半导体导波空间光开关

本文论述构成未来光节点系统关键器件的导波半导体光交换器件的特性。采用半导体ＭＱＷ波导的ＱＣＳＥ制成全封装２×２和４×４光开关组件，并加以评估。这些组件能分组交换１０Ｇｂ／ｓ的光信号，并能以１／８去复用成１．２５Ｇｂ／ｓ，这些组件很有希望作为高速交换器件。     

光交换技术

光交换技术是令世人瞩目的新技术，这项技术的实用化将是２１世纪发展的必然趋势。因此，本文论述了光交换技术发展的过程，介绍了三类光交换系统的概况和光器件突破性的进展新及结构接排，对光交换系统的发展前景做了乐观的分析。     

光子交换器件的研究动向和存在问题

介绍了光子交换的特点和分类，以及光子交换器件的最新研究动向，提出了光子交换器件需要突破的关键技术和问题，指出了光子交换器件必然能在通信系统中应用的前景。     

全光交换机的新功能

现在，运营商为了减少运营成本和增加收入，正在热衷于采用全新的、基于新一代光器件的智能型光网络。这些新器件能提供新功能和多种功能的集成。其中，一个较为典型的例子就是全光交换器件。交换机已经从原始的简单光学机械装置发展成具有新功能的高速光器件。新功能如动态可调光衰耗和光层组播等已经被引入到光交换器件中。表1将下一代光交换技术和传统光交换技术作了简单的对比。下一代光交换机的特点是性能更好、功能更丰富。性能上的改善将为更多的新应用架起一个宽广的平台（如图1）。其范围包括从网络新技术到全新的系统集成。光层保…     

光网络中的光交换技术

在对光交换技术深入研究的基础上，对光网络中的关键器件，声光可调滤波器及光缓存器作了详细介绍，最后对光交换的发展前景作了展望。     

光无源器件国内市场分析

本文就国内光无源器件的发展及市场现状加以介绍,并分析了供需之问的矛盾,预测了今后三五年国内光通信及光纤传感器技术对光无源器件的需求,借以指出近期国内光无源器件研究和生产方向。     

新光路由交换技术及其发展应用

在不久的将来,数据业务将超过话音业务,这意味着现在的面向连接的线路交换网络必须进行改造更新,以支持分组交换数据业务。当前的光交换技术使我们能够采取某种方式更快地在WDM网络上传送大带宽的业务。在业界所研究、探讨的光交换机制中,基于MPLS作控制平面的OXC越来越受到人们的重视,最有影响力和最有前途的是光分组交换和光突发交换技术及由其构成的路由交换机。 经过30余年对光交换的研究。在器件研究技术的推动下,光交换系统技术的研究有了很大进展。从发展过程看,可分为两个阶段：第一阶段进行电控光交换,即信号交换是全光的,而光器件的控制仍由电子电路完成。目前试验系统大都处于这一水平,相关成果报道也比较多。 第二阶段为全光交换技术,即系统的逻辑、控制及交换均由光子完成,关于这方面的报道还比较少。 一、新的光交换技术光交换系统按功能结构可分为光交换网络和控制回路两大部分。按交换形式可分为光路交换、光分组交换网光突发交换。光路交换又可分为空分、时分和波分／频分交换,以及由这些交换网络组合而成的结合型。1．光分组交换（1）光ATM交换 通常,光ATM交换采用波分复用、电或光缓冲技术,由波长进行路由选择。 信元的波长作为选路信息,依...     

全光网络中的MEMS光开关研究新进展

光开关是未来全光网络中关键的光交换器件。MEMS技术由于其自身的诸多优点而被认为是目前最有前景的光器件制作技术之一。本文简要论述了MEMS光开关与其他类型光开关的区别,介绍了MEMS光开关的特性,并分别就二维、三维及最近提出的一维MEMS光开关进行了介绍和比较。最后,综合探讨了MEMS光开关目前所面临的各种挑战。     

光因特网中的关键光器件技术研究

对光因特网中的关键光器件技术进行了探讨与研究。下一代光通信网络的发展,关键在于其光器件技术的突破上,要克服光网络节点处理的速率瓶颈、实现全光联网、高效传送和交换IP业务,就必须积极研究开发新的光器件。在光开关技术、光纤放大器技术、波长变换器技术以及其它关键光器件技术上有所突破,是建设光因特网的关键所在。     

IDT推出低功耗PCI Express交换产品系列

日前，IDT公司推出了优化的PCI Express（PCIe）交换产品系列。其PRECISE系列目前包括10种PCle交换器件。这些器件符合PCI Express1．1规范，采用业界广泛的通道，端口配置，可为用户提供广泛的系统设计选择：还可为48通道，12端口交换器件提供24Gbit／s的交换带宽。8通道，5端口交换器件可在低端提供4Gbit／s的吞吐量。这些交换器是专为应对高端服务器、存储和通信设备以及工业和消费类应用等系统的I/O连接挑战而优化的，它们可支持高达2048byte的有效负载关键设计，可实现最佳数据吞吐性能。     

Influence of mode competition on the fast wavelength switching ofan SG-DBR laser

Because the sampled grating distributed Bragg reflector (SG-DBR) laser is among the most attractive sources for wavelength division multiplexing (WDM) systems, it is important and necessary to investigate its wavelength switching characteristics. This behavior will set the capability limits for reallocation in wavelength-routed optical networks. In this paper, that mode competition plays an important role in the wavelength switching dynamics of DBR-type tunable lasers is confirmed experimentally. By using a time-resolved spectrum technique, the loss-dependent mode competition behavior has been directly observed, for the first time, from measurements of wavelength switching on an SG-DBR laser     

Photonics in future telecommunications

In future telecommunication systems, efforts will be made to exhaust the almost unlimited transmission capacity of optical fibers by applying optical frequency-division-multiplexing (OFDM) techniques. The switching elements of such networks must be able to process OFDM signals as well as time-division-multiplexing (TDM) signals. The extent to which optical signal processing can be brought into use instead of present-day electronic signal processing in such switching elements is examined. Several experiments involving OFDM technologies are described which are intended to underline the significance of those technologies for future telecommunication networks. Various techniques for and experiments on the optical switching of signals in the frequency, space, and time domain are described. Experiments dealing with optical signal regeneration are described     

Design and analysis of micromechanical tunable interferometers forWDM free-space optical interconnection

This paper proposes a new concept of high density chip-to-chip optical interconnection based on wavelength division multiplexing (WDM), which can be realized as a microelectromechanical system (MEMS) device. The output signals from a preprocessing integrated circuit (IC) chip (N channels) are converted to optical signals of different wavelengths by using wavelength tunable laser diodes and projected onto an array of wavelength-selective photodiodes. Channel connection is made by wavelength matching between the light sources and detectors, by using micromechanical Fabry-Perot interferometers. In this scheme arbitrary 1 to 1 connection as well as 1 to N or N to 1 connection is available. Since the input/output connections are made in an optical manner, the switching state can be reconfigured and the whole switching system can be integrated in a compact space. We have investigated design principle of the micromechanical Fabry-Perot interferometers for tunable photodiodes to maximize the switching contrast and channel density in a given wavelength range. The preliminary interferometer arrays are implemented by silicon-based surface micromachining     

A novel IP with MPLS over WDM-based broad-band wavelength switchedIP network

This paper presents a new technology for constructing IP over photonic systems. An IP with multiprotocol label switching (MPLS) over wavelength division multiplexing (WDM)-based broad-band IP network architecture and protocol is proposed and analyzed in this paper, which supports variable-length IP-like optical packet label switching and optical virtual path routing. This system tries to merge into one layer the functionalities of the wavelength switching, SONET mux/demux, and IP routing, and is sometimes known as the concept of optical MPLS. The label banding, forwarding/switching process, and node architecture of the proposed network are discussed and studied. A unique as well as important function of a lambda/label edge router (LER) is a flow assembly device that can encompass MPLS' forward equivalence classes, label stacking, and label switching path aggregation function. At the same time, a particular function of the core label switching router is wavelength merging. A fiber delay line is used to delay the data stream in order to process the label information and resolve contention. Transmission bit error rate measurements of the baseband data stream and back-to-back is also demonstrated to show its feasibility     

Semiconductor laser diode optical amplifiers/gates in photonicpacket switching

In this paper, we will describe how semiconductor laser diode optical amplifiers/gates can be used in the photonic packet switching systems based on wavelength division multiplexed (WDM) techniques. First, we show that cross-gain modulation (XGM) can be suppressed when the device is used in the transparent condition of the waveguide material even when the input signal power exceeds +18 dBm. We then discuss an appropriate encoding for the optical signal. Experimental results show that high bit rate Manchester-encoding enables the use of semiconductor laser diode optical amplifiers/gates in the gain condition as well as the transparent condition. Finally, a new photonic packet receiver which utilizes a semiconductor laser diode optical amplifier as a packet power equalizer is proposed. This receiver accepts 17 dB power fluctuation at nanosecond speed for 10 Gb/s Manchester-encoded signal     

Modeling of ionizing radiation effect on optoelectronic-integrated devices (OEIDs)

The ionizing radiation effect on the static and dynamic behavior of an optoelectronic-integrated device composed of a hetrojunction phototransistor and light-emitting diode is studied theoretically. First, the device characteristics before irradiation are investigated based on the equivalent circuit of the constituent devices and the optical feedback inside the device. Second, the effect of neutron irradiation flux on transient behavior of this device is theoretically studied. It was noticed that, the neutron irradiation flux reduces the transient response in both the amplification and switching modes. Also, neutron irradiation flux increases the switching voltage of the device and decreases the output current, this means that the ON state device which exposed to this irradiation flux will turn to the OFF state because it will need higher value of switching voltage. Either increasing the amount of input light or the applied voltage is required to turn the device to the ON state again. This type of models can be exploited as optical amplifier, optical switching device and other applications.     

Prechirp technique as a linear dispersion compensation forultrahigh-speed long-span intensity modulation directed detectionoptical communication systems

Prechirp technique, as a linear dispersion compensation for intensity modulation direct detection (IM-DD) optical transmission systems, has been investigated theoretically and experimentally. This technique is based on a predistortion technique in an optical transmitter. Implementation to the ordinary IM-DD optical transmitter, which uses an external intensity modulator, is easily realized merely by adding a small injection current modulation to a semiconductor laser diode, allowable optical transmission fiber dispersion will be more than doubled with this technique, modified prechirp technique, which utilizes a time division superimposing prechirped bit streams, has also been investigated to achieve greater dispersion compensation capability     

基于半导体光放大器的可扩展型光开关矩阵

未来的高速和高度灵活的光分组交换网络要求开关速度达到纳秒量级且集成度高的大规模空间光开关矩阵。在分析了基于半导体光放大器的常用结构形式的光开关矩阵存在规模局限性的基础上,综述了新型的可实现大规模集成的基于半导体光放大器的光开关矩阵的基本原理和研究现状。     

Terminology for photonic matrix switches

A classification scheme is suggested here for matrix switches that use photonic principles, generally for broadband signal routing. The classification considers three independent properties, providing for a large number of categories with properties that differ in identifiable ways. Salient properties of each class are noted. Matrices are classified in the following ways: according to the switching principles used i.e. optical or optoelectronic; according to the multiplexing system used in the switch i.e. space division, modulation division or carrier division; and according to the optical configuration of the switched systems, i.e. centrally switched, optically extended or distributed. Examples of the various types are given     

电力系统中MEMS光开关切换路径优化控制的方法

针对电力系统中微机电系统(MEMS)光开关在切换备纤时可能受到光控信号的影响而造成光时域反射仪(OTDR)发生损坏的问题,文章提出了一种电力系统中MEMS光开关切换路径优化控制的方法,在对MEMS光开关进行完整的扫描后得到其精确的光信号通道功率等高图,然后再对其切换路径进行优化控制,使得MEMS光开关可以在平衡控制通道...