Multimode polymer waveguide components for complex on-board optical topologies

Multimode polymer waveguides are an attractive transmission medium for board-level optical links as they provide high bandwidth, relaxed alignment tolerances, and can be directly integrated onto conventional printed circuit boards. However, the performance of multimode waveguide components depends on the launch conditions at the component input, complicating their use in topologies that require the concatenation of multiple multimode components. This paper presents key polymer components for a multichannel optical bus and reports their performance under different launch conditions, enabling useful rules that can be used to design complex interconnection topologies to be derived. The components studied are multimode signal splitters and combiners, 90°-crossings, S-bends, and 90°-bends. By varying the width of the splitter arms, a splitting ratio between 1% and 95% is achieved from the 1 × 2 splitters, while low-loss signal combining is demonstrated with the waveguide combiners. It is shown that a 3 dB improvement in the combiner excess loss can be achieved by increasing the bus width by 50 μm. The worst-case insertion loss of 50 × 100 μm waveguide crossings is measured to be 0.1 dB/crossing. An empirical method is proposed and used to estimate the insertion losses of on-board optical paths of a polymeric four-channel optical bus module. Good agreement is achieved between the predicted and measured values. Although the components and empirical method have been tailored for use in a multichannel optical bus architecture, they can be used for any on-board optical interconnection topology. © 1983-2012 IEEE.

A 40 Gb/s scalable optical polymer backplane using a regenerative shared bus architecture

The first multi-channel optical backplane demonstrator using on-board multimode polymer waveguides and a scalable shared-bus regenerative architecture is reported. The system allows bus extension by cascading multiple polymeric bus modules, and enables error-free 4×10 Gb/s interconnection between any two card interfaces on the bus.

A 40 Gb/s optical bus for optical backplane interconnections

Optical technologies have received large interest in recent years for use in board-level interconnects. Polymer multimode waveguides in particular, constitute a promising technology for high-capacity optical backplanes as they can be cost-effectively integrated onto conventional printed circuit boards (PCBs). This paper presents the first optical backplane demonstrator based on the use of PCB-integrated polymer multimode waveguides and a regenerative shared bus architecture. The backplane demonstrator is formed with commercially-available low-cost electronic and photonic components onto conventional FR4 substrates and comprises two opto-electronic (OE) bus modules interconnected via a prototype regenerator unit. The system enables interconnection between the connected cards over four optical channels, each operating at 10 Gb/s. Bus extension is achieved by cascading OE bus modules via 3R regenerator units, overcoming therefore the inherent limitation of optical bus topologies in the maximum number of cards that can be connected to the bus. Details of the design, fabrication, and assembly of the different parts of this optical bus backplane are presented and related optical and data transmission characterisation studies are reported. The optical layer of the OE bus modules comprises a four-channel three-card waveguide layout that is compatible with VCSEL/PD arrays and ribbon fibres. All on-board optical paths exhibit insertion losses below 13 dB and intra-channel crosstalk lower than -29 dB. The robustness of the signal distribution from the bus inputs to all respective bus output ports in the presence of input misalignment is demonstrated, while 1 dB input alignment tolerances of approximately ±10 μm are obtained. The electrical layer of the OE bus modules comprises the essential driving circuitry for 1×4 VCSEL and PD arrays and the corresponding control and power regulation circuits. The interface between the optical and electrical layers of the bus modules is achieved with simple OE connectors that enable end-fired optical coupling into and out of the on-board polymer waveguides. The backplane demonstrator achieves error-free (BER < 10-12) 10 Gb/s data transmission over each optical channel, enabling therefore, an aggregate interconnection capacity of 40 Gb/s between any connected cards. © 1983-2012 IEEE.

Low loss and low crosstalk multimode polymer waveguide crossings for high-speed optical interconnects

Multimode polymer waveguide crossings exhibiting the lowest reported excess loss of 0.006dB/crossing and crosstalk values as low as -30dB are presented. Their potential for use in high-speed dense optical interconnection architectures is demonstrated. © 2007 Optical Society of America.

Sub-nanosecond silicon-on-insulator optical micro-ring switch with low crosstalk

We demonstrate a sub-nanosecond electro-optical switch with low crosstalk in a silicon-on-insulator (SOI) dual-coupled micro-ring embedded with p-i-n diodes. A crosstalk of -23 dB is obtained in the 20-mu m-radius micro-ring with the well-designing asymmetric dual-coupling structure. By optimizations of the doping profiles and the fabrication processes, the sub-nanosecond switch-on/off time of < 400 ps is finally realized under an electrical pre-emphasized driving signal. This compact and fast-response micro-ring switch, which can be fabricated by complementary metal oxide semiconductor (CMOS) compatible technologies, have enormous potential in optical interconnects of multicore networks-on-chip.

THE MATRIX ANALYSIS FOR AN OPTICAL FREE-SPACE SWITCHING NETWORK AND AN OPTICAL CROSSOVER NETWORK WITH 4-FUNCTION INTERCHANGE NODES

A matrix analysis for free-space switching networks, such as perfect shuffle-exchange omega, crossover and Banyan is presented. On the basis of matrix analysis, the equivalence of these three switching networks and the route selection between input and output ports are simply explained. Furthermore, an optical crossover switching network, where MQW SEED arrays are used as electrically addressed four-function interchange nodes, is described and the optical crossover interconnection of 64 x 64, and high-speed four-function, interchange nodes is demonstrated in the experiment.

Recent Progress in Silicon Electro-optic Modulators for High Speed Applications

Silicon-based high-speed electro-optical modulator is the key component of silicon photonics for future communiction and interconnection systems. In this paper, introduced are the optical mudulation mechanisms in silicon, reviewed are some recent progresses in high-speed silicon modulators, and analyzed are advantages and shortages of the silicon modulators of different types.

Integrated MMI optical couplers and optical switches in Silicon-on-insulator technology

Integrated multimode interference coupler based on silicon-on-insulator has been become a kind of more and more attractive device in optical systems. Thin cladding layers (<1.0mum) can be used in SOI waveguide due to the large index step between Si and SiO2, making them compatible with the VLSI technology. Here we demonstrate the design and fabrication of multimode interference (MMI) optical couplers and optical switches in SOI technology.

Synthesis and characterization of PCL/PEG/PCL triblock copolymers by using calcium catalyst

Triblock copolymer PCL-PEG-PCL was prepared by ring-opening polymerization of epsilon-caprolactone (CL) in the presence of poly(ethylene glycol) catalyzed by calcium ammoniate at 60 degreesC in xylene solution. The copolymer composition and triblock structure were confirmed by H-1 NMR and C-13 WR measurements. The differential scanning calorimetry and wide-angle X-ray diffraction analyses revealed the micro-domain structure in the copolymer. The melting temperature T-c and crystallization temperature T-c of the PEG domain were influenced by the relative length of the PCL blocks. This was caused by the strong covalent interconnection between the two domains. Aqueous micelles were prepared from the triblock copolymer. The critical micelle concentration was determined to be 0.4-1.2 mg/l by fluorescence technique using pyrene as probe, depending on the length of PCL blocks, and lower than that of corresponding PCL-PEG diblock copolymers. The H-1 NMR spectrum of the micelles in D2O demonstrated only the -CH2CH2O- signal and thus confirmed. the PCL-core/PEG-shell structure of the micelles.

WIA网络与MODBUS网络互联设计与实现

本文首先介绍了WIA技术和Modbus协议的基本原理和结构,然后详细介绍了互联过程中使用的两种方式:透明传输方式和协议转换方式。分析了两种方式的适用范围和改造难度,并给出了实现案例。

工业无线通信与现场总线集成和互连的研究

近年来快速发展的无线通信技术对工业企业具有极大的吸引力，有助于工业企业降低生产成本、提高生产效率。但在目前阶段，无线通信信道开放和易受干扰、易错的通信特性以及现有的现场总线技术广泛的应用和人力、资金和技术等方面的巨大投入，使得工业无线技术还不可能、也没有必要完全替代现有的有线通信技术。因此，与现有的现场总线等有线通信技术共存和混合使用是当前工业无线通信技术发展和应用的主要方向之一。 工业通信为面向对生产过程监视、控制和管理的自动化系统提供通信服务，具有确定性、硬实时和高可靠性的通信要求。而工业无线通信与有线现场总线的集成和互连会产生一定的问题，影响自动化系统的正常运行。本文针对工业无线通信和有线现场总线集成和互连中存在的互操作和通信性能问题进行了深入的研究，并对WIA-PA和基金会现场总线的集成和互连进行了具体的实现和分析。 本论文首先系统地分析了工业无线通信技术与有线现场总线在工业企业中集成和互连的应用需求，指出了混合现场网段、有线和无线现场网段间、不同层次有线和无线网络的集成和互连是工业无线通信与现场总线混合使用的主要应用方式，并根据工业自动化系统和通信的特点和要求得出互操作和通信性能是集成和互连过程中存在的主要问题。 其次，分析了实现工业无线通信和现场总线集成和互连互操作中的关键问题，即设备、用户应用对象和通信协议各层之间的互操作。提出了以协议转换方式系统实现互操作的理论方法。协议转换可以根据通信协议的异同在不同的通信层次通过协议级、服务级和混合的方式实现，为互操作的实现提供理论和实现基础。 然后，分析了工业无线通信和现场总线集成和互连的通信性能问题，根据自动化系统通信的特点和要求，针对预定周期性通信提出了系统通信调度映射、通信关系和服务转换、资源预留和通信转发和响应方法，对非周期通信提出了优先级及其映射机制、通信关系和服务转换、通信转发和响应以及拥塞控制方法来保证通信的确定、实时和可靠性。 最后，将所提出的方法具体应用于WIA-PA和基金会现场总线的集成和互连，针对通信协议的具体特点，利用通信网关实现了两种协议最高层信息之间的互操作，实现了保证设备间不同通信任务性能的方法，满足了工业自动化系统的要求。

远程数据库访问系统客户／服务器体系结构模型的设计与实现

远程数据库访问（ＲＤＡ）是ＯＳＩ应用层一个特别应用服务元素（ＳＡＳＥ），是数据库基础标准，是构造分布数据库开放式体系结构的基础．本文遵照国际标准ＲＤＡ模型、服务、协议，研究并给出实现ＲＤＡ客户／服务器体系结构模型、方法与系统原型。

总线桥:概念、方法和实现

在基于不同总线标准的个人计算机、工程工作站以及一些工业控制机间建立高速的并行通信通道,将它们构成多机系统,能够以较小的代价获得增强的系统特性.本文引入了一种在系统总线间提供并行数据通道的异种总线互连底板——总线桥的概念,讨论了它的结构和工作原理,提出了其实现方案,并着重描述了为总线桥定义的双向并行通讯协议 BBP(Bus Bridge Prtocol)

Information Processing and Transmission in Cellular Automata

A cellular automaton is an iterative array of very simple identical information processing machines called cells. Each cell can communicate with neighboring cells. At discrete moments of time the cells can change from one state to another as a function of the states of the cell and its neighbors. Thus on a global basis, the collection of cells is characterized by some type of behavior. The goal of this investigation was to determine just how simple the individual cells could be while the global behavior achieved some specified criterion of complexity ??ually the ability to perform a computation or to reproduce some pattern. The chief result described in this thesis is that an array of identical square cells (in two dimensions), each cell of which communicates directly with only its four nearest edge neighbors and each of which can exist in only two states, can perform any computation. This computation proceeds in a straight forward way. A configuration is a specification of the states of all the cells in some area of the iterative array. Another result described in this thesis is the existence of a self-reproducing configuration in an array of four-state cells, a reduction of four states from the previously known eight-state case. The technique of information processing in cellular arrays involves the synthesis of some basic components. Then the desired behaviors are obtained by the interconnection of these components. A chapter on components describes some sets of basic components. Possible applications of the results of this investigation, descriptions of some interesting phenomena (for vanishingly small cells), and suggestions for further study are given later.