/SDH网络在容量、可靠性和网络传送效率方面都得到迅速提高。光传送网主要提供如下功能：不同网络客户的透明传送、不同管理域的互联、光信道连接和保护、性能监测和告警监视、网络管理。目前光网络的单信道的传送速率(图1)和网络的传送容量在迅速增加，以满足不断增长的互联网的业务需求。单纤复用的…     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

中国建立EB级存储实验室,致力云计算应用(英文)

正With the support of 863 programs,Sugon Information Industry Co.,Ltd.,set up a dawning EB-class storage laboratory to address massive data storage requirements and largescale cloud computing demonstration applications.The Dawning EB-class cloud storage system adopts advanced fault-tolerant architecture,efficient data fault-tolerant algorithms with user authentication and data encryption policies to deal with the"lost""wrong"and"stolen"problems of data for ensuring the reliability and safety of the EB-class storage system in the public network application environments.The Dawning EB-class Storage Laboratory taking advan-