几种新型宽带光接入方案及关键光电器件

介绍了近几年来出现的几种新型光接入WDM-PON、TDM/WDM PON等方案和关键光电子器件,分析和讨论了这几种方案的特点和应用前景,指出了40G TDM/WDM PON是商用化程度最高的宽带无源光接入方案,单片集成式与阵列集成式可调谐激光器是40G TDM/WDM PON核心器件和难点。     

光收发器中光电集成接收芯片的实现

针对应用于850nm光通信中的10/100Mbit/s收发器,提出采用0.5μm标准CMOS工艺对其光接收芯片实现Si基单片集成。整体芯片面积为0.6mm2,共集成了一个双光电二极管的(DPD)光电探测器和一个跨阻前置放大电路,功耗为100mW,并给出了具体的测试性能结果。结果表明,在850nm光照下,光接收芯片带宽达到53MHz,工作速率为72Mbit/s。重点介绍了DPD光电探测器的原理和结构,并给出了相应的制造过程和电路等效模型,对整个光接收芯片进行了多种实用性测试,可以满足系统的性能要求。     

一种新型的OADM上/下路(Add/Drop)实现方案

设计了一种新型的基于声光可调谐滤波器(AOTF)的光分插复用器(OADM)上/下路实现方案.该方案用于可重构型OADM中,实现信号的上载与下载.设计内容主要包括上/下路功能模块的组成和具体实现原理,即上/下路的光源产生信号以及电光调制过程.     

FSAN OAN-WG and future issues for broadband optical access networks

Network operators are aiming to provide a broadband access network to facilitate the next-generation telecom services. They have established the Full Services Access Networks (FSAN) group in order to find the best way to achieve early and cost-effective deployment of broadband optical access systems. They concluded that a single worldwide broadband access system should be investigated in the FSAN and then standardized in the international standards bodies such as the ITU-T. This article outlines the FSAN organization and the study targets for its Optical Access Network working group, and some key future study issues in terms of optical distribution network requirements and the required system functionalities of the B-PON system. It also describes its standardization strategy and the interaction between the FSAN and ITU-T     

Mesh networks for broadband access

Broadband wireless access systems must satisfy exacting technical and commercial requirements. In this paper, the author describes a novel approach that uses Internet-like routing to bridge the infamous `last mile'     

光神经网络中的半导体光电器件

叙述了光神经网络的基本概念，并介绍了光神经网络中使用中的半导体光电器件， 体可调制光电检测器（ＶＳＰＤ），具有内存贮光神经芯片，人工视网膜芯片，以及不对称的Ｆａｂｒｙ－Ｐｅｒｏｔ调制器（ＡＦＰＭ）的最新研究结果。     

Optical and optoelectronic devices for optical fiber transmissionsystems

The present status and research trends in light sources, detectors, and various optical components are described, focusing mainly on those for single-mode fiber systems. Laser-diode and light-emitting-diode sources are described, and their problems and advantages are examined. The features of optical detectors, namely, avalanche and p-i-n photodiodes are discussed. A method of comparing the performance of optical receivers with different detectors, by examining the minimum detectable power at a specified error probability for the received pulses, is presented. Optical components such as optical filters, couplers, dividers, isolators, connectors, and switches are considered briefly. The potential of optoelectronic integrated circuits is discussed     

Semiconductor optoelectronic devices for free-space optical communications

LIGHT emitting devices based AlGaAs lasers are very useful radiation sources in free-space opticalcommunications systems. Following a brief review of the properties of individual injection lasers, more complex devices are described. These include (or are relevant to) monolithic integration configurations of the lasers with their electronic driving circuitry, power combining methods of semiconductor lasers, and electronic methods of steering the radiation patterns of semiconductor lasers and laser arrays. Fabrication of such devices is one of the major prerequisites for realizing fully the potential advantages of free-space optical communications.     

Novel algorithm for time division multiple access in broadband ISDN passive optical networks

For shared access to a broadband communication network using the asynchronous transfer mode (ATM) a passive optical network (PON) has previously been proposed. A novel algorithm to evaluate the time division multiple access (TDMA) protocol which controls the traffic from the various subscribers towards the shared access equipment (upstream direction) is proposed. It uses counters to estimate the moment of a data packet arrival at the subscriber side. By this ‘look-ahead’ technique no extra upstream channels are needed to initiate the polling by the subscriber. The algorithm guarantees fair access for all subscribers and minimizes the necessary overhead. Both the maximum access delay and overhead may be readily calculated, and the obtained results were supported by numerical simulation. Applicability in the standard broadband network environment has been proved by hardware design simulation.     

On the establishment of an access VPN in broadband access networks

Many corporate networks use the Internet as a cost-effective substitute for expensive leased lines and long-distance telephone calls, for allowing their users to have on-demand connectivity into their intranets through ad hoc tunnels, a concept known as access VPN. Establishing an access VPN in a broadband access network is very often a difficult networking challenge that requires several tunnels to be established between the various involved entities. This is especially the case in an open broadband access network where the association between a host and its ISP is not known to the network in advance. This article discusses several schemes for establishing an access VPN in a broadband access network, and explains the need for the various tunnels in each scheme.     

宽、窄带综合接入方案分析

随着电信市场的放开,各运营商间的竞争日趋加剧,特别是“最后一公里”的接入市场显得尤为激烈。在接入网领域,一些公共场所(如人口流动较大的车站、码头等)和通信费率较高的大客户成为各运营商竞争的焦点。公共场所用户具有简单的宽窄带综合接入需求:他们只需要宽带接入业务和窄带话音业务、对服务质量没有严格要求;而大客户则具有丰富的接入服务需求,如宽、窄带综合接入、严格的QoS保证、VPN和统一维护管理等。此外,在一些新建节点,用户对宽窄带业务的需求比较零散且不确定;在有窄带接入网络、但缺乏宽带接入设备的边远地区,出现了少量的…     

全光通信用关键光电子器件

近几年来，光纤通信在宽带网络 技术急速发展的推动和信息呈爆炸式增长需求的牵引下，发展速度比以往任何时候都更加迅猛。传统语音业务的年增长率只有５～１０％，而以Ｉｎｔｅｒｎｅｔ为代表的数据业务的年增长率却达到了２０－３０％。与传统的电话相比，Ｉｎｔｅｒｎｅｔ的最大特点不是人与人之间的一对一通信，而是人与机器（数据库）之间的一对Ｎ的通信。由于将全世界分散的数据库连接起来，使得整个网络中的信息量急剧增加。 另一方面，过去几年来，以ＤＷＤＭ为代表的宽带技术使系统带宽的增长比摩尔定律（约１８个月翻一番）还要快…