Consortium GARR and the European National Research and Education Networks Optical Infrastructure Developments

Abstract

GARR is engineering its next generation of the Italian Research and Education Network (GARR-X), which will exploit a countrywide optical infrastructure based on DWDM equipment and advanced multi-domain services. The trend is common in all National Research and Education Networks [1 TERENA NREN Compendium. http://www.terena.org/activities/compendium ISSN 1569-4496 [Google Scholar]] in Europe and worldwide. NRENs are relying more and more on direct use of optical equipment to fulfill the researchers' requirements. These hybrid networks are built to provide services on a multi-domain environment both at the circuit and at the IP layer for researchers in, for example, radio astronomy (eVLBI [2 European Very Long Baseline Interferometry http://www.evlbi.org [Google Scholar]]), GRID computing (EGEE [3 Enabling Grids for E-sciencE http://public.eu-egee.org [Google Scholar]], LHC [4 The Large Hadron Collider http://lhc.web.cern.ch/lhc [Google Scholar]]), high-performance computing (DEISA [5 The Distributed European Infrastructure for Supercomputing Applications http://www.deisa.org [Google Scholar]]). This article outlines the status and issues of ongoing research activities in GARR [6 http://www.garr.it/garr-b-home-engl.shtmlConsortium GARR, the Italian NREN [Google Scholar]] and NRENs to provide, manage, and evolve dedicated optical-based networks for providing multi-domain end-to-end services. The research is performed mainly in the framework of the European Commission co-funded project GÉANT2 [7 The pan-European R&E network http://www.geant2.net [Google Scholar]].     

A novel low-swing interconnect optimization model with delay and bandwidth constraints

Interconnect power and repeater area are important in the interconnect optimization of nanometer scale integrated circuits.Based on the RLC interconnect delay model,by wire sizing,wire spacing and adopting low-swing interconnect technology,this paper proposed a power-area optimization model considering delay and bandwidth constraints simultaneously.The optimized model is verified based on 65-nm and 90-nm complementary metal-oxide semiconductor(CMOS) interconnect parameters.The verified results show that averages of 36% of interconnect power and 26% of repeater area can be saved under 65-nm CMOS process.The proposed model is especially suitable for the computer-aided design of nanometer scale systems-on-chip.     

多束速调管的增益带宽

 研究了M个束、N个共振腔的多束速调管(MBK)的增益和带宽，得到了描述小信号增益和带宽与器件结构参数和电子束参数关系的公式，给出了在不同参数下增益随频率的变化曲线。分析了多腔对增益，多束对带宽的影响。计算结果表明：多腔可以提高增益；多束可以降低Q值，从而可以增中带宽，带宽增加工了3.6%，还可以提高增益；对于MBK，频率交叉调谐对增加带宽不如频率调谐好；空间电荷波只对增益有影响，对带宽没有影响。最后，预估一种L带多束速调管的增益带宽为8.1%。     

一种通带平坦的粗波分复用/解复用器件的研制

随着粗波分复用(CWDM)系统在城域网和接入网中日益广泛的应用,人们对粗波分复用／解复用器的研究也逐渐展开。报道了一种8通道波长间隔为20nm的粗复用／解复用器。该器件基于阵列波导光栅(AWG)原理设计,利用平面光波导技术(PLC)制作,采用多模干涉输入结构和“S”形阵列波导结构,实现了较宽的通带宽度和较低的串扰。实验测得1dB带宽大于10nm,相邻串扰大于24dB,非相邻串扰大于32dB。介绍了其设计原理和制作过程,给出了光束传播法(BPM)数值模拟结果,并和实验结果进行了对比。     

超宽带聚合物调制器的优化设计

设计了一种以聚合物作为材料的低损耗、宽带宽的Mach—Zehnder光波导调制器。分析了调制器的脊波导的模式特性,设计了脊波导的结构,并使用BPM软件模拟了脊形波导的光场分布;通过对光场分布的分析,优化了脊形波导的宽度Wg,脊高6,芯层高度H。同时对聚合物调制器的电极进行了优化,包括电极宽度W和电极间距D,使得调制器有较小的导体损耗以及较好的阻抗匹配。并结合了脊波导的结构参数和电极的优化参数,给出了优化结果,它能够使微波的有效折射率与光波的有效折射率达到匹配,从而使带宽达到177GHz,导体损耗为0．2569dB／cm·GHz1／2。