WorldWideScience

Sample records for switched optical networks

  1. Optical packet switched networks

    DEFF Research Database (Denmark)

    Hansen, Peter Bukhave

    1999-01-01

    Optical packet switched networks are investigated with emphasis on the performance of the packet switch blocks. Initially, the network context of the optical packet switched network is described showing that a packet network will provide transparency, flexibility and bridge the granularity gap...... in interferometric wavelength converters is investigated showing that a 10 Gbit/s 19 4x4 swich blocks can be cascaded at a BER of 10-14. An analytical traffic model enables the calculation of the traffice performance of a WDM packet network. Hereby the importance of WDM and wavelegth conversion in the switch blocks...... is established as a flexible means to reduce the optical buffer, e.g., the number of fibre delay lines for a 16x16 switch block is reduced from 23 to 6 by going from 2 to 8 wavelength channels pr. inlet. Additionally, a component count analysis is carried out to illustrate the trade-offs in the switch block...

  2. Circuit switched optical networks

    DEFF Research Database (Denmark)

    Kloch, Allan

    2003-01-01

    Some of the most important components required for enabling optical networking are investigated through both experiments and modelling. These all-optical components are the wavelength converter, the regenerator and the space switch. When these devices become "off-the-shelf" products, optical cross......, it is expected that the optical solution will offer an economical benefit for hight bit rate networks. This thesis begins with a discussion of the expected impact on communications systems from the rapidly growing IP traffic, which is expected to become the dominant source for traffic. IP traffic has some...... characteristics, which are best supported by an optical network. The interest for such an optical network is exemplified by the formation of the ACTS OPEN project which aim was to investigate the feasibility of an optical network covering Europe. Part of the work presented in this thesis is carried out within...

  3. Optical computer switching network

    Science.gov (United States)

    Clymer, B.; Collins, S. A., Jr.

    1985-01-01

    The design for an optical switching system for minicomputers that uses an optical spatial light modulator such as a Hughes liquid crystal light valve is presented. The switching system is designed to connect 80 minicomputers coupled to the switching system by optical fibers. The system has two major parts: the connection system that connects the data lines by which the computers communicate via a two-dimensional optical matrix array and the control system that controls which computers are connected. The basic system, the matrix-based connecting system, and some of the optical components to be used are described. Finally, the details of the control system are given and illustrated with a discussion of timing.

  4. Optical Multidimensional Switching for Data Center Networks

    OpenAIRE

    Kamchevska, Valerija; Galili, Michael; Oxenløwe, Leif Katsuo; Berger, Michael Stübert

    2017-01-01

    Optical switches are known for the ability to provide high bandwidth connectivity at a relatively low power consumption and low latency. Several recent demonstrations on optical data center architectures confirm the potential for introducing all-optical switching within the data center, thus avoiding power hungry optical-electrical-optical conversions at each node. This Ph.D. thesis focuses precisely on the application of optical technologies in data center networks where optics is not only u...

  5. Optical Multidimensional Switching for Data Center Networks

    DEFF Research Database (Denmark)

    Kamchevska, Valerija

    2017-01-01

    . Software controlled switching using an on-chip integrated fiber switch is demonstrated and enabling of additional network functionalities such as multicast and optical grooming is experimentally confirmed. Altogether this work demonstrates the potential of optical switching technologies...... for the purpose of deploying optical switching within the network. First, the Hi-Ring data center architecture is proposed. It is based on optical multidimensional switching nodes that provide switching in hierarchically layered space, wavelength and time domain. The performance of the Hi-Ring architecture...... is evaluated experimentally and successful switching of both high capacity wavelength connections and time-shared subwavelengthconnections is demonstrated. Error-free performance is also achieved when transmitting 7 Tbit/s using multicore fiber, confirming the ability to scale the network. Moreover...

  6. All-optical signal processing for optical packet switching networks

    NARCIS (Netherlands)

    Liu, Y.; Hill, M.T.; Calabretta, N.; Tangdiongga, E.; Geldenhuys, R.; Zhang, S.; Li, Z.; Waardt, de H.; Khoe, G.D.; Dorren, H.J.S.; Iftekharuddin, K.M.; awwal, A.A.S.

    2005-01-01

    We discuss how all-optical signal processing might play a role in future all-optical packet switched networks. We introduce a concept of optical packet switches that employ entirely all-optical signal processing technology. The optical packet switch is made out of three functional blocks: the

  7. Optical burst switching based satellite backbone network

    Science.gov (United States)

    Li, Tingting; Guo, Hongxiang; Wang, Cen; Wu, Jian

    2018-02-01

    We propose a novel time slot based optical burst switching (OBS) architecture for GEO/LEO based satellite backbone network. This architecture can provide high speed data transmission rate and high switching capacity . Furthermore, we design the control plane of this optical satellite backbone network. The software defined network (SDN) and network slice (NS) technologies are introduced. Under the properly designed control mechanism, this backbone network is flexible to support various services with diverse transmission requirements. Additionally, the LEO access and handoff management in this network is also discussed.

  8. Node design in optical packet switched networks

    DEFF Research Database (Denmark)

    Nord, Martin

    2006-01-01

    The thesis discusses motivation, realisation and performance of the Optical Packet Switching (OPS) network paradigm. The work includes proposals for designs and methods to efficiently use both the wavelength- and time domain for contention resolution in asynchronous operation. The project has also......S parameter. Finally, the thesis includes a proposal for a node design and associated MAC protocol for an OPS ring topology metropolitan area network with high throughput and fairness, also for unbalanced traffic....... proposed parallel designs to overcome scalability constraints and to support migration scenarios. Furthermore, it has proposed and demonstrated optical input processing schemes for hybrids networks to simultaneously support OPS and Optical Circuit Switching. Quality of Service (QoS) differentiation enables...

  9. Analyses of resource reservation schemes for optical burst switching networks

    Science.gov (United States)

    Solanska, Michaela; Scholtz, Lubomir; Ladanyi, Libor; Mullerova, Jarmila

    2017-12-01

    With growing demands of Internet Protocol services for transmission capacity and speed, the Optical Burst Switching presents the solution for future high-speed optical networks. Optical Burst Switching is a technology for transmitting large amounts of data bursts through a transparent optical switching network. To successfully transmit bursts over OBS network and reach the destination node, resource reservation schemes have to be implemented to allocate resources and configure optical switches for that burst at each node. The one-way resource reservation schemes and the performance evaluation of reservation schemes are presented. The OBS network model is performed using OMNeT++ simulation environment. During the reservation of network resources, the optical cross-connect based on semiconductor optical amplifier is used as the core node. Optical switches based on semiconductor optical amplifiers are a promising technology for high-speed optical communication networks.

  10. Quality of service in optical packet switched networks

    CERN Document Server

    Rahbar, Akbar G

    2015-01-01

    This book is a comprehensive study on OPS networks, its architectures, and developed techniques for improving its quality of switching and managing quality of service.  The book includes: Introduction to OPS networks, OOFDM networks, GMPLS-enabled optical networks, QoS in OPS networks Hybrid contention avoidance/resolution schemes in both long-haul and metro optical networks Hybrid optical switching schemes

  11. Error rate degradation due to switch crosstalk in large modular switched optical networks

    DEFF Research Database (Denmark)

    Saxtoft, Christian; Chidgey, P.

    1993-01-01

    A theoretical model of an optical network incorporating wavelength selective elements, amplifiers, couplers and switches is presented. The model is used to evaluate a large modular switch optical network that provides the capability of adapting easily to changes in network traffic requirements. T....... The network dimensions are shown to be limited by the optical crosstalk in the switch matrices and by the polarization dependent loss in the optical components...

  12. Software Defined Networking (SDN) controlled all optical switching networks with multi-dimensional switching architecture

    Science.gov (United States)

    Zhao, Yongli; Ji, Yuefeng; Zhang, Jie; Li, Hui; Xiong, Qianjin; Qiu, Shaofeng

    2014-08-01

    Ultrahigh throughout capacity requirement is challenging the current optical switching nodes with the fast development of data center networks. Pbit/s level all optical switching networks need to be deployed soon, which will cause the high complexity of node architecture. How to control the future network and node equipment together will become a new problem. An enhanced Software Defined Networking (eSDN) control architecture is proposed in the paper, which consists of Provider NOX (P-NOX) and Node NOX (N-NOX). With the cooperation of P-NOX and N-NOX, the flexible control of the entire network can be achieved. All optical switching network testbed has been experimentally demonstrated with efficient control of enhanced Software Defined Networking (eSDN). Pbit/s level all optical switching nodes in the testbed are implemented based on multi-dimensional switching architecture, i.e. multi-level and multi-planar. Due to the space and cost limitation, each optical switching node is only equipped with four input line boxes and four output line boxes respectively. Experimental results are given to verify the performance of our proposed control and switching architecture.

  13. Self-Management of Hybrid Optical and Packet Switching Networks

    NARCIS (Netherlands)

    Fioreze, Tiago; Pras, Aiko

    Hybrid optical and packet switching networks enable data to be forwarded at multiple levels. Large IP flows at the IP level may be therefore moved to the optical level bypassing the per hop routing decisions of the IP level. Such move could be beneficial since congested IP networks could be

  14. Self-Management of Hybrid Optical and Packet Switching Networks

    NARCIS (Netherlands)

    Fioreze, Tiago

    2010-01-01

    Hybrid optical and packet switching networks are composed of multi-service hybrid devices that enable forwarding of data at multiple levels. Large IP flows at the IP level may be therefore moved to the optical level bypassing therefore the per hop routing decisions of the IP level. Such move could

  15. Architectures of electro-optical packet switched networks

    DEFF Research Database (Denmark)

    Berger, Michael Stubert

    2004-01-01

    and examines possible architectures for future high capacity networks with high capacity nodes. It is assumed that optics will play a key role in this scenario, and in this respect, the European IST research project DAVID aimed at proposing viable architectures for optical packet switching, exploiting the best...... from optics and electronics. An overview of the DAVID network architecture is given, focusing on the MAN and WAN architecture as well as the MPLS based network hierarchy. A statistical model of the optical slot generation process is presented and utilised to evaluate delay vs. efficiency. Furthermore...... architecture for a buffered crossbar switch is presented. The architecture uses two levels of backpressure (flow control) with different constraints on round trip time. No additional scheduling complexity is introduced, and for the actual example shown, a reduction in memory of 75% was obtained at the cost...

  16. Traffic analysis and signal processing in optical packet switched networks

    DEFF Research Database (Denmark)

    Fjelde, Tina

    2002-01-01

    /s optical packet switched network exploiting the best of optics and electronics, is used as a thread throughout the thesis. An overview of the DAVID network architecture is given, focussing on the MAN and WAN architecture as well as the MPLS-based network hierarchy. Subsequently, the traffic performance...... of the DAVID core optical packet router, which exploits wavelength conversion and fibre delay-line buffers for contention resolution, is analysed using a numerical model developed for that purpose. The robustness of the shared recirculating loop buffer with respect to´bursty traffic is demonstrated...... the injection of an additional clock signal into the IWC is presented. Results show very good transmission capabilities combined with a high-speed response. It is argued that signal regeneration is an inherent attribute of the IWC employed as a wavelength converter due to the sinusoidal transfer function...

  17. Quantum key based burst confidentiality in optical burst switched networks.

    Science.gov (United States)

    Balamurugan, A M; Sivasubramanian, A

    2014-01-01

    The optical burst switching (OBS) is an emergent result to the technology concern that could achieve a feasible network in future. They are endowed with the ability to meet the bandwidth requirement of those applications that require intensive bandwidth. There are more domains opening up in the OBS that evidently shows their advantages and their capability to face the future network traffic. However, the concept of OBS is still far from perfection facing issues in case of security threat. The transfer of optical switching paradigm to optical burst switching faces serious downfall in the fields of burst aggregation, routing, authentication, dispute resolution, and quality of service (QoS). This paper deals with employing RC4 (stream cipher) to encrypt and decrypt bursts thereby ensuring the confidentiality of the burst. Although the use of AES algorithm has already been proposed for the same issue, by contrasting the two algorithms under the parameters of burst encryption and decryption time, end-to-end delay, it was found that RC4 provided better results. This paper looks to provide a better solution for the confidentiality of the burst in OBS networks.

  18. Quantum Key Based Burst Confidentiality in Optical Burst Switched Networks

    Directory of Open Access Journals (Sweden)

    A. M. Balamurugan

    2014-01-01

    Full Text Available The optical burst switching (OBS is an emergent result to the technology concern that could achieve a feasible network in future. They are endowed with the ability to meet the bandwidth requirement of those applications that require intensive bandwidth. There are more domains opening up in the OBS that evidently shows their advantages and their capability to face the future network traffic. However, the concept of OBS is still far from perfection facing issues in case of security threat. The transfer of optical switching paradigm to optical burst switching faces serious downfall in the fields of burst aggregation, routing, authentication, dispute resolution, and quality of service (QoS. This paper deals with employing RC4 (stream cipher to encrypt and decrypt bursts thereby ensuring the confidentiality of the burst. Although the use of AES algorithm has already been proposed for the same issue, by contrasting the two algorithms under the parameters of burst encryption and decryption time, end-to-end delay, it was found that RC4 provided better results. This paper looks to provide a better solution for the confidentiality of the burst in OBS networks.

  19. Scalable Active Optical Access Network Using Variable High-Speed PLZT Optical Switch/Splitter

    Science.gov (United States)

    Ashizawa, Kunitaka; Sato, Takehiro; Tokuhashi, Kazumasa; Ishii, Daisuke; Okamoto, Satoru; Yamanaka, Naoaki; Oki, Eiji

    This paper proposes a scalable active optical access network using high-speed Plumbum Lanthanum Zirconate Titanate (PLZT) optical switch/splitter. The Active Optical Network, called ActiON, using PLZT switching technology has been presented to increase the number of subscribers and the maximum transmission distance, compared to the Passive Optical Network (PON). ActiON supports the multicast slot allocation realized by running the PLZT switch elements in the splitter mode, which forces the switch to behave as an optical splitter. However, the previous ActiON creates a tradeoff between the network scalability and the power loss experienced by the optical signal to each user. It does not use the optical power efficiently because the optical power is simply divided into 0.5 to 0.5 without considering transmission distance from OLT to each ONU. The proposed network adopts PLZT switch elements in the variable splitter mode, which controls the split ratio of the optical power considering the transmission distance from OLT to each ONU, in addition to PLZT switch elements in existing two modes, the switching mode and the splitter mode. The proposed network introduces the flexible multicast slot allocation according to the transmission distance from OLT to each user and the number of required users using three modes, while keeping the advantages of ActiON, which are to support scalable and secure access services. Numerical results show that the proposed network dramatically reduces the required number of slots and supports high bandwidth efficiency services and extends the coverage of access network, compared to the previous ActiON, and the required computation time for selecting multicast users is less than 30msec, which is acceptable for on-demand broadcast services.

  20. Hybrid Wavelength Routed and Optical Packet Switched Ring Networks for the Metropolitan Area Network

    DEFF Research Database (Denmark)

    Nord, Martin

    2005-01-01

    Increased data traffic in the metropolitan area network calls for new network architectures. This paper evaluates optical ring architectures based on optical packet switching, wavelength routing, and hybrid combinations of the two concepts. The evaluation includes overall throughput and fairness...... attractive when traffic is unbalanced....

  1. Optical Switching for Dynamic Distribution of Wireless-Over-Fiber Signals in Active Optical Networks

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Rodes, Guillermo; Tafur Monroy, Idelfonso

    2012-01-01

    In this paper, we report on an experimental validation of dynamic distribution of wireless-over-fiber by employing optical switching using semiconductor optical amplifiers; we also provide a channel distribution scheme and a generic topology for such an optical switch. The experiment consists...... of a four wavelength-division-multiplexed channel system operating on a WiMax frequency band and employing an orthogonal-frequency-division-multiplexing modulation at 625 Mbits/s per channel, transmission of the data over 20 km of optical fiber, and active switching in a 1 × 16 active optical switch....... The results show a negligible power penalty on each channel for both the best and the worst case in terms of inter-channel crosstalk. The presented system is highly scalable both in terms of port count and throughput, a desirable feature in highly branched access networks, and is modulation- and frequency...

  2. Novel approach for all-optical packet switching in wide-area networks

    Science.gov (United States)

    Chlamtac, Imrich; Fumagalli, Andrea F.; Wedzinga, Gosse

    1998-09-01

    All-optical Wavelength Division Multiplexing (WDM) networks are believed to be a fundamental component in future high speed backbones. However, while wavelength routing made circuit switching in WDM feasible the reality of extant optical technology does not yet provide the necessary devices to achieve individual optical packet switching. This paper proposes to achieve all-optical packet switching in WDM Wide Area Networks (WANs) via a novel technique, called slot routing. Using slot routing, entire slots, each carrying multiple packets on distinct wavelengths, are switched transparently and individually. As a result packets can be optically transmitted and switched in the network using available fast and wavelength non-sensitive devices. The proposed routing technique leads to an optical packet switching solution, that is simple, practical, and unique as it makes it possible to build a WDM all-optical WAN with optical devices based on proven technologies.

  3. Supporting differentiated quality of service in optical burst switched networks

    Science.gov (United States)

    Zhou, Bin; Bassiouni, Mostafa A.

    2006-01-01

    We propose and evaluate two new schemes for providing differentiated services in optical burst switched (OBS) networks. The two new schemes are suitable for implementation in OBS networks using just-in-time (JIT) or just-enough-time (JET) scheduling protocols. The first scheme adjusts the size of the search space for a free wavelength based on the priority level of the burst. A simple equation is used to divide the search spectrum into two parts: a base part and an adjustable part. The size of the adjustable part increases as the priority of the burst becomes higher. The scheme is very easy to implement and does not demand any major software or hardware resources in optical cross-connects. The second scheme reduces the dropping probability of bursts with higher priorities through the use of different proactive discarding rates in the network access station (NAS) of the source node. Our extensive simulation tests using JIT show that both schemes are capable of providing tangible quality of service (QoS) differentiation without negatively impacting the throughput of OBS networks.

  4. Optical switching systems using nanostructures

    DEFF Research Database (Denmark)

    Stubkjær, Kristian

    2004-01-01

    High capacity multiservice optical networks require compact and efficient switches. The potential benefits of optical switch elements based on nanostructured material are reviewed considering various material systems.......High capacity multiservice optical networks require compact and efficient switches. The potential benefits of optical switch elements based on nanostructured material are reviewed considering various material systems....

  5. QKD-Based Secured Burst Integrity Design for Optical Burst Switched Networks

    Science.gov (United States)

    Balamurugan, A. M.; Sivasubramanian, A.; Parvathavarthini, B.

    2016-03-01

    The field of optical transmission has undergone numerous advancements and is still being researched mainly due to the fact that optical data transmission can be done at enormous speeds. It is quite evident that people prefer optical communication when it comes to large amount of data involving its transmission. The concept of switching in networks has matured enormously with several researches, architecture to implement and methods starting with Optical circuit switching to Optical Burst Switching. Optical burst switching is regarded as viable solution for switching bursts over networks but has several security vulnerabilities. However, this work exploited the security issues associated with Optical Burst Switching with respect to integrity of burst. This proposed Quantum Key based Secure Hash Algorithm (QKBSHA-512) with enhanced compression function design provides better avalanche effect over the conventional integrity algorithms.

  6. Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system

    NARCIS (Netherlands)

    Miao, W.; Luo, J.; Di Lucente, S.; Dorren, H.J.S.; Calabretta, N.

    2013-01-01

    We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. 4×4 dynamic switch operation at 40 Gb/s reported 300ns minimum end-to-end latency (including 25m transmission link) and

  7. A novel implementation of TCP Vegas for optical burst switched networks

    KAUST Repository

    Shihada, Basem; Zhang, Qiong; Ho, Pin-Han; Jue, Jason P.

    2010-01-01

    TCP performance over bufferless Optical Burst Switched (OBS) networks could be significantly degraded due to the misinterpretation of network congestion status (referred to as false congestion detection). It has been reported that burst

  8. FAST TCP over optical burst switched networks: Modeling and stability analysis

    KAUST Repository

    Shihada, Basem; El-Ferik, Sami; Ho, Pin-Han

    2013-01-01

    congestion-control mechanism in bufferless Optical Burst Switched Networks (OBS). The paper first shows that random burst contentions are essential to stabilize the network, but cause throughput degradation in FAST TCP flows when a burst with all the packets

  9. Performance of highly connected photonic switching lossless metro-access optical networks

    Science.gov (United States)

    Martins, Indayara Bertoldi; Martins, Yara; Barbosa, Felipe Rudge

    2018-03-01

    The present work analyzes the performance of photonic switching networks, optical packet switching (OPS) and optical burst switching (OBS), in mesh topology of different sizes and configurations. The "lossless" photonic switching node is based on a semiconductor optical amplifier, demonstrated and validated with experimental results on optical power gain, noise figure, and spectral range. The network performance was evaluated through computer simulations based on parameters such as average number of hops, optical packet loss fraction, and optical transport delay (Am). The combination of these elements leads to a consistent account of performance, in terms of network traffic and packet delivery for OPS and OBS metropolitan networks. Results show that a combination of highly connected mesh topologies having an ingress e-buffer present high efficiency and throughput, with very low packet loss and low latency, ensuring fast data delivery to the final receiver.

  10. Energy efficiency benefits of introducing optical switching in Data Center Networks

    DEFF Research Database (Denmark)

    Pilimon, Artur; Zeimpeki, Alexandra; Fagertun, Anna Manolova

    2017-01-01

    layers of the network topology. The analysis is based on network-level simulations using a transport network planning tool applied to small-scale setups of the considered DCNs. The obtained results show that introducing all-optical switching within the DCN leads to reduced power consumption in all......In this paper we analyze the impact of WDM-enhanced optical circuit switching on the power consumption of multiple Data Center Network (DCN) architectures. Traditional three-tier Tree, Fat-Tree and a ring-based structure are evaluated and optical switching is selectively introduced on different...... an optically switched core benefits most the ring-based network. For the latter, the core ring nodes need fewer long-reach transponders at the trunk interfaces and benefit from more efficient traffic grooming in the access part....

  11. Optical slotted circuit switched network: a bandwidth efficient alternative to wavelength-routed network

    Science.gov (United States)

    Li, Yan; Collier, Martin

    2007-11-01

    Wavelength-routed networks have received enormous attention due to the fact that they are relatively simple to implement and implicitly offer Quality of Service (QoS) guarantees. However, they suffer from a bandwidth inefficiency problem and require complex Routing and Wavelength Assignment (RWA). Most attempts to address the above issues exploit the joint use of WDM and TDM technologies. The resultant TDM-based wavelength-routed networks partition the wavelength bandwidth into fixed-length time slots organized as a fixed-length frame. Multiple connections can thus time-share a wavelength and the grooming of their traffic leads to better bandwidth utilization. The capability of switching in both wavelength and time domains in such networks also mitigates the RWA problem. However, TMD-based wavelength-routed networks work in synchronous mode and strict synchronization among all network nodes is required. Global synchronization for all-optical networks which operate at extremely high speed is technically challenging, and deploying an optical synchronizer for each wavelength involves considerable cost. An Optical Slotted Circuit Switching (OSCS) architecture is proposed in this paper. In an OSCS network, slotted circuits are created to better utilize the wavelength bandwidth than in classic wavelength-routed networks. The operation of the protocol is such as to avoid the need for global synchronization required by TDM-based wavelength-routed networks.

  12. Monolithic InP-based fast optical switch module for optical networks of the future

    DEFF Research Database (Denmark)

    Xi, Chen; Regan, James; Durrant, Tim

    2015-01-01

    We summarized the development of Venture Photonics’ sub-10 ns fast optical switch which demonstrates low insertion loss, excellent crosstalk level and polarization independent switching performance.......We summarized the development of Venture Photonics’ sub-10 ns fast optical switch which demonstrates low insertion loss, excellent crosstalk level and polarization independent switching performance....

  13. 40 Gbit/s NRZ Packet-Length Insensitive Header Extraction for Optical Label Switching Networks

    DEFF Research Database (Denmark)

    Seoane, Jorge; Kehayas, E; Avramopoulos, H.

    2006-01-01

    A simple method for 40 Gbit/s NRZ header extraction based on envelope detection for optical label switching networks is presented. The scheme is insensitive to packet length and spacing and can be single-chip integrated cost-effectively......A simple method for 40 Gbit/s NRZ header extraction based on envelope detection for optical label switching networks is presented. The scheme is insensitive to packet length and spacing and can be single-chip integrated cost-effectively...

  14. Optically triggered high voltage switch network and method for switching a high voltage

    Science.gov (United States)

    El-Sharkawi, Mohamed A.; Andexler, George; Silberkleit, Lee I.

    1993-01-19

    An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

  15. Optically triggered high voltage switch network and method for switching a high voltage

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawi, Mohamed A. (Renton, WA); Andexler, George (Everett, WA); Silberkleit, Lee I. (Mountlake Terrace, WA)

    1993-01-19

    An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

  16. The Swiss Education and Research Network - SWITCH - Upgrades Optical Network to Transport 10 Gbps Using Sorrento Networks DWDM Platform

    CERN Multimedia

    2003-01-01

    "Sorrento Networks, a supplier of optical transport networking equipment for carriers and enterprises worldwide, today announced that SWITCH successfully completed 10 Gbps BER tests on the 220 km Zurich to Manno and 360 km Zurich to Geneva links in September and November 2003, using Sorrento's GigaMux DWDM system" (1/2 page).

  17. A cross-stacked plasmonic nanowire network for high-contrast femtosecond optical switching.

    Science.gov (United States)

    Lin, Yuanhai; Zhang, Xinping; Fang, Xiaohui; Liang, Shuyan

    2016-01-21

    We report an ultrafast optical switching device constructed by stacking two layers of gold nanowires into a perpendicularly crossed network, which works at a speed faster than 280 fs with an on/off modulation depth of about 22.4%. The two stacks play different roles in enhancing consistently the optical switching performance due to their different dependence on the polarization of optical electric fields. The cross-plasmon resonance based on the interaction between the perpendicularly stacked gold nanowires and its Fano-coupling with Rayleigh anomaly is the dominant mechanism for such a high-contrast optical switching device.

  18. Six-port optical switch for cluster-mesh photonic network-on-chip

    Science.gov (United States)

    Jia, Hao; Zhou, Ting; Zhao, Yunchou; Xia, Yuhao; Dai, Jincheng; Zhang, Lei; Ding, Jianfeng; Fu, Xin; Yang, Lin

    2018-05-01

    Photonic network-on-chip for high-performance multi-core processors has attracted substantial interest in recent years as it offers a systematic method to meet the demand of large bandwidth, low latency and low power dissipation. In this paper we demonstrate a non-blocking six-port optical switch for cluster-mesh photonic network-on-chip. The architecture is constructed by substituting three optical switching units of typical Spanke-Benes network to optical waveguide crossings. Compared with Spanke-Benes network, the number of optical switching units is reduced by 20%, while the connectivity of routing path is maintained. By this way the footprint and power consumption can be reduced at the expense of sacrificing the network latency performance in some cases. The device is realized by 12 thermally tuned silicon Mach-Zehnder optical switching units. Its theoretical spectral responses are evaluated by establishing a numerical model. The experimental spectral responses are also characterized, which indicates that the optical signal-to-noise ratios of the optical switch are larger than 13.5 dB in the wavelength range from 1525 nm to 1565 nm. Data transmission experiment with the data rate of 32 Gbps is implemented for each optical link.

  19. Compound semiconductor optical waveguide switch

    Science.gov (United States)

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  20. Synchronization in a Random Length Ring Network for SDN-Controlled Optical TDM Switching

    DEFF Research Database (Denmark)

    Kamchevska, Valerija; Cristofori, Valentina; Da Ros, Francesco

    2016-01-01

    . In addition, we propose a novel synchronization algorithm that enables automatic synchronization of software defined networking controlled all-optical TDM switching nodes connected in a ring network. Besides providing synchronization, the algorithm also can facilitate dynamic slot size change and failure......In this paper we focus on optical time division multiplexed (TDM) switching and its main distinguishing characteristics compared with other optical subwavelength switching technologies. We review and discuss in detail the synchronization requirements that allow for proper switching operation...... detection. We experimentally validate the algorithm behavior and achieve correct operation for three different ring lengths. Moreover, we experimentally demonstrate data plane connectivity in a ring network composed of three nodes and show successful wavelength division multiplexing space division...

  1. Burst switched optical networks supporting legacy and future service types

    DEFF Research Database (Denmark)

    Franzl, Gerald; Hayat, Faisal; Holynski, Tomasz

    2011-01-01

    Focusing on the principles and the paradigm of OBS an overview addressing expectable performance and application issues is presented. Proposals on OBS were published over a decade and the presented techniques spread into many directions. The paper comprises discussions of several challenges that ...... and found capable to overcome shortcomings of recent proposals. In conclusion, an OBS that offers different connection types may support most client demands within a sole optical network layer....

  2. Feasibility of Optical Packet Switched WDM Networks without Packet Synchronisation Under Bursty Traffic Conditions

    DEFF Research Database (Denmark)

    Fjelde, Tina; Hansen, Peter Bukhave; Kloch, Allan

    1999-01-01

    We show that complex packet synchronisation may be avoided in optical packetswitched networks. Detailed traffic analysis demonstrates that packet lossratios of 1e-10 are feasible under bursty traffic conditions for a highcapacity network consisting of asynchronously operated add-drop switch...

  3. All-optical header recognizer for optical packet switched networks : exploiting nonlinear gain and index dynamics in semiconductor optical amplifiers for low power operation and photonic integration device

    NARCIS (Netherlands)

    Calabretta, N.; Dorren, H.J.S.

    2009-01-01

    The increase of the internet traffic leads to future optical networks requiring tens of Tb/s of capacity. Current electronic circuit switches are limited by the scalability of the electronic switching fabrics, power consumption and dissipation in the opto- electronic conversion. All-optical packet

  4. High performance SDN enabled flat data center network architecture based on scalable and flow-controlled optical switching system

    NARCIS (Netherlands)

    Calabretta, N.; Miao, W.; Dorren, H.J.S.

    2015-01-01

    We demonstrate a reconfigurable virtual datacenter network by utilizing statistical multiplexing offered by scalable and flow-controlled optical switching system. Results show QoS guarantees by the priority assignment and load balancing for applications in virtual networks.

  5. Fuzzy-Based Adaptive Hybrid Burst Assembly Technique for Optical Burst Switched Networks

    Directory of Open Access Journals (Sweden)

    Abubakar Muhammad Umaru

    2014-01-01

    Full Text Available The optical burst switching (OBS paradigm is perceived as an intermediate switching technology for future all-optical networks. Burst assembly that is the first process in OBS is the focus of this paper. In this paper, an intelligent hybrid burst assembly algorithm that is based on fuzzy logic is proposed. The new algorithm is evaluated against the traditional hybrid burst assembly algorithm and the fuzzy adaptive threshold (FAT burst assembly algorithm via simulation. Simulation results show that the proposed algorithm outperforms the hybrid and the FAT algorithms in terms of burst end-to-end delay, packet end-to-end delay, and packet loss ratio.

  6. Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system.

    Science.gov (United States)

    Miao, Wang; Luo, Jun; Di Lucente, Stefano; Dorren, Harm; Calabretta, Nicola

    2014-02-10

    We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. Modular structure with distributed control results in port-count independent optical switch reconfiguration time. RF tone in-band labeling technique allowing parallel processing of the label bits ensures the low latency operation regardless of the switch port-count. Hardware flow control is conducted at optical level by re-using the label wavelength without occupying extra bandwidth, space, and network resources which further improves the performance of latency within a simple structure. Dynamic switching including multicasting operation is validated for a 4 x 4 system. Error free operation of 40 Gb/s data packets has been achieved with only 1 dB penalty. The system could handle an input load up to 0.5 providing a packet loss lower that 10(-5) and an average latency less that 500 ns when a buffer size of 16 packets is employed. Investigation on scalability also indicates that the proposed system could potentially scale up to large port count with limited power penalty.

  7. Efficient IP Traffic over Optical Network Based on Wavelength Translation Switching

    DEFF Research Database (Denmark)

    Jha, Vikas; Kalia, Kartik; Chowdhary, Bhawani Shankar

    2016-01-01

    With the advent of TCP/IP protocol suite the overall era of communication technologies had been redefined. Now, we can’t ignore the presence of huge amount of IP traffic; data, voice or video increasing day by day creating more pressure on existing communicating media and supporting back bone....... With the humongous popularity of Internet the overall traffic on Internet has the same story. Focusing on transmission of IP traffic in an optical network with signals remaining in their optical nature generated at particular wavelength, proposed is the switching of optically generated IP packets through optical...... cross connects based on translation of wavelength when an IP packet is crossing the optical cross connect. Adding the concepts of layer 3 routing protocols along with the wavelength translation scheme, will help in spanning the overall optical network for a larger area....

  8. An analytical approach to optical burst switched networks

    CERN Document Server

    Venkatesh, T

    2010-01-01

    This book presents the latest results on modeling and analysis of OBS networks. It classifies all the literature on the topic, and its scope extends to include discussion of high-speed communication networks with limited or no buffers.

  9. Switch configuration for migration to optical fiber network

    Science.gov (United States)

    Zobrist, George W.

    1993-01-01

    The purpose is to investigate the migration of an Ethernet LAN segment to fiber optics. At the present time it is proposed to support a Fiber Distributed Data Interface (FDDI) backbone and to upgrade the VAX cluster to fiber optic interface. Possibly some workstations will have an FDDI interface. The remaining stations on the Ethernet LAN will be segmented. The rationale for migrating from the present Ethernet configuration to a fiber optic backbone is due to the increase in the number of workstations and the movement of applications to a windowing environment, extensive document transfers, and compute intensive applications.

  10. Latching micro optical switch

    Science.gov (United States)

    Garcia, Ernest J; Polosky, Marc A

    2013-05-21

    An optical switch reliably maintains its on or off state even when subjected to environments where the switch is bumped or otherwise moved. In addition, the optical switch maintains its on or off state indefinitely without requiring external power. External power is used only to transition the switch from one state to the other. The optical switch is configured with a fixed optical fiber and a movable optical fiber. The movable optical fiber is guided by various actuators in conjunction with a latching mechanism that configure the switch in one position that corresponds to the on state and in another position that corresponds to the off state.

  11. Method to optimize optical switch topology for photonic network-on-chip

    Science.gov (United States)

    Zhou, Ting; Jia, Hao

    2018-04-01

    In this paper, we propose a method to optimize the optical switch by substituting optical waveguide crossings for optical switching units and an optimizing algorithm to complete the optimization automatically. The functionality of the optical switch remains constant under optimization. With this method, we simplify the topology of optical switch, which means the insertion loss and power consumption of the whole optical switch can be effectively minimized. Simulation result shows that the number of switching units of the optical switch based on Spanke-Benes can be reduced by 16.7%, 20%, 20%, 19% and 17.9% for the scale from 4 × 4 to 8 × 8 respectively. As a proof of concept, the experimental demonstration of an optimized six-port optical switch based on Spanke-Benes structure by means of silicon photonics chip is reported.

  12. Burst switching without guard interval in all-optical software-define star intra-data center network

    Science.gov (United States)

    Ji, Philip N.; Wang, Ting

    2014-02-01

    Optical switching has been introduced in intra-data center networks (DCNs) to increase capacity and to reduce power consumption. Recently we proposed a star MIMO OFDM-based all-optical DCN with burst switching and software-defined networking. Here, we introduce the control procedure for the star DCN in detail for the first time. The timing, signaling, and operation are described for each step to achieve efficient bandwidth resource utilization. Furthermore, the guidelines for the burst assembling period selection that allows burst switching without guard interval are discussed. The star all-optical DCN offers flexible and efficient control for next-generation data center application.

  13. Synchronization Algorithm for SDN-controlled All-Optical TDM Switching in a Random Length Ring Network

    DEFF Research Database (Denmark)

    Kamchevska, Valerija; Cristofori, Valentina; Da Ros, Francesco

    2016-01-01

    We propose and demonstrate an algorithm that allows for automatic synchronization of SDN-controlled all-optical TDM switching nodes connected in a ring network. We experimentally show successful WDM-SDM transmission of data bursts between all ring nodes.......We propose and demonstrate an algorithm that allows for automatic synchronization of SDN-controlled all-optical TDM switching nodes connected in a ring network. We experimentally show successful WDM-SDM transmission of data bursts between all ring nodes....

  14. Impact of Bimodal Traffic on Latency in Optical Burst Switching Networks

    Directory of Open Access Journals (Sweden)

    Yuhua Chen

    2008-01-01

    Full Text Available This paper analyzes the impact of bimodal traffic composition on latency in optical burst switching networks. In particular, it studies the performance degradation to short-length packets caused by longer packets, both of which are part of a heterogeneous traffic model. The paper defines a customer satisfaction index for each of the classes of traffic, and a composite satisfaction index. The impact of higher overall utilization of the network as well as that of the ratio of the traffic mix on each of the customer satisfaction indices is specifically addressed.

  15. High optical label switching add-drop multiplexer nodes with nanoseconds latency for 5G metro/access networks

    NARCIS (Netherlands)

    Calabretta, N.; Miao, W.; De Waardt, H.

    2016-01-01

    We present a novel optical add-drop multiplexer for next-generation metro/access networks by exploiting optical label switching technology. Experimental results of a ring network show nanoseconds add/drop operation including multicasting and power equalization of 50Gb/s data.

  16. All-fiber optical mode switching based on cascaded mode selective couplers for short-reach MDM networks

    Science.gov (United States)

    Ren, Fang; Li, Juhao; Wu, Zhongying; Yu, Jinyi; Mo, Qi; Wang, Jianping; He, Yongqi; Chen, Zhangyuan; Li, Zhengbin

    2017-04-01

    We propose and experimentally demonstrate an all-fiber optical mode switching structure supporting independent switching, exchanging, adding, and dropping functionalities in which each mode can be switched individually. The mode switching structure consists of cascaded mode selective couplers (MSCs) capable of exciting and selecting specific higher order modes in few-mode fibers with high efficiency and one multiport optical switch routing the independent spatial modes to their destinations. The data carried on three different spatial modes can be switched, exchanged, added, and dropped through this all-fiber structure. For this experimental demonstration, optical on-off-keying (OOK) signals at 10-Gb/s carried on three spatial modes are successfully processed with open and clear eye diagrams. The mode switch exhibits power penalties of less than 3.1 dB after through operation, less than 2.7 dB after exchange operation, less than 2.8 dB after switching operation, and less than 1.6 dB after mode adding and dropping operations at the bit-error rate (BER) of 10-3, while all three channels carried on three spatial modes are simultaneously routed. The proposed structure, compatible with current optical switching networks based on single-mode fibers, can potentially be used to expand the switching scalability in advanced and flexible short-reach mode-division multiplexing-based networks.

  17. FAST TCP over optical burst switched networks: Modeling and stability analysis

    KAUST Repository

    Shihada, Basem

    2013-04-01

    FAST TCP is important for promoting data-intensive applications since it can cleverly react to both packet loss and delay for detecting network congestion. This paper provides a continuous time model and extensive stability analysis of FAST TCP congestion-control mechanism in bufferless Optical Burst Switched Networks (OBS). The paper first shows that random burst contentions are essential to stabilize the network, but cause throughput degradation in FAST TCP flows when a burst with all the packets from a single round is dropped. Second, it shows that FAST TCP is vulnerable to burst delay and fails to detect network congestion due to the little variation of round-trip time, thus unstable. Finally it shows that introducing extra delays by implementing burst retransmission stabilizes FAST TCP over OBS. The paper proves that FAST TCP is not stable over barebone OBS. However, it is locally, exponentially, and asymptotically stable over OBS with burst retransmission.

  18. Enhanced just-in-time plus protocol for optical burst switching networks

    Science.gov (United States)

    Rodrigues, Joel J. P. C.; Gregório, José M. B.; Vasilakos, Athanasios V.

    2010-07-01

    We propose a new one-way resource reservation protocol for optical burst switching (OBS) networks, called Enhanced Just-in-Time Plus (E-JIT+). The protocol is described in detail, and its formal specification is presented, following an extended finite state machine approach. The performance evaluation of E-JIT+ is analyzed in comparison with other proposed OBS protocols (JIT+ and E-JIT) for the following network topologies: rings; degree-two, degree-three, and degree-four chordal rings; mesh-torus; NSFNET; ARPANET; FCCN-NET; and the European Optical Network. We evaluate and compare the performance of the different protocols in terms of burst loss probability, taking into account the most important OBS network parameters. It was shown that E-JIT+ performs better than available one-way resource reservation protocols for all the evaluated network topologies. Moreover, the scalability of E-JIT+ was observed, and when the network traffic increases, the burst loss probability also increases, leading to a worse network performance.

  19. Secured Hash Based Burst Header Authentication Design for Optical Burst Switched Networks

    Science.gov (United States)

    Balamurugan, A. M.; Sivasubramanian, A.; Parvathavarthini, B.

    2017-12-01

    The optical burst switching (OBS) is a promising technology that could meet the fast growing network demand. They are featured with the ability to meet the bandwidth requirement of applications that demand intensive bandwidth. OBS proves to be a satisfactory technology to tackle the huge bandwidth constraints, but suffers from security vulnerabilities. The objective of this proposed work is to design a faster and efficient burst header authentication algorithm for core nodes. There are two important key features in this work, viz., header encryption and authentication. Since the burst header is an important in optical burst switched network, it has to be encrypted; otherwise it is be prone to attack. The proposed MD5&RC4-4S based burst header authentication algorithm runs 20.75 ns faster than the conventional algorithms. The modification suggested in the proposed RC4-4S algorithm gives a better security and solves the correlation problems between the publicly known outputs during key generation phase. The modified MD5 recommended in this work provides 7.81 % better avalanche effect than the conventional algorithm. The device utilization result also shows the suitability of the proposed algorithm for header authentication in real time applications.

  20. High-performance flat data center network architecture based on scalable and flow-controlled optical switching system

    Science.gov (United States)

    Calabretta, Nicola; Miao, Wang; Dorren, Harm

    2016-03-01

    Traffic in data centers networks (DCNs) is steadily growing to support various applications and virtualization technologies. Multi-tenancy enabling efficient resource utilization is considered as a key requirement for the next generation DCs resulting from the growing demands for services and applications. Virtualization mechanisms and technologies can leverage statistical multiplexing and fast switch reconfiguration to further extend the DC efficiency and agility. We present a novel high performance flat DCN employing bufferless and distributed fast (sub-microsecond) optical switches with wavelength, space, and time switching operation. The fast optical switches can enhance the performance of the DCNs by providing large-capacity switching capability and efficiently sharing the data plane resources by exploiting statistical multiplexing. Benefiting from the Software-Defined Networking (SDN) control of the optical switches, virtual DCNs can be flexibly created and reconfigured by the DCN provider. Numerical and experimental investigations of the DCN based on the fast optical switches show the successful setup of virtual network slices for intra-data center interconnections. Experimental results to assess the DCN performance in terms of latency and packet loss show less than 10^-5 packet loss and 640ns end-to-end latency with 0.4 load and 16- packet size buffer. Numerical investigation on the performance of the systems when the port number of the optical switch is scaled to 32x32 system indicate that more than 1000 ToRs each with Terabit/s interface can be interconnected providing a Petabit/s capacity. The roadmap to photonic integration of large port optical switches will be also presented.

  1. A novel implementation of TCP Vegas for optical burst switched networks

    KAUST Repository

    Shihada, Basem

    2010-07-01

    TCP performance over bufferless Optical Burst Switched (OBS) networks could be significantly degraded due to the misinterpretation of network congestion status (referred to as false congestion detection). It has been reported that burst retransmission in the OBS domain can improve the TCP throughput by hiding burst loss events from the upper TCP layer, which can effectively reduce the congestion window fluctuation at the expense of introducing additional delay. However, the additional delay may cause performance degradation for delay-based TCP implementations that are sensitive to packet round trip time in estimating the network congestion status. In this paper, a novel implementation of TCP Vegas that adopts a threshold-based mechanism is proposed for identifying the network congestion status in OBS networks. Analytical models are developed to evaluate the throughput of conventional TCP Vegas and threshold-based Vegas over OBS networks with burst retransmission. Simulation is conducted to validate the analytical model and to compare threshold-based Vegas with a number of legacy TCP implementations, such as TCP Sack and TCP Reno. The analytical model can be used to obtain a proper threshold value that results in an optimal steady state TCP throughput.

  2. Multiple-mode reconfigurable electro-optic switching network for optical fiber sensor array

    Science.gov (United States)

    Chen, Ray T.; Wang, Michael R.; Jannson, Tomasz; Baumbick, Robert

    1991-01-01

    This paper reports the first switching network compatible with multimode fibers. A one-to-many cascaded reconfigurable interconnection was built. A thin glass substrate was used as the guiding medium which provides not only higher coupling efficiency from multimode fiber to waveguide but also better tolerance of phase-matching conditions. Involvement of a total-internal-reflection hologram and multimode waveguide eliminates interface problems between fibers and waveguides. The DCG polymer graft has proven to be reliable from -180 C to +200 C. Survivability of such an electrooptic system in harsh environments is further ensured. LiNbO3 was chosen as the E-O material because of its stability at high temperatures (phase-transition temperature of more than 1000 C) and maturity of E-O device technology. Further theoretical calculation was conducted to provide the optimal interaction length and device capacitance.

  3. Effective preemptive scheduling scheme for optical burst-switched networks with cascaded wavelength conversion consideration

    Science.gov (United States)

    Gao, Xingbo

    2010-03-01

    We introduce a new preemptive scheduling technique for next-generation optical burst switching (OBS) networks considering the impact of cascaded wavelength conversions. It has been shown that when optical bursts are transmitted all optically from source to destination, each wavelength conversion performed along the lightpath may cause certain signal-to-noise deterioration. If the distortion of the signal quality becomes significant enough, the receiver would not be able to recover the original data. Accordingly, subject to this practical impediment, we improve a recently proposed fair channel scheduling algorithm to deal with the fairness problem and aim at burst loss reduction simultaneously in OBS environments. In our scheme, the dynamic priority associated with each burst is based on a constraint threshold and the number of already conducted wavelength conversions among other factors for this burst. When contention occurs, a new arriving superior burst may preempt another scheduled one according to their priorities. Extensive simulation results have shown that the proposed scheme further improves fairness and achieves burst loss reduction as well.

  4. A Novel QKD-based Secure Edge Router Architecture Design for Burst Confidentiality in Optical Burst Switched Networks

    Science.gov (United States)

    Balamurugan, A. M.; Sivasubramanian, A.

    2014-06-01

    The Optical Burst Switching (OBS) is an emergent result to the technology issue that could achieve a viable network in future. They have the ability to meet the bandwidth requisite of those applications that call for intensive bandwidth. The field of optical transmission has undergone numerous advancements and is still being researched mainly due to the fact that optical data transmission can be done at enormous speeds. The concept of OBS is still far from perfection facing issues in case of security threat. The transfer of optical switching paradigm to optical burst switching faces serious downfall in the fields of burst aggregation, routing, authentication, dispute resolution and quality of service (QoS). This paper proposes a framework based on QKD based secure edge router architecture design to provide burst confidentiality. The QKD protocol offers high level of confidentiality as it is indestructible. The design architecture was implemented in FPGA using diverse models and the results were taken. The results show that the proposed model is suitable for real time secure routing applications of the Optical burst switched networks.

  5. Quasi-Optical Network Analyzers and High-Reliability RF MEMS Switched Capacitors

    Science.gov (United States)

    Grichener, Alexander

    The thesis first presents a 2-port quasi-optical scalar network analyzer consisting of a transmitter and receiver both built in planar technology. The network analyzer is based on a Schottky-diode mixer integrated inside a planar antenna and fed differentially by a CPW transmission line. The antenna is placed on an extended hemispherical high-resistivity silicon substrate lens. The LO signal is swept from 3-5 GHz and high-order harmonic mixing in both up- and down- conversion mode is used to realize the 15-50 GHz RF bandwidth. The network analyzer resulted in a dynamic range of greater than 40 dB and was successfully used to measure a frequency selective surface with a second-order bandpass response. Furthermore, the system was built with circuits and components for easy scaling to millimeter-wave frequencies which is the primary motivation for this work. The application areas for a millimeter and submillimeter-wave network analyzer include material characterization and art diagnostics. The second project presents several RF MEMS switched capacitors designed for high-reliability operation and suitable for tunable filters and reconfigurable networks. The first switched-capacitor resulted in a digital capacitance ratio of 5 and an analog capacitance ratio of 5-9. The analog tuning of the down-state capacitance is enhanced by a positive vertical stress gradient in the the beam, making it ideal for applications that require precision tuning. A thick electroplated beam resulted in Q greater than 100 at C to X-band frequencies, and power handling of 0.6-1.1 W. The design also minimized charging in the dielectric, resulting in excellent reliability performance even under hot-switched and high power (1 W) conditions. The second switched-capacitor was designed without any dielectric to minimize charging. The device was hot-switched at 1 W of RF power for greater than 11 billion cycles with virtually no change in the C-V curve. The final project presents a 7-channel

  6. Optically beamformed beam-switched adaptive antennas for fixed and mobile broadband wireless access networks

    NARCIS (Netherlands)

    Piqueras, M.A.; Grosskopf, G.; Vidal, B.; Herrera Llorente, J.; Martinez, J.M.; Sanchis, P.; Polo, V.; Corral, J.L.; Marceaux, A.; Galière, J.; Lopez, J.; Enard, A.; Valard, J.-L.; Parillaud, O.; Estèbe, E.; Vodjdani, N.; Choi, M.-S.; Besten, den J.H.; Soares, F.M.; Smit, M.K.; Marti, J.

    2006-01-01

    In this paper, a 3-bit optical beamforming architecture based in 2×2 optical switches and dispersive media is proposed and demonstrated. The performance of this photonic beamformer is experimentally demonstrated at 42.7 GHz in both transmission and reception modes. The progress achieved for

  7. An effective implementation scheme of just-in-time protocol for optical burst switching networks

    Science.gov (United States)

    Wu, Guiling; Li, Xinwan; Chen, Jian-Ping; Wang, Hui

    2005-02-01

    Optical burst switching (OBS) has been emerging as a promising technology that can effectively support the next generation IP-oriented transportation networks. JIT signaling protocol for OBS is relatively simple and easy to be implemented by hardware. This paper presented an effective scheme to implement the JIT protocol, which not only can effectively implement reservation and release of optical channels based on JIT, but also can process the failure of channel reservation and release due to loss of burst control packets. The scheme includes: (1) a BHP (burst head packet) path table is designed and built at each OBS node. It is used to guarantee the corresponding burst control packet, i.e. BHP, BEP (burst end packet) and BEP_ACK (BEP acknowledgement), to be transmitted in the same path. (2) The timed retransmission of BEP and the reversed deletion of the item in BHP path tables triggered by the corresponding BEP_ACK are combined to solve the problems caused by the loss of the signaling messages in channel reservation and release process. (3) Burst head packets and BEP_ACK are transmitted using "best-effort" method. Related signaling messages and their formats for the proposed scheme are also given.

  8. Reconfigurable high-speed optical fibre networks: Optical wavelength conversion and switching using VCSELs to eliminate channel collisions

    Science.gov (United States)

    Boiyo, Duncan Kiboi; Chabata, T. V.; Kipnoo, E. K. Rotich; Gamatham, R. R. G.; Leitch, A. W. R.; Gibbon, T. B.

    2017-01-01

    We experimentally provide an alternative solution to channel collisions through up-wavelength conversion and switching by using vertical cavity surface-emitting lasers (VCSELs). This has been achieved by utilizing purely optical wavelength conversion on VCSELs at the low attenuation, 1550 nm transmission window. The corresponding transmission and bit error-rate (BER) performance evaluation is also presented. In this paper, two 1550 nm VCSELs with 50-150 GHz channel spacing are modulated with a 10 Gb/s NRZ PRBS 27-1 data and their interferences investigated. A channel interference penalty range of 0.15-1.63 dB is incurred for 150-50 GHz channel spacing without transmission. To avoid channel collisions and to minimize high interference penalties, the transmitting VCSEL with data is injected into the side-mode of a slave VCSEL to obtain a new up converted wavelength. A 16 dB extinction ratio of the incoming wavelength is achieved when a 15 dBm transmitting beam is injected into the side-mode of a -4.5 dBm slave VCSEL. At 8.5 Gb/s, a 1.1 dB conversion and a 0.5 dB transmission penalties are realized when the converted wavelength is transmitted over a 24.7 km G.655 fibre. This work offers a low-cost, effective wavelength conversion and channel switching to reduce channel collision probability by reconfiguring channels at the node of networks.

  9. Scalable optical packet switch architecture for low latency and high load computer communication networks

    NARCIS (Netherlands)

    Calabretta, N.; Di Lucente, S.; Nazarathy, Y.; Raz, O.; Dorren, H.J.S.

    2011-01-01

    High performance computer and data-centers require PetaFlop/s processing speed and Petabyte storage capacity with thousands of low-latency short link interconnections between computers nodes. Switch matrices that operate transparently in the optical domain are a potential way to efficiently

  10. A hybrid optical switch architecture to integrate IP into optical networks to provide flexible and intelligent bandwidth on demand for cloud computing

    Science.gov (United States)

    Yang, Wei; Hall, Trevor J.

    2013-12-01

    The Internet is entering an era of cloud computing to provide more cost effective, eco-friendly and reliable services to consumer and business users. As a consequence, the nature of the Internet traffic has been fundamentally transformed from a pure packet-based pattern to today's predominantly flow-based pattern. Cloud computing has also brought about an unprecedented growth in the Internet traffic. In this paper, a hybrid optical switch architecture is presented to deal with the flow-based Internet traffic, aiming to offer flexible and intelligent bandwidth on demand to improve fiber capacity utilization. The hybrid optical switch is capable of integrating IP into optical networks for cloud-based traffic with predictable performance, for which the delay performance of the electronic module in the hybrid optical switch architecture is evaluated through simulation.

  11. Optical fiber switch

    Science.gov (United States)

    Early, James W.; Lester, Charles S.

    2002-01-01

    Optical fiber switches operated by electrical activation of at least one laser light modulator through which laser light is directed into at least one polarizer are used for the sequential transport of laser light from a single laser into a plurality of optical fibers. In one embodiment of the invention, laser light from a single excitation laser is sequentially transported to a plurality of optical fibers which in turn transport the laser light to separate individual remotely located laser fuel ignitors. The invention can be operated electro-optically with no need for any mechanical or moving parts, or, alternatively, can be operated electro-mechanically. The invention can be used to switch either pulsed or continuous wave laser light.

  12. Including 10-Gigabit-capable Passive Optical Network under End-to-End Generalized Multi-Protocol Label Switching Provisioned Quality of Service

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Gavler, Anders; Wessing, Henrik

    2012-01-01

    of the network where quality of service signaling is bridged. This article proposes strategies for generalized multi-protocol label switching control over next emerging passive optical network standard, i.e., the 10-gigabit-capable passive optical network. Node management and resource allocation approaches...... are discussed, and possible issues are raised. The analysis shows that consideration of a 10-gigabit-capable passive optical network as a generalized multi-protocol label switching controlled domain is valid and may advance end-to-end quality of service provisioning for passive optical network based customers.......End-to-end quality of service provisioning is still a challenging task despite many years of research and development in this area. Considering a generalized multi-protocol label switching based core/metro network and resource reservation protocol capable home gateways, it is the access part...

  13. THESEUS: A wavelength division multiplexed/microwave subcarrier multiplexed optical network, its ATM switch applications and device requirements

    Science.gov (United States)

    Xin, Wei

    1997-10-01

    A Terabit Hybrid Electro-optical /underline[Se]lf- routing Ultrafast Switch (THESEUS) has been proposed. It is a self-routing wavelength division multiplexed (WDM) / microwave subcarrier multiplexed (SCM) asynchronous transfer mode (ATM) switch for the multirate ATM networks. It has potential to be extended to a large ATM switch as 1000 x 1000 without internal blocking. Among the advantages of the hybrid implementation are flexibility in service upgrade, relaxed tolerances on optical filtering, protocol simplification and less processing overhead. For a small ATM switch, the subcarrier can be used as output buffers to solve output contention. A mathematical analysis was conducted to evaluate different buffer configurations. A testbed has been successfully constructed. Multirate binary data streams have been switched through the testbed and error free reception ([<]10-9 bit error rate) has been achieved. A simple, intuitive theoretical model has been developed to describe the heterodyne optical beat interference. A new concept of interference time and interference length has been introduced. An experimental confirmation has been conducted. The experimental results match the model very well. It shows that a large portion of optical bandwidth is wasted due to the beat interference. Based on the model, several improvement approaches have been proposed. The photo-generated carrier lifetime of silicon germanium has been measured using time-resolved reflectivity measurement. Via oxygen ion implantation, the carrier lifetime has been reduced to as short as 1 ps, corresponding to 1 THz of photodetector bandwidth. It has also been shown that copper dopants act as recombination centers in the silicon germanium.

  14. A tri-state optical switch for local area network communications

    Science.gov (United States)

    Simms, Garfield

    1993-01-01

    This novel structure is a heterojunction phototransistor which can be used as an emitter-detector, and when placed in a quiescent mode, the device becomes a passive transmitter. By varying the voltage bias, this novel device will switch between all three modes of operation. Such a device has broad application in network environments with operation speeds of less than 50 MHz and distances of less than 1 km, e.g. automobiles, airplanes, and intra-instrumentation. During this period, the emission mode for this device was studied and mathematically modeled.

  15. Optical network democratization.

    Science.gov (United States)

    Nejabati, Reza; Peng, Shuping; Simeonidou, Dimitra

    2016-03-06

    The current Internet infrastructure is not able to support independent evolution and innovation at physical and network layer functionalities, protocols and services, while at same time supporting the increasing bandwidth demands of evolving and heterogeneous applications. This paper addresses this problem by proposing a completely democratized optical network infrastructure. It introduces the novel concepts of the optical white box and bare metal optical switch as key technology enablers for democratizing optical networks. These are programmable optical switches whose hardware is loosely connected internally and is completely separated from their control software. To alleviate their complexity, a multi-dimensional abstraction mechanism using software-defined network technology is proposed. It creates a universal model of the proposed switches without exposing their technological details. It also enables a conventional network programmer to develop network applications for control of the optical network without specific technical knowledge of the physical layer. Furthermore, a novel optical network virtualization mechanism is proposed, enabling the composition and operation of multiple coexisting and application-specific virtual optical networks sharing the same physical infrastructure. Finally, the optical white box and the abstraction mechanism are experimentally evaluated, while the virtualization mechanism is evaluated with simulation. © 2016 The Author(s).

  16. Low-Crosstalk Composite Optical Crosspoint Switches

    Science.gov (United States)

    Pan, Jing-Jong; Liang, Frank

    1993-01-01

    Composite optical switch includes two elementary optical switches in tandem, plus optical absorbers. Like elementary optical switches, composite optical switches assembled into switch matrix. Performance enhanced by increasing number of elementary switches. Advantage of concept: crosstalk reduced to acceptably low level at moderate cost of doubling number of elementary switches rather than at greater cost of tightening manufacturing tolerances and exerting more-precise control over operating conditions.

  17. Neuromorphic atomic switch networks.

    Directory of Open Access Journals (Sweden)

    Audrius V Avizienis

    Full Text Available Efforts to emulate the formidable information processing capabilities of the brain through neuromorphic engineering have been bolstered by recent progress in the fabrication of nonlinear, nanoscale circuit elements that exhibit synapse-like operational characteristics. However, conventional fabrication techniques are unable to efficiently generate structures with the highly complex interconnectivity found in biological neuronal networks. Here we demonstrate the physical realization of a self-assembled neuromorphic device which implements basic concepts of systems neuroscience through a hardware-based platform comprised of over a billion interconnected atomic-switch inorganic synapses embedded in a complex network of silver nanowires. Observations of network activation and passive harmonic generation demonstrate a collective response to input stimulus in agreement with recent theoretical predictions. Further, emergent behaviors unique to the complex network of atomic switches and akin to brain function are observed, namely spatially distributed memory, recurrent dynamics and the activation of feedforward subnetworks. These devices display the functional characteristics required for implementing unconventional, biologically and neurally inspired computational methodologies in a synthetic experimental system.

  18. Burst-Switched Optical Networks Supporting Legacy and Future Service Types

    Directory of Open Access Journals (Sweden)

    Gerald Franzl

    2011-01-01

    Full Text Available Focusing on the principles and the paradigm of OBS an overview addressing expectable performance and application issues is presented. Proposals on OBS were published over a decade and the presented techniques spread into many directions. The paper comprises discussions of several challenges that OBS meets, in order to compile the big picture. The OBS principle is presented unrestricted to individual proposals and trends. Merits are openly discussed, considering basic teletraffic theory and common traffic characterisation. A more generic OBS paradigm than usual is impartially discussed and found capable to overcome shortcomings of recent proposals. In conclusion, an OBS that offers different connection types may support most client demands within a sole optical network layer.

  19. Routing and Disaster Awareness in Optical Networks

    NARCIS (Netherlands)

    Muhammad Iqbal, M.A.F.

    2016-01-01

    Optical networks facilitate the configurations of high-speed network connections with tremendous bandwidth between the optical switches. Optical switches are interconnected by optical fibers that act as the mediums in which data are transferred using lightpaths. Due to the importance of optical

  20. Design of optical switches by illusion optics

    International Nuclear Information System (INIS)

    Shoorian, H R; Abrishamian, M S

    2013-01-01

    In this paper, illusion optics theory is employed to form Bragg gratings in an optical waveguide in order to design an optical switch. By using an illusion device at a certain distance from the waveguide, the effective refractive index of the waveguide is remotely modulated, turning the waveguide into a distributed Bragg reflector (DBR) which blocks the waves at a stop band. By removing the illusion device, the waves propagate through the waveguide again. In addition, this method is used to remotely tune DBR optical properties such as resonant frequency and bandwidth in a wide range, which leads to a tunable filter for optical switching applications. Finally, using an illusion device at a distance, an optical cavity is created by inserting defects remotely in a DBR without any physical damage in the primary device. (paper)

  1. Design of optical switches by illusion optics

    Science.gov (United States)

    Shoorian, H. R.; Abrishamian, M. S.

    2013-05-01

    In this paper, illusion optics theory is employed to form Bragg gratings in an optical waveguide in order to design an optical switch. By using an illusion device at a certain distance from the waveguide, the effective refractive index of the waveguide is remotely modulated, turning the waveguide into a distributed Bragg reflector (DBR) which blocks the waves at a stop band. By removing the illusion device, the waves propagate through the waveguide again. In addition, this method is used to remotely tune DBR optical properties such as resonant frequency and bandwidth in a wide range, which leads to a tunable filter for optical switching applications. Finally, using an illusion device at a distance, an optical cavity is created by inserting defects remotely in a DBR without any physical damage in the primary device.

  2. Assembly and offset assignment scheme for self-similar traffic in optical burst switched networks

    CSIR Research Space (South Africa)

    Muwonge, KB

    2007-10-01

    Full Text Available at the Label Edge Router (LER) to buffer traffic in the electronic domain. Burst assembly and offset assignment schemes are implemented in a complementary manner to improve QoS of an OBS network. The authors show that OBS network performance is directly related...

  3. A novel scalable and low latency hybrid data center network architecture based on flow controlled fast optical switches

    NARCIS (Netherlands)

    Yan, Fulong; Guelbenzu, Gonzalo; Calabretta, Nicola

    2018-01-01

    We present a novel hybrid DCN based on flow-controlled fast optical switches. Results show packet loss < 1.4E-5 and latency < 2.4μs for 100,000 servers (0.3 load). Costs and power consumptions are also compared with current technologies.

  4. Experimental Demonstration of Multidimensional Switching Nodes for All-Optical Data Center Networks

    DEFF Research Database (Denmark)

    Kamchevska, Valerija; Medhin, Ashenafi Kiros; Da Ros, Francesco

    2016-01-01

    architecture allows for scaling in different dimensions while at the same time providing support for connections with different granularity. The ring topology reduces the number of different physical links required, leading to simplified cabling and easier link management, while optical bypass holds...

  5. Zero Trust Cloud Networks using Transport Access Control and High Availability Optical Bypass Switching

    Directory of Open Access Journals (Sweden)

    Casimer DeCusatis

    2017-04-01

    Full Text Available Cyberinfrastructure is undergoing a radical transformation as traditional enterprise and cloud computing environments hosting dynamic, mobile workloads replace telecommunication data centers. Traditional data center security best practices involving network segmentation are not well suited to these new environments. We discuss a novel network architecture, which enables an explicit zero trust approach, based on a steganographic overlay, which embeds authentication tokens in the TCP packet request, and first-packet authentication. Experimental demonstration of this approach is provided in both an enterprise-class server and cloud computing data center environment.

  6. Large aperture optical switching devices

    International Nuclear Information System (INIS)

    Goldhar, J.; Henesian, M.A.

    1983-01-01

    We have developed a new approach to constructing large aperture optical switches for next generation inertial confinement fusion lasers. A transparent plasma electrode formed in low pressure ionized gas acts as a conductive coating to allow the uniform charging of the optical faces of an electro-optic material. In this manner large electric fields can be applied longitudinally to large aperture, high aspect ratio Pockels cells. We propose a four-electrode geometry to create the necessary high conductivity plasma sheets, and have demonstrated fast (less than 10 nsec) switching in a 5x5 cm aperture KD*P Pockels cell with such a design. Detaid modelling of Pockels cell performance with plasma electrodes has been carried out for 15 and 30 cm aperture designs

  7. Optical Switching and Bit Rates of 40 Gbit/s and above

    DEFF Research Database (Denmark)

    Ackaert, A.; Demester, P.; O'Mahony, M.

    2003-01-01

    Optical switching in WDM networks introduces additional aspects to the choice of single channel bit rates compared to WDM transmission systems. The mutual impact of optical switching and bit rates of 40 Gbps and above is discussed....

  8. Principles of broadband switching and networking

    CERN Document Server

    Liew, Soung C

    2010-01-01

    An authoritative introduction to the roles of switching and transmission in broadband integrated services networks Principles of Broadband Switching and Networking explains the design and analysis of switch architectures suitable for broadband integrated services networks, emphasizing packet-switched interconnection networks with distributed routing algorithms. The text examines the mathematical properties of these networks, rather than specific implementation technologies. Although the pedagogical explanations in this book are in the context of switches, many of the fundamenta

  9. Lightness : a function-virtualizable software defined data center network with all-optical circuit/packet switching

    NARCIS (Netherlands)

    Saridis, G.; Peng, S.; Yan, Y.; Aguado, A.; Guo, B.; Arslan, M.; Jackson, C.; Miao, W.; Calabretta, N.; Agraz, F.; Spadaro, S.; Bernini, G.; Ciulli, N.; Zervas, G.; Nejabati, R.; Simeonidou, D.

    2016-01-01

    Modern high-performance Data Centers are responsible for delivering a huge variety of cloud applications to the end-users, which are increasingly pushing the limits of currently deployed computing and network infrastructure. All-optical dynamic data center network (DCN) architectures are strong

  10. Optical switches based on surface plasmons

    International Nuclear Information System (INIS)

    Chen Cong; Wang Pei; Yuan Guanghui; Wang Xiaolei; Min Changjun; Deng Yan; Lu Yonghua; Ming Hai

    2008-01-01

    Great attention is being paid to surface plasmons (SPs) because of their potential applications in sensors, data storage and bio-photonics. Recently, more and more optical switches based on surface plasmon effects have been demonstrated either by simulation or experimentally. This article describes the principles, advantages and disadvantages of various types of optical switches based on SPs, in particular the all-optical switches. (authors)

  11. Switch-connected HyperX network

    Science.gov (United States)

    Chen, Dong; Heidelberger, Philip

    2018-02-13

    A network system includes a plurality of sub-network planes and global switches. The sub-network planes have a same network topology as each other. Each of the sub-network planes includes edge switches. Each of the edge switches has N ports. Each of the global switches is configured to connect a group of edge switches at a same location in the sub-network planes. In each of the sub-network planes, some of the N ports of each of the edge switches are connected to end nodes, and others of the N ports are connected to other edge switches in the same sub-network plane, other of the N ports are connected to at least one of the global switches.

  12. High speed all optical networks

    Science.gov (United States)

    Chlamtac, Imrich; Ganz, Aura

    1990-01-01

    An inherent problem of conventional point-to-point wide area network (WAN) architectures is that they cannot translate optical transmission bandwidth into comparable user available throughput due to the limiting electronic processing speed of the switching nodes. The first solution to wavelength division multiplexing (WDM) based WAN networks that overcomes this limitation is presented. The proposed Lightnet architecture takes into account the idiosyncrasies of WDM switching/transmission leading to an efficient and pragmatic solution. The Lightnet architecture trades the ample WDM bandwidth for a reduction in the number of processing stages and a simplification of each switching stage, leading to drastically increased effective network throughputs. The principle of the Lightnet architecture is the construction and use of virtual topology networks, embedded in the original network in the wavelength domain. For this construction Lightnets utilize the new concept of lightpaths which constitute the links of the virtual topology. Lightpaths are all-optical, multihop, paths in the network that allow data to be switched through intermediate nodes using high throughput passive optical switches. The use of the virtual topologies and the associated switching design introduce a number of new ideas, which are discussed in detail.

  13. Pinning Synchronization of Switched Complex Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Liming Du

    2015-01-01

    Full Text Available Network topology and node dynamics play a key role in forming synchronization of complex networks. Unfortunately there is no effective synchronization criterion for pinning synchronization of complex dynamical networks with switching topology. In this paper, pinning synchronization of complex dynamical networks with switching topology is studied. Two basic problems are considered: one is pinning synchronization of switched complex networks under arbitrary switching; the other is pinning synchronization of switched complex networks by design of switching when synchronization cannot achieved by using any individual connection topology alone. For the two problems, common Lyapunov function method and single Lyapunov function method are used respectively, some global synchronization criteria are proposed and the designed switching law is given. Finally, simulation results verify the validity of the results.

  14. Scalable optical switches for computing applications

    NARCIS (Netherlands)

    White, I.H.; Aw, E.T.; Williams, K.A.; Wang, Haibo; Wonfor, A.; Penty, R.V.

    2009-01-01

    A scalable photonic interconnection network architecture is proposed whereby a Clos network is populated with broadcast-and-select stages. This enables the efficient exploitation of an emerging class of photonic integrated switch fabric. A low distortion space switch technology based on recently

  15. Soft optics in intelligent optical networks

    Science.gov (United States)

    Shue, Chikong; Cao, Yang

    2001-10-01

    In addition to the recent advances in Hard-optics that pushes the optical transmission speed, distance, wave density and optical switching capacity, Soft-optics provides the necessary intelligence and control software that reduces operational costs, increase efficiency, and enhances revenue generating services by automating optimal optical circuit placement and restoration, and enabling value-added new services like Optical VPN. This paper describes the advances in 1) Overall Hard-optics and Soft-optics 2) Layered hierarchy of Soft-optics 3) Component of Soft-optics, including hard-optics drivers, Management Soft-optics, Routing Soft-optics and System Soft-optics 4) Key component of Routing and System Soft-optics, namely optical routing and signaling (including UNI/NNI and GMPLS signaling). In summary, the soft-optics on a new generation of OXC's enables Intelligent Optical Networks to provide just-in-time service delivery and fast restoration, and real-time capacity management that eliminates stranded bandwidth. It reduces operational costs and provides new revenue opportunities.

  16. Synchronization in complex networks with switching topology

    International Nuclear Information System (INIS)

    Wang, Lei; Wang, Qing-guo

    2011-01-01

    This Letter investigates synchronization issues of complex dynamical networks with switching topology. By constructing a common Lyapunov function, we show that local and global synchronization for a linearly coupled network with switching topology can be evaluated by the time average of second smallest eigenvalues corresponding to the Laplacians of switching topology. This result is quite powerful and can be further used to explore various switching cases for complex dynamical networks. Numerical simulations illustrate the effectiveness of the obtained results in the end. -- Highlights: → Synchronization of complex networks with switching topology is investigated. → A common Lyapunov function is established for synchronization of switching network. → The common Lyapunov function is not necessary to monotonically decrease with time. → Synchronization is determined by the second smallest eigenvalue of its Laplacian. → Synchronization criterion can be used to investigate various switching cases.

  17. Dimensioning of 10 Gbit/s all-optical packet switched networks based on optical label swapping routers with multistage 2R regeneration.

    Science.gov (United States)

    Puerto, G; Ortega, B; Manzanedo, M D; Martínez, A; Pastor, D; Capmany, J; Kovacs, G

    2006-10-30

    This paper describes both the experimental and theoretical investigations on the cascadability of all-optical routers in optical label swapping networks incorporating a multistage wavelength conversion with 2R regeneration. A full description of a novel experimental setup allows the packet by packet measurement up to 16 hops with 10 Gb/s payload showing 1 dB penalty with 10(-12) bit error rate. Similarly, the simulations on the system allow a prediction on the cascadability of the router up to 64 hops.

  18. Stateless multicast switching in software defined networks

    OpenAIRE

    Reed, Martin J.; Al-Naday, Mays; Thomos, Nikolaos; Trossen, Dirk; Petropoulos, George; Spirou, Spiros

    2016-01-01

    Multicast data delivery can significantly reduce traffic in operators' networks, but has been limited in deployment due to concerns such as the scalability of state management. This paper shows how multicast can be implemented in contemporary software defined networking (SDN) switches, with less state than existing unicast switching strategies, by utilising a Bloom Filter (BF) based switching technique. Furthermore, the proposed mechanism uses only proactive rule insertion, and thus, is not l...

  19. Optically coupled cavities for wavelength switching

    Energy Technology Data Exchange (ETDEWEB)

    Costazo-Caso, Pablo A; Granieri, Sergio; Siahmakoun, Azad, E-mail: pcostanzo@ing.unlp.edu.ar, E-mail: granieri@rose-hulman.edu, E-mail: siahmako@rose-hulman.edu [Department of Physics and Optical Engineering, Rose-Hulman Institute of Technology, 5500 Wabash Avenue, Terre Haute, IN 47803 (United States)

    2011-01-01

    An optical bistable device which presents hysteresis behavior is proposed and experimentally demonstrated. The system finds applications in wavelength switching, pulse reshaping and optical bistability. It is based on two optically coupled cavities named master and slave. Each cavity includes a semiconductor optical amplifier (SOA), acting as the gain medium of the laser, and two pair of fiber Bragg gratings (FBG) which define the lasing wavelength (being different in each cavity). Finally, a variable optical coupler (VOC) is employed to couple both cavities. Experimental characterization of the system performance is made analyzing the effects of the coupling coefficient between the two cavities and the driving current in each SOA. The properties of the hysteretic bistable curve and switching can be controlled by adjusting these parameters and the loss in the cavities. By selecting the output wavelength ({lambda}{sub 1} or {lambda}{sub 2}) with an external filter it is possible to choose either the invert or non-invert switched signal. Experiments were developed employing both optical discrete components and a photonic integrated circuit. They show that for 8 m-long cavities the maximum switching frequency is about 500 KHz, and for 4 m-long cavities a minimum rise-time about 21 ns was measured. The switching time can be reduced by shortening the cavity lengths and using photonic integrated circuits.

  20. Enhancing the Quality of Service for Real Time Traffic over Optical Burst Switching (OBS Networks with Ensuring the Fairness for Other Traffics.

    Directory of Open Access Journals (Sweden)

    Mohammed A Al-Shargabi

    Full Text Available Optical burst switching (OBS networks have been attracting much consideration as a promising approach to build the next generation optical Internet. A solution for enhancing the Quality of Service (QoS for high priority real time traffic over OBS with the fairness among the traffic types is absent in current OBS' QoS schemes. In this paper we present a novel Real Time Quality of Service with Fairness Ratio (RT-QoSFR scheme that can adapt the burst assembly parameters according to the traffic QoS needs in order to enhance the real time traffic QoS requirements and to ensure the fairness for other traffic. The results show that RT-QoSFR scheme is able to fulfill the real time traffic requirements (end to end delay, and loss rate ensuring the fairness for other traffics under various conditions such as the type of real time traffic and traffic load. RT-QoSFR can guarantee that the delay of the real time traffic packets does not exceed the maximum packets transfer delay value. Furthermore, it can reduce the real time traffic packets loss, at the same time guarantee the fairness for non real time traffic packets by determining the ratio of real time traffic inside the burst to be 50-60%, 30-40%, and 10-20% for high, normal, and low traffic loads respectively.

  1. Chirality in nonlinear optics and optical switching

    NARCIS (Netherlands)

    Meijer, E.W.; Feringa, B.L.

    1993-01-01

    Chirality in molecular opto-electronics is limited sofar to the use of optically active liquid crystals and a number of optical phenomena are related to the helical macroscopic structure obtained by using one enantiomer, only. In this paper, the use of chirality in nonlinear optics and optical

  2. Software-defined networking control plane for seamless integration of multiple silicon photonic switches in Datacom networks.

    Science.gov (United States)

    Shen, Yiwen; Hattink, Maarten H N; Samadi, Payman; Cheng, Qixiang; Hu, Ziyiz; Gazman, Alexander; Bergman, Keren

    2018-04-16

    Silicon photonics based switches offer an effective option for the delivery of dynamic bandwidth for future large-scale Datacom systems while maintaining scalable energy efficiency. The integration of a silicon photonics-based optical switching fabric within electronic Datacom architectures requires novel network topologies and arbitration strategies to effectively manage the active elements in the network. We present a scalable software-defined networking control plane to integrate silicon photonic based switches with conventional Ethernet or InfiniBand networks. Our software-defined control plane manages both electronic packet switches and multiple silicon photonic switches for simultaneous packet and circuit switching. We built an experimental Dragonfly network testbed with 16 electronic packet switches and 2 silicon photonic switches to evaluate our control plane. Observed latencies occupied by each step of the switching procedure demonstrate a total of 344 µs control plane latency for data-center and high performance computing platforms.

  3. Optical multicast system for data center networks.

    Science.gov (United States)

    Samadi, Payman; Gupta, Varun; Xu, Junjie; Wang, Howard; Zussman, Gil; Bergman, Keren

    2015-08-24

    We present the design and experimental evaluation of an Optical Multicast System for Data Center Networks, a hardware-software system architecture that uniquely integrates passive optical splitters in a hybrid network architecture for faster and simpler delivery of multicast traffic flows. An application-driven control plane manages the integrated optical and electronic switched traffic routing in the data plane layer. The control plane includes a resource allocation algorithm to optimally assign optical splitters to the flows. The hardware architecture is built on a hybrid network with both Electronic Packet Switching (EPS) and Optical Circuit Switching (OCS) networks to aggregate Top-of-Rack switches. The OCS is also the connectivity substrate of splitters to the optical network. The optical multicast system implementation requires only commodity optical components. We built a prototype and developed a simulation environment to evaluate the performance of the system for bulk multicasting. Experimental and numerical results show simultaneous delivery of multicast flows to all receivers with steady throughput. Compared to IP multicast that is the electronic counterpart, optical multicast performs with less protocol complexity and reduced energy consumption. Compared to peer-to-peer multicast methods, it achieves at minimum an order of magnitude higher throughput for flows under 250 MB with significantly less connection overheads. Furthermore, for delivering 20 TB of data containing only 15% multicast flows, it reduces the total delivery energy consumption by 50% and improves latency by 55% compared to a data center with a sole non-blocking EPS network.

  4. A microcomputer for a packet switched network

    International Nuclear Information System (INIS)

    Seller, P.; Bairstow, R.; Barlow, J.; Waters, M.

    1982-12-01

    The Bubble Chamber Research Group of the Rutherford and Appleton Laboratory has a large film analysis facility. This comprises 16 digitising tables used for the measurement of bubble chamber film. Each of these tables has an associated microcomputer. These microcomputers are linked by a star structured packet switched local area network (LAN) to a VAX 11/780. The LAN, and in particular a microcomputer of novel architecture designed to act as the central switch of the network, is described. (author)

  5. The experimental optical burst switching system

    Science.gov (United States)

    Li, Xinwan; Chen, Jian-Ping; Wu, Guiling; Wang, Hui; Lu, Jialin; Ye, Ailun

    2005-02-01

    The first optical burst switching (OBS) system has been demonstrated in China, which includes three edge routers and one core-node. A kind of fast wavelength selective optical switching was used in the system. The core OBS node consists of a kind of wavelength selective optical switch we developed. It consists of two SOA switches and one wavelength selective thin film filter with centre wavelength at one wavelength. There are one input optical fiber and two output fibers, each fiber carries two wavelengths. The Dell PE2650 servers act as the edge OBS routers. The wavelength of each data channel is located in C-band and the bit rate is at 1.25Gbps. The control channel uses bit rate of 100Mbps at wavelength of 1310 nm. A novel effective scheme for Just-In-Time (JIT) protocol was proposed and implemented. OBS services, such as Video on Demand (VOD) and file transfer protocol (FTP), have been demonstrated. Assembling and scheduling methods that are capable to guarantee the QoS (quality of service) of the transported service are studied.

  6. Power requirements reducing of FBG based all-optical switching

    Science.gov (United States)

    Scholtz, Ľubomír.; Solanská, Michaela; Ladányi, Libor; Müllerová, Jarmila

    2017-12-01

    Although Fiber Bragg gratings (FBGs) are well known devices, their using as all-optical switching elements has been still examined. Current research is focused on optimization of their properties for their using in future all-optical networks. The main problem are high switching intensities needed for achieving the changes of the transmission state. Over several years switching intensities have been reduced from hundreds of GW/cm2 to tens of MW/cm2 by selecting appropriate gratings and signal parameters or using suitable materials. Two principal nonlinear effects with similar power requirements can result in the bistable transmission/reflection of an input optical pulse. In the self-phase modulation (SPM) regime switching is achieved by the intense probe pulse itself. Using cross-phase modulation (XPM) a strong pump alters the FBG refractive index experienced by a weak probe pulse. As a result of this the detuning of the probe pulse from the center of the photonic band gap occurs. Using of XPM the effect of modulation instability is reduced. Modulation instability which is the main SPM degradation mechanism. We focused on nonlinear FBGs based on chalcogenide glasses which are very often used in various applications. Thanks to high nonlinear parameters chalcogenide glasses are suitable candidates for reducing switching intensities of nonlinear FBGs.

  7. Optical Performance Monitoring and Signal Optimization in Optical Networks

    DEFF Research Database (Denmark)

    Petersen, Martin Nordal

    2006-01-01

    The thesis studies performance monitoring for the next generation optical networks. The focus is on all-optical networks with bit-rates of 10 Gb/s or above. Next generation all-optical networks offer large challenges as the optical transmitted distance increases and the occurrence of electrical-optical......-electrical regeneration points decreases. This thesis evaluates the impact of signal degrading effects that are becoming of increasing concern in all-optical high-speed networks due to all-optical switching and higher bit-rates. Especially group-velocity-dispersion (GVD) and a number of nonlinear effects will require...... enhanced attention to avoid signal degradations. The requirements for optical performance monitoring features are discussed, and the thesis evaluates the advantages and necessity of increasing the level of performance monitoring parameters in the physical layer. In particular, methods for optical...

  8. High-performance flat data center network architecture based on scalable and flow-controlled optical switching system

    NARCIS (Netherlands)

    Calabretta, N.; Miao, W.; Dorren, H.J.S.; Schroder, H.; Chen, R.T.

    2016-01-01

    Traffic in data centers networks (DCNs) is steadily growing to support various applications and virtualization technologies. Multi-tenancy enabling efficient resource utilization is considered as a key requirement for the next generation DCs resulting from the growing demands for services and

  9. All-optical packet/circuit switching-based data center network for enhanced scalability, latency and throughput

    NARCIS (Netherlands)

    Perelló, J.; Spadaro, S.; Ricciardi, S.; Careglio, D.; Peng, S.; Nejabati, R.; Zervas, G.; Simeonidou, D.; Predieri, A.; Biancani, M.; Dorren, H.J.S.; Di Lucente, S.; Luo, J.; Calabretta, N.; Bernini, G.; Ciulli, N.; Sancho, J.C.; Iordache, S.; Farreras, M.; Becerra, Y.; Liou, C.; Hussain, I.; Yin, Y.; Liu, L.; Proietti, R.

    2013-01-01

    Applications running inside data centers are enabled through the cooperation of thousands of servers arranged in racks and interconnected together through the data center network. Current DCN architectures based on electronic devices are neither scalable to face the massive growth of DCs, nor

  10. All-optical OXC transition strategy from WDM optical network to elastic optical network.

    Science.gov (United States)

    Chen, Xin; Li, Juhao; Guo, Bingli; Zhu, Paikun; Tang, Ruizhi; Chen, Zhangyuan; He, Yongqi

    2016-02-22

    Elastic optical network (EON) has been proposed recently as a spectrum-efficient optical layer to adapt to rapidly-increasing traffic demands instead of current deployed wavelength-division-multiplexing (WDM) optical network. In contrast with conventional WDM optical cross-connect (OXCs) based on wavelength selective switches (WSSs), the EON OXCs are based on spectrum selective switches (SSSs) which are much more expensive than WSSs, especially for large-scale switching architectures. So the transition cost from WDM OXCs to EON OXCs is a major obstacle to realizing EON. In this paper, we propose and experimentally demonstrate a transition OXC (TOXC) structure based on 2-stage cascading switching architectures, which make full use of available WSSs in current deployed WDM OXCs to reduce number and port count of required SSSs. Moreover, we propose a contention-aware spectrum allocation (CASA) scheme for EON built with the proposed TOXCs. We show by simulation that the TOXCs reduce the network capital expenditure transiting from WDM optical network to EON about 50%, with a minor traffic blocking performance degradation and about 10% accommodated traffic number detriment compared with all-SSS EON OXC architectures.

  11. Investment in electricity networks with transmission switching

    DEFF Research Database (Denmark)

    Villumsen, Jonas Christoffer; Philpott, A.B.

    2012-01-01

    allows the solution of large problem instances. The methodology is illustrated by its application to a problem of determining the optimal investment in switching equipment and transmission capacity for an existing network. Computational tests on IEEE test networks with 73 nodes and 118 nodes confirm...

  12. Optimizing POF/PCF based optical switch for indoor LAN

    International Nuclear Information System (INIS)

    Bhuiyan, M M I; Rashid, M M; Ahmed, Sayem; Bhuiyan, M; Kajihara, M

    2013-01-01

    For indoor local area network (LAN) the Polymer optical fiber (POF) is mostly appropriate, because of its large core diameter and flexible material. A 1×2 optical switch for indoor LAN using POF and a shape memory alloy (SMA) coil actuator with magnetic latches was successfully fabricated and tested. To achieve switching by the movement of a POF, large displacement is necessary because the core diameter is large (e.g., 0.486mm). A SMA coil actuator is used for large displacement and a magnetic latching system is used for fixing the position of the shifted POF. The insertion loss is 0.40 to 0.50dB and crosstalk is more than 50dB without index-matching oil. Switching speed is less than 1s at a driving current of 80mA. A cycling test was performed 1.4 million times. Polymer clad fiber optical (PCF) switch also fabricated and tasted

  13. Modeling GMPLS and Optical MPLS Networks

    DEFF Research Database (Denmark)

    Christiansen, Henrik Lehrmann; Wessing, Henrik

    2003-01-01

    . The MPLS concept is attractive because it can work as a unifying control structure. covering all technologies. This paper describes how a novel scheme for optical MPLS and circuit switched GMPLS based networks can incorporated in such multi-domain, MPLS-based scenarios and how it could be modeled. Network...

  14. 160-Gb/s Silicon All-Optical Packet Switch for Buffer-less Optical Burst Switching

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Pu, Minhao

    2015-01-01

    We experimentally demonstrate a 160-Gb/s Ethernet packet switch using an 8.6-mm-long silicon nanowire for optical burst switching, based on cross phase modulation in silicon. One of the four packets at the bit rate of 160 Gb/s is switched by an optical control signal using a silicon based 1 × 1 all......-optical packet switch. Error free performance (BER silicon packet switch based optical burst switching, which might be desirable for high-speed interconnects within a short...

  15. Cognitive Dynamic Optical Networks

    DEFF Research Database (Denmark)

    de Miguel, Ignacio; Duran, Ramon J.; Lorenzo, Ruben M.

    2013-01-01

    Cognitive networks are a promising solution for the control of heterogeneous optical networks. We review their fundamentals as well as a number of applications developed in the framework of the EU FP7 CHRON project.......Cognitive networks are a promising solution for the control of heterogeneous optical networks. We review their fundamentals as well as a number of applications developed in the framework of the EU FP7 CHRON project....

  16. A Lossless Switch for Data Acquisition Networks

    CERN Document Server

    Jereczek, Grzegorz Edmund; The ATLAS collaboration

    2015-01-01

    The recent trends in software-defined networking (SDN) and network function virtualization (NFV) are boosting the advance of software-based packet processing and forwarding on commodity servers. Although performance has traditionally been the challenge of this approach, this situation changes with modern server platforms. High performance load balancers, proxies, virtual switches and other network functions can be now implemented in software and not limited to specialized commercial hardware, thus reducing cost and increasing the flexibility. In this paper we design a lossless software-based switch for high bandwidth data acquisition (DAQ) networks, using the ATLAS experiment at CERN as a case study. We prove that it can effectively solve the incast pathology arising from the many-to-one communication pattern present in DAQ networks by providing extremely high buffering capabilities. We evaluate this on a commodity server equipped with twelve 10 Gbps Ethernet interfaces providing a total bandwidth of 120 Gbps...

  17. High speed all-optical networks

    Science.gov (United States)

    Chlamtac, Imrich

    1993-01-01

    An inherent problem of conventional point-to-point WAN architectures is that they cannot translate optical transmission bandwidth into comparable user available throughput due to the limiting electronic processing speed of the switching nodes. This report presents the first solution to WDM based WAN networks that overcomes this limitation. The proposed Lightnet architecture takes into account the idiosyncrasies of WDM switching/transmission leading to an efficient and pragmatic solution. The Lightnet architecture trades the ample WDM bandwidth for a reduction in the number of processing stages and a simplification of each switching stage, leading to drastically increased effective network throughputs.

  18. Switching performance of OBS network model under prefetched real traffic

    Science.gov (United States)

    Huang, Zhenhua; Xu, Du; Lei, Wen

    2005-11-01

    Optical Burst Switching (OBS) [1] is now widely considered as an efficient switching technique in building the next generation optical Internet .So it's very important to precisely evaluate the performance of the OBS network model. The performance of the OBS network model is variable in different condition, but the most important thing is that how it works under real traffic load. In the traditional simulation models, uniform traffics are usually generated by simulation software to imitate the data source of the edge node in the OBS network model, and through which the performance of the OBS network is evaluated. Unfortunately, without being simulated by real traffic, the traditional simulation models have several problems and their results are doubtable. To deal with this problem, we present a new simulation model for analysis and performance evaluation of the OBS network, which uses prefetched IP traffic to be data source of the OBS network model. The prefetched IP traffic can be considered as real IP source of the OBS edge node and the OBS network model has the same clock rate with a real OBS system. So it's easy to conclude that this model is closer to the real OBS system than the traditional ones. The simulation results also indicate that this model is more accurate to evaluate the performance of the OBS network system and the results of this model are closer to the actual situation.

  19. Optical Access Networks

    Science.gov (United States)

    Zheng, Jun; Ansari, Nirwan

    2005-06-01

    Call for Papers: Optical Access Networks With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks have been receiving tremendous attention from both academia and industry. A large number of research activities have been carried out or

  20. Compact integrated optical devices for optical sensor and switching applications

    NARCIS (Netherlands)

    Kauppinen, L.J.

    2010-01-01

    This thesis describes the design, fabrication, and characterization of compact optical devices for sensing and switching applications. Our focus has been to realize the devices using CMOS-compatible fabrication processes. Particularly the silicon photonics fabrication platform, ePIXfab, has been

  1. Optical Interconnects for Future Data Center Networks

    CERN Document Server

    Bergman, Keren; Tomkos, Ioannis

    2013-01-01

    Optical Interconnects for Future Data Center Networks covers optical networks and how they can provide high bandwidth, energy efficient interconnects with increased communication bandwidth. This volume, with contributions from leading researchers in the field, presents an integrated view of the expected future requirements of data centers and serves as a reference for some of the most advanced and promising solutions proposed by researchers from leading universities, research labs, and companies. The work also includes several novel architectures, each demonstrating different technologies such as optical circuits, optical switching, MIMO optical OFDM, and others. Additionally, Optical Interconnects for Future Data Center Networks provides invaluable insights into the benefits and advantages of optical interconnects and how they can be a promising alternative for future data center networks.

  2. Delayed switching applied to memristor neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Frank Z.; Yang Xiao; Lim Guan [Future Computing Group, School of Computing, University of Kent, Canterbury (United Kingdom); Helian Na [School of Computer Science, University of Hertfordshire, Hatfield (United Kingdom); Wu Sining [Xyratex, Havant (United Kingdom); Guo Yike [Department of Computing, Imperial College, London (United Kingdom); Rashid, Md Mamunur [CERN, Geneva (Switzerland)

    2012-04-01

    Magnetic flux and electric charge are linked in a memristor. We reported recently that a memristor has a peculiar effect in which the switching takes place with a time delay because a memristor possesses a certain inertia. This effect was named the ''delayed switching effect.'' In this work, we elaborate on the importance of delayed switching in a brain-like computer using memristor neural networks. The effect is used to control the switching of a memristor synapse between two neurons that fire together (the Hebbian rule). A theoretical formula is found, and the design is verified by a simulation. We have also built an experimental setup consisting of electronic memristive synapses and electronic neurons.

  3. Delayed switching applied to memristor neural networks

    International Nuclear Information System (INIS)

    Wang, Frank Z.; Yang Xiao; Lim Guan; Helian Na; Wu Sining; Guo Yike; Rashid, Md Mamunur

    2012-01-01

    Magnetic flux and electric charge are linked in a memristor. We reported recently that a memristor has a peculiar effect in which the switching takes place with a time delay because a memristor possesses a certain inertia. This effect was named the ''delayed switching effect.'' In this work, we elaborate on the importance of delayed switching in a brain-like computer using memristor neural networks. The effect is used to control the switching of a memristor synapse between two neurons that fire together (the Hebbian rule). A theoretical formula is found, and the design is verified by a simulation. We have also built an experimental setup consisting of electronic memristive synapses and electronic neurons.

  4. Wavelength switching in an optical klystron

    International Nuclear Information System (INIS)

    Berryman, K.W.; Smith, T.I.

    1995-01-01

    A symmetric optical klystron consists of two identical undulator sections separated a dispersive section. For a device of a given length, an optical klystron is capable of producing much more bunching, and therefore more gain, than a traditional undulator. Another consequence of introducing dispersion between two undulator sections is that the overall spontaneous radiation pattern results from the interference between the two undulator sections, and as such resembles a standard undulator radiation pattern modulated by a sinusoidal interference term. The presence of several wavelength peaks in the spontaneous lineshape implies an equal number of peaks in the gain spectrum. If the strength of the dispersion section is adjusted to provide nearly equal gain on the two largest of these peaks, then they will compete, and the FEL may switch wavelengths based on noise, cavity length, or other perturbations. We provide the first observations of this behavior, using the FIREFLY system at the Stanford Picosecond FEL Center. In FIREFLY, relative wavelength switching by more than 3%--more than twice the laser linewidth-has been observed by varying dispersion section strength, while at intermediate points stable switching has also been observed as a function of cavity length

  5. Cognitive Dynamic Optical Networks

    DEFF Research Database (Denmark)

    de Miguel, Ignacio; Duran, Ramon J.; Jimenez, Tamara

    2013-01-01

    The use of cognition is a promising element for the control of heterogeneous optical networks. Not only are cognitive networks able to sense current network conditions and act according to them, but they also take into account the knowledge acquired through past experiences; that is, they include...... learning with the aim of improving performance. In this paper, we review the fundamentals of cognitive networks and focus on their application to the optical networking area. In particular, a number of cognitive network architectures proposed so far, as well as their associated supporting technologies......, are reviewed. Moreover, several applications, mainly developed in the framework of the EU FP7 Cognitive Heterogeneous Reconfigurable Optical Network (CHRON) project, are also described....

  6. Optical Switching for Dynamic Distribution of Wireless-over-Fiber Signals

    DEFF Research Database (Denmark)

    Rodes Lopez, Guillermo Arturo; Vegas Olmos, Juan José; Karinou, Fotini

    2012-01-01

    In this paper, we report on an experimental validation of dynamic distribution of wireless-over-fiber by employing optical switching using semiconductor optical amplifiers; the rest of the network was designed according to the channel distribution over the optical spectra required by the optical...... switch. An experimental validation was also conducted. The experiment consists of a four wavelength division multiplexed (WDM) channel system operating on a WiMax frequency band, and employing an orthogonal frequency-division multiplexing (OFDM) modulation at 625 Mbit/s per channel, transmission...... of the data over 20 km of optical fiber, and active switching in a one-by-sixteen active optical switch. The results show a negligible power penalty on each channel, for both the best and the worst case in terms of inter-channel crosstalk....

  7. Optimal on/off scheme for all-optical switching

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Heuck, Mikkel; Mørk, Jesper

    2012-01-01

    We present a two-pulsed on/off scheme based on coherent control for fast switching of the optical energy in a micro cavity and use calculus of variations to optimize the switching in terms of energy.......We present a two-pulsed on/off scheme based on coherent control for fast switching of the optical energy in a micro cavity and use calculus of variations to optimize the switching in terms of energy....

  8. All-optical devices for ultrafast packet switching

    DEFF Research Database (Denmark)

    Dorren, H.J.S.; HerreraDorren, J.; Raz, O.

    2007-01-01

    We discuss integrated devices for all-optical packet switching. We focus on monolithically integrated all-optical flip-flops, ultra-fast semiconductor based wavelength converters and explain the operation principles. Finally, a 160 Gb/s all-optical packet switching experiment over 110 km of field...

  9. Design and analysis of photonic optical switches with improved wavelength selectivity

    Science.gov (United States)

    Wielichowski, Marcin; Patela, Sergiusz

    2005-09-01

    Efficient optical modulators and switches are the key elements of the future all-optical fiber networks. Aside from numerous advantages, the integrated optical devices suffer from excessive longitudinal dimensions. The dimensions may be significantly reduced with help of periodic structures, such as Bragg gratings, arrayed waveguides or multilayer structures. In this paper we describe methods of analysis and example of analytical results of a photonic switch with properties modified by the application of periodic change of effective refractive index. The switch is composed of a strip-waveguide directional coupler and a transversal Bragg grating.

  10. Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating.

    Science.gov (United States)

    Said, Asmaa; Salah, Abeer; Fattah, Gamal Abdel

    2017-05-12

    Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin's rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications.

  11. OpenFlow Switching Performance using Network Simulator - 3

    OpenAIRE

    Sriram Prashanth, Naguru

    2016-01-01

    Context. In the present network inventive world, there is a quick expansion of switches and protocols, which are used to cope up with the increase in customer requirement in the networking. With increasing demand for higher bandwidths and lower latency and to meet these requirements new network paths are introduced. To reduce network load in present switching network, development of new innovative switching is required. These required results can be achieved by Software Define Network or Trad...

  12. Optical Access Networks

    Science.gov (United States)

    Zheng, Jun; Ansari, Nirwan

    2005-01-01

    Call for Papers: Optical Access Networks Guest Editors Jun Zheng, University of Ottawa Nirwan Ansari, New Jersey Institute of Technology Submission Deadline: 1 June 2005 Background With the wide deployment of fiber-optic technology over the past two decades, we have witnessed a tremendous growth of bandwidth capacity in the backbone networks of today's telecommunications infrastructure. However, access networks, which cover the "last-mile" areas and serve numerous residential and small business users, have not been scaled up commensurately. The local subscriber lines for telephone and cable television are still using twisted pairs and coaxial cables. Most residential connections to the Internet are still through dial-up modems operating at a low speed on twisted pairs. As the demand for access bandwidth increases with emerging high-bandwidth applications, such as distance learning, high-definition television (HDTV), and video on demand (VoD), the last-mile access networks have become a bandwidth bottleneck in today's telecommunications infrastructure. To ease this bottleneck, it is imperative to provide sufficient bandwidth capacity in the access networks to open the bottleneck and thus present more opportunities for the provisioning of multiservices. Optical access solutions promise huge bandwidth to service providers and low-cost high-bandwidth services to end users and are therefore widely considered the technology of choice for next-generation access networks. To realize the vision of optical access networks, however, many key issues still need to be addressed, such as network architectures, signaling protocols, and implementation standards. The major challenges lie in the fact that an optical solution must be not only robust, scalable, and flexible, but also implemented at a low cost comparable to that of existing access solutions in order to increase the economic viability of many potential high-bandwidth applications. In recent years, optical access networks

  13. Concave switching in single-hop and multihop networks

    NARCIS (Netherlands)

    Walton, N.

    2015-01-01

    Switched queueing networks model wireless networks, input-queued switches, and numerous other networked communications systems. We consider an (\\(\\alpha ,g\\))-switch policy; these policies provide a generalization of the MaxWeight policies of Tassiulas and Ephremides (IEEE Trans Autom Control

  14. Software-Controlled Next Generation Optical Circuit Switching for HPC and Cloud Computing Datacenters

    Directory of Open Access Journals (Sweden)

    Muhammad Imran

    2015-11-01

    Full Text Available In this paper, we consider the performance of optical circuit switching (OCS systems designed for data center networks by using network-level simulation. Recent proposals have used OCS in data center networks but the relatively slow switching times of OCS-MEMS switches (10–100 ms and the latencies of control planes in these approaches have limited their use to the largest data center networks with workloads that last several seconds. Herein, we extend the applicability and generality of these studies by considering dynamically changing short-lived circuits in software-controlled OCS switches, using the faster switching technologies that are now available. The modelled switch architecture features fast optical switches in a single hop topology with a centralized, software-defined optical control plane. We model different workloads with various traffic aggregation parameters to investigate the performance of such designs across usage patterns. Our results show that, with suitable choices for the OCS system parameters, delay performance comparable to that of electrical data center networks can be obtained.

  15. Advanced optical components for next-generation photonic networks

    Science.gov (United States)

    Yoo, S. J. B.

    2003-08-01

    Future networks will require very high throughput, carrying dominantly data-centric traffic. The role of Photonic Networks employing all-optical systems will become increasingly important in providing scalable bandwidth, agile reconfigurability, and low-power consumptions in the future. In particular, the self-similar nature of data traffic indicates that packet switching and burst switching will be beneficial in the Next Generation Photonic Networks. While the natural conclusion is to pursue Photonic Packet Switching and Photonic Burst Switching systems, there are significant challenges in realizing such a system due to practical limitations in optical component technologies. Lack of a viable all-optical memory technology will continue to drive us towards exploring rapid reconfigurability in the wavelength domain. We will introduce and discuss the advanced optical component technologies behind the Photonic Packet Routing system designed and demonstrated at UC Davis. The system is capable of packet switching and burst switching, as well as circuit switching with 600 psec switching speed and scalability to 42 petabit/sec aggregated switching capacity. By utilizing a combination of rapidly tunable wavelength conversion and a uniform-loss cyclic frequency (ULCF) arrayed waveguide grating router (AWGR), the system is capable of rapidly switching the packets in wavelength, time, and space domains. The label swapping module inside the Photonic Packet Routing system containing a Mach-Zehnder wavelength converter and a narrow-band fiber Bragg-grating achieves all-optical label swapping with optical 2R (potentially 3R) regeneration while maintaining optical transparency for the data payload. By utilizing the advanced optical component technologies, the Photonic Packet Routing system successfully demonstrated error-free, cascaded, multi-hop photonic packet switching and routing with optical-label swapping. This paper will review the advanced optical component technologies

  16. Advanced Functionalities for Highly Reliable Optical Networks

    DEFF Research Database (Denmark)

    An, Yi

    This thesis covers two research topics concerning optical solutions for networks e.g. avionic systems. One is to identify the applications for silicon photonic devices for cost-effective solutions in short-range optical networks. The other one is to realise advanced functionalities in order...... to increase the availability of highly reliable optical networks. A cost-effective transmitter based on a directly modulated laser (DML) using a silicon micro-ring resonator (MRR) to enhance its modulation speed is proposed, analysed and experimentally demonstrated. A modulation speed enhancement from 10 Gbit...... interconnects and network-on-chips. A novel concept of all-optical protection switching scheme is proposed, where fault detection and protection trigger are all implemented in the optical domain. This scheme can provide ultra-fast establishment of the protection path resulting in a minimum loss of data...

  17. Atomic switch networks as complex adaptive systems

    Science.gov (United States)

    Scharnhorst, Kelsey S.; Carbajal, Juan P.; Aguilera, Renato C.; Sandouk, Eric J.; Aono, Masakazu; Stieg, Adam Z.; Gimzewski, James K.

    2018-03-01

    Complexity is an increasingly crucial aspect of societal, environmental and biological phenomena. Using a dense unorganized network of synthetic synapses it is shown that a complex adaptive system can be physically created on a microchip built especially for complex problems. These neuro-inspired atomic switch networks (ASNs) are a dynamic system with inherent and distributed memory, recurrent pathways, and up to a billion interacting elements. We demonstrate key parameters describing self-organized behavior such as non-linearity, power law dynamics, and multistate switching regimes. Device dynamics are then investigated using a feedback loop which provides control over current and voltage power-law behavior. Wide ranging prospective applications include understanding and eventually predicting future events that display complex emergent behavior in the critical regime.

  18. Architecture and evaluation of software-defined optical switching matrix for hybrid data centers

    DEFF Research Database (Denmark)

    Mehmeri, Victor; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2016-01-01

    A software architecture is proposed for hybrid packet/optical data centers employing programmable NETCONF-enabled optical switching matrix, and a performance evaluation is presented comparing hybrid and electrical-only architectures for elephant flows under different traffic patterns. Network...

  19. A metropolitan optical network with support for multicasting in the optical domain

    NARCIS (Netherlands)

    Dey, D.; Koonen, A.M.J.; Bochove, van A.C.; Geuzebroek, D.; Salvador, M.R.; Berghmans, F.; Thienpont, H.; Danckaert, J.; Desmet, L.

    2001-01-01

    We present the FLAMINGO1 network architecture, an all-optical wavelength-and-timeslotted Metropolitan Optical Network based on a multiple-ring topology. A couple of important aspects of this architecture include all-optical packet switching at intermediate nodes on a ring and the ability to put IP

  20. A Metropolitan Optical Network with support for multicasting in the optical domain

    NARCIS (Netherlands)

    Dey, D.; Koonen, A.M.J.; van Bochove, A.C.; Geuzebroek, D.H.; Salvador, M.R.; Thienpont, H.; Berghmans, F.; Danckaert, J.; Desmet, L.

    2001-01-01

    We present the FLAMINGO1 network architecture, an all-optical wavelength-and-timeslotted Metropolitan Optical Network based on a multiple-ring topology. A couple of important aspects of this architecture include all-optical packet switching at intermediate nodes on a ring and the ability to put IP

  1. First Field Trial of Optical Label-Based Switching and Packet Drop on a 477km NTON/Sprint Link

    International Nuclear Information System (INIS)

    Hernandez, V J; Pan, Z; Cao, J; Tsui, V K; Bansal, Y; Fong, S K H; Zhang, Y; Jeon, M Y; Yoo, S J B; Bodtker, B; Bond, S; Lennon, W J; Higashi, H; Lyles, B; McDonald, R

    2001-01-01

    We demonstrate the first field trial of optical label-based wavelength switching and packet drop on 476.8km of the National Transparent Optical Network. Subcarrier multiplexed labels control a switch fabric that includes a tunable wavelength converter and arrayed waveguide grating router

  2. Ultrafast optical switching in three-dimensional photonic crystals

    OpenAIRE

    Mazurenko, D.A.

    2004-01-01

    The rapidly expanding research on photonic crystals is driven by potential applications in all-optical switches, optical computers, low-threshold lasers, and holographic data storage. The performance of such devices might surpass the speed of traditional electronics by several orders of magnitude and may result in a true revolution in nanotechnology. The heart of such devices would likely be an optical switching element. This thesis analyzes different regimes of ultrafast all-optical switchin...

  3. Organization of the channel-switching process in parallel computer systems based on a matrix optical switch

    Science.gov (United States)

    Golomidov, Y. V.; Li, S. K.; Popov, S. A.; Smolov, V. B.

    1986-01-01

    After a classification and analysis of electronic and optoelectronic switching devices, the design principles and structure of a matrix optical switch is described. The switching and pair-exclusion operations in this type of switch are examined, and a method for the optical switching of communication channels is elaborated. Finally, attention is given to the structural organization of a parallel computer system with a matrix optical switch.

  4. High Availability in Optical Networks

    Science.gov (United States)

    Grover, Wayne D.; Wosinska, Lena; Fumagalli, Andrea

    2005-09-01

    concepts for survivability, or papers on availability analysis methods or results. Customer, vendor, and researcher viewpoints and priorities will all be given consideration. Especially valuable to the community would be papers that include or provide measured data on actual reliability and availability performance of optical networking components or systems. The scope of the papers includes, but is not limited to, the following topics: Reliability and availability measurement techniques specific to optical network devices or services. Data on SRLG statistics and frequency of different actual failure causes. Real-life accounts or data on failure and repair rates or projected values for use in availability analysis. Availability analysis methods, especially for survivable networks with reconfigurable or adaptive failure-specific responses. Availability analysis and comparisons of basic schemes for survivability. Differentiated availability schemes. Design for Multiple Quality of Protection. Different schemes for on-demand survivable service provisioning. Basic comparisons or proposals of new survivability mechanisms and architectures. Concepts yielding higher than 1+1 protection switching availability at less than 100% redundancy. Survivable service provisioning in domains of optical transparency: dealing with signal impairments. To submit to this special issue, follow the normal procedure for submission to JON, indicating "Feature Issue: Optical Network Availability" in the "Comments" field of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line "Feature Issue: Optical Network Availability." Additional information can be found on the JON website: http://www.osa-jon.org/submission/

  5. Cost-effective method of manufacturing a 3D MEMS optical switch

    Science.gov (United States)

    Carr, Emily; Zhang, Ping; Keebaugh, Doug; Chau, Kelvin

    2009-02-01

    growth of data and video transport networks. All-optical switching eliminates the need for optical-electrical conversion offering the ability to switch optical signals transparently: independent of data rates, formats and wavelength. It also provides network operators much needed automation capabilities to create, monitor and protect optical light paths. To further accelerate the market penetration, it is necessary to identify a path to reduce the manufacturing cost significantly as well as enhance the overall system performance, uniformity and reliability. Currently, most MEMS optical switches are assembled through die level flip-chip bonding with either epoxies or solder bumps. This is due to the alignment accuracy requirements of the switch assembly, defect matching of individual die, and cost of the individual components. In this paper, a wafer level assembly approach is reported based on silicon fusion bonding which aims to reduce the packaging time, defect count and cost through volume production. This approach is successfully demonstrated by the integration of two 6-inch wafers: a mirror array wafer and a "snap-guard" wafer, which provides a mechanical structure on top of the micromirror to prevent electrostatic snap-down. The direct silicon-to-silicon bond eliminates the CTEmismatch and stress issues caused by non-silicon bonding agents. Results from a completed integrated switch assembly will be presented, which demonstrates the reliability and uniformity of some key parameters of this MEMS optical switch.

  6. A nonlinear plasmonic waveguide based all-optical bidirectional switching

    Science.gov (United States)

    Bana, Xiaoqiang; Pang, Xingxing; Li, Xiaohui; Hu, Bin; Guo, Yixuan; Zheng, Hairong

    2018-01-01

    In this paper, an all-optical switching with a nanometer coupled ring resonator is demonstrated based on the nonlinear material. By adjusting the light intensity, we implement the resonance wavelength from 880 nm to 940 nm in the nonlinear material structure monocyclic. In the bidirectional switch structure, the center wavelength (i.e. 880 nm) is fixed. By changing the light intensity from I = 0 to I = 53 . 1 MW /cm2, the function of optical switching can be obtained. The results demonstrate that both the single-ring cavity and the T-shaped double-ring structure can realize the optical switching effect. This work takes advantage of the simple structure. The single-ring cavity plasmonic switches have many advantages, such as nanoscale size, low pumping light intensity, ultrafast response time (femtosecond level), etc. It is expected that the proposed all-optical integrated devices can be potentially applied in optical communication, signal processing, and signal sensing, etc.

  7. Flexible optical network components based on densely integrated microring resonators

    NARCIS (Netherlands)

    Geuzebroek, D.H.

    2005-01-01

    This thesis addresses the design, realization and characterization of reconfigurable optical network components based on multiple microring resonators. Since thermally tunable microring resonators can be used as wavelength selective space switches, very compact devices with high complexity and

  8. Performance Monitoring Techniques Supporting Cognitive Optical Networking

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Borkowski, Robert; Zibar, Darko

    2013-01-01

    High degree of heterogeneity of future optical networks, such as services with different quality-of-transmission requirements, modulation formats and switching techniques, will pose a challenge for the control and optimization of different parameters. Incorporation of cognitive techniques can help...... to solve this issue by realizing a network that can observe, act, learn and optimize its performance, taking into account end-to-end goals. In this letter we present the approach of cognition applied to heterogeneous optical networks developed in the framework of the EU project CHRON: Cognitive...... Heterogeneous Reconfigurable Optical Network. We focus on the approaches developed in the project for optical performance monitoring, which enable the feedback from the physical layer to the cognitive decision system by providing accurate description of the performance of the established lightpaths....

  9. Optical Network Testbeds Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Joe Mambretti

    2007-06-01

    This is the summary report of the third annual Optical Networking Testbed Workshop (ONT3), which brought together leading members of the international advanced research community to address major challenges in creating next generation communication services and technologies. Networking research and development (R&D) communities throughout the world continue to discover new methods and technologies that are enabling breakthroughs in advanced communications. These discoveries are keystones for building the foundation of the future economy, which requires the sophisticated management of extremely large qualities of digital information through high performance communications. This innovation is made possible by basic research and experiments within laboratories and on specialized testbeds. Initial network research and development initiatives are driven by diverse motives, including attempts to solve existing complex problems, the desire to create powerful new technologies that do not exist using traditional methods, and the need to create tools to address specific challenges, including those mandated by large scale science or government agency mission agendas. Many new discoveries related to communications technologies transition to wide-spread deployment through standards organizations and commercialization. These transition paths allow for new communications capabilities that drive many sectors of the digital economy. In the last few years, networking R&D has increasingly focused on advancing multiple new capabilities enabled by next generation optical networking. Both US Federal networking R&D and other national R&D initiatives, such as those organized by the National Institute of Information and Communications Technology (NICT) of Japan are creating optical networking technologies that allow for new, powerful communication services. Among the most promising services are those based on new types of multi-service or hybrid networks, which use new optical networking

  10. A multi-ring optical packet and circuit integrated network with optical buffering.

    Science.gov (United States)

    Furukawa, Hideaki; Shinada, Satoshi; Miyazawa, Takaya; Harai, Hiroaki; Kawasaki, Wataru; Saito, Tatsuhiko; Matsunaga, Koji; Toyozumi, Tatuya; Wada, Naoya

    2012-12-17

    We newly developed a 3 × 3 integrated optical packet and circuit switch-node. Optical buffers and burst-mode erbium-doped fiber amplifiers with the gain flatness are installed in the 3 × 3 switch-node. The optical buffer can prevent packet collisions and decrease packet loss. We constructed a multi-ring optical packet and circuit integrated network testbed connecting two single-ring networks and a client network by the 3 × 3 switch-node. For the first time, we demonstrated 244 km fiber transmission and 5-node hopping of multiplexed 14-wavelength 10 Gbps optical paths and 100 Gbps optical packets encapsulating 10 Gigabit Ethernet frames on the testbed. Error-free (frame error rate optical packets of various packet lengths. In addition, successful avoidance of packet collisions by optical buffers was confirmed.

  11. Optical storage networking

    Science.gov (United States)

    Mohr, Ulrich

    2001-11-01

    For efficient business continuance and backup of mission- critical data an inter-site storage network is required. Where traditional telecommunications costs are prohibitive for all but the largest organizations, there is an opportunity for regional carries to deliver an innovative storage service. This session reveals how a combination of optical networking and protocol-aware SAN gateways can provide an extended storage networking platform with the lowest cost of ownership and the highest possible degree of reliability, security and availability. Companies of every size, with mainframe and open-systems environments, can afford to use this integrated service. Three mayor applications are explained; channel extension, Network Attached Storage (NAS), Storage Area Networks (SAN) and how optical networks address the specific requirements. One advantage of DWDM is the ability for protocols such as ESCON, Fibre Channel, ATM and Gigabit Ethernet, to be transported natively and simultaneously across a single fiber pair, and the ability to multiplex many individual fiber pairs over a single pair, thereby reducing fiber cost and recovering fiber pairs already in use. An optical storage network enables a new class of service providers, Storage Service Providers (SSP) aiming to deliver value to the enterprise by managing storage, backup, replication and restoration as an outsourced service.

  12. Software architecture for hybrid electrical/optical data center network

    DEFF Research Database (Denmark)

    Mehmeri, Victor; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2016-01-01

    This paper presents hardware and software architecture based on Software-Defined Networking (SDN) paradigm and OpenFlow/NETCONF protocols for enabling topology management of hybrid electrical/optical switching data center networks. In particular, a development on top of SDN open-source controller...... OpenDaylight is presented to control an optical switching matrix based on Micro-Electro-Mechanical System (MEMS) technology....

  13. Transmission in Optically Transparent Core Networks

    Science.gov (United States)

    Kilper, Dan; Jensen, Rich; Petermann, Klaus; Karasek, Miroslav

    2007-03-01

    topics suitable for inclusion in this feature issue are: Optically transparent system design issues, transmission experiments, and field trials Optically transparent network architectures and topologies Dispersion management in reconfigurable and mesh systems Optically transparent network device and sub-system performance, design, characterization and control, including: amplifiers, transmitters, receivers, switches, add/drop multiplexers Transient and fault management Physical layer system control Monitoring and compensation to support transparency Wavelength routing and planning as they relate to physical layer transmission Hardware cost and configuration optimization for optically transparent networks To submit to this special issue, follow the normal procedure for submission to JON and select "TTCN" in the features indicator of the online submission form. For all other questions relating to this feature issue, please send an e-mail to jon@osa.org, subject line "TTCN." Additional information can be found on the JON website: . Submission Deadline: 15 June 2007

  14. CO2 laser pulse switching by optically excited semiconductors

    International Nuclear Information System (INIS)

    Silva, V.L. da.

    1986-01-01

    The construction and the study of a semi-conductor optical switch used for generating short infrared pulses and to analyse the semiconductor characteristics, are presented. The switch response time depends on semiconductor and control laser characteristics. The results obtained using a Ge switch controlled by N 2 , NdYag and Dye lasers are presented. The response time was 50 ns limited by Ge recombination time. The reflectivity increased from 7% to 59% using N 2 laser to control the switch. A simple model for semiconductor optical properties that explain very well the experimental results, is also presented. (author) [pt

  15. Cognitive Heterogeneous Reconfigurable Optical Networks (CHRON): Enabling Technologies and Techniques

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Zibar, Darko; Guerrero Gonzalez, Neil

    2011-01-01

    We present the approach of cognition applied to heterogeneous optical networks developed in the framework of the EU project CHRON: Cognitive Heterogeneous Reconfigurable Optical Network. We introduce and discuss in particular the technologies and techniques that will enable a cognitive optical...... network to observe, act, learn and optimizes its performance, taking into account its high degree of heterogeneity with respect to quality of service, transmission and switching techniques....

  16. A study on Optical Labelling Techniques for All-Optical Networks

    DEFF Research Database (Denmark)

    Holm-Nielsen, Pablo Villanueva

    2005-01-01

    Optical switching has been proposed as an effective solution to overcoming the potential electronic bottleneck in all-optical network nodes carrying IP over WDM. The solution builds on the use of optical labelling as a mean to route packets or bursts of packets through the network. In addition...... of an intermediate wavelength between label erasure and label insertion. The above mentioned functionalities are assembled in whole network systems experiments that validates the different labelling schemes with respect to transmission, wavelength conversion, label swapping and retransmission. Optical labelling...... and specially the orthogonal schemes for optical labelling, are thus shown to be an effective solution to all-optical networks....

  17. Development of optical packet and circuit integrated ring network testbed.

    Science.gov (United States)

    Furukawa, Hideaki; Harai, Hiroaki; Miyazawa, Takaya; Shinada, Satoshi; Kawasaki, Wataru; Wada, Naoya

    2011-12-12

    We developed novel integrated optical packet and circuit switch-node equipment. Compared with our previous equipment, a polarization-independent 4 × 4 semiconductor optical amplifier switch subsystem, gain-controlled optical amplifiers, and one 100 Gbps optical packet transponder and seven 10 Gbps optical path transponders with 10 Gigabit Ethernet (10GbE) client-interfaces were newly installed in the present system. The switch and amplifiers can provide more stable operation without equipment adjustments for the frequent polarization-rotations and dynamic packet-rate changes of optical packets. We constructed an optical packet and circuit integrated ring network testbed consisting of two switch nodes for accelerating network development, and we demonstrated 66 km fiber transmission and switching operation of multiplexed 14-wavelength 10 Gbps optical paths and 100 Gbps optical packets encapsulating 10GbE frames. Error-free (frame error rate optical packets of various packet lengths and packet rates, and stable operation of the network testbed was confirmed. In addition, 4K uncompressed video streaming over OPS links was successfully demonstrated. © 2011 Optical Society of America

  18. DLP technolgy: applications in optical networking

    Science.gov (United States)

    Yoder, Lars A.; Duncan, Walter M.; Koontz, Elisabeth M.; So, John; Bartlett, Terry A.; Lee, Benjamin L.; Sawyers, Bryce D.; Powell, Donald; Rancuret, Paul

    2001-11-01

    For the past five years, Digital Light Processing (DLP) technology from Texas Instruments has made significant inroads in the projection display market. With products encompassing the world's smallest data & video projectors, HDTVs, and digital cinema, DLP is an extremely flexible technology. At the heart of these display solutions is Texas Instruments Digital Micromirror Device (DMD), a semiconductor-based light switch array of thousands of individually addressable, tiltable, mirror-pixels. With success of the DMD as a spatial light modulator in the visible regime, the use of DLP technology under the constraints of coherent, infrared light for optical networking applications is being explored. As a coherent light modulator, the DMD device can be used in Dense Wavelength Division Multiplexed (DWDM) optical networks to dynamically manipulate and shape optical signals. This paper will present the fundamentals of using DLP with coherent wavefronts, discuss inherent advantages of the technology, and present several applications for DLP in dynamic optical networks.

  19. Optical packet switched design with relaxed maximum hardware parameters and high service-class granularity for flexible switch node dimensioning

    DEFF Research Database (Denmark)

    Nord, Martin

    2004-01-01

    This work proposes a quality of service differentiation algorithm, improving the service class granularity and isolation of our recently presented waveband plane based design. The design aims at overcoming potential hardware limitations and increasing the switch node dimensioning flexibility...... in core networks. Exploiting the wavelength dimension for contention resolution, using partially shared wavelength converter pools, avoids optical buffers and reduces wavelength converter count. These benefits are illustrated by numerical simulations, and are highlighted in a dimensioning study with three...

  20. Optical network scaling: roles of spectral and spatial aggregation.

    Science.gov (United States)

    Arık, Sercan Ö; Ho, Keang-Po; Kahn, Joseph M

    2014-12-01

    As the bit rates of routed data streams exceed the throughput of single wavelength-division multiplexing channels, spectral and spatial traffic aggregation become essential for optical network scaling. These aggregation techniques reduce network routing complexity by increasing spectral efficiency to decrease the number of fibers, and by increasing switching granularity to decrease the number of switching components. Spectral aggregation yields a modest decrease in the number of fibers but a substantial decrease in the number of switching components. Spatial aggregation yields a substantial decrease in both the number of fibers and the number of switching components. To quantify routing complexity reduction, we analyze the number of multi-cast and wavelength-selective switches required in a colorless, directionless and contentionless reconfigurable optical add-drop multiplexer architecture. Traffic aggregation has two potential drawbacks: reduced routing power and increased switching component size.

  1. Optical packet switching in HPC : an analysis of applications performance

    NARCIS (Netherlands)

    Meyer, Hugo; Sancho, Jose Carlos; Mrdakovic, Milica; Miao, Wang; Calabretta, Nicola

    2018-01-01

    Optical Packet Switches (OPS) could provide the needed low latency transmissions in today large data centers. OPS can deliver lower latency and higher bandwidth than traditional electrical switches. These features are needed for parallel High Performance Computing (HPC) applications. For this

  2. Experimental demonstrations of all-optical networking functions for WDM optical networks

    Science.gov (United States)

    Gurkan, Deniz

    The deployment of optical networks will enable high capacity links between users but will introduce the problems associated with transporting and managing more channels. Many network functions should be implemented in optical domain; main reasons are: to avoid electronic processing bottlenecks, to achieve data-format and data-rate independence, to provide reliable and cost efficient control and management information, to simultaneously process multiple wavelength channel operation for wavelength division multiplexed (WDM) optical networks. The following novel experimental demonstrations of network functions in the optical domain are presented: Variable-bit-rate recognition of the header information in a data packet. The technique is reconfigurable for different header sequences and uses optical correlators as look-up tables. The header is processed and a signal is sent to the switch for a series of incoming data packets at 155 Mb/s, 622 Mb/s, and 2.5 Gb/s in a reconfigurable network. Simultaneous optical time-slot-interchange and wavelength conversion of the bits in a 2.5-Gb/s data stream to achieve a reconfigurable time/wavelength switch. The technique uses difference-frequency-generation (DFG) for wavelength conversion and fiber Bragg gratings (FBG) as wavelength-dependent optical time buffers. The WDM header recognition module simultaneously recognizing two header bits on each of two 2.5-Gbit/s WDM packet streams. The module is tunable to enable reconfigurable look-up tables. Simultaneous and independent label swapping and wavelength conversion of two WDM channels for a multi-protocol label switching (MPLS) network. Demonstration of label swapping of distinct 8-bit-long labels for two WDM data channels is presented. Two-dimensional code conversion module for an optical code-division multiple-access (O-CDMA) local area network (LAN) system. Simultaneous wavelength conversion and time shifting is achieved to enable flexible code conversion and increase code re

  3. An electromagnetically actuated fiber optic switch using magnetized ferromagnetic materials

    Science.gov (United States)

    Pandojirao-S, Praveen; Dhaubanjar, Naresh; Phuyal, Pratibha C.; Chiao, Mu; Chiao, J.-C.

    2008-03-01

    This paper presents the design, fabrication and testing of a fiber optic switch actuated electromagnetically. The ferromagnetic gel coated optical fiber is actuated using external electromagnetic fields. The ferromagnetic gel consists of ferromagnetic powders dispersed in epoxy. The fabrication utilizes a simple cost-effective coating setup. A direct fiberto-fiber alignment eliminates the need for complementary optical parts and the displacement of fiber switches the laser coupling. The magnetic characteristics of magnetized ferromagnetic materials are performed using alternating gradient magnetometer and the magnetic hysteresis curves are measured for different ferromagnetic materials including iron, cobalt, and nickel. Optical fiber switches with various fiber lengths are actuated and their static and dynamic responses for the same volume of ferromagnetic gel are summarized. The highest displacement is 1.345 mm with an input current of 260mA. In this paper, the performance of fiber switches with various coating materials is presented.

  4. Optical network design and planning

    CERN Document Server

    Simmons, Jane M

    2014-01-01

    This book takes a pragmatic approach to designing state-of-the-art optical networks for backbone, regional, and metro-core networks.   Algorithms and methodologies related to routing, regeneration, wavelength assignment, subrate-traffic grooming, and protection are presented, with an emphasis on optical-bypass-enabled (or all-optical) networks. There are numerous case studies throughout the text to illustrate the concepts, using realistic networks and traffic sets. A full chapter of economic studies offers guidelines as to when and how optical-bypass technology should be deployed. There is also extensive coverage of recent research to provide insight into how optical networks are likely to evolve. The second edition includes new chapters on dynamic optical networking and flexible/elastic optical networks. There is expanded coverage of new physical-layer technology and its impact on network design, along with enhanced coverage of ROADM architectures, including the colorless, directionless, contentionless, a...

  5. Average contraction and synchronization of complex switched networks

    International Nuclear Information System (INIS)

    Wang Lei; Wang Qingguo

    2012-01-01

    This paper introduces an average contraction analysis for nonlinear switched systems and applies it to investigating the synchronization of complex networks of coupled systems with switching topology. For a general nonlinear system with a time-dependent switching law, a basic convergence result is presented according to average contraction analysis, and a special case where trajectories of a distributed switched system converge to a linear subspace is then investigated. Synchronization is viewed as the special case with all trajectories approaching the synchronization manifold, and is thus studied for complex networks of coupled oscillators with switching topology. It is shown that the synchronization of a complex switched network can be evaluated by the dynamics of an isolated node, the coupling strength and the time average of the smallest eigenvalue associated with the Laplacians of switching topology and the coupling fashion. Finally, numerical simulations illustrate the effectiveness of the proposed methods. (paper)

  6. Optimization of multicast optical networks with genetic algorithm

    Science.gov (United States)

    Lv, Bo; Mao, Xiangqiao; Zhang, Feng; Qin, Xi; Lu, Dan; Chen, Ming; Chen, Yong; Cao, Jihong; Jian, Shuisheng

    2007-11-01

    In this letter, aiming to obtain the best multicast performance of optical network in which the video conference information is carried by specified wavelength, we extend the solutions of matrix games with the network coding theory and devise a new method to solve the complex problems of multicast network switching. In addition, an experimental optical network has been testified with best switching strategies by employing the novel numerical solution designed with an effective way of genetic algorithm. The result shows that optimal solutions with genetic algorithm are accordance with the ones with the traditional fictitious play method.

  7. Intelligentization: an efficient means to get more from optical networking

    Science.gov (United States)

    Chen, Zhi Yun

    2001-10-01

    Infocom is a term used to describe the merger of Information and Communications and is used to show the radical changes in today's network traffic. The continuous growth of Infocom traffic, especially that of Internet, is driving Infocom networks to expand rapidly. To service providers, the traffic is consuming the bandwidth of their network. Simultaneously, users are complaining too slow, the net never stopped in China. It is the reality faced by both the service providers and equipment vendors. Demands from both the customers and competition in market call for an efficient network infrastructure. What should a Service Provider do? This paper will first analyze the development trends of optical networking and the formation of the concepts of Intelligent Optical Network (ION) and Automatic Switched Optical Network (ASON) as a solution to this problem. Next it will look at the ways to bring intelligence into optical networks, discussing the benefits to service providers by showing some application examples. Finally, it concludes that the development of optical networking has arrived at a point of introducing intelligence into optical networks. The intelligent optical networks and Automatic Switched Optical Networks will immediately bring a wide range of benefit to service providers, equipment vendors, and, of course, the end users.

  8. Enterasys Networks delivers 10-Gigabit ethernet for the enterprise with new matrix E1 switching family

    CERN Multimedia

    2001-01-01

    Enterasys Networks Inc., today announced its new Matrix E1 family of 10-Gigabit and Gigabit Ethernet switches. The Matrix E1 Optical Access Switch (OAS) enables organizations to deliver applications at 10-Gb speeds across a single fibre optic pair. Jacques Altaber, deputy leader of IT at CERN said "High-bandwith solutions are essential to leveraging more computing power, so 10-Gb Ethernet is the next logical step for us...The Matrix E1 allows us to provide the networking support that our scientists need and gives us a certain future for bandwidth and computing expansion".

  9. 160 Gb/s all-optical packet switching field experiment

    DEFF Research Database (Denmark)

    Dorren, H.J.S.; Herrera, J.; Raz, O.

    2007-01-01

    We discus an all-optical packet switching experiment over 110 km of field installed optical fiber. The switching node is controlled by solely photonic control circuits.......We discus an all-optical packet switching experiment over 110 km of field installed optical fiber. The switching node is controlled by solely photonic control circuits....

  10. Optical cross-connect circuit using hitless wavelength selective switch.

    Science.gov (United States)

    Goebuchi, Yuta; Hisada, Masahiko; Kato, Tomoyuki; Kokubun, Yasuo

    2008-01-21

    We have proposed and demonstrated the basic elements of a full matrix optical switching circuit (cross-connect circuit) using a hitless wavelength selective switch (WSS). The cross-connect circuits are made of a multi-wavelength channel selective switch consisting of cascaded hitless WSSs, and a multi-port switch. These switching elements are realized through the individual Thermo-Optic (TO) tuning of a series-coupled microring resonator, and can switch arbitrary wavelength channels without blocking other wavelength channels during tuning. We demonstrate a four wavelength selective switch using a parallel topology of double series coupled microring resonators and a three wavelength selective switch using a parallel topology of quadruple series coupled microring resonators. Since the spectrum shape of quadruple series coupled microring is much more box-like than the double series, a high extinction ratio of 39.0-46.6 dB and low switching cross talk of 19.3-24.5 dB were achieved.

  11. Integrated optical switch circuit operating under FPGA control

    NARCIS (Netherlands)

    Stabile, R.; Zal, M.; Williams, K.A.; Bienstman, P.; Morthier, G.; Roelkens, G.; et al., xx

    2011-01-01

    Integrated photonic circuits are enabling an abrupt step change in networking systems providing massive bandwidth and record transmission. The increasing complexity of high connectivity photonic integrated switches requires sophisticated control planes and more intimate high speed electronics. Here

  12. Control Plane Strategies for Elastic Optical Networks

    DEFF Research Database (Denmark)

    Turus, Ioan

    Networks (EONs) concept is proposed as a solution to enable a more flexible handling of the optical capacity and allows an increase of available capacity over the existing optical infrastructure. One main requirement for enabling EONs is to have a flexible spectrum structure (i.e.Flex-Grid) which allows...... the spectrum to be used as an on-demand resource. Flex-Grid raises new challenges for controlling the dynamic spectrum slots environment. This thesis addresses, as part of the Celtic project “Elastic Optical Networks” (EONet), the control of Flex-Grid architectures by extending the capabilities of a GMPLS...... (Generalized Multi-Protocol Label Switching)-based control framework in accordance with existing IETF standards and recommendations. The usual approach of extending capacity in transport networks by incrementally adding more optical resources results in a very inefficient usage and determines a high power...

  13. All-optical routing and switching for three-dimensional photonic circuitry

    Science.gov (United States)

    Keil, Robert; Heinrich, Matthias; Dreisow, Felix; Pertsch, Thomas; Tünnermann, Andreas; Nolte, Stefan; Christodoulides, Demetrios N.; Szameit, Alexander

    2011-01-01

    The ability to efficiently transmit and rapidly process huge amounts of data has become almost indispensable to our daily lives. It turned out that all-optical networks provide a very promising platform to deal with this task. Within such networks opto-optical switches, where light is directed by light, are a crucial building block for an effective operation. In this article, we present an experimental analysis of the routing and switching behaviour of light in two-dimensional evanescently coupled waveguide arrays of Y- and T-junction geometries directly inscribed into fused silica using ultrashort laser pulses. These systems have the fundamental advantage of supporting three-dimensional network topologies, thereby breaking the limitations on complexity associated with planar structures while maintaining a high dirigibility of the light. Our results show how such arrays can be used to control the flow of optical signals within integrated photonic circuits. PMID:22355612

  14. Optical backplane interconnect switch for data processors and computers

    Science.gov (United States)

    Hendricks, Herbert D.; Benz, Harry F.; Hammer, Jacob M.

    1989-01-01

    An optoelectronic integrated device design is reported which can be used to implement an all-optical backplane interconnect switch. The switch is sized to accommodate an array of processors and memories suitable for direct replacement into the basic avionic multiprocessor backplane. The optical backplane interconnect switch is also suitable for direct replacement of the PI bus traffic switch and at the same time, suitable for supporting pipelining of the processor and memory. The 32 bidirectional switchable interconnects are configured with broadcast capability for controls, reconfiguration, and messages. The approach described here can handle a serial interconnection of data processors or a line-to-link interconnection of data processors. An optical fiber demonstration of this approach is presented.

  15. Optimised Design and Analysis of All-Optical Networks

    DEFF Research Database (Denmark)

    Glenstrup, Arne John

    2002-01-01

    through various experiments and is shown to produce good results and to be able to scale up to networks of realistic sizes. A novel method, subpath wavelength grouping, for routing connections in a multigranular all-optical network where several wavelengths can be grouped and switched at band and fibre......This PhD thesis presents a suite of methods for optimising design and for analysing blocking probabilities of all-optical networks. It thus contributes methodical knowledge to the field of computer assisted planning of optical networks. A two-stage greenfield optical network design optimiser...... is developed, based on shortest-path algorithms and a comparatively new metaheuristic called simulated allocation. It is able to handle design of all-optical mesh networks with optical cross-connects, considers duct as well as fibre and node costs, and can also design protected networks. The method is assessed...

  16. Deterministic bound for avionics switched networks according to networking features using network calculus

    Directory of Open Access Journals (Sweden)

    Feng HE

    2017-12-01

    Full Text Available The state of the art avionics system adopts switched networks for airborne communications. A major concern in the design of the networks is the end-to-end guarantee ability. Analytic methods have been developed to compute the worst-case delays according to the detailed configurations of flows and networks within avionics context, such as network calculus and trajectory approach. It still lacks a relevant method to make a rapid performance estimation according to some typically switched networking features, such as networking scale, bandwidth utilization and average flow rate. The goal of this paper is to establish a deterministic upper bound analysis method by using these networking features instead of the complete network configurations. Two deterministic upper bounds are proposed from network calculus perspective: one is for a basic estimation, and another just shows the benefits from grouping strategy. Besides, a mathematic expression for grouping ability is established based on the concept of network connecting degree, which illustrates the possibly minimal grouping benefit. For a fully connected network with 4 switches and 12 end systems, the grouping ability coming from grouping strategy is 15–20%, which just coincides with the statistical data (18–22% from the actual grouping advantage. Compared with the complete network calculus analysis method for individual flows, the effectiveness of the two deterministic upper bounds is no less than 38% even with remarkably varied packet lengths. Finally, the paper illustrates the design process for an industrial Avionics Full DupleX switched Ethernet (AFDX networking case according to the two deterministic upper bounds and shows that a better control for network connecting, when designing a switched network, can improve the worst-case delays dramatically. Keywords: Deterministic bound, Grouping ability, Network calculus, Networking features, Switched networks

  17. Low threshold all-optical crossbar switch on GaAs-GaAlAs channel waveguide arrays

    Science.gov (United States)

    Jannson, Tomasz; Kostrzewski, Andrew

    1994-09-01

    During the Phase 2 project entitled 'Low Threshold All-Optical Crossbar Switch on GaAs - GaAlAs Channel Waveguide Array,' Physical Optics Corporation (POC) developed the basic principles for the fabrication of all-optical crossbar switches. Based on this development. POC fabricated a 2 x 2 GaAs/GaAlAs switch that changes the direction of incident light with minimum insertion loss and nonlinear distortion. This unique technology can be used in both analog and digital networks. The applications of this technology are widespread. Because the all-optical network does not have any speed limitations (RC time constant), POC's approach will be beneficial to SONET networks, phased array radar networks, very high speed oscilloscopes, all-optical networks, IR countermeasure systems, BER equipment, and the fast growing video conferencing network market. The novel all-optical crossbar switch developed in this program will solve interconnect problems. and will be a key component in the widely proposed all-optical 200 Gb/s SONET/ATM networks.

  18. Strategies for optical transport network recovery under epidemic network failures

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova; Kosteas, Vasileios

    2015-01-01

    The current trend in deploying automatic control plane solutions for increased flexibility in the optical transport layer leads to numerous advantages for both the operators and the customers, but also pose challenges related to the stability of the network and its ability to operate in a robust...... manner under different failure scenarios. This work evaluates two rerouting strategies and proposes four policies for failure handling in a connection-oriented optical transport network, under generalized multiprotocol label switching control plane. The performance of the strategies and the policies......, and that there exist a clear trade-off between policy performance and network resource consumption, which must be addressed by network operators for improved robustness of their transport infrastructures. Applying proactive methods for avoiding areas where epidemic failures spread results in 50% less connections...

  19. A packet-switched network for data readout from the LHC inner detector

    International Nuclear Information System (INIS)

    Ostby, J.M.; Sorasen, O.

    1994-01-01

    This paper presents a network which can be used for data fusion in the planned LHC (Large Hadron Collider) ATLAS experiment at CERN. The network named SWIPP (SWitched Interconnection of Parallel Processors), is built of 16 x 16 star switches and protocol engines connected by pairs of optical fibers. Each channel is designed to carry up to 1 Gbps in each direction. The paper will give a brief introduction to SWIPP principles and ASIC implementation. Some of the advantages offered by the network will be mentioned

  20. Ultrafast optical switching in three-dimensional photonic crystals

    NARCIS (Netherlands)

    Mazurenko, D.A.

    2004-01-01

    The rapidly expanding research on photonic crystals is driven by potential applications in all-optical switches, optical computers, low-threshold lasers, and holographic data storage. The performance of such devices might surpass the speed of traditional electronics by several orders of magnitude

  1. Consideration for wavelength multiplexing versus time multiplexing in optical transport network

    DEFF Research Database (Denmark)

    Limal, Emmanuel; Stubkjær, Kristian Elmholdt

    1999-01-01

    We compare optical wavelength multiplexing and time multiplexing techniquesfor optical transport network by studying the space switch sizes of OXCs andtheir interfaces as a function of the fraction of add/drop traffic....

  2. Optically controlled redshift switching effects in hybrid fishscale metamaterials

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2018-05-01

    Full Text Available We numerically demonstrate optically controlled THz response in a hybrid fishscale metamaterial with embedded photoconductive silicon at oblique incidence of TE wave. The oblique incidence allows excitation of Fano-type trapped mode resonance in a 2-fold rotational symmetric metamaterial. The hybrid fishscale metamaterial exhibits an optically controlled redshift switching effect in the THz range. The switching effect is dominated by the conductivity of the silicon instead of mechanically adjusting angles of incidence. The tuning frequency range is up to 0.3THz with a large modulation depth and high transmission in the “ON” state. The fishscale metamaterial-based switching has been experimentally verified by its microwave counterpart integrated by variable resistors. Our work provides an alternative route to realize tunable Fano-type response in metamaterials and is of importance to active manipulation, sensing and switching of THz waves in practical applications.

  3. Optically controlled redshift switching effects in hybrid fishscale metamaterials

    Science.gov (United States)

    Wang, Yu; Zhu, Jinwei; Zhang, Hao; Zhang, Wenxing; Dong, Guohua; Ye, Peng; Lv, Tingting; Zhu, Zheng; Li, Yuxiang; Guan, Chunying; Shi, Jinhui

    2018-05-01

    We numerically demonstrate optically controlled THz response in a hybrid fishscale metamaterial with embedded photoconductive silicon at oblique incidence of TE wave. The oblique incidence allows excitation of Fano-type trapped mode resonance in a 2-fold rotational symmetric metamaterial. The hybrid fishscale metamaterial exhibits an optically controlled redshift switching effect in the THz range. The switching effect is dominated by the conductivity of the silicon instead of mechanically adjusting angles of incidence. The tuning frequency range is up to 0.3THz with a large modulation depth and high transmission in the "ON" state. The fishscale metamaterial-based switching has been experimentally verified by its microwave counterpart integrated by variable resistors. Our work provides an alternative route to realize tunable Fano-type response in metamaterials and is of importance to active manipulation, sensing and switching of THz waves in practical applications.

  4. Optical networks a practical perspective

    CERN Document Server

    Ramaswami, Rajiv

    2001-01-01

    This fully updated and expanded second edition of Optical Networks: A Practical Perspective succeeds the first as the authoritative source for information on optical networking technologies and techniques. Written by two of the field's most respected individuals, it covers componentry and transmission in detail but also emphasizes the practical networking issues that affect organizations as they evaluate, deploy, or develop optical solutions. This book captures all the hard-to-find information on architecture, control and management, and other communications topics that

  5. Ultralow power all-optical switch

    DEFF Research Database (Denmark)

    Nguyen, H.; Grange, T.; Reznychenko, B.

    2017-01-01

    Optical logic down to the single photon level holds the promise of data processing with a better energy efficiency than electronic devices [1]. In addition, preservation of quantum coherence in such logical components could lead to optical quantum logical gates [2--4]. Optical logic requires......-level systems coupled to light via a tailored photonic environment [8--13]. However optical logic requires two-mode non-linearities [14, 15]. Here we take advantage of the large coupling efficiency and the broadband operation of a photonic wire containing a semiconductor quantum dot (QD) [16] to implement...... an all-optical logical component, wherein as few as 10 photons per QD lifetime in one mode control the reflectivity of another, spectrally distinct, mode. Whether classical or quantum, optical communication has proven to be the best choice for long distance information distribution. All-optical data...

  6. Characterization of IP Flows Eligible for Lambda-Connections in Optical Networks

    NARCIS (Netherlands)

    Fioreze, Tiago; Oude Wolbers, Mattijs; van de Meent, R.; Pras, Aiko

    2008-01-01

    The advance on data transmission in optical networks has allowed data forwarding decisions to be taken at multiple levels in the protocol stack (e.g., at network and optical levels). With such capability, big IP flows can be moved from the network level and switched completely at the optical level

  7. Clustering promotes switching dynamics in networks of noisy neurons

    Science.gov (United States)

    Franović, Igor; Klinshov, Vladimir

    2018-02-01

    Macroscopic variability is an emergent property of neural networks, typically manifested in spontaneous switching between the episodes of elevated neuronal activity and the quiescent episodes. We investigate the conditions that facilitate switching dynamics, focusing on the interplay between the different sources of noise and heterogeneity of the network topology. We consider clustered networks of rate-based neurons subjected to external and intrinsic noise and derive an effective model where the network dynamics is described by a set of coupled second-order stochastic mean-field systems representing each of the clusters. The model provides an insight into the different contributions to effective macroscopic noise and qualitatively indicates the parameter domains where switching dynamics may occur. By analyzing the mean-field model in the thermodynamic limit, we demonstrate that clustering promotes multistability, which gives rise to switching dynamics in a considerably wider parameter region compared to the case of a non-clustered network with sparse random connection topology.

  8. Quantifying the dynamics of coupled networks of switches and oscillators.

    Directory of Open Access Journals (Sweden)

    Matthew R Francis

    Full Text Available Complex network dynamics have been analyzed with models of systems of coupled switches or systems of coupled oscillators. However, many complex systems are composed of components with diverse dynamics whose interactions drive the system's evolution. We, therefore, introduce a new modeling framework that describes the dynamics of networks composed of both oscillators and switches. Both oscillator synchronization and switch stability are preserved in these heterogeneous, coupled networks. Furthermore, this model recapitulates the qualitative dynamics for the yeast cell cycle consistent with the hypothesized dynamics resulting from decomposition of the regulatory network into dynamic motifs. Introducing feedback into the cell-cycle network induces qualitative dynamics analogous to limitless replicative potential that is a hallmark of cancer. As a result, the proposed model of switch and oscillator coupling provides the ability to incorporate mechanisms that underlie the synchronized stimulus response ubiquitous in biochemical systems.

  9. Optical network control plane for multi-domain networking

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva

    This thesis focuses on multi-domain routing for traffice engineering and survivability support in optical transport networks under the Generalized Multi-Protocol Label Switching (GMPLS) control framework. First, different extensions to the Border Gateway Protocol for multi-domain Traffic...... process are not enough for efficient TE in mesh multi-domain networks. Enhancing the protocol with multi-path dissemination capability, combined with the employment of an end-to-end TE metric proves to be a highly efficient solution. Simulation results show good performance characteristics of the proposed...... is not as essential for improved network performance as the length of the provided paths. Second, the issue of multi-domain survivability support is analyzed. An AS-disjoint paths is beneficial not only for resilience support, but also for facilitating adequate network reactions to changes in the network, which...

  10. On the fly all-optical packet switching based on hybrid WDM/OCDMA labeling scheme

    Science.gov (United States)

    Brahmi, Houssem; Giannoulis, Giannis; Menif, Mourad; Katopodis, Vasilis; Kalavrouziotis, Dimitrios; Kouloumentas, Christos; Groumas, Panos; Kanakis, Giannis; Stamatiadis, Christos; Avramopoulos, Hercules; Erasme, Didier

    2014-02-01

    We introduce a novel design of an all-optical packet routing node that allows for the selection and forwarding of optical packets based on the routing information contained in hybrid wavelength division multiplexing/optical code division multiple access (WDM/OCDMA) labels. A stripping paradigm of optical code-label is adopted. The router is built around an optical-code gate that consists in an optical flip-flop controlled by two fiber Bragg grating correlators and is combined with a Mach-Zehnder interferometer (MZI)-based forwarding gate. We experimentally verify the proof-of-principle operation of the proposed self-routing node under NRZ and OCDMA packet traffic conditions. The successful switching of elastic NRZ payload at 40 Gb/s controlled by DS-OCDMA coded labels and the forwarding operation of encoded data using EQC codes are presented. Proper auto-correlation functions are obtained with higher than 8.1 dB contrast ratio, suitable to efficiently trigger the latching device with a contrast ratio of 11.6 dB and switching times below 3.8 ns. Error-free operation is achieved with 1.5 dB penalty for 40 Gb/s NRZ data and with 2.1 dB penalty for DS-OCDMA packets. The scheme can further be applied to large-scale optical packet switching networks by exploiting efficient optical coders allocated at different WDM channels.

  11. All-Optical Switching in Photonic Crystal Cavities

    DEFF Research Database (Denmark)

    Heuck, Mikkel

    All-Optical switching in photonic crystal waveguide-cavity structures is studied predominantly theoretically and numerically, but also from an experimental point of view. We have calculated the first order perturbations to the resonance frequency and decay rate of cavity modes, using a mathematical...... exhibiting Fano resonances. These devices were predicted to be superior to structures with the more well-known Lorentzian line shape in terms of energy consumption and switching contrast. Finally, the mathematical framework of optimal control theory was employed as a general setting, in which the optical...... faster than the photon lifetime by utilizing interference effects....

  12. Implementation of automatic protection switching in an optical cross connect

    OpenAIRE

    Uy, Jason

    2005-01-01

    Having a reliable network is a hard requirement for Telecommunication companies when deploying new networks. Service providers and enterprise customers lose a lot of money any time an interruption of internet service occurs. The SONETISDH specification specifies several different types of topology that support redundancy. An Automatic Protection Switching (APS) mechanism is specified for each topology to dictate how a network behaves in a failure event. For this project, a software implementa...

  13. Synchronization of Switched Interval Networks and Applications to Chaotic Neural Networks

    OpenAIRE

    Cao, Jinde; Alofi, Abdulaziz; Al-Mazrooei, Abdullah; Elaiw, Ahmed

    2013-01-01

    This paper investigates synchronization problem of switched delay networks with interval parameters uncertainty, based on the theories of the switched systems and drive-response technique, a mathematical model of the switched interval drive-response error system is established. Without constructing Lyapunov-Krasovskii functions, introducing matrix measure method for the first time to switched time-varying delay networks, combining Halanay inequality technique, synchroniza...

  14. Metro Optical Networks for Homeland Security

    Science.gov (United States)

    Bechtel, James H.

    Metro optical networks provide an enticing opportunity for strengthening homeland security. Many existing and emerging fiber-optic networks can be adapted for enhanced security applications. Applications include airports, theme parks, sports venues, and border surveillance systems. Here real-time high-quality video and captured images can be collected, transported, processed, and stored for security applications. Video and data collection are important also at correctional facilities, courts, infrastructure (e.g., dams, bridges, railroads, reservoirs, power stations), and at military and other government locations. The scaling of DWDM-based networks allows vast amounts of data to be collected and transported including biometric features of individuals at security check points. Here applications will be discussed along with potential solutions and challenges. Examples of solutions to these problems are given. This includes a discussion of metropolitan aggregation platforms for voice, video, and data that are SONET compliant for use in SONET networks and the use of DWDM technology for scaling and transporting a variety of protocols. Element management software allows not only network status monitoring, but also provides optimized allocation of network resources through the use of optical switches or electrical cross connects.

  15. Optical protocols for terabit networks

    Science.gov (United States)

    Chua, P. L.; Lambert, J. L.; Morookian, J. M.; Bergman, L. A.

    1991-01-01

    This paper describes a new fiber-optic local area network technology providing 100X improvement over current technology, has full crossbar funtionality, and inherent data security. Based on optical code-division multiple access (CDMA), using spectral phase encoding/decoding of optical pulses, networking protocols are implemented entirely in the optical domain and thus conventional networking bottlenecks are avoided. Component and system issues for a proof-of-concept demonstration are discussed, as well as issues for a more practical and commercially exploitable system. Possible terrestrial and aerospace applications of this technology, and its impact on other technologies are explored. Some initial results toward realization of this concept are also included.

  16. Developing a New HSR Switching Node (SwitchBox for Improving Traffic Performance in HSR Networks

    Directory of Open Access Journals (Sweden)

    Nguyen Xuan Tien

    2016-01-01

    Full Text Available High availability is crucial for industrial Ethernet networks as well as Ethernet-based control systems such as automation networks and substation automation systems (SAS. Since standard Ethernet does not support fault tolerance capability, the high availability of Ethernet networks can be increased by using redundancy protocols. Various redundancy protocols for Ethernet networks have been developed and standardized, such as rapid spanning tree protocol (RSTP, media redundancy protocol (MRP, parallel redundancy protocol (PRP, high-availability seamless redundancy (HSR and others. RSTP and MRP have switchover delay drawbacks. PRP provides zero recovery time, but requires a duplicate network infrastructure. HSR operation is similar to PRP, but HSR uses a single network. However, the standard HSR protocol is mainly applied to ring-based topologies and generates excessively unnecessary redundant traffic in the network. In this paper, we develop a new switching node for the HSR protocol, called SwitchBox, which is used in HSR networks in order to support any network topology and significantly reduce redundant network traffic, including unicast, multicast and broadcast traffic, compared with standard HSR. By using the SwitchBox, HSR not only provides seamless communications with zero switchover time in case of failure, but it is also easily applied to any network topology and significantly reduces unnecessary redundant traffic in HSR networks.

  17. Development of laser marking system with electro-optic Q-switch

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Kim, Jeong Moog; Kim, Kwang Suk; Park, Seung Kyu; Baik, Sung Hoon.

    1995-11-01

    We developed a high repetition electro-optic Q switch Nd:YAG laser and scan system for laser marking. We localized the scan mirrors and their mounts. We made the database for the optical properties of commercial flat-field lenses with our optics design software. We fabricated the detailed network between the galvanometer based beam scanning system and the laser generator. To accelerate the commercialization by the joint company, the training and transfer of technology were pursued in the joint participation by company researchers from the early stage. (author). 8 refs., 6 tabs., 27 figs

  18. Development of laser marking system with electro-optic Q-switch

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Jung; Kim, Jeong Moog; Kim, Kwang Suk; Park, Seung Kyu; Baik, Sung Hoon

    1995-11-01

    We developed a high repetition electro-optic Q switch Nd:YAG laser and scan system for laser marking. We localized the scan mirrors and their mounts. We made the database for the optical properties of commercial flat-field lenses with our optics design software. We fabricated the detailed network between the galvanometer based beam scanning system and the laser generator. To accelerate the commercialization by the joint company, the training and transfer of technology were pursued in the joint participation by company researchers from the early stage. (author). 8 refs., 6 tabs., 27 figs.

  19. Engineered Multifunctional Nanophotonic Materials for Ultrafast Optical Switching

    Science.gov (United States)

    2012-11-02

    and Co3 + placed at tetrahedral and octahedral sites, respectively. Single -layer thin films of Co3O4 nanoparticles have large optical nonlinearity and...the first two methodologies in systems having weakly resonant structures, including 3-D and/or 1-D photonic crystal structures (i.e. nonlinear Bragg...Nonlinear optical transmission of lead phthalocyanine-doped nematic liquid crystal composites for multiscale nonlinear switching from nanosecond to

  20. The Robustness of Stochastic Switching Networks

    OpenAIRE

    Loh, Po-Ling; Zhou, Hongchao; Bruck, Jehoshua

    2009-01-01

    Many natural systems, including chemical and biological systems, can be modeled using stochastic switching circuits. These circuits consist of stochastic switches, called pswitches, which operate with a fixed probability of being open or closed. We study the effect caused by introducing an error of size ∈ to each pswitch in a stochastic circuit. We analyze two constructions – simple series-parallel and general series-parallel circuits – and prove that simple series-parallel circuits are robus...

  1. Carbon nanotube network-silicon oxide non-volatile switches.

    Science.gov (United States)

    Liao, Albert D; Araujo, Paulo T; Xu, Runjie; Dresselhaus, Mildred S

    2014-12-08

    The integration of carbon nanotubes with silicon is important for their incorporation into next-generation nano-electronics. Here we demonstrate a non-volatile switch that utilizes carbon nanotube networks to electrically contact a conductive nanocrystal silicon filament in silicon dioxide. We form this device by biasing a nanotube network until it physically breaks in vacuum, creating the conductive silicon filament connected across a small nano-gap. From Raman spectroscopy, we observe coalescence of nanotubes during breakdown, which stabilizes the system to form very small gaps in the network~15 nm. We report that carbon nanotubes themselves are involved in switching the device to a high resistive state. Calculations reveal that this switching event occurs at ~600 °C, the temperature associated with the oxidation of nanotubes. Therefore, we propose that, in switching to a resistive state, the nanotube oxidizes by extracting oxygen from the substrate.

  2. Optical implementation of (3, 3, 2) regular rectangular CC-Banyan optical network

    Science.gov (United States)

    Yang, Junbo; Su, Xianyu

    2007-07-01

    CC-Banyan network plays an important role in the optical interconnection network. Based on previous reports of (2, 2, 3) the CC-Banyan network, another rectangular-Banyan network, i.e. (3, 3, 2) rectangular CC-Banyan network, has been discussed. First, according to its construction principle, the topological graph and the routing rule of (3, 3, 2) rectangular CC-Banyan network have been proposed. Then, the optically experimental setup of (3, 3, 2) rectangular CC-Banyan network has been designed and achieved. Each stage of node switch consists of phase spatial light modulator (PSLM) and polarizing beam-splitter (PBS), and fiber has been used to perform connection between adjacent stages. PBS features that s-component (perpendicular to the incident plane) of the incident light beam is reflected, and p-component (parallel to the incident plane) passes through it. According to switching logic, under the control of external electrical signals, PSLM functions to control routing paths of the signal beams, i.e. the polarization of each optical signal is rotated or not rotated 90° by a programmable PSLM. Finally, the discussion and analysis show that the experimental setup designed here can realize many functions such as optical signal switch and permutation. It has advantages of large number of input/output-ports, compact in structure, and low energy loss. Hence, the experimental setup can be used in optical communication and optical information processing.

  3. Fully reconfigurable 2x2 optical cross-connect using tunable wavelength switching modules

    DEFF Research Database (Denmark)

    Liu, Fenghai; Zheng, Xueyan; Pedersen, Rune Johan Skullerud

    2001-01-01

    A modular tunable wavelength switching module is proposed and used to construct 2x2 fully reconfigurable optical cross-connects. Large size optical switch is avoided in the OXC and it is easy to upgrade to more wavelength channels.......A modular tunable wavelength switching module is proposed and used to construct 2x2 fully reconfigurable optical cross-connects. Large size optical switch is avoided in the OXC and it is easy to upgrade to more wavelength channels....

  4. Synchronization in slowly switching networks of coupled oscillators

    Science.gov (United States)

    Zhou, Jie; Zou, Yong; Guan, Shuguang; Liu, Zonghua; Boccaletti, S.

    2016-01-01

    Networks whose structure of connections evolves in time constitute a big challenge in the study of synchronization, in particular when the time scales for the evolution of the graph topology are comparable with (or even longer than) those pertinent to the units’ dynamics. We here focus on networks with a slow-switching structure, and show that the necessary conditions for synchronization, i.e. the conditions for which synchronization is locally stable, are determined by the time average of the largest Lyapunov exponents of transverse modes of the switching topologies. Comparison between fast- and slow-switching networks allows elucidating that slow-switching processes prompt synchronization in the cases where the Master Stability Function is concave, whereas fast-switching schemes facilitate synchronization for convex curves. Moreover, the condition of slow-switching enables the introduction of a control strategy for inducing synchronization in networks with arbitrary structure and coupling strength, which is of evident relevance for broad applications in real world systems. PMID:27779253

  5. Stabilization Strategies of Supply Networks with Stochastic Switched Topology

    Directory of Open Access Journals (Sweden)

    Shukai Li

    2013-01-01

    Full Text Available In this paper, a dynamical supply networks model with stochastic switched topology is presented, in which the stochastic switched topology is dependent on a continuous time Markov process. The goal is to design the state-feedback control strategies to stabilize the dynamical supply networks. Based on Lyapunov stability theory, sufficient conditions for the existence of state feedback control strategies are given in terms of matrix inequalities, which ensure the robust stability of the supply networks at the stationary states and a prescribed H∞ disturbance attenuation level with respect to the uncertain demand. A numerical example is given to illustrate the effectiveness of the proposed method.

  6. The Advent of WDM and the All-Optical Network: A Reality Check.

    Science.gov (United States)

    Lutkowitz, Mark

    1998-01-01

    Discussion of the telecommunications industry focuses on WDM (wavelength division multiplexing) as a solution for dealing with capacity constraints. Highlights include fiber optic technology; cross-connecting and switching wavelengths; SONET (Synchronous Optical Network) and wavelength networking; and optical TDM (Time Division Multiplexing). (LRW)

  7. Bipolar resistive switching behaviors of ITO nanowire networks

    Directory of Open Access Journals (Sweden)

    Qiang Li

    2016-02-01

    Full Text Available We have fabricated indium tin oxide (ITO nanowire (NW networks on aluminum electrodes using electron beam evaporation. The Ag/ITO-NW networks/Al capacitor exhibits bipolar resistive switching behavior. The resistive switching characteristics of ITO-NW networks are related to the morphology of NWs. The x-ray photoelectron spectroscopy was used to obtain the chemical nature from the NWs surface, investigating the oxygen vacancy state. A stable switching voltages and a clear memory window were observed in needle-shaped NWs. The ITO-NW networks can be used as a new two-dimensional metal oxide material for the fabrication of high-density memory devices.

  8. OPSquare : assessment of a novel flat optical data center network architecture under realistic data center traffic

    NARCIS (Netherlands)

    Miao, W.; Yan, F.; Raz, O.; Calabretta, N.

    2016-01-01

    The performances of OPSquare flat data-center network based on flow-controlled optical switches are investigated. Results show <1E-6 packet loss and <2µs end-to-end latency for 0.3 load when scaling to 40960 servers with 32×32 optical switches.

  9. Network switching strategy for energy conservation in heterogeneous networks.

    Directory of Open Access Journals (Sweden)

    Yujae Song

    Full Text Available In heterogeneous networks (HetNets, the large-scale deployment of small base stations (BSs together with traditional macro BSs is an economical and efficient solution that is employed to address the exponential growth in mobile data traffic. In dense HetNets, network switching, i.e., handovers, plays a critical role in connecting a mobile terminal (MT to the best of all accessible networks. In the existing literature, a handover decision is made using various handover metrics such as the signal-to-noise ratio, data rate, and movement speed. However, there are few studies on handovers that focus on energy efficiency in HetNets. In this paper, we propose a handover strategy that helps to minimize energy consumption at BSs in HetNets without compromising the quality of service (QoS of each MT. The proposed handover strategy aims to capture the effect of the stochastic behavior of handover parameters and the expected energy consumption due to handover execution when making a handover decision. To identify the validity of the proposed handover strategy, we formulate a handover problem as a constrained Markov decision process (CMDP, by which the effects of the stochastic behaviors of handover parameters and consequential handover energy consumption can be accurately reflected when making a handover decision. In the CMDP, the aim is to minimize the energy consumption to service an MT over the lifetime of its connection, and the constraint is to guarantee the QoS requirements of the MT given in terms of the transmission delay and call-dropping probability. We find an optimal policy for the CMDP using a combination of the Lagrangian method and value iteration. Simulation results verify the validity of the proposed handover strategy.

  10. A low-latency optical switch architecture using integrated μm SOI-based contention resolution and switching

    Science.gov (United States)

    Mourgias-Alexandris, G.; Moralis-Pegios, M.; Terzenidis, N.; Cherchi, M.; Harjanne, M.; Aalto, T.; Vyrsokinos, K.; Pleros, N.

    2018-02-01

    The urgent need for high-bandwidth and high-port connectivity in Data Centers has boosted the deployment of optoelectronic packet switches towards bringing high data-rate optics closer to the ASIC, realizing optical transceiver functions directly at the ASIC package for high-rate, low-energy and low-latency interconnects. Even though optics can offer a broad range of low-energy integrated switch fabrics for replacing electronic switches and seamlessly interface with the optical I/Os, the use of energy- and latency-consuming electronic SerDes continues to be a necessity, mainly dictated by the absence of integrated and reliable optical buffering solutions. SerDes undertakes the role of optimally synergizing the lower-speed electronic buffers with the incoming and outgoing optical streams, suggesting that a SerDes-released chip-scale optical switch fabric can be only realized in case all necessary functions including contention resolution and switching can be implemented on a common photonic integration platform. In this paper, we demonstrate experimentally a hybrid Broadcast-and-Select (BS) / wavelength routed optical switch that performs both the optical buffering and switching functions with μm-scale Silicon-integrated building blocks. Optical buffering is carried out in a silicon-integrated variable delay line bank with a record-high on-chip delay/footprint efficiency of 2.6ns/mm2 and up to 17.2 nsec delay capability, while switching is executed via a BS design and a silicon-integrated echelle grating, assisted by SOA-MZI wavelength conversion stages and controlled by a FPGA header processing module. The switch has been experimentally validated in a 3x3 arrangement with 10Gb/s NRZ optical data packets, demonstrating error-free switching operation with a power penalty of <5dB.

  11. Quantum optics. All-optical routing of single photons by a one-atom switch controlled by a single photon.

    Science.gov (United States)

    Shomroni, Itay; Rosenblum, Serge; Lovsky, Yulia; Bechler, Orel; Guendelman, Gabriel; Dayan, Barak

    2014-08-22

    The prospect of quantum networks, in which quantum information is carried by single photons in photonic circuits, has long been the driving force behind the effort to achieve all-optical routing of single photons. We realized a single-photon-activated switch capable of routing a photon from any of its two inputs to any of its two outputs. Our device is based on a single atom coupled to a fiber-coupled, chip-based microresonator. A single reflected control photon toggles the switch from high reflection (R ~ 65%) to high transmission (T ~ 90%), with an average of ~1.5 control photons per switching event (~3, including linear losses). No additional control fields are required. The control and target photons are both in-fiber and practically identical, making this scheme compatible with scalable architectures for quantum information processing. Copyright © 2014, American Association for the Advancement of Science.

  12. On-Chip SDM Switching for Unicast, Multicast and Traffic Grooming in Data Center Networks

    DEFF Research Database (Denmark)

    Kamchevska, Valerija; Ding, Yunhong; Dalgaard, Kjeld

    2017-01-01

    This paper reports on the use of a novel photonic integrated circuit that facilitates multicast and grooming in an optical data center architecture. The circuit allows for on-chip spatial multiplexing and demultiplexing as well as fiber core switching. Using this device, we experimentally verify...... that multicast and/or grooming can be successfully performed along the full range of output ports, for different group size and different power ratio. Moreover, we experimentally demonstrate SDM transmission and 5 Tbit/s switching using the on-chip fiber switch with integrated fan-in/fan-out devices and achieve...... errorfree performance (BER≤10-9) for a network scenario including simultaneous unicast/multicast switching and traffic grooming....

  13. Optical Neural Network Classifier Architectures

    National Research Council Canada - National Science Library

    Getbehead, Mark

    1998-01-01

    We present an adaptive opto-electronic neural network hardware architecture capable of exploiting parallel optics to realize real-time processing and classification of high-dimensional data for Air...

  14. Modeling and Analysis of Modal Switching in Networked Transport Systems

    International Nuclear Information System (INIS)

    Hante, Falk M.; Leugering, Guenter; Seidman, Thomas I.

    2009-01-01

    We consider networked transport systems defined on directed graphs: the dynamics on the edges correspond to solutions of transport equations with space dimension one. In addition to the graph setting, a major consideration is the introduction and propagation of discontinuities in the solutions when the system may discontinuously switch modes, naturally or as a hybrid control. This kind of switching has been extensively studied for ordinary differential equations, but not much so far for systems governed by partial differential equations. In particular, we give well-posedness results for switching as a control, both in finite horizon open loop operation and as feedback based on sensor measurements in the system

  15. Synchronization of Switched Interval Networks and Applications to Chaotic Neural Networks

    Directory of Open Access Journals (Sweden)

    Jinde Cao

    2013-01-01

    Full Text Available This paper investigates synchronization problem of switched delay networks with interval parameters uncertainty, based on the theories of the switched systems and drive-response technique, a mathematical model of the switched interval drive-response error system is established. Without constructing Lyapunov-Krasovskii functions, introducing matrix measure method for the first time to switched time-varying delay networks, combining Halanay inequality technique, synchronization criteria are derived for switched interval networks under the arbitrary switching rule, which are easy to verify in practice. Moreover, as an application, the proposed scheme is then applied to chaotic neural networks. Finally, numerical simulations are provided to illustrate the effectiveness of the theoretical results.

  16. Complete achromatic and robustness electro-optic switch between two integrated optical waveguides

    Science.gov (United States)

    Huang, Wei; Kyoseva, Elica

    2018-01-01

    In this paper, we present a novel design of electro-optic modulator and optical switching device, based on current integrated optics technique. The advantages of our optical switching device are broadband of input light wavelength, robustness against varying device length and operation voltages, with reference to previous design. Conforming to our results of previous paper [Huang et al, phys. lett. a, 90, 053837], the coupling of the waveguides has a hyperbolic-secant shape. while detuning has a sign flip at maximum coupling, we called it as with a sign flip of phase mismatch model. The a sign flip of phase mismatch model can produce complete robust population transfer. In this paper, we enhance this device to switch light intensity controllable, by tuning external electric field based on electro-optic effect.

  17. All-optical switching based on optical fibre long period gratings modified bacteriorhodopsin

    Science.gov (United States)

    Korposh, S.; James, S.; Partridge, M.; Sichka, M.; Tatam, R.

    2018-05-01

    All-optical switching using an optical fibre long-period gating (LPG) modified with bacteriorhodopsin (bR) is demonstrated. The switching process is based on the photo-induced RI change of bR, which in turn changes the phase matching conditions of the mode coupling by the LPG, leading to modulation of the propagating light. The effect was studied with an LPG immersed into a bR solution and with LPGs coated with the bR films, deposited onto the LPGs using the layer-by-layer electrostatic self-assembly (LbL) method. The dependence of the all-optical switching efficiency upon the concentration of the bR solution and on the grating period of the LPG was also studied. In addition, an in-fibre Mach-Zehnder interferometer (MZI) composed of a cascaded LPG pair separated by 30 mm and modified with bR was used to enhance the wavelength range of all-optical switching. The switching wavelength is determined by the grating period of the LPG. Switching efficiencies of 16% and 35% were observed when an LPG and an MZI were immersed into bR solutions, respectively. The switching time for devices coated with bR-films was within 1 s, 10 times faster than that observed for devices immersed into bR solution.

  18. Observability of Automata Networks: Fixed and Switching Cases.

    Science.gov (United States)

    Li, Rui; Hong, Yiguang; Wang, Xingyuan

    2018-04-01

    Automata networks are a class of fully discrete dynamical systems, which have received considerable interest in various different areas. This brief addresses the observability of automata networks and switched automata networks in a unified framework, and proposes simple necessary and sufficient conditions for observability. The results are achieved by employing methods from symbolic computation, and are suited for implementation using computer algebra systems. Several examples are presented to demonstrate the application of the results.

  19. Atom-loss-induced quantum optical bi-stability switch

    International Nuclear Information System (INIS)

    Wu Bao-Jun; Cui Fu-Cheng

    2012-01-01

    We investigate the nonlinear dynamics of a system composed of a cigar-shaped Bose—Einstein condensate and an optical cavity with the two sides coupled dispersively. By adopting discrete-mode approximation for the condensate, taking atom loss as a necessary part of the model to analyze the evolution of the system, while using trial and error method to find out steady states of the system as a reference, numerical simulation demonstrates that with a constant pump, atom loss will trigger a quantum optical bi-stability switch, which predicts a new interesting phenomenon for experiments to verify

  20. Tunable photonic bandgap fiber based devices for optical networks

    DEFF Research Database (Denmark)

    Alkeskjold, Thomas Tanggaard; Scolari, Lara; Rottwitt, Karsten

    2005-01-01

    In future all optical networks one of the enabling technologies is tunable elements including reconfigurable routers, switches etc. Thus, the development of a technology platform that allows construction of tuning components is critical. Lately, microstructured optical fibers, filled with liquid......, for example a liquid crystal that changes optical properties when subjected to, for example, an optical or an electrical field. The utilization of these two basic properties allows design of tunable optical devices for optical networks. In this work, we focus on applications of such devices and discuss recent...... crystals, have proven to be a candidate for such a platform. Microstructured optical fibers offer unique wave-guiding properties that are strongly related to the design of the air holes in the cladding of the fiber. These wave-guiding properties may be altered by filling the air holes with a material...

  1. Modeling of Semiconductor Optical Amplifier Gain Characteristics for Amplification and Switching

    Science.gov (United States)

    Mahad, Farah Diana; Sahmah, Abu; Supa'at, M.; Idrus, Sevia Mahdaliza; Forsyth, David

    2011-05-01

    The Semiconductor Optical Amplifier (SOA) is presently commonly used as a booster or pre-amplifier in some communication networks. However, SOAs are also a strong candidate for utilization as multi-functional elements in future all-optical switching, regeneration and also wavelength conversion schemes. With this in mind, the purpose of this paper is to simulate the performance of the SOA for improved amplification and switching functions. The SOA is modeled and simulated using OptSim software. In order to verify the simulated results, a MATLAB mathematical model is also used to aid the design of the SOA. Using the model, the gain difference between simulated and mathematical results in the unsaturated region is <1dB. The mathematical analysis is in good agreement with the simulation result, with only a small offset due to inherent software limitations in matching the gain dynamics of the SOA.

  2. Communication Network Architectures Based on Ethernet Passive Optical Network for Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2016-03-01

    Full Text Available Nowadays, with large-scale offshore wind power farms (WPFs becoming a reality, more efforts are needed to maintain a reliable communication network for WPF monitoring. Deployment topologies, redundancy, and network availability are the main items to enhance the communication reliability between wind turbines (WTs and control centers. Traditional communication networks for monitoring and control (i.e., supervisory control and data acquisition (SCADA systems using switched gigabit Ethernet will not be sufficient for the huge amount of data passing through the network. In this paper, the optical power budget, optical path loss, reliability, and network cost of the proposed Ethernet Passive Optical Network (EPON-based communication network for small-size offshore WPFs have been evaluated for five different network architectures. The proposed network model consists of an optical network unit device (ONU deployed on the WT side for collecting data from different internal networks. All ONUs from different WTs are connected to a central optical line terminal (OLT, placed in the control center. There are no active electronic elements used between the ONUs and the OLT, which reduces the costs and complexity of maintenance and deployment. As fiber access networks without any protection are characterized by poor reliability, three different protection schemes have been configured, explained, and discussed. Considering the cost of network components, the total implementation expense of different architectures with, or without, protection have been calculated and compared. The proposed network model can significantly contribute to the communication network architecture for next generation WPFs.

  3. Dynamic optical resource allocation for mobile core networks with software defined elastic optical networking.

    Science.gov (United States)

    Zhao, Yongli; Chen, Zhendong; Zhang, Jie; Wang, Xinbo

    2016-07-25

    Driven by the forthcoming of 5G mobile communications, the all-IP architecture of mobile core networks, i.e. evolved packet core (EPC) proposed by 3GPP, has been greatly challenged by the users' demands for higher data rate and more reliable end-to-end connection, as well as operators' demands for low operational cost. These challenges can be potentially met by software defined optical networking (SDON), which enables dynamic resource allocation according to the users' requirement. In this article, a novel network architecture for mobile core network is proposed based on SDON. A software defined network (SDN) controller is designed to realize the coordinated control over different entities in EPC networks. We analyze the requirement of EPC-lightpath (EPCL) in data plane and propose an optical switch load balancing (OSLB) algorithm for resource allocation in optical layer. The procedure of establishment and adjustment of EPCLs is demonstrated on a SDON-based EPC testbed with extended OpenFlow protocol. We also evaluate the OSLB algorithm through simulation in terms of bandwidth blocking ratio, traffic load distribution, and resource utilization ratio compared with link-based load balancing (LLB) and MinHops algorithms.

  4. Trends in Optical Networks

    Indian Academy of Sciences (India)

    Integrated TDM/IP Service Network: Built using next-generation SDH · Case 2: ISP Backbone over SONET/SDH · Solution for the PoPs · Solution for the Gateway site · Case 3: Ethernet Leased Line Services over Existing Infrastructure · Transport for Mobile Voice/Data Networks · Functions needed for mapping Ethernet to ...

  5. Fiber-Optic Pyrometer with Optically Powered Switch for Temperature Measurements.

    Science.gov (United States)

    Vázquez, Carmen; Pérez-Prieto, Sandra; López-Cardona, Juan D; Tapetado, Alberto; Blanco, Enrique; Moreno-López, Jorge; Montero, David S; Lallana, Pedro C

    2018-02-06

    We report the experimental results on a new infrared fiber-optic pyrometer for very localized and high-speed temperature measurements ranging from 170 to 530 °C using low-noise photodetectors and high-gain transimpedance amplifiers with a single gain mode in the whole temperature range. We also report a shutter based on an optical fiber switch which is optically powered to provide a reference signal in an optical fiber pyrometer measuring from 200 to 550 °C. The tests show the potential of remotely powering via optical means a 300 mW power-hungry optical switch at a distance of 100 m, avoiding any electromagnetic interference close to the measuring point.

  6. Fiber-Optic Pyrometer with Optically Powered Switch for Temperature Measurements

    Directory of Open Access Journals (Sweden)

    Carmen Vázquez

    2018-02-01

    Full Text Available We report the experimental results on a new infrared fiber-optic pyrometer for very localized and high-speed temperature measurements ranging from 170 to 530 °C using low-noise photodetectors and high-gain transimpedance amplifiers with a single gain mode in the whole temperature range. We also report a shutter based on an optical fiber switch which is optically powered to provide a reference signal in an optical fiber pyrometer measuring from 200 to 550 °C. The tests show the potential of remotely powering via optical means a 300 mW power-hungry optical switch at a distance of 100 m, avoiding any electromagnetic interference close to the measuring point.

  7. Experimental and theoretical investigation of semiconductor optical amplifier (SOA) based all-optical switches

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup

    2004-01-01

    This thesis analyzes semiconductor optical amplifier (SOA) based all-optical switches experimentally and through numerical simulations. These devices are candidates for optical signal processing functionalities such as wavelength conversion, regeneration, and logic processing in future transparent......, consisting of an SOA and an asymmetric MZI filter, is analyzed in the small-signal regime, and the obtainable modulation bandwidth is expressed analytically. A new optical spectrum approach to small signal analysis is introduced, and is used to assess the bandwidth enhancing effect of different optical...... filters, as well the impact of the filter phase response. Experiments at 40 Gb/s verify the predictions of the small-signal analysis. Wavelength conversion is demonstrated experimentally at 40 Gb/s using a simple filtering-assisted scheme with an ultra-low optical switching energy, and up to 80 Gb...

  8. Moving the boundary between wavelength resources in optical packet and circuit integrated ring network.

    Science.gov (United States)

    Furukawa, Hideaki; Miyazawa, Takaya; Wada, Naoya; Harai, Hiroaki

    2014-01-13

    Optical packet and circuit integrated (OPCI) networks provide both optical packet switching (OPS) and optical circuit switching (OCS) links on the same physical infrastructure using a wavelength multiplexing technique in order to deal with best-effort services and quality-guaranteed services. To immediately respond to changes in user demand for OPS and OCS links, OPCI networks should dynamically adjust the amount of wavelength resources for each link. We propose a resource-adjustable hybrid optical packet/circuit switch and transponder. We also verify that distributed control of resource adjustments can be applied to the OPCI ring network testbed we developed. In cooperation with the resource adjustment mechanism and the hybrid switch and transponder, we demonstrate that automatically allocating a shared resource and moving the wavelength resource boundary between OPS and OCS links can be successfully executed, depending on the number of optical paths in use.

  9. Design issues of optical router for metropolitan optical network (MON) applications

    Science.gov (United States)

    Wei, Wei; Zeng, QingJi

    2001-10-01

    The popularity of the Internet has caused the traffic on the Metro Area Network (MAN) to grow drastically every year. It is believed that Wavelength Division Multiplexing (WDM) has become a cornerstone technology in the MAN. Solutions to provide a MAN with high bandwidth, good scalability and easy management are being constantly searched from both IP and WDM. In this paper we firstly propose a metro optical network architecture based on GMPLS--a flexible, highly scalable IP over WDM optical network architecture for the delivery of public network IP services. Two kinds of node including Electronic Label Switching Router (E-LSR) and Optical Router (O-LSR) are involved in this metro optical network architecture. Secondly, we mainly focus on design issues of OR including multi-granularity electro-optical hybrid switching fabrics, intelligent OTU, contro l plane software and etc. And we also discuss some issues such as routing, forwarding and management of OR. Finally, we reach conclusions that OR based on GMPLS and hybrid-switching fabrics is suitable for current multi-services application environment of MON and optimistic for IP traffic transfer.

  10. Optical Network Virtualisation Using Multitechnology Monitoring and SDN-Enabled Optical Transceiver

    Science.gov (United States)

    Ou, Yanni; Davis, Matthew; Aguado, Alejandro; Meng, Fanchao; Nejabati, Reza; Simeonidou, Dimitra

    2018-05-01

    We introduce the real-time multi-technology transport layer monitoring to facilitate the coordinated virtualisation of optical and Ethernet networks supported by optical virtualise-able transceivers (V-BVT). A monitoring and network resource configuration scheme is proposed to include the hardware monitoring in both Ethernet and Optical layers. The scheme depicts the data and control interactions among multiple network layers under the software defined network (SDN) background, as well as the application that analyses the monitored data obtained from the database. We also present a re-configuration algorithm to adaptively modify the composition of virtual optical networks based on two criteria. The proposed monitoring scheme is experimentally demonstrated with OpenFlow (OF) extensions for a holistic (re-)configuration across both layers in Ethernet switches and V-BVTs.

  11. Optical resonators and neural networks

    Science.gov (United States)

    Anderson, Dana Z.

    1986-08-01

    It may be possible to implement neural network models using continuous field optical architectures. These devices offer the inherent parallelism of propagating waves and an information density in principle dictated by the wavelength of light and the quality of the bulk optical elements. Few components are needed to construct a relatively large equivalent network. Various associative memories based on optical resonators have been demonstrated in the literature, a ring resonator design is discussed in detail here. Information is stored in a holographic medium and recalled through a competitive processes in the gain medium supplying energy to the ring rsonator. The resonator memory is the first realized example of a neural network function implemented with this kind of architecture.

  12. Advanced Modulation Formats in Cognitive Optical Networks: EU project CHRON Demonstration

    DEFF Research Database (Denmark)

    Borkowski, Robert; Caballero Jambrina, Antonio; Klonidis, Dimitris

    2014-01-01

    We demonstrate real-time path establishment and switching of coherent modulation formats (QPSK, 16QAM) within an optical network driven by cognitive algorithms. Cognition aims at autonomous configuration optimization to satisfy quality of transmission requirements.......We demonstrate real-time path establishment and switching of coherent modulation formats (QPSK, 16QAM) within an optical network driven by cognitive algorithms. Cognition aims at autonomous configuration optimization to satisfy quality of transmission requirements....

  13. Optical switching in nonlinear photonic crystals lightly doped with nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mahi R [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada); Lipson, R H [Department of Chemistry, University of Western Ontario, London, ON N6A 5B7 (Canada)

    2008-01-14

    A possible switching mechanism has been investigated for nonlinear photonic crystals doped with an ensemble of non-interacting three-level nanoparticles. In this scheme, an intense pump laser field is used to change the refractive index of the nonlinear photonic crystal while a weaker probe field monitors an absorption transition in the nanoparticles. In the absence of the strong laser field the system transmits the probe field when the resonance energy of the nanoparticles lies near the edge of the photonic band gap due to strong coupling between the photonic crystal and the nanoparticles. However, upon application of an intense pump laser field the system becomes absorbing due to a band edge frequency shift that arises due to a nonlinear Kerr effect which changes the refractive index of the crystal. It is anticipated that the optical switching mechanism described in this work can be used to make new types of photonic devices.

  14. Optical switching of nuclear spin-spin couplings in semiconductors.

    Science.gov (United States)

    Goto, Atsushi; Ohki, Shinobu; Hashi, Kenjiro; Shimizu, Tadashi

    2011-07-05

    Two-qubit operation is an essential part of quantum computation. However, solid-state nuclear magnetic resonance quantum computing has not been able to fully implement this functionality, because it requires a switchable inter-qubit coupling that controls the time evolutions of entanglements. Nuclear dipolar coupling is beneficial in that it is present whenever nuclear-spin qubits are close to each other, while it complicates two-qubit operation because the qubits must remain decoupled to prevent unwanted couplings. Here we introduce optically controllable internuclear coupling in semiconductors. The coupling strength can be adjusted externally through light power and even allows on/off switching. This feature provides a simple way of switching inter-qubit couplings in semiconductor-based quantum computers. In addition, its long reach compared with nuclear dipolar couplings allows a variety of options for arranging qubits, as they need not be next to each other to secure couplings.

  15. Optical switching of nuclear spin–spin couplings in semiconductors

    Science.gov (United States)

    Goto, Atsushi; Ohki, Shinobu; Hashi, Kenjiro; Shimizu, Tadashi

    2011-01-01

    Two-qubit operation is an essential part of quantum computation. However, solid-state nuclear magnetic resonance quantum computing has not been able to fully implement this functionality, because it requires a switchable inter-qubit coupling that controls the time evolutions of entanglements. Nuclear dipolar coupling is beneficial in that it is present whenever nuclear–spin qubits are close to each other, while it complicates two-qubit operation because the qubits must remain decoupled to prevent unwanted couplings. Here we introduce optically controllable internuclear coupling in semiconductors. The coupling strength can be adjusted externally through light power and even allows on/off switching. This feature provides a simple way of switching inter-qubit couplings in semiconductor-based quantum computers. In addition, its long reach compared with nuclear dipolar couplings allows a variety of options for arranging qubits, as they need not be next to each other to secure couplings. PMID:21730962

  16. Fibre optic networks for safeguards applications

    International Nuclear Information System (INIS)

    Smith, B.G.R.; Chare, P.; Barrier, A.

    1991-01-01

    The Euratom Safeguards Directorate has recently installed a fibre optic network in a new large scale nuclear facility in the European Communities. The selection, installation and commissioning of the fibre optic network is discussed from the viewpoint of network topology, physical testing, trouble shooting and authentication. The future use of fibre optic networks for safeguards applications is discussed

  17. Monolithic, High-Speed Fiber-Optic Switching Array for Lidar, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed optical device is a fiber-based multi-channel switch to quickly switch a fiber-coupled laser among many possible output channels to create a fiber-based...

  18. Study on multiple-hops performance of MOOC sequences-based optical labels for OPS networks

    Science.gov (United States)

    Zhang, Chongfu; Qiu, Kun; Ma, Chunli

    2009-11-01

    In this paper, we utilize a new study method that is under independent case of multiple optical orthogonal codes to derive the probability function of MOOCS-OPS networks, discuss the performance characteristics for a variety of parameters, and compare some characteristics of the system employed by single optical orthogonal code or multiple optical orthogonal codes sequences-based optical labels. The performance of the system is also calculated, and our results verify that the method is effective. Additionally it is found that performance of MOOCS-OPS networks would, negatively, be worsened, compared with single optical orthogonal code-based optical label for optical packet switching (SOOC-OPS); however, MOOCS-OPS networks can greatly enlarge the scalability of optical packet switching networks.

  19. Experimental performance evaluation of software defined networking (SDN) based data communication networks for large scale flexi-grid optical networks.

    Science.gov (United States)

    Zhao, Yongli; He, Ruiying; Chen, Haoran; Zhang, Jie; Ji, Yuefeng; Zheng, Haomian; Lin, Yi; Wang, Xinbo

    2014-04-21

    Software defined networking (SDN) has become the focus in the current information and communication technology area because of its flexibility and programmability. It has been introduced into various network scenarios, such as datacenter networks, carrier networks, and wireless networks. Optical transport network is also regarded as an important application scenario for SDN, which is adopted as the enabling technology of data communication networks (DCN) instead of general multi-protocol label switching (GMPLS). However, the practical performance of SDN based DCN for large scale optical networks, which is very important for the technology selection in the future optical network deployment, has not been evaluated up to now. In this paper we have built a large scale flexi-grid optical network testbed with 1000 virtual optical transport nodes to evaluate the performance of SDN based DCN, including network scalability, DCN bandwidth limitation, and restoration time. A series of network performance parameters including blocking probability, bandwidth utilization, average lightpath provisioning time, and failure restoration time have been demonstrated under various network environments, such as with different traffic loads and different DCN bandwidths. The demonstration in this work can be taken as a proof for the future network deployment.

  20. Monolithic, High-Speed Fiber-Optic Switching Array for Lidar

    Science.gov (United States)

    Suckow, Will; Roberts, Tony; Switzer, Gregg; Terwilliger, Chelle

    2011-01-01

    Current fiber switch technologies use mechanical means to redirect light beams, resulting in slow switch time, as well as poor reliability due to moving parts wearing out quickly at high speeds. A non-mechanical ability to switch laser output into one of multiple fibers within a fiber array can provide significant power, weight, and costs savings to an all-fiber system. This invention uses an array of crystals that act as miniature prisms to redirect light as an electric voltage changes the prism s properties. At the heart of the electro-optic fiber-optic switch is an electro- optic crystal patterned with tiny prisms that can deflect the beam from the input fiber into any one of the receiving fibers arranged in a linear array when a voltage is applied across the crystal. Prism boundaries are defined by a net dipole moment in the crystal lattice that has been poled opposite to the surrounding lattice fabricated using patterned, removable microelectrodes. When a voltage is applied across the crystal, the resulting electric field changes the index of refraction within the prism boundaries relative to the surrounding substrate, causing light to deflect slightly according to Snell s Law. There are several materials that can host the necessary monolithic poled pattern (including, but not limited to, SLT, KTP, LiNbO3, and Mg:LiNbO3). Be cause this is a solid-state system without moving parts, it is very fast, and does not wear down easily. This invention is applicable to all fiber networks, as well as industries that use such networks. The unit comes in a compact package, can handle both low and high voltages, and has a high reliability (100,000 hours without maintenance).

  1. Robust network topologies for generating switch-like cellular responses.

    Directory of Open Access Journals (Sweden)

    Najaf A Shah

    2011-06-01

    Full Text Available Signaling networks that convert graded stimuli into binary, all-or-none cellular responses are critical in processes ranging from cell-cycle control to lineage commitment. To exhaustively enumerate topologies that exhibit this switch-like behavior, we simulated all possible two- and three-component networks on random parameter sets, and assessed the resulting response profiles for both steepness (ultrasensitivity and extent of memory (bistability. Simulations were used to study purely enzymatic networks, purely transcriptional networks, and hybrid enzymatic/transcriptional networks, and the topologies in each class were rank ordered by parametric robustness (i.e., the percentage of applied parameter sets exhibiting ultrasensitivity or bistability. Results reveal that the distribution of network robustness is highly skewed, with the most robust topologies clustering into a small number of motifs. Hybrid networks are the most robust in generating ultrasensitivity (up to 28% and bistability (up to 18%; strikingly, a purely transcriptional framework is the most fragile in generating either ultrasensitive (up to 3% or bistable (up to 1% responses. The disparity in robustness among the network classes is due in part to zero-order ultrasensitivity, an enzyme-specific phenomenon, which repeatedly emerges as a particularly robust mechanism for generating nonlinearity and can act as a building block for switch-like responses. We also highlight experimentally studied examples of topologies enabling switching behavior, in both native and synthetic systems, that rank highly in our simulations. This unbiased approach for identifying topologies capable of a given response may be useful in discovering new natural motifs and in designing robust synthetic gene networks.

  2. 160 Gbit/s optical packet switching using a silicon chip

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Galili, Michael

    2012-01-01

    We have successfully demonstrated 160 Gbit/s all-optical packet switching based on cross-phase modulation using a silicon chip. Error free performance is achieved for the 4-to-1 switched 160 Gbit/s packet.......We have successfully demonstrated 160 Gbit/s all-optical packet switching based on cross-phase modulation using a silicon chip. Error free performance is achieved for the 4-to-1 switched 160 Gbit/s packet....

  3. Optimal Switch Configuration in Software-Defined Networks

    Directory of Open Access Journals (Sweden)

    Béla GENGE

    2016-06-01

    Full Text Available The emerging Software-Defined Networks (SDN paradigm facilitates innovative applications and enables the seamless provisioning of resilient communications. Nevertheless, the installation of communication flows in SDN requires careful planning in order to avoid configuration errors and to fulfill communication requirements. In this paper we propose an approach that installs automatically and optimally static flows in SDN switches. The approach aims to select high capacity links and shortest path routing, and enforces communication link and switch capacity limitations. Experimental results demonstrate the effectiveness and scalability of the developed methodology.

  4. Switching Fuzzy Guaranteed Cost Control for Nonlinear Networked Control Systems

    Directory of Open Access Journals (Sweden)

    Linqin Cai

    2014-01-01

    Full Text Available This paper deals with the problem of guaranteed cost control for a class of nonlinear networked control systems (NCSs with time-varying delay. A guaranteed cost controller design method is proposed to achieve the desired control performance based on the switched T-S fuzzy model. The switching mechanism is introduced to handle the uncertainties of NCSs. Based on Lyapunov functional approach, some sufficient conditions for the existence of state feedback robust guaranteed cost controller are presented. Simulation results show that the proposed method is effective to guarantee system’s global asymptotic stability and quality of service (QoS.

  5. 3-5 modulation and switching devices for optical systems applications

    Science.gov (United States)

    Singh, Jasprit; Bhattacharya, Pallab

    1995-04-01

    The thrust for this three year program has been to develop novel devices and systems applications for multiple quantum well based devices. We have investigated architectures based upon the quantum confined Stark effect (QCSE), a means by which excitonic resonances in a quantum well are electric field tuned to shift the peaked absorption spectrum of the material. The devices based upon this concept have been used, in the past, to realize switching structures employing the characteristic negative differential resistance available in PIN-MQW diodes under illumination. We have focuses, primarily on three schemes based upon the QCSE, to extend the utility of quantum well based devices. Firstly, we have developed, tested and optimized a novel tunable optical filter for wavelength selective applications. Secondly, we have demonstrated an MQW based scheme for optical pattern recognition which we have applied towards header recognition in a packet switching network environment. Thirdly, we have extended previous MQW based switching schemes to implement an optical read only memory (ROM) which can store two bits of information on a single sight, read by two different probe wavelengths of light.

  6. Electro-optical switching of liquid crystals of graphene oxide

    Science.gov (United States)

    Song, Jang-Kun

    Electric field effects on aqueous graphene-oxide (GO) dispersions are reviewed in this chapter. In isotropic and biphasic regimes of GO dispersions, in which the inter-particle friction is low, GO particles sensitively respond to the application of electric field, producing field-induced optical birefringence. The electro-optical sensitivity dramatically decreases as the phase transits to the nematic phase; the increasing inter-particle friction hinders the rotational switching of GO particles. The corresponding Kerr coefficient reaches the maximum near the isotropic to biphasic transition concentration, at which the Kerr coefficient is found be c.a. 1:8 · 10-5 mV-2, the highest value ever reported in all Kerr materials. The exceptionally large Kerr effect arises from the Maxwell- Wagner polarization of GO particles with an extremely large aspect ratio and a thick electrical double layer (EDL). The polarization sensitively depends on the ratio of surface and bulk conductivities in dispersions. As a result, low ion concentration in bulk solvent is highly required to achieve a quality electro-optical switching in GO dispersions. Spontaneous vinylogous carboxylic reaction in GO particles produces H+ ions, resulting in spontaneous degradation of electro-optical response with time, hence the removal of residual ions by using a centrifuge cleaning process significantly improves the electro-optical sensitivity. GO particle size is another important parameter for the Kerr coefficient and the response time. The best performance is observed in a GO dispersion with c.a. 0.5 μm mean size. Dielectrophoretic migration of GO particles can be also used to manipulate GO particles in solution. Using these unique features of GO dispersions, one can fabricate GO liquid crystal devices similar to conventional liquid crystal displays; the large Kerr effect allows fabricating a low power device working at extremely low electric fields.

  7. Using Self-management for Establishing Light Paths in Optical Networks: an Overview

    NARCIS (Netherlands)

    Fioreze, Tiago; Pras, Aiko

    2006-01-01

    Current optical networks are generally composed of multi-service optical switches, which enable forwarding of data at multiple levels. Huge flows at the packet-level (IP-level) may be moved to the optical-level, which is faster than the packet-level. Such move could be beneficial since congested IP

  8. The Fragility of Interdependency: Coupled Networks Switching Phenomena

    Science.gov (United States)

    Stanley, H. Eugene

    2013-03-01

    Recent disasters ranging from abrupt financial ``flash crashes'' and large-scale power outages to sudden death among the elderly dramatically exemplify the fact that the most dangerous vulnerability is hiding in the many interdependencies among different networks. In the past year, we have quantified failures in model of interconnected networks, and demonstrated the need to consider mutually dependent network properties in designing resilient systems. Specifically, we have uncovered new laws governing the nature of switching phenomena in coupled networks, and found that phenomena that are continuous ``second order'' phase transitions in isolated networks become discontinuous abrupt ``first order'' transitions in interdependent networks [S. V. Buldyrev, R. Parshani, G. Paul, H. E. Stanley, and S. Havlin, ``Catastrophic Cascade of Failures in Interdependent Networks,'' Nature 464, 1025 (2010); J. Gao, S. V. Buldyrev, H. E. Stanley, and S. Havlin, ``Novel Behavior of Networks Formed from Interdependent Networks,'' Nature Physics 8, 40 (2012). We conclude by discussing the network basis for understanding sudden death in the elderly, and the possibility that financial ``flash crashes'' are not unlike the catastrophic first-order failure incidents occurring in coupled networks. Specifically, we study the coupled networks that are responsible for financial fluctuations. It appears that ``trend switching phenomena'' that we uncover are remarkably independent of the scale over which they are analyzed. For example, we find that the same laws governing the formation and bursting of the largest financial bubbles also govern the tiniest finance bubbles, over a factor of 1,000,000,000 in time scale [T. Preis, J. Schneider, and H. E. Stanley, ``Switching Processes in Financial Markets,'' Proc. Natl. Acad. Sci. USA 108, 7674 (2011); T. Preis and H. E. Stanley, ``Bubble Trouble: Can a Law Describe Bubbles and Crashes in Financial Markets?'' Physics World 24, No. 5, 29 (May 2011

  9. Optical networks and laboratory services

    International Nuclear Information System (INIS)

    Ciaffoni, O.; Ferrer, M.L.; Trasatti, L.

    1987-01-01

    Possible technical solutions to the problem of high speed data links between laboratories are presented. Long distance networks (WAN), ranging from tens to hundreds of kilometers, offer a variety of possibilities, from standard 64 Kbit/s connections to optical fiber links and radio or satellite Mbit channels. Short range (up to 2-3 km) communications are offered by many existing LAN (local area network) standards up to 10 Mbit/s. The medium distance range (around 10 km) can be covered by high performance fiber optic links and the now emerging MAN (metropolitan area network) protocols. A possible area of application is between the Gran Sasso Tunnel Laboratory, the outside installations and other Italien and foreign laboratories. (orig.)

  10. Fast and low power Michelson interferometer thermo-optical switch on SOI.

    Science.gov (United States)

    Song, Junfeng; Fang, Q; Tao, S H; Liow, T Y; Yu, M B; Lo, G Q; Kwong, D L

    2008-09-29

    We designed and fabricated silicon-on-insulator based Michelson interferometer (MI) thermo-optical switches with deep etched trenches for heat-isolation. Switch power was reduced approximately 20% for the switch with deep etched trenches, and the MI saved approximately 50% power than that of the Mach-Zehnder interferometer. 10.6 mW switch power, approximately 42 micros switch time for the MI with deep trenches, 13.14 mW switch power and approximately 34 micros switch time for the MI without deep trenches were achieved.

  11. Optically controlled multiple switching operations of DNA biopolymer devices

    International Nuclear Information System (INIS)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu; Fruk, Ljiljana; Hung, Yu-Chueh

    2015-01-01

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices

  12. Optically controlled multiple switching operations of DNA biopolymer devices

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Chao-You; Tu, Waan-Ting; Lin, Yi-Tzu [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Fruk, Ljiljana [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Hung, Yu-Chueh, E-mail: ychung@ee.nthu.edu.tw [Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Department of Electrical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2015-12-21

    We present optically tunable operations of deoxyribonucleic acid (DNA) biopolymer devices, where a single high-resistance state, write-once read-many-times memory state, write-read-erase memory state, and single low-resistance state can be achieved by controlling UV irradiation time. The device is a simple sandwich structure with a spin-coated DNA biopolymer layer sandwiched by two electrodes. Upon irradiation, the electrical properties of the device are adjusted owing to a phototriggered synthesis of silver nanoparticles in DNA biopolymer, giving rise to multiple switching scenarios. This technique, distinct from the strategy of doping of pre-formed nanoparticles, enables a post-film fabrication process for achieving optically controlled memory device operations, which provides a more versatile platform to fabricate organic memory and optoelectronic devices.

  13. Compact wireless control network protocol with fast path switching

    Directory of Open Access Journals (Sweden)

    Yasutaka Kawamoto

    2017-08-01

    Full Text Available Sensor network protocol stacks require the addition or adjustment of functions based on customer requirements. Sensor network protocols that require low delay and low packet error rate (PER, such as wireless control networks, often adopt time division multiple access (TDMA. However, it is difficult to add or adjust functions in protocol stacks that use TDMA methods. Therefore, to add or adjust functions easily, we propose NES-SOURCE, a compact wireless control network protocol with a fast path-switching function. NES-SOURCE is implemented using carrier sense multiple access/collision avoidance (CSMA/CA rather than TDMA. Wireless control networks that use TDMA prevent communication failure by duplicating the communication path. If CSMA/CA networks use duplicate paths, collisions occur frequently, and communication will fail. NES-SOURCE switches paths quickly when communication fails, which reduces the effect of communication failures. Since NES-SOURCE is implemented using CSMA/CA rather than TDMA, the implementation scale is less than one-half that of existing network stacks. Furthermore, since NES-SOURCE’s code complexity is low, functions can be added or adjusted easily and quickly. Communication failures occur owing to changes in the communication environment and collisions. Experimental results demonstrate that the proposed NES-SOURCE’s path-switching function reduces the amount of communication failures when the communication environment changes owing to human movement and others. Furthermore, we clarify the relationships among the probability of a changing communication environment, the collision occurrence rate, and the PER of NES-SOURCE.

  14. Optical switching based on the manipulation of microparticles in a colloidal liquid using strong scattering force

    International Nuclear Information System (INIS)

    Liu Jin; Liu Zheng-Qi; Feng Tian-Hua; Dai Qiao-Feng; Wu Li-Jun; Lan Sheng

    2010-01-01

    This paper demonstrates the realization of an optical switch by optically manipulating a large number of polystyrene spheres contained in a capillary. The strong scattering force exerted on polystyrene spheres with a large diameter of 4.3 μm is employed to realize the switching operation. A transparent window is opened for the signal light when the polystyrene spheres originally located at the beam centre are driven out of the beam region by the strong scattering force induced by the control light. The switching dynamics under different incident powers is investigated and compared with that observed in the optical switch based on the formation of optical matter. It is found that a large extinction ratio of ∼ 30 dB and fast switching-on and switching-off times can be achieved in this type of switch. (classical areas of phenomenology)

  15. Wireless optical network for a home network

    Science.gov (United States)

    Bouchet, Olivier; Porcon, Pascal; Walewski, Joachim W.; Nerreter, Stefan; Langer, Klaus-Dieter; Fernández, Luz; Vucic, Jelena; Kamalakis, Thomas; Ntogari, Georgia; Neokosmidis, Ioannis; Gueutier, Eric

    2010-08-01

    During the European collaborative project OMEGA, two optical-wireless prototypes have been developed. The first prototype operates in the near-infrared spectral region and features Giga Ethernet connectivity, a simple transceiver architecture due to the use of on-off keying, a multi-sector transceiver, and an ultra-fast switch for sector-to-sector hand over. This full-duplex system, composed by one base station and one module, transmits data on three meters. The second prototype is a visible-light-communications system based on DMT signal processing and an adapted MAC sublayer. Data rates around to 100 Mb/s at the physical layer are achieved. This broadcast system, composed also by one base station and one module, transmits data up to two meters. In this paper we present the adapted optical wireless media-access-control sublayer protocol for visible-light communications. This protocol accommodates link adaptation from 128 Mb/s to 1024 Mb/s with multi-sector coverage, and half-duplex or full-duplex transmission.

  16. Performance verification of network function virtualization in software defined optical transport networks

    Science.gov (United States)

    Zhao, Yongli; Hu, Liyazhou; Wang, Wei; Li, Yajie; Zhang, Jie

    2017-01-01

    With the continuous opening of resource acquisition and application, there are a large variety of network hardware appliances deployed as the communication infrastructure. To lunch a new network application always implies to replace the obsolete devices and needs the related space and power to accommodate it, which will increase the energy and capital investment. Network function virtualization1 (NFV) aims to address these problems by consolidating many network equipment onto industry standard elements such as servers, switches and storage. Many types of IT resources have been deployed to run Virtual Network Functions (vNFs), such as virtual switches and routers. Then how to deploy NFV in optical transport networks is a of great importance problem. This paper focuses on this problem, and gives an implementation architecture of NFV-enabled optical transport networks based on Software Defined Optical Networking (SDON) with the procedure of vNFs call and return. Especially, an implementation solution of NFV-enabled optical transport node is designed, and a parallel processing method for NFV-enabled OTN nodes is proposed. To verify the performance of NFV-enabled SDON, the protocol interaction procedures of control function virtualization and node function virtualization are demonstrated on SDON testbed. Finally, the benefits and challenges of the parallel processing method for NFV-enabled OTN nodes are simulated and analyzed.

  17. Protocol independent transmission method in software defined optical network

    Science.gov (United States)

    Liu, Yuze; Li, Hui; Hou, Yanfang; Qiu, Yajun; Ji, Yuefeng

    2016-10-01

    With the development of big data and cloud computing technology, the traditional software-defined network is facing new challenges (e.i., ubiquitous accessibility, higher bandwidth, more flexible management and greater security). Using a proprietary protocol or encoding format is a way to improve information security. However, the flow, which carried by proprietary protocol or code, cannot go through the traditional IP network. In addition, ultra- high-definition video transmission service once again become a hot spot. Traditionally, in the IP network, the Serial Digital Interface (SDI) signal must be compressed. This approach offers additional advantages but also bring some disadvantages such as signal degradation and high latency. To some extent, HD-SDI can also be regard as a proprietary protocol, which need transparent transmission such as optical channel. However, traditional optical networks cannot support flexible traffics . In response to aforementioned challenges for future network, one immediate solution would be to use NFV technology to abstract the network infrastructure and provide an all-optical switching topology graph for the SDN control plane. This paper proposes a new service-based software defined optical network architecture, including an infrastructure layer, a virtualization layer, a service abstract layer and an application layer. We then dwell on the corresponding service providing method in order to implement the protocol-independent transport. Finally, we experimentally evaluate that proposed service providing method can be applied to transmit the HD-SDI signal in the software-defined optical network.

  18. High-speed packet switching network to link computers

    CERN Document Server

    Gerard, F M

    1980-01-01

    Virtually all of the experiments conducted at CERN use minicomputers today; some simply acquire data and store results on magnetic tape while others actually control experiments and help to process the resulting data. Currently there are more than two hundred minicomputers being used in the laboratory. In order to provide the minicomputer users with access to facilities available on mainframes and also to provide intercommunication between various experimental minicomputers, CERN opted for a packet switching network back in 1975. It was decided to use Modcomp II computers as switching nodes. The only software to be taken was a communications-oriented operating system called Maxcom. Today eight Modcomp II 16-bit computers plus six newer Classic minicomputers from Modular Computer Services have been purchased for the CERNET data communications networks. The current configuration comprises 11 nodes connecting more than 40 user machines to one another and to the laboratory's central computing facility. (0 refs).

  19. Maximizing the optical network capacity.

    Science.gov (United States)

    Bayvel, Polina; Maher, Robert; Xu, Tianhua; Liga, Gabriele; Shevchenko, Nikita A; Lavery, Domaniç; Alvarado, Alex; Killey, Robert I

    2016-03-06

    Most of the digital data transmitted are carried by optical fibres, forming the great part of the national and international communication infrastructure. The information-carrying capacity of these networks has increased vastly over the past decades through the introduction of wavelength division multiplexing, advanced modulation formats, digital signal processing and improved optical fibre and amplifier technology. These developments sparked the communication revolution and the growth of the Internet, and have created an illusion of infinite capacity being available. But as the volume of data continues to increase, is there a limit to the capacity of an optical fibre communication channel? The optical fibre channel is nonlinear, and the intensity-dependent Kerr nonlinearity limit has been suggested as a fundamental limit to optical fibre capacity. Current research is focused on whether this is the case, and on linear and nonlinear techniques, both optical and electronic, to understand, unlock and maximize the capacity of optical communications in the nonlinear regime. This paper describes some of them and discusses future prospects for success in the quest for capacity. © 2016 The Authors.

  20. Optical switching in data centers : architectures based on optical packet/burst switching

    NARCIS (Netherlands)

    Calabretta, Nicola; Miao, Wang; Testa, F.; Pavesi, L.

    2017-01-01

    Driven by the cloud computing, Internet of things, and emerging big data applications, more stringent requirements in terms of high bandwidth, low latency, and large interconnectivity are imposed on the communications within the data centers (DC). Traditional intra-DC network based on electronic

  1. Using Alloy to Formally Model and Reason About an OpenFlow Network Switch

    OpenAIRE

    Mirzaei, Saber; Bahargam, Sanaz; Skowyra, Richard; Kfoury, Assaf; Bestavros, Azer

    2016-01-01

    Openflow provides a standard interface for separating a network into a data plane and a programmatic control plane. This enables easy network reconfiguration, but introduces the potential for programming bugs to cause network effects. To study OpenFlow switch behavior, we used Alloy to create a software abstraction describing the internal state of a network and its OpenFlow switches. This work is an attempt to model the static and dynamic behaviour a network built using OpenFlow switches.

  2. Dynamic Protection of Optical Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée

    2008-01-01

    This thesis deals with making optical networks resilient to failures. The recovery performance of path, segment and span restoration is evaluated in a network with limited wavelength conversion capability using both standard and enhanced wavelength assignment schemes. The enhanced wavelength...... stubs at the failure adjacent nodes. Both modifcations have a positive influence on the recovery percentage. The recovery enhancements are applicable in both single and multi-domain network environments. Stub release, where the still working parts of a failure affected connection are released prior...... of the modularity of capacity units is investigated for resilient network design. Different span upgrading strategies and algorithms for finding restoration paths are evaluated. Furthermore, the capacity effciency of constraining restoration requests for the same destination node to the same restoration path...

  3. Threshold Switching Induced by Controllable Fragmentation in Silver Nanowire Networks.

    Science.gov (United States)

    Wan, Tao; Pan, Ying; Du, Haiwei; Qu, Bo; Yi, Jiabao; Chu, Dewei

    2018-01-24

    Silver nanowire (Ag NW) networks have been widely studied because of a great potential in various electronic devices. However, nanowires usually undergo a fragmentation process at elevated temperatures due to the Rayleigh instability that is a result of reduction of surface/interface energy. In this case, the nanowires become completely insulating due to the formation of randomly distributed Ag particles with a large distance and further applications are hindered. Herein, we demonstrate a novel concept based on the combination of ultraviolet/ozone irradiation and a low-temperature annealing process to effectively utilize and control the fragmentation behavior to realize the resistive switching performances. In contrast to the conventional fragmentation, the designed Ag/AgO x interface facilitates a unique morphology of short nanorod-like segments or chains of tiny Ag nanoparticles with a very small spacing distance, providing conduction paths for achieving the tunneling process between the isolated fragments under the electric field. On the basis of this specific morphology, the Ag NW network has a tunable resistance and shows volatile threshold switching characteristics with a high selectivity, which is the ON/OFF current ratio in selector devices. Our concept exploits a new function of Ag NW network, i.e., resistive switching, which can be developed by designing a controllable fragmentation.

  4. Network simulations of optical illusions

    Science.gov (United States)

    Shinbrot, Troy; Lazo, Miguel Vivar; Siu, Theo

    We examine a dynamical network model of visual processing that reproduces several aspects of a well-known optical illusion, including subtle dependencies on curvature and scale. The model uses a genetic algorithm to construct the percept of an image, and we show that this percept evolves dynamically so as to produce the illusions reported. We find that the perceived illusions are hardwired into the model architecture and we propose that this approach may serve as an archetype to distinguish behaviors that are due to nature (i.e. a fixed network architecture) from those subject to nurture (that can be plastically altered through learning).

  5. Cavity switching : A novel resource for solid-state quantum optics

    NARCIS (Netherlands)

    Sattler, T.; Peinke, E.; Bleuse, J.; Claudon, J.; Vos, W. L.; Gerard, J.M.

    2017-01-01

    We present switching experiments performed on pillar microcavities containing a collection of quantum dots (QDs). Switching events are probed using QD luminescence, after ultrafast optical injection of free carriers. We observe large switching amplitudes (by as much as 20 linewidths), as well as

  6. All-optical switching in lithium niobate directional couplers with cascaded nonlinearity

    NARCIS (Netherlands)

    Schiek, R.; Baek, Y.; Krijnen, Gijsbertus J.M.; Stegeman, G.I.; Baumann, I.; Sohler, W.

    1996-01-01

    We report on intensity-dependent switching in lithium niobate directional couplers. Large nonlinear phase shifts that are due to cascading detune the coupling between the coupler branches, which makes all-optical switching possible. Depending on the input intensity, the output could be switched

  7. Novel scheme for efficient and cost-effective forwarding of packets in optical networks without header modification

    DEFF Research Database (Denmark)

    Wessing, Henrik; Fjelde, Tina; Christiansen, Henrik Lehrmann

    2001-01-01

    We present a novel scheme for addressing the outputs in optical packet switches and demonstrate its good scalability. The scheme requires neither header modification nor distribution of routing information to the packet switches, thus reducing optical component count while simplifying network...

  8. Monolithic, High-Speed Fiber-Optic Switching Array for Lidar, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This NASA SBIR Phase II effort will develop a 1 x 10 prototype non-mechanical fiber optic switch for use with high power lasers. The proposed optical device is a...

  9. The cascaded amplifier and saturable absorber (CASA) all-optical switch

    DEFF Research Database (Denmark)

    Hilliger, E.; Berger, J.; Weber, H. G.

    2001-01-01

    The cascaded amplifier and saturable absorber is presented as a new all-optical switching scheme for optical signal processing applications. First demultiplexing experiments demonstrate the principle of operation of this scheme....

  10. Routing and wavelength assignment based on normalized resource and constraints for all-optical network

    Science.gov (United States)

    Joo, Seong-Soon; Nam, Hyun-Soon; Lim, Chang-Kyu

    2003-08-01

    With the rapid growth of the Optical Internet, high capacity pipes is finally destined to support end-to-end IP on the WDM optical network. Newly launched 2D MEMS optical switching module in the market supports that expectations of upcoming a transparent optical cross-connect in the network have encouraged the field applicable research on establishing real all-optical transparent network. To open up a customer-driven bandwidth services, design of the optical transport network becomes more challenging task in terms of optimal network resource usage. This paper presents a practical approach to finding a route and wavelength assignment for wavelength routed all-optical network, which has λ-plane OXC switches and wavelength converters, and supports that optical paths are randomly set up and released by dynamic wavelength provisioning to create bandwidth between end users with timescales on the order of seconds or milliseconds. We suggest three constraints to make the RWA problem become more practical one on deployment for wavelength routed all-optical network in network view: limitation on maximum hop of a route within bearable optical network impairments, limitation on minimum hops to travel before converting a wavelength, and limitation on calculation time to find all routes for connections requested at once. We design the NRCD (Normalized Resource and Constraints for All-Optical Network RWA Design) algorithm for the Tera OXC: network resource for a route is calculated by the number of internal switching paths established in each OXC nodes on the route, and is normalized by ratio of number of paths established and number of paths equipped in a node. We show that it fits for the RWA algorithm of the wavelength routed all-optical network through real experiments on the distributed objects platform.

  11. Column Generation for Transmission Switching of Electricity Networks with Unit Commitment

    DEFF Research Database (Denmark)

    Villumsen, Jonas Christoffer; Philpott, Andy B.

    2011-01-01

    This paper presents the problem of finding the minimum cost dispatch and commitment of power generation units in a transmission network with active switching.We use the term active switching to denote the use of switches to optimize network topology in an operational context. We propose a Dantzig...

  12. High-speed 2 × 2 silicon-based electro-optic switch with nanosecond switch time

    International Nuclear Information System (INIS)

    Xue-Jun, Xu; Shao-Wu, Chen; Hai-Hua, Xu; Yang, Sun; Yu-De, Yu; Jin-Zhong, Yu; Qi-Ming, Wang

    2009-01-01

    A 2 × 2 electro-optic switch is experimentally demonstrated using the optical structure of a Mach–Zehnder interferometer (MZI) based on a submicron rib waveguide and the electrical structure of a PIN diode on silicon-on-insulator (SOI). The switch behaviour is achieved through the plasma dispersion effect of silicon. The device has a modulation arm of 1 mm in length and cross-section of 400 nm×340 nm. The measurement results show that the switch has a V π L π figure of merit of 0.145 V·cm and the extinction ratios of two output ports and cross talk are 40 dB, 28 dB and −28 dB, respectively. A 3 dB modulation bandwidth of 90 MHz and a switch time of 6.8 ns for the rise edge and 2.7 ns for the fall edge are also demonstrated

  13. Optical Networks Solutions planning - performances - management

    DEFF Research Database (Denmark)

    Fenger, Christian

    2002-01-01

    It has been a decisive goal in the compilation of this thesis to make us capable of realizing the future national and regional telecommunication networks in an efficient and resource optimal way. By future telecommunication network is assumed an all optical network where the information in transit...... are kept optical and not converted into the optical domain. The focus is on the scientific results achieved throughout the Ph.D. period. Five subjects – all increasing the understanding of optical networks – are studied. Static wavelength routed optical networks are studied. Management on terms...... of lightpath allocation and design is considered. By using statistical models (simultaneous analysis of many networks) the correspondence between parameters determining the network topology and the performance of the optical network is found. These dependencies are important knowledge in the process...

  14. Robust stability analysis of switched Hopfield neural networks with time-varying delay under uncertainty

    International Nuclear Information System (INIS)

    Huang He; Qu Yuzhong; Li Hanxiong

    2005-01-01

    With the development of intelligent control, switched systems have been widely studied. Here we try to introduce some ideas of the switched systems into the field of neural networks. In this Letter, a class of switched Hopfield neural networks with time-varying delay is investigated. The parametric uncertainty is considered and assumed to be norm bounded. Firstly, the mathematical model of the switched Hopfield neural networks is established in which a set of Hopfield neural networks are used as the individual subsystems and an arbitrary switching rule is assumed; Secondly, robust stability analysis for such switched Hopfield neural networks is addressed based on the Lyapunov-Krasovskii approach. Some criteria are given to guarantee the switched Hopfield neural networks to be globally exponentially stable for all admissible parametric uncertainties. These conditions are expressed in terms of some strict linear matrix inequalities (LMIs). Finally, a numerical example is provided to illustrate our results

  15. Noise-induced polarization switching in complex networks

    Science.gov (United States)

    Haerter, Jan O.; Díaz-Guilera, Albert; Serrano, M. Ángeles

    2017-04-01

    The combination of bistability and noise is ubiquitous in complex systems, from biology to social interactions, and has important implications for their functioning and resilience. Here we use a simple three-state dynamical process, in which nodes go from one pole to another through an intermediate state, to show that noise can induce polarization switching in bistable systems if dynamical correlations are significant. In large, fully connected networks, where dynamical correlations can be neglected, increasing noise yields a collapse of bistability to an unpolarized configuration where the three possible states of the nodes are equally likely. In contrast, increased noise induces abrupt and irreversible polarization switching in sparsely connected networks. In multiplexes, where each layer can have a different polarization tendency, one layer is dominant and progressively imposes its polarization state on the other, offsetting or promoting the ability of noise to switch its polarization. Overall, we show that the interplay of noise and dynamical correlations can yield discontinuous transitions between extremes, which cannot be explained by a simple mean-field description.

  16. Scalable In-Band Optical Notch-Filter Labeling for Ultrahigh Bit Rate Optical Packet Switching

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros; Galili, Michael; Oxenløwe, Leif Katsuo

    2014-01-01

    We propose a scalable in-band optical notch-filter labeling scheme for optical packet switching of high-bit-rate data packets. A detailed characterization of the notch-filter labeling scheme and its effect on the quality of the data packet is carried out in simulation and verified by experimental...... demonstrations. The scheme is able to generate more than 91 different labels that can be applied to 640-Gb/s optical time division multiplexed packets causing an eye opening penalty of $1.2-dB. Experimental demonstration shows that up to 256 packets can be uniquely labeled by employing up to eight notch filters...... with only 0.9-dB power penalty to achieve BER of 1E-9. Using the proposed labeling scheme, optical packet switching of 640 Gb/s data packets is experimentally demonstrated in which two data packets are labeled by making none and one spectral hole using a notch filter and are switched using a LiNbO$_3...

  17. Ultrafast optical switching of three-dimensional Si inverse opal photonic band gap crystals

    NARCIS (Netherlands)

    Euser, T.G.; Wei, Hong; Kalkman, Jeroen; Jun, Yoonho; Polman, Albert; Norris, David J.; Vos, Willem L.

    2007-01-01

    We present ultrafast optical switching experiments on three-dimensional photonic band gap crystals. Switching the Si inverse opal is achieved by optically exciting free carriers by a two-photon process. We probe reflectivity in the frequency range of second order Bragg diffraction where the photonic

  18. Controllable thousand-port low-latency optical packet switch architecture for short link applications

    NARCIS (Netherlands)

    Di Lucente, S.; Nazarathy, J.; Raz, O.; Calabretta, N.; Dorren, H.J.S.; Bienstman, P.; Morthier, G.; Roelkens, G.; et al., xx

    2011-01-01

    The implementation of a low-latency optical packet switch architecture that is controllable while scaling to over thousand ports is investigated in this paper. Optical packet switches with thousand of input/output ports are promising devices to improve the performance of short link applications in

  19. All-optical membrane inp switch on silicon for access applications

    NARCIS (Netherlands)

    Raz, O.; Tassaert, M.; Roelkens, G.C.; Dorren, H.J.S.

    2012-01-01

    Using an integrated membrane switch on SOI, optical clock distribution is achieved while all-optical switching of datapackets is maintained. Transmission through 25km SMF is demonstrated with 1.5dB penalty, limited by signal OSNR and pump extinction.

  20. The handbook of optical communication networks

    CERN Document Server

    Ilyas, Mohammad

    2003-01-01

    The Handbook of Optical Communication Networks presents comprehensive, up-to-date technical information on integrated, state-of-the-art optical networks. Beginning with an in-depth intoduction to the field, top international authorities explore every major aspect of optical networks, from basic concepts to research grade material. Their discussions cover all of the essential topics, including protocols, resource management, routing and wavelength assignment in WDM networks, connection management, survivability, enabling technologies, and future trends.

  1. Compact Si-based asymmetric MZI waveguide on SOI as a thermo-optical switch

    Science.gov (United States)

    Rizal, C. S.; Niraula, B.

    2018-03-01

    A compact low power consuming asymmetric MZI based optical modulator with fast response time has been proposed on SOI platform. The geometrical and performance characteristics were analyzed in depth and optimized using coupled mode analysis and FDTD simulation tools, respectively. It was tested with and without implementation of thermo-optic (TO) effect. The device showed good frequency modulating characteristics when tested without the implementation of the TO effect. The fabricated device showed quality factor, Q ≈ 10,000, and this value is comparable to the Q of the device simulated with 25% transmission loss, showing FSR of 0.195 nm, FWHM ≈ 0.16 nm, and ER of 13 dB. With TO effect, it showed temperature sensitivity of 0.01 nm/°C and FSR of 0.19 nm. With the heater length of 4.18 mm, the device required 0.26 mW per π shift power with a switching voltage of 0.309 V, response time of 10 μ, and figure-of-merit of 2.6 mW μs. All of these characteristics make this device highly attractive for use in integrated Si photonics network as optical switch and wavelength modulator.

  2. Architecture Design and Experimental Platform Demonstration of Optical Network based on OpenFlow Protocol

    Science.gov (United States)

    Xing, Fangyuan; Wang, Honghuan; Yin, Hongxi; Li, Ming; Luo, Shenzi; Wu, Chenguang

    2016-02-01

    With the extensive application of cloud computing and data centres, as well as the constantly emerging services, the big data with the burst characteristic has brought huge challenges to optical networks. Consequently, the software defined optical network (SDON) that combines optical networks with software defined network (SDN), has attracted much attention. In this paper, an OpenFlow-enabled optical node employed in optical cross-connect (OXC) and reconfigurable optical add/drop multiplexer (ROADM), is proposed. An open source OpenFlow controller is extended on routing strategies. In addition, the experiment platform based on OpenFlow protocol for software defined optical network, is designed. The feasibility and availability of the OpenFlow-enabled optical nodes and the extended OpenFlow controller are validated by the connectivity test, protection switching and load balancing experiments in this test platform.

  3. Optimizing the next generation optical access networks

    DEFF Research Database (Denmark)

    Amaya Fernández, Ferney Orlando; Soto, Ana Cardenas; Tafur Monroy, Idelfonso

    2009-01-01

    Several issues in the design and optimization of the next generation optical access network (NG-OAN) are presented. The noise, the distortion and the fiber optic nonlinearities are considered to optimize the video distribution link in a passive optical network (PON). A discussion of the effect...

  4. All-optical Data Vortex node using an MZI-SOA switch array

    DEFF Research Database (Denmark)

    Jung, H.D.; Tafur Monroy, Idelfonso; Koonen, A.M.J.

    2007-01-01

    We propose and demonstrate a new structure of a Data Vortex switch node for all-optical routing of wavelength-division-multiplexing (WDM) 10-Gb/s optical packets. The proposed node consists of two Mach-Zehnder interferometers with integrated semiconductor optical amplifier: an optical AND gate...

  5. Field trial of 160 Gb/s all-optical packet switching

    NARCIS (Netherlands)

    Liu, Y.; Herrera Llorente, J.; Raz, O.; Tangdiongga, E.; Marti, J.; Ramos, F.; Maxwell, G.D.; Poustie, A.; Mulvad, H.C.H.; Hill, M.T.; Waardt, de H.; Khoe, G.D.; Koonen, A.M.J.; Dorren, H.J.S.; Nakano, Y.

    2007-01-01

    We present the results of a transmission experiment, over 110 km of field installed fiber, for an all-optical 160 Gb/s packet switching system. The system uses in-band optical labels which are processed entirely in the optical domain using a narrow-band all-optical filter. The label decision

  6. SDN-Enabled Dynamic Feedback Control and Sensing in Agile Optical Networks

    Science.gov (United States)

    Lin, Likun

    Fiber optic networks are no longer just pipelines for transporting data in the long haul backbone. Exponential growth in traffic in metro-regional areas has pushed higher capacity fiber toward the edge of the network, and highly dynamic patterns of heterogeneous traffic have emerged that are often bursty, severely stressing the historical "fat and dumb pipe" static optical network, which would need to be massively over-provisioned to deal with these loads. What is required is a more intelligent network with a span of control over the optical as well as electrical transport mechanisms which enables handling of service requests in a fast and efficient way that guarantees quality of service (QoS) while optimizing capacity efficiency. An "agile" optical network is a reconfigurable optical network comprised of high speed intelligent control system fed by real-time in situ network sensing. It provides fast response in the control and switching of optical signals in response to changing traffic demands and network conditions. This agile control of optical signals is enabled by pushing switching decisions downward in the network stack to the physical layer. Implementing such agility is challenging due to the response dynamics and interactions of signals in the physical layer. Control schemes must deal with issues such as dynamic power equalization, EDFA transients and cascaded noise effects, impairments due to self-phase modulation and dispersion, and channel-to-channel cross talk. If these issues are not properly predicted and mitigated, attempts at dynamic control can drive the optical network into an unstable state. In order to enable high speed actuation of signal modulators and switches, the network controller must be able to make decisions based on predictive models. In this thesis, we consider how to take advantage of Software Defined Networking (SDN) capabilities for network reconfiguration, combined with embedded models that access updates from deployed network

  7. Materials and devices for all-optical helicity-dependent switching

    Science.gov (United States)

    Salah El Hadri, Mohammed; Hehn, Michel; Malinowski, Grégory; Mangin, Stéphane

    2017-04-01

    Since the first observation of ultrafast demagnetization in Ni thin films by Beaurepaire et al 20 years ago, understanding the interaction between ultrashort laser pulses and magnetization has become a topic of huge interest. In 2007, an intriguing discovery related to ultrafast demagnetization was the observation of all-optical switching (AOS) of magnetization in ferrimagnetic GdFeCo alloy films using only femtosecond laser pulses. This review discusses the recent studies elucidating several key issues regarding the all-optical switching phenomenon. Although AOS had long been restricted to GdFeCo alloys, it turned out to be a more general phenomenon for a variety of ferrimagnetic as well as ferromagnetic materials. This discovery helped pave the way for the integration of all-optical writing in data storage industries. Nevertheless, theoretical models explaining the switching in GdFeCo alloy films do not appear to apply in the other materials, thus questioning the uniqueness of the microscopic origin of all-optical switching. By investigating the integration of all-optical switching in spintronic devices, two types of all-optical switching mechanism have been distinguished: a single-pulse heat-only switching in ferrimagnetic GdFeCo alloys, and a two regime helicity-dependent switching in both ferrimagnetic TbCo alloys and ferromagnetic Co/Pt multilayers. Another key issue discussed in this review is the necessary condition for the observation of all-optical switching. Many models have been proposed but are strongly challenged by the discovery of such switching in ferromagnets. A comprehensive investigation of the magnetic parameters governing all-optical switching demonstrate that its observation requires magnetic domains larger than the laser spot size during the cooling process; such a criterion is common for both ferri- and ferro-magnets. These investigations strongly improve our understanding and give intriguing insights into the rich physics of the ultrafast

  8. Scalability of optical networks : crosstalk limitations

    NARCIS (Netherlands)

    Tafur Monroy, I.

    2000-01-01

    Optical networks represent a promising solution for the future high capacity and flexible transport network. This paper presents a model for the performance evaluation of optical networks with respect to linear crosstalk and accumulated spontaneous emission noise. The proposed model is intended for

  9. Exponentially convergent state estimation for delayed switched recurrent neural networks.

    Science.gov (United States)

    Ahn, Choon Ki

    2011-11-01

    This paper deals with the delay-dependent exponentially convergent state estimation problem for delayed switched neural networks. A set of delay-dependent criteria is derived under which the resulting estimation error system is exponentially stable. It is shown that the gain matrix of the proposed state estimator is characterised in terms of the solution to a set of linear matrix inequalities (LMIs), which can be checked readily by using some standard numerical packages. An illustrative example is given to demonstrate the effectiveness of the proposed state estimator.

  10. Path searching in switching networks using cellular algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Koczy, L T; Langer, J; Legendi, T

    1981-01-01

    After a survey of the important statements in the paper A Mathematical Model of Path Searching in General Type Switching Networks (see IBID., vol.25, no.1, p.31-43, 1981) the authors consider the possible implementation for cellular automata of the algorithm introduced there. The cellular field used consists of 5 neighbour 8 state cells. Running times required by a traditional serial processor and by the cellular field, respectively, are compared. By parallel processing this running time can be reduced. 5 references.

  11. Global Asymptotic Stability of Switched Neural Networks with Delays

    Directory of Open Access Journals (Sweden)

    Zhenyu Lu

    2015-01-01

    Full Text Available This paper investigates the global asymptotic stability of a class of switched neural networks with delays. Several new criteria ensuring global asymptotic stability in terms of linear matrix inequalities (LMIs are obtained via Lyapunov-Krasovskii functional. And here, we adopt the quadratic convex approach, which is different from the linear and reciprocal convex combinations that are extensively used in recent literature. In addition, the proposed results here are very easy to be verified and complemented. Finally, a numerical example is provided to illustrate the effectiveness of the results.

  12. All-Optical Network Subsystems Using Integrated SOA-Based Optical Gates and Flip-Flops for Label-Swapped Netorks

    DEFF Research Database (Denmark)

    Seoane, Jorge; Holm-Nielsen, Pablo Villanueva; Kehayas, E.

    2006-01-01

    In this letter, we demonstrate that all-optical network subsystems, offering intelligence in the optical layer, can be constructed by functional integration of integrated all-optical logic gates and flip-flops. In this context, we show 10-Gb/s all-optical 2-bit label address recognition......-level advantages of these all-optical subsystems combined with their realization with compact integrated devices, suggest that they are strong candidates for future packet/label switched optical networks....... by interconnecting two optical gates that perform xor operation on incoming optical labels. We also demonstrate 40-Gb/s all-optical wavelength-switching through an optically controlled wavelength converter, consisting of an integrated flip-flop prototype device driven by an integrated optical gate. The system...

  13. Experimental demonstration of software defined data center optical networks with Tbps end-to-end tunability

    Science.gov (United States)

    Zhao, Yongli; Zhang, Jie; Ji, Yuefeng; Li, Hui; Wang, Huitao; Ge, Chao

    2015-10-01

    The end-to-end tunability is important to provision elastic channel for the burst traffic of data center optical networks. Then, how to complete the end-to-end tunability based on elastic optical networks? Software defined networking (SDN) based end-to-end tunability solution is proposed for software defined data center optical networks, and the protocol extension and implementation procedure are designed accordingly. For the first time, the flexible grid all optical networks with Tbps end-to-end tunable transport and switch system have been online demonstrated for data center interconnection, which are controlled by OpenDayLight (ODL) based controller. The performance of the end-to-end tunable transport and switch system has been evaluated with wavelength number tuning, bit rate tuning, and transmit power tuning procedure.

  14. Doubly differential star-16-QAM for fast wavelength switching coherent optical packet transceiver.

    Science.gov (United States)

    Liu, Fan; Lin, Yi; Walsh, Anthony J; Yu, Yonglin; Barry, Liam P

    2018-04-02

    A coherent optical packet transceiver based on doubly differential star 16-ary quadrature amplitude modulation (DD-star-16-QAM) is presented for spectrally and energy efficient reconfigurable networks. The coding and decoding processes for this new modulation format are presented, simulations and experiments are then performed to investigate the performance of the DD-star-16-QAM in static and dynamic scenarios. The static results show that the influence of frequency offset (FO) can be cancelled out by doubly differential (DD) coding and the correction range is only limited by the electronic bandwidth of the receivers. In the dynamic scenario with a time-varying FO and linewidth, the DD-star-16-QAM can overcome the time-varying FO, and the switching time of around 70 ns is determined by the time it takes the dynamic linewidth to reach the requisite level. This format can thus achieve a shorter waiting time after switching tunable lasers than the commonly used square-16-QAM, in which the transmission performance is limited by the frequency transients after the wavelength switch.

  15. Investigations and Simulations of All optical Switches in linear state Based on Photonic Crystal Directional Coupler

    Directory of Open Access Journals (Sweden)

    S. Maktoobi

    2014-10-01

    Full Text Available Switching is a principle process in digital computers and signal processing systems. The growth of optical signal processing systems, draws particular attention to design of ultra-fast optical switches. In this paper, All Optical Switches in linear state Based On photonic crystal Directional coupler is analyzed and simulated. Among different methods, the finite difference time domain method (FDTD is a preferable method and is used. We have studied the application of photonic crystal lattices, the physics of optical switching and photonic crystal Directional coupler. In this paper, Electric field intensity and the power output that are two factors to improve the switching performance and the device efficiency are investigated and simulated. All simulations are performed by COMSOL software.

  16. A rapid protection switching method in carrier ethernet ring networks

    Science.gov (United States)

    Yuan, Liang; Ji, Meng

    2008-11-01

    Abstract: Ethernet is the most important Local Area Network (LAN) technology since more than 90% data traffic in access layer is carried on Ethernet. From 10M to 10G, the improving Ethernet technology can be not only used in LAN, but also a good choice for MAN even WAN. MAN are always constructed in ring topology because the ring network could provide resilient path protection by using less resource (fibre or cable) than other network topologies. In layer 2 data networks, spanning tree protocol (STP) is always used to protect transmit link and preventing the formation of logic loop in networks. However, STP cannot guarantee the efficiency of service convergence when link fault happened. In fact, convergent time of networks with STP is about several minutes. Though Rapid Spanning Tree Protocol (RSTP) and Multi-Spanning Tree Protocol (MSTP) improve the STP technology, they still need a couple of seconds to achieve convergence, and can not provide sub-50ms protection switching. This paper presents a novel rapid ring protection method (RRPM) for carrier Ethernet. Unlike other link-fault detection method, it adopts distributed algorithm to detect link fault rapidly (sub-50ms). When networks restore from link fault, it can revert to the original working state. RRPM can provide single ring protection and interconnected ring protection without the formation of super loop. In normal operation, the master node blocks the secondary port for all non-RRPM Ethernet frames belonging to the given RRPM Ring, thereby avoiding a loop in the ring. When link fault happens, the node on which the failure happens moves from the "ring normal" state to the "ring fault" state. It also sends "link down" frame immediately to other nodes and blocks broken port and flushes its forwarding database. Those who receive "link down" frame will flush forwarding database and master node should unblock its secondary port. When the failure restores, the whole ring will revert to the normal state. That is

  17. Quantum optics of optomechanical networks

    International Nuclear Information System (INIS)

    Stannigel, K.

    2012-01-01

    This thesis proposes various setups in which micro-mechanical resonators and optomechanical systems can be combined with other quantum systems, such as solid-state qubits or atomic ensembles, in a beneficial way. These hybrid systems open up new ways for quantum control, and several protocols and applications for quantum information processing and, in particular, for quantum networks are presented. Part I describes an optically mediated coupling between the vibrational modes of a semi-transparent dielectric membrane and the center-of-mass motion of an atomic ensemble. Using the sophisticated toolbox available for the control of atomic systems, this setting enables an indirect manipulation of the membrane, including, for example, cooling it to the vibrational ground state. A fully quantum mechanical treatment of this open system is given in terms of the quantum stochastic Schrödinger equation. In Part II we explore the potential of optomechanical systems for quantum information processing applications. First, we introduce the concept of an optomechanical transducer, where a micro-mechanical resonator mediates an interaction between a solid-state based qubit on the one hand, and photons in an optical cavity on the other hand. The resulting qubit-light interface is shown to enable quantum state transfers between two distant solid-state qubits, thereby making them available for quantum networking applications. Second, we study multi-mode optomechanical systems in the single-photon single-phonon strong coupling regime. We predict quantum signatures of this interaction, which could be observed in future experiments, and provide a route towards possible applications of these systems as quantum information processing units. Part III presents a dissipative state preparation scheme for cascaded quantum networks. In such networks excitations can only propagate along a single spatial direction and the optomechanical transducer represents one way of realizing them. We show, in

  18. Optical processes in the performance and recovery of gas-phase switches

    International Nuclear Information System (INIS)

    Gundersen, M.

    1982-01-01

    In this paper several optical processes that may be used to affect gas-phase switch performance and operation are discussed, and approaches using a laser to increase recovery rates of switches are presented. In the latter the laser is used during the recovery phase rather than the conductive or closure phase. This papper suggests that it should be possible to use a low-power laser (e.g., one that is technologically feasible to use as part of a switch) to assist in opening the switch by quenching excited atomic and/or molecular species. The application of laser-induced energy extraction to gas-phase switches is also discussed

  19. Novel Scheme for Packet Forwarding without Header Modifications in Optical Networks

    DEFF Research Database (Denmark)

    Wessing, Henrik; Christiansen, Henrik Lehrmann; Fjelde, Tina

    2002-01-01

    We present a novel scheme for packet forwarding in optical packet-switched networks and we further demonstrate its good scalability through simulations. The scheme requires neither header modification nor any label distribution protocol, thus reducing component cost while simplifying network...

  20. Developing A Generic Optical Avionic Network

    DEFF Research Database (Denmark)

    Zhang, Jiang; An, Yi; Berger, Michael Stübert

    2011-01-01

    We propose a generic optical network design for future avionic systems in order to reduce the weight and power consumption of current networks on board. A three-layered network structure over a ring optical network topology is suggested, as it can provide full reconfiguration flexibility...... and support a wide range of avionic applications. Segregation can be made on different hierarchies according to system criticality and security requirements. The structure of each layer is discussed in detail. Two network configurations are presented, focusing on how to support different network services...... by such a network. Finally, three redundancy scenarios are discussed and compared....

  1. Enterasys Networks delivers standards-based 10-Gigabit ethernet modules for its Enterasys X-Pedition Routers and Enterasys Matrix Switches

    CERN Multimedia

    2002-01-01

    Enterasys Networks Inc. has announced new 10-Gigabit Ethernet modules for the Enterasys X-Pedition ER16 routers and Enterasys Matrix E1 OAS (Optical Access Switch). The addition of 10-Gigabit Ethernet technology enables the Enterasys X-Pedition ER16 enables real-time delivery of high-bandwidth, advanced applications across local area network (LAN), wide area network (WAN) and metropolitan area network (MAN) environments (1/2 page).

  2. Cross-layer design in optical networks

    CERN Document Server

    Brandt-Pearce, Maïté; Demeester, Piet; Saradhi, Chava

    2013-01-01

    Optical networks have become an integral part of the communications infrastructure needed to support society’s demand for high-speed connectivity.  Cross-Layer Design in Optical Networks addresses topics in optical network design and analysis with a focus on physical-layer impairment awareness and network layer service requirements, essential for the implementation and management of robust scalable networks.  The cross-layer treatment includes bottom-up impacts of the physical and lambda layers, such as dispersion, noise, nonlinearity, crosstalk, dense wavelength packing, and wavelength line rates, as well as top-down approaches to handle physical-layer impairments and service requirements.

  3. Optical Time Division Switching Using Multiple Stages of Fiber Optic Delay Lines.

    Science.gov (United States)

    Spanke, Ronald Anthony

    Optical Time Slot Interchanges (OTSIs) can be realized by guided wave LiNbO_3 optical switches performing space division switching of optical fiber delay lines. In this dissertation the problems of reducing the total length of fiber required and also of improving the SNR characteristics of this OTSI function are addressed. Several new OTSI architectures are proposed to reduce the total fiber length while still obtaining excellent SNR characteristics. These reduced fiber architectures include the Distributed Input Delay, Distributed Output Delay, the 2-Stage decomposition and the Distributed Input/Output Delay architectures. A Parallel Feedback (PFB) OTSI architecture is proposed that achieves the theoretical minimum number of delay fibers and the theoretical minimum total length of delay fiber for a given OTSI function. Broadcast OTSI architectures are proposed that enable the data in an incoming time slot to be broadcast to one or more outgoing time slots. These broadcast OTSI architectures include the Time-Dup-Time (TDT) system, Passive Splitter/Active Combiner (PS/AC) equivalents of the point -to-point reduced fiber architectures, and the broadcast PFB architecture. For each of the point-to-point and the broadcast OTSI architectures proposed, a detailed characterization of the architecture is performed including an analysis of number of fibers, total fiber length, number of optical switches and drivers, attenuation and SNR characteristics. This dissertation also proposes several new techniques for improving the system SNR and for calibration of the OTSI architectures. A cascaded noise reduction and a differential attenuation compensation technique are used to achieve a significantly higher system SNR at the output of the OTSI. In-situ calibration techniques are discussed to determine the optimum operating voltages for the LiNbO _3 switches when alternating between states every time slot. These techniques attempt to compensate for an output power drift problem

  4. CW all optical self switching in nonlinear chalcogenide nano plasmonic directional coupler

    Science.gov (United States)

    Motamed-Jahromi, Leila; Hatami, Mohsen

    2018-04-01

    In this paper we obtain the coupling coefficient of plasmonic directional coupler (PDC) made up of two parallel monolayer waveguides filled with high nonlinear chalcogenide material for TM mode in continues wave (CW) regime. In addition, we assume each waveguides acts as a perturbation to other waveguide. Four nonlinear-coupled equations are derived. Transfer distances are numerically calculated and used for deriving length of all optical switch. The length of designed switch is in the range of 10-1000 μm, and the switching power is in the range of 1-100 W/m. Obtained values are suitable for designing all optical elements in the integrated optical circuits.

  5. Optical network security using unipolar Walsh code

    Science.gov (United States)

    Sikder, Somali; Sarkar, Madhumita; Ghosh, Shila

    2018-04-01

    Optical code-division multiple-access (OCDMA) is considered as a good technique to provide optical layer security. Many research works have been published to enhance optical network security by using optical signal processing. The paper, demonstrates the design of the AWG (arrayed waveguide grating) router-based optical network for spectral-amplitude-coding (SAC) OCDMA networks with Walsh Code to design a reconfigurable network codec by changing signature codes to against eavesdropping. In this paper we proposed a code reconfiguration scheme to improve the network access confidentiality changing the signature codes by cyclic rotations, for OCDMA system. Each of the OCDMA network users is assigned a unique signature code to transmit the information and at the receiving end each receiver correlates its own signature pattern a(n) with the receiving pattern s(n). The signal arriving at proper destination leads to s(n)=a(n).

  6. Software Switching for High Throughput Data Acquisition Networks

    CERN Document Server

    AUTHOR|(CDS)2089787; Lehmann Miotto, Giovanna

    The bursty many-to-one communication pattern, typical for data acquisition systems, is particularly demanding for commodity TCP/IP and Ethernet technologies. The problem arising from this pattern is widely known in the literature as \\emph{incast} and can be observed as TCP throughput collapse. It is a result of overloading the switch buffers, when a specific node in a network requests data from multiple sources. This will become even more demanding for future upgrades of the experiments at the Large Hadron Collider at CERN. It is questionable whether commodity TCP/IP and Ethernet technologies in their current form will be still able to effectively adapt to bursty traffic without losing packets due to the scarcity of buffers in the networking hardware. This thesis provides an analysis of TCP/IP performance in data acquisition networks and presents a novel approach to incast congestion in these networks based on software-based packet forwarding. Our first contribution lies in confirming the strong analogies bet...

  7. Design and implementation of optical switches based on nonlinear plasmonic ring resonators: Circular, square and octagon

    Science.gov (United States)

    Ghadrdan, Majid; Mansouri-Birjandi, Mohammad Ali

    2018-05-01

    In this paper, all-optical plasmonic switches (AOPS) based on various configurations of circular, square and octagon nonlinear plasmonic ring resonators (NPRR) were proposed and numerically investigated. Each of these configurations consisted of two metal-insulator-metal (MIM) waveguides coupled to each other by a ring resonator (RR). Nonlinear Kerr effect was used to show switching performance of the proposed NPRR. The result showed that the octagon switch structure had lower threshold power and higher transmission ratio than square and circular switch structures. The octagon switch structure had a low threshold power equal to 7.77 MW/cm2 and the high transmission ratio of approximately 0.6. Therefore, the octagon switch structure was an appropriate candidate to be applied in optical integration circuits as an AOPS.

  8. Analysis of physical layer performance of data center with optical wavelength switches based on advanced modulation formats

    Science.gov (United States)

    Ahmad, Iftikhar; Chughtai, Mohsan Niaz

    2018-05-01

    In this paper the IRIS (Integrated Router Interconnected spectrally), an optical domain architecture for datacenter network is analyzed. The IRIS integrated with advanced modulation formats (M-QAM) and coherent optical receiver is analyzed. The channel impairments are compensated using the DSP algorithms following the coherent receiver. The proposed scheme allows N2 multiplexed wavelengths for N×N size. The performance of the N×N-IRIS switch with and without wavelength conversion is analyzed for different Baud rates over M-QAM modulation formats. The performance of the system is analyzed in terms of bit error rate (BER) vs OSNR curves.

  9. Block-free optical quantum Banyan network based on quantum state fusion and fission

    International Nuclear Information System (INIS)

    Zhu Chang-Hua; Meng Yan-Hong; Quan Dong-Xiao; Zhao Nan; Pei Chang-Xing

    2014-01-01

    Optical switch fabric plays an important role in building multiple-user optical quantum communication networks. Owing to its self-routing property and low complexity, a banyan network is widely used for building switch fabric. While, there is no efficient way to remove internal blocking in a banyan network in a classical way, quantum state fusion, by which the two-dimensional internal quantum states of two photons could be combined into a four-dimensional internal state of a single photon, makes it possible to solve this problem. In this paper, we convert the output mode of quantum state fusion from spatial-polarization mode into time-polarization mode. By combining modified quantum state fusion and quantum state fission with quantum Fredkin gate, we propose a practical scheme to build an optical quantum switch unit which is block free. The scheme can be extended to building more complex units, four of which are shown in this paper. (general)

  10. Energy challenges in optical access and aggregation networks.

    Science.gov (United States)

    Kilper, Daniel C; Rastegarfar, Houman

    2016-03-06

    Scalability is a critical issue for access and aggregation networks as they must support the growth in both the size of data capacity demands and the multiplicity of access points. The number of connected devices, the Internet of Things, is growing to the tens of billions. Prevailing communication paradigms are reaching physical limitations that make continued growth problematic. Challenges are emerging in electronic and optical systems and energy increasingly plays a central role. With the spectral efficiency of optical systems approaching the Shannon limit, increasing parallelism is required to support higher capacities. For electronic systems, as the density and speed increases, the total system energy, thermal density and energy per bit are moving into regimes that become impractical to support-for example requiring single-chip processor powers above the 100 W limit common today. We examine communication network scaling and energy use from the Internet core down to the computer processor core and consider implications for optical networks. Optical switching in data centres is identified as a potential model from which scalable access and aggregation networks for the future Internet, with the application of integrated photonic devices and intelligent hybrid networking, will emerge. © 2016 The Author(s).

  11. Engineering Silver Nanowire Networks: From Transparent Electrodes to Resistive Switching Devices.

    Science.gov (United States)

    Du, Haiwei; Wan, Tao; Qu, Bo; Cao, Fuyang; Lin, Qianru; Chen, Nan; Lin, Xi; Chu, Dewei

    2017-06-21

    Metal nanowires (NWs) networks with high conductance have shown potential applications in modern electronic components, especially the transparent electrodes over the past decade. In metal NW networks, the electrical connectivity of nanoscale NW junction can be modulated for various applications. In this work, silver nanowire (Ag NW) networks were selected to achieve the desired functions. The Ag NWs were first synthesized by a classic polyol process, and spin-coated on glass to fabricate transparent electrodes. The as-fabricated electrode showed a sheet resistance of 7.158 Ω □ -1 with an optical transmittance of 79.19% at 550 nm, indicating a comparable figure of merit (FOM, or Φ TC ) (13.55 × 10 -3 Ω -1 ). Then, two different post-treatments were designed to tune the Ag NWs for not only transparent electrode but also for threshold resistive switching (RS) application. On the one hand, the Ag NW film was mechanically pressed to significantly improve the conductance by reducing the junction resistance. On the other hand, an Ag@AgO x core-shell structure was deliberately designed by partial oxidation of Ag NWs through simple ultraviolet (UV)-ozone treatment. The Ag core can act as metallic interconnect and the insulating AgO x shell acts as a switching medium to provide a conductive pathway for Ag filament migration. By fabricating Ag/Ag@AgO x /Ag planar structure, a volatile threshold switching characteristic was observed and an on/off ratio of ∼100 was achieved. This work showed that through different post-treatments, Ag NW network can be engineered for diverse functions, transforming from transparent electrodes to RS devices.

  12. 640 Gbit/s Optical Packet Switching using a Novel In-Band Optical Notch-Filter Labeling Scheme

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros; Galili, Michael; Oxenløwe, Leif Katsuo

    2014-01-01

    Optical packet switching of 640 Gbit/s data packets is reported using an in-band optical labeling technique based on notch-filtering of the data spectrum and extracting the label using a bandpass filter. BER 10􀀀9 is achieved.......Optical packet switching of 640 Gbit/s data packets is reported using an in-band optical labeling technique based on notch-filtering of the data spectrum and extracting the label using a bandpass filter. BER 10􀀀9 is achieved....

  13. 3 x 3 free-space optical router based on crossbar network and its control algorithm

    Science.gov (United States)

    Hou, Peipei; Sun, Jianfeng; Yu, Zhou; Lu, Wei; Wang, Lijuan; Liu, Liren

    2015-08-01

    A 3 × 3 free-space optical router, which comprises optical switches and polarizing beam splitter (PBS) and based on crossbar network, is proposed in this paper. A control algorithm for the 3 × 3 free-space optical router is also developed to achieve rapid control without rearrangement. In order to test the performance of the network based on 3 × 3 free-space optical router and that of the algorithm developed for the optical router, experiments are designed. The experiment results show that the interconnection network based on the 3 × 3 free-space optical router has low cross talk, fast connection speed. Under the control of the algorithm developed, a non-block and real free interconnection network is obtained based on the 3 × 3 free-space optical router we proposed.

  14. Designing in-building optical fiber networks

    NARCIS (Netherlands)

    Koonen, A.M.J.; Boom, van den H.P.A.; Tangdiongga, E.; Jung, H.D.; Guignard, P.

    2010-01-01

    Optical fiber in-building networks carrying wired and wireless services can outperform CAT-5E networks regarding versatility and installation costs. POF-based point-to-point architectures are optimum for small buildings, and (optically routed) SMF-based bus architectures for larger buildings.

  15. Switching of light with light using cold atoms inside a hollow optical fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Peyronel, Thibault

    2010-01-01

    We demonstrate a fiber-optical switch that operates with a few hundred photons per switching pulse. The light-light interaction is mediated by laser-cooled atoms. The required strong interaction between atoms and light is achieved by simultaneously confining photons and atoms inside the microscopic...... hollow core of a single-mode photonic-crystal fiber....

  16. Multichannel all–optical switch based on a thin slab of resonant two–level emitters

    Directory of Open Access Journals (Sweden)

    Malikov Ramil

    2017-01-01

    Full Text Available We discuss the possibility of using a thin layer of inhomogeneously broadened resonant emitters as a multichannel all–optical switch. Switching time from the lower stable branch of the system's bistable characteristics to the upper one and vice versa, which determines the speed of operation of a bistable device, is studied.

  17. A note on the consensus finding problem in communication networks with switching topologies

    KAUST Repository

    Haskovec, Jan

    2014-01-01

    In this note, we discuss the problem of consensus finding in communication networks of agents with dynamically switching topologies. In particular, we consider the case of directed networks with unbalanced matrices of communication rates. We

  18. Optical Subsystems for Next Generation Access Networks

    DEFF Research Database (Denmark)

    Lazaro, J.A; Polo, V.; Schrenk, B.

    2011-01-01

    Recent optical technologies are providing higher flexibility to next generation access networks: on the one hand, providing progressive FTTx and specifically FTTH deployment, progressively shortening the copper access network; on the other hand, also opening fixed-mobile convergence solutions...... in next generation PON architectures. It is provided an overview of the optical subsystems developed for the implementation of the proposed NG-Access Networks....

  19. Azo biphenyl polyurethane: Preparation, characterization and application for optical waveguide switch

    Science.gov (United States)

    Jiang, Yan; Da, Zulin; Qiu, Fengxian; Yang, Dongya; Guan, Yijun; Cao, Guorong

    2018-01-01

    Azo waveguide polymers are of particular interest in the design of materials for applications in optical switch. The aim of this contribution was the synthesis and thermo-optic waveguide switch properties of azo biphenyl polyurethanes. A series of monomers and azo biphenyl polyurethanes (Azo BPU1 and Azo BPU2) were synthesized and characterized by FT-IR, UV-Vis spectroscopy and 1H NMR. The physical and mechanical properties of thin polymer films were measured. The refractive index and thermo-optic coefficient (dn/dT) of polymer films were investigated for TE (transversal electric) polarizations by ATR technique. The transmission loss of film was measured using the Charge Coupled Device digital imaging devices. The results showed the Azo BPU2 containing chiral azobenzene chromophore had higher dn/dT and lower transmission loss. Subsequently, a 1 × 2 Y-branch and 2 × 2 Mach-Zehnder optical switches based on the prepared polymers were designed and simulated. The results showed that the power consumption of all switches was less than 1.0 mW. Compared with 1 × 2 Y-branch optical switch, the 2 × 2 Mach-Zehnder optical switches based on the same polymer have the faster response time, which were about only 1.2 and 2.0 ms, respectively.

  20. Synchronization of Switched Neural Networks With Communication Delays via the Event-Triggered Control.

    Science.gov (United States)

    Wen, Shiping; Zeng, Zhigang; Chen, Michael Z Q; Huang, Tingwen

    2017-10-01

    This paper addresses the issue of synchronization of switched delayed neural networks with communication delays via event-triggered control. For synchronizing coupled switched neural networks, we propose a novel event-triggered control law which could greatly reduce the number of control updates for synchronization tasks of coupled switched neural networks involving embedded microprocessors with limited on-board resources. The control signals are driven by properly defined events, which depend on the measurement errors and current-sampled states. By using a delay system method, a novel model of synchronization error system with delays is proposed with the communication delays and event-triggered control in the unified framework for coupled switched neural networks. The criteria are derived for the event-triggered synchronization analysis and control synthesis of switched neural networks via the Lyapunov-Krasovskii functional method and free weighting matrix approach. A numerical example is elaborated on to illustrate the effectiveness of the derived results.

  1. Combining SDM-Based Circuit Switching with Packet Switching in a Router for On-Chip Networks

    Directory of Open Access Journals (Sweden)

    Angelo Kuti Lusala

    2012-01-01

    Full Text Available A Hybrid router architecture for Networks-on-Chip “NoC” is presented, it combines Spatial Division Multiplexing “SDM” based circuit switching and packet switching in order to efficiently and separately handle both streaming and best-effort traffic generated in real-time applications. Furthermore the SDM technique is combined with Time Division Multiplexing “TDM” technique in the circuit switching part in order to increase path diversity, thus improving throughput while sharing communication resources among multiple connections. Combining these two techniques allows mitigating the poor resource usage inherent to circuit switching. In this way Quality of Service “QoS” is easily provided for the streaming traffic through the circuit-switched sub-router while the packet-switched sub-router handles best-effort traffic. The proposed hybrid router architectures were synthesized, placed and routed on an FPGA. Results show that a practicable Network-on-Chip “NoC” can be built using the proposed router architectures. 7 × 7 mesh NoCs were simulated in SystemC. Simulation results show that the probability of establishing paths through the NoC increases with the number of sub-channels and has its highest value when combining SDM with TDM, thereby significantly reducing contention in the NoC.

  2. Finding Elephant Flows for Optical Networks

    NARCIS (Netherlands)

    Fioreze, Tiago; Oude Wolbers, Mattijs; van de Meent, R.; Pras, Aiko

    2007-01-01

    Optical networks are fast and reliable networks that enable, amongst others, dedicated light paths to be established for elephant IP flows. Elephant IP flows are characterized by being small in number, but long in time and high in traffic volume. Moving these flows from the general IP network to

  3. Routing in Optical and Stochastic Networks

    NARCIS (Netherlands)

    Yang, S.

    2015-01-01

    In most types of networks (e.g., optical or transportation networks), finding one or more best paths from a source to a destination, is one of the biggest concerns of network users and providers. This process is known as routing. The routing problems differ accordingly depending on different

  4. Cognitive Optical Network Testbed: EU Project CHRON

    DEFF Research Database (Denmark)

    Borkowski, Robert; Duran, Ramon J.; Kachris, Christoforos

    2015-01-01

    The aim of cognition in optical networks is to introduce intelligence into the control plane that allows for autonomous end-to-end performance optimization and minimization of required human intervention, particularly targeted at heterogeneous network scenarios. A cognitive network observes, lear...

  5. Optical protocols for advanced spacecraft networks

    Science.gov (United States)

    Bergman, Larry A.

    1991-01-01

    Most present day fiber optic networks are in fact extensions of copper wire networks. As a result, their speed is still limited by electronics even though optics is capable of running three orders of magnitude faster. Also, the fact that photons do not interact with one another (as electrons do) provides optical communication systems with some unique properties or new functionality that is not readily taken advantage of with conventional approaches. Some of the motivation for implementing network protocols in the optical domain, a few possible approaches including optical code-division multiple-access (CDMA), and how this class of networks can extend the technology life cycle of the Space Station Freedom (SSF) with increased performance and functionality are described.

  6. Optical protocols for advanced spacecraft networks

    Science.gov (United States)

    Bergman, Larry A.

    1991-09-01

    Most present day fiber optic networks are in fact extensions of copper wire networks. As a result, their speed is still limited by electronics even though optics is capable of running three orders of magnitude faster. Also, the fact that photons do not interact with one another (as electrons do) provides optical communication systems with some unique properties or new functionality that is not readily taken advantage of with conventional approaches. Some of the motivation for implementing network protocols in the optical domain, a few possible approaches including optical code-division multiple-access (CDMA), and how this class of networks can extend the technology life cycle of the Space Station Freedom (SSF) with increased performance and functionality are described.

  7. Fault location in optical networks

    Science.gov (United States)

    Stevens, Rick C [Apple Valley, MN; Kryzak, Charles J [Mendota Heights, MN; Keeler, Gordon A [Albuquerque, NM; Serkland, Darwin K [Albuquerque, NM; Geib, Kent M [Tijeras, NM; Kornrumpf, William P [Schenectady, NY

    2008-07-01

    One apparatus embodiment includes an optical emitter and a photodetector. At least a portion of the optical emitter extends a radial distance from a center point. The photodetector provided around at least a portion of the optical emitter and positioned outside the radial distance of the portion of the optical emitter.

  8. Optical True Time Delay for Phased Array Antennas Composed of 2×2 Optical MEMS Switches and Fiber Delay Lines

    Institute of Scientific and Technical Information of China (English)

    Back-Song; Lee; Jong-Dug; Shin; Boo-Gyoun; Kim

    2003-01-01

    We proposed an optical true time delay (TTD) for phased array antennas (PAAs) composed of 2×2 optical MEMS switches, single-mode fiber delay lines, and a fixed wavelength laser diode. A 3-bit TTD for 10 GHz PAAs was implemented with a time delay error less than ± 0.2 ps.

  9. Enabling Technologies for Cognitive Optical Networks

    DEFF Research Database (Denmark)

    Borkowski, Robert

    Cognition is a new paradigm for optical networking, in which the network has capabilities to observe, plan, decide, and act autonomously in order to optimize the end-to-end performance and minimize the need for human supervision. This PhD thesis expands the state of the art on cognitive optical......, and machine learning algorithms that make cognition possible. Secondly, advanced optical performance monitoring (OPM) capabilities performed via digital signal processing (DSP) that provide CONs with necessary feedback information allowing for autonomous network optimization. The research results presented...... in this thesis were carried out in the framework of the EU project Cognitive Heterogeneous Reconfigurable Optical Network (CHRON), whose aim was to develop an architecture and implement a testbed of a cognitive network able to self-configure and self-optimize to efficiently use available resources. In order...

  10. Time Shared Optical Network (TSON): a novel metro architecture for flexible multi-granular services.

    Science.gov (United States)

    Zervas, Georgios S; Triay, Joan; Amaya, Norberto; Qin, Yixuan; Cervelló-Pastor, Cristina; Simeonidou, Dimitra

    2011-12-12

    This paper presents the Time Shared Optical Network (TSON) as metro mesh network architecture for guaranteed, statistically-multiplexed services. TSON proposes a flexible and tunable time-wavelength assignment along with one-way tree-based reservation and node architecture. It delivers guaranteed sub-wavelength and multi-granular network services without wavelength conversion, time-slice interchange and optical buffering. Simulation results demonstrate high network utilization, fast service delivery, and low end-to-end delay on a contention-free sub-wavelength optical transport network. In addition, implementation complexity in terms of Layer 2 aggregation, grooming and optical switching has been evaluated. © 2011 Optical Society of America

  11. Optical networking in CESNET2 gigabit network

    Czech Academy of Sciences Publication Activity Database

    Radil, J.; Boháč, L.; Karásek, Miroslav

    2003-01-01

    Roč. 58, 11/12 (2003), s. 1/20-20/20 ISSN 0003-4347 R&D Projects: GA AV ČR IAA2067202 Institutional research plan: CEZ:AV0Z2067918 Keywords : optical fibre amplifiers * wavelength division multiplexing * optical communication Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.239, year: 2003

  12. Pulse power requirements for large aperture optical switches based on plasma electrode Pockels cells

    International Nuclear Information System (INIS)

    Rhodes, M.A.; Taylor, J.

    1992-06-01

    We discuss very large-aperture optical switches (greater than 30 x 30 cm) as an enabling technology for inertial confinement fusion drivers based on multipass laser amplifiers. Large-scale laser fusion drivers such as the Nova laser have been based on single-pass amplifier designs in part because of the unavailability of a suitable large-aperture switch. We are developing an optical switch based on a Pockels cell employing plasma-electrodes. A plasma-electrode Pockels cell (PEPC) is a longitudinal-mode Pockels cell in which a plasma discharge is formed on each side of an electro-optic crystal (typically KDP or deuterated KDP, often designated KD*P). The plasmas formed on either side of the crystal act as transparent electrodes for a switching-pulse and are intended to allow uniform charging of the entire crystal. The switching-pulse is a nominally rectangular high-voltage pulse equal to the half-wave voltage V x ( 8 kV for KD*P or 17 kV for KDP) and is applied across the crystal via the plasma-electrodes. When the crystal is charged to V x , the polarization of an incoming, linearly polarized, laser beam is rotated by 90 degree. When used in conjunction with an appropriate, passive polarizer, an optical switch is thus realized. A switch with a clear aperture of 37 x 37 cm is now in construction for the Beamlet laser which will serve as a test bed for this switch as well as other technologies required for an advanced NOVA laser design. In this paper, we discuss the unique power electronics requirements of PEPC optical switches

  13. A STUDY OF SOLID STATE LASER PASSIVE OPTICAL Q-SWITCHING OPERATION REGIME (Part 1

    Directory of Open Access Journals (Sweden)

    Ion LĂNCRĂNJAN

    2009-09-01

    Full Text Available This paper is the first of a four series treating, theoretically with experimental comparison, the issue of solid state laser passive optical Q-switching regime. In this first paper the technique of solid state lasers passive optical Q-switching is numerically investigated considering the case of longitudinally and transversally uniform photon, population inversion and absorption centres densities. The coupled differential equations defining photon, population inversion and absorption centres densities are numerically solved being the basis of passively optical Q-switched laser functional simulation. The numerical simulations are performed using the several software packages, mostly SCILAB programs. The developed SCILAB programs can be used for a large range of saturable absorption centre and active media parameters, mainly the initial (low signal optical transmittance of the passive optical Q-switch. The developed FORTRAN and SCILAB programs can be applied for passively Q-switched solid state lasers of several types emitting at several NIR wavelengths, in domain 1 ÷ 2 μm. For validating the numerical simulation results are compared with The results of the numerical simulation are compared with experimentally obtained ones, in the case of a LiF:F2- passively Q-switched Nd:YAG. A good agreement between the two kinds of results is observed.

  14. High-performance, scalable optical network-on-chip architectures

    Science.gov (United States)

    Tan, Xianfang

    The rapid advance of technology enables a large number of processing cores to be integrated into a single chip which is called a Chip Multiprocessor (CMP) or a Multiprocessor System-on-Chip (MPSoC) design. The on-chip interconnection network, which is the communication infrastructure for these processing cores, plays a central role in a many-core system. With the continuously increasing complexity of many-core systems, traditional metallic wired electronic networks-on-chip (NoC) became a bottleneck because of the unbearable latency in data transmission and extremely high energy consumption on chip. Optical networks-on-chip (ONoC) has been proposed as a promising alternative paradigm for electronic NoC with the benefits of optical signaling communication such as extremely high bandwidth, negligible latency, and low power consumption. This dissertation focus on the design of high-performance and scalable ONoC architectures and the contributions are highlighted as follow: 1. A micro-ring resonator (MRR)-based Generic Wavelength-routed Optical Router (GWOR) is proposed. A method for developing any sized GWOR is introduced. GWOR is a scalable non-blocking ONoC architecture with simple structure, low cost and high power efficiency compared to existing ONoC designs. 2. To expand the bandwidth and improve the fault tolerance of the GWOR, a redundant GWOR architecture is designed by cascading different type of GWORs into one network. 3. The redundant GWOR built with MRR-based comb switches is proposed. Comb switches can expand the bandwidth while keep the topology of GWOR unchanged by replacing the general MRRs with comb switches. 4. A butterfly fat tree (BFT)-based hybrid optoelectronic NoC (HONoC) architecture is developed in which GWORs are used for global communication and electronic routers are used for local communication. The proposed HONoC uses less numbers of electronic routers and links than its counterpart of electronic BFT-based NoC. It takes the advantages of

  15. All-optical femtosecond switch using two-photon absorption

    International Nuclear Information System (INIS)

    Yavuz, D. D.

    2006-01-01

    Utilizing a two-photon absorption scheme in an alkali-metal vapor cell, we suggest a technique where a strong laser beam switches off another laser beam of different wavelength in femtosecond time scales

  16. Wavelength switching dynamics of two-colour semiconductor lasers with optical injection and feedback

    International Nuclear Information System (INIS)

    Osborne, S; Heinricht, P; Brandonisio, N; Amann, A; O’Brien, S

    2012-01-01

    The wavelength switching dynamics of two-colour semiconductor lasers with optical injection and feedback are presented. These devices incorporate slotted regions etched into the laser ridge waveguide for tailoring the output spectrum. Experimental measurements are presented demonstrating that optical injection in one or both modes of these devices can induce wavelength bistability. Measured switching dynamics with modulated optical injection are shown to be in excellent agreement with numerical simulations based on a simple rate equation model. We also demonstrate experimentally that time-delayed optical feedback can induce wavelength bistability for short external cavity lengths. Numerical simulations indicate that this two-colour optical feedback system can provide fast optical memory functionality based on injected optical pulses without the need for an external holding beam. (paper)

  17. Ultra-Fast All-Optical Self-Aware Protection Switching Based on a Bistable Laser Diode

    DEFF Research Database (Denmark)

    An, Yi; Vukovic, Dragana; Lorences Riesgo, Abel

    2014-01-01

    We propose a novel concept of all-optical protection switching with link failure automatic awareness based on AOWFF. The scheme is experimentally demonstrated using a single MG-Y laser diode with a record switching time ~200 ps....

  18. Experimental demonstration of time- and mode-division multiplexed passive optical network

    Science.gov (United States)

    Ren, Fang; Li, Juhao; Tang, Ruizhi; Hu, Tao; Yu, Jinyi; Mo, Qi; He, Yongqi; Chen, Zhangyuan; Li, Zhengbin

    2017-07-01

    A time- and mode-division multiplexed passive optical network (TMDM-PON) architecture is proposed, in which each optical network unit (ONU) communicates with the optical line terminal (OLT) independently utilizing both different time slots and switched optical linearly polarized (LP) spatial modes. Combination of a mode multiplexer/demultiplexer (MUX/DEUX) and a simple N × 1 optical switch is employed to select the specific LP mode in each ONU. A mode-insensitive power splitter is used for signal broadcast/combination between OLT and ONUs. We theoretically propose a dynamic mode and time slot assignment scheme for TMDM-PON based on inter-ONU priority rating, in which the time delay and packet loss ratio's variation tendency are investigated by simulation. Moreover, we experimentally demonstrate 2-mode TMDM-PON transmission over 10 km FMF with 10-Gb/s on-off keying (OOK) signal and direct detection.

  19. Epidemic Network Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Katsikas, Dimitrios; Fagertun, Anna Manolova

    2013-01-01

    This paper presents a failure propagation model for transport networks which are affected by epidemic failures. The network is controlled using the GMPLS protocol suite. The Susceptible Infected Disabled (SID) epidemic model is investigated and new signaling functionality of GMPLS to support...

  20. Optical switching and photoluminescence in erbium-implanted vanadium dioxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Herianto, E-mail: mail@heriantolim.com; Stavrias, Nikolas; Johnson, Brett C.; McCallum, Jeffrey C. [School of Physics, University of Melbourne, Parkville, Victoria 3010 (Australia); Marvel, Robert E.; Haglund, Richard F. [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37240 (United States)

    2014-03-07

    Vanadium dioxide (VO{sub 2}) is under intensive consideration for optical switching due to its reversible phase transition, which features a drastic and rapid shift in infrared reflectivity. Classified as an insulator–to–metal transition, the phase transition in VO{sub 2} can be induced thermally, electrically, and optically. When induced optically, the transition can occur on sub-picosecond time scales. It is interesting to dope VO{sub 2} with erbium ions (Er{sup 3+}) and observe their combined properties. The first excited-state luminescence of Er{sup 3+} lies within the wavelength window of minimal transmission-loss in silicon and has been widely utilized for signal amplification and generation in silicon photonics. The incorporation of Er{sup 3+} into VO{sub 2} could therefore result in a novel photonic material capable of simultaneous optical switching and amplification. In this work, we investigate the optical switching and photoluminescence in Er-implanted VO{sub 2} thin films. Thermally driven optical switching is demonstrated in the Er-implanted VO{sub 2} by infrared reflectometry. Photoluminescence is observed in the thin films annealed at ∼800 °C or above. In addition, Raman spectroscopy and a statistical analysis of switching hysteresis are carried out to assess the effects of the ion implantation on the VO{sub 2} thin films. We conclude that Er-implanted VO{sub 2} can function as an optical switch and amplifier, but with reduced switching quality compared to pure VO{sub 2}.

  1. Optical switching at 1.55um in silicon racetrack resonators using phase change materials

    NARCIS (Netherlands)

    Rudé, M.; Pello, J.; Simpson, R.E.; Osmond, J.; Roelkens, G.C.; Tol, van der J.J.G.M.; Pruneri, V.

    2013-01-01

    An optical switch operating at a wavelength of 1.55¿µm and showing a 12 dB modulation depth is introduced. The device is implemented in a silicon racetrack resonator using an overcladding layer of the phase change data storage material Ge2Sb2Te5, which exhibits high contrast in its optical

  2. Fiber-optical switch using cam-micromotor driven by scratch drive actuators

    Science.gov (United States)

    Kanamori, Y.; Aoki, Y.; Sasaki, M.; Hosoya, H.; Wada, A.; Hane, K.

    2005-01-01

    We fabricated a 1 × 1 fiber-optic switch using a cam-micromotor driven by scratch drive actuators (SDAs). Using the cam-micromotor, mechanical translation and precise positioning of an optical fiber were performed. An optical fiber of diameter 50 µm was bent and pushed out with a cam-mechanism driven by the SDAs fabricated by surface micromachining. The maximum rotation speed of the cam-micromotor was 7.5 rpm at a driving frequency of 1.5 kHz. The transient time of the switch to attenuate coupling efficiency less than -40 dB was around 10 ms.

  3. A novel micro/nano 1 × 4 mechanical optical switch

    Science.gov (United States)

    Lin, Wu-Lang; Fan, Kuang-Chao; Chiang, Li-Hung; Yang, Yao-Joe; Kuo, Wen-Cheng; Chung, Tien-Tung

    2006-07-01

    This paper presents the design, fabrication and testing of a novel 1 × 4 mechanical optical switch, whose components are fabricated by precision machining and MEMS technologies. The switch uses two relays as the two actuators whose switching direction is perpendicular to each other by an orthogonal arrangement. We adopt a direct fiber-to-fiber principle that aligns the input fiber directly to four output fibers. This configuration eliminates the use of traditional parts such as collimators, turning mirrors or prisms. In addition, due to the use of a fiber holder, the fiber position errors could be reduced to less than 0.27 µm using the two-stage geometry error reduction principle. We have successfully developed a simple and low-cost switch, which performs like most of the 1 × 4 mechanical optical switches that dominate the optics communications market. The advantages of our switch are a small size (20 × 20 × 25 mm3), low cost, high reliability, and the latching function does not need external force for maintaining the state. The experimental results showed that the insertion losses of the four channels are ch1: 0.68 dB, ch2: 1.49 dB, ch3: 0.71 dB and ch4: 0.97 dB. The switching time is 5 ms, the crosstalk <=80 dB. The reliability tests of the insertion loss after 10 000 cycles in four channels yield ch1: 1.67 dB, ch2: 1.63 dB, ch3: 0.75 dB and ch4: 0.98 dB. The size and the cost of our 1 × 4 mechanical optical switch are only about 1/5-1/10 and 1/10 of the series-connect-type and prism-type switches, respectively.

  4. Metropolitan Optical Networks 1995 Annual Report

    DEFF Research Database (Denmark)

    Kristensen, Martin; Jouanno, Jean-Marc; Malone, Kevin

    1996-01-01

    The annual report describes the research carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1995. L.M. Ericsson is prime contractor and 12 partners including DTU is involved in the project.......The annual report describes the research carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1995. L.M. Ericsson is prime contractor and 12 partners including DTU is involved in the project....

  5. Metropolitan Optical Networks 1996 Annual Report

    DEFF Research Database (Denmark)

    Kristensen, Martin; Jouanno, Jean-Marc; Malone, Kevin

    1997-01-01

    The report desribes the reasearch carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1996. L.M. Ericsson is prime contractor and 12 partners are involved in the project including DTU, i.e. EMI and MIC.......The report desribes the reasearch carried out in the ACTS-project METON (Metropolitan Optical Networks) in 1996. L.M. Ericsson is prime contractor and 12 partners are involved in the project including DTU, i.e. EMI and MIC....

  6. NATO Advanced Research Workshop on Optical Switching in Low-Dimensional Systems

    CERN Document Server

    Bányai, L

    1989-01-01

    This book contains all the papers presented at the NATO workshop on "Optical Switching in Low Dimensional Systems" held in Marbella, Spain from October 6th to 8th, 1988. Optical switching is a basic function for optical data processing, which is of technological interest because of its potential parallelism and its potential speed. Semiconductors which exhibit resonance enhanced optical nonlinearities in the frequency range close to the band edge are the most intensively studied materials for optical bistability and fast gate operation. Modern crystal growth techniques, particularly molecular beam epitaxy, allow the manufacture of semiconductor microstructures such as quantum wells, quantum wires and quantum dots in which the electrons are only free to move in two, one or zero dimensions, of the optically excited electron-hole pairs in these low respectively. The spatial confinement dimensional structures gives rise to an enhancement of the excitonic nonlinearities. Furthermore, the variations of the microstr...

  7. Programs for control of an analog-signal switching network

    International Nuclear Information System (INIS)

    D'Ottavio, T.; Enriquez, R.; Katz, R.; Skelly, J.

    1989-01-01

    A suite of programs has been developed to control the network of analog-signal switching multiplexers in the AGS complex. The software is driven by a relational database which describes the architecture of the multiplexer tree and the set of available analog signals. Signals are routed through a three-layer multiplexer tree, to be made available at four consoles each with three 4-trace oscilloscopes. A menu-structured operator interface program is available at each console, to accept requests to route any available analog signal to any of that console's 12 oscilloscope traces. A common routing-server program provides automatic routing-server program provides automatic routing of requested signals through the layers of multiplexers, maintaining a reservation database to denote free and in-use trunks. Expansion of the analog signal system is easily accommodated in software by adding new signals, trunks, multiplexers, or consoles to the database. Programmatic control of the triggering signals for each of the oscilloscopes is also provided. 3 refs., 4 figs., 3 tabs

  8. Switching dynamics in reaction networks induced by molecular discreteness

    International Nuclear Information System (INIS)

    Togashi, Yuichi; Kaneko, Kunihiko

    2007-01-01

    To study the fluctuations and dynamics in chemical reaction processes, stochastic differential equations based on the rate equation involving chemical concentrations are often adopted. When the number of molecules is very small, however, the discreteness in the number of molecules cannot be neglected since the number of molecules must be an integer. This discreteness can be important in biochemical reactions, where the total number of molecules is not significantly larger than the number of chemical species. To elucidate the effects of such discreteness, we study autocatalytic reaction systems comprising several chemical species through stochastic particle simulations. The generation of novel states is observed; it is caused by the extinction of some molecular species due to the discreteness in their number. We demonstrate that the reaction dynamics are switched by a single molecule, which leads to the reconstruction of the acting network structure. We also show the strong dependence of the chemical concentrations on the system size, which is caused by transitions to discreteness-induced novel states

  9. Optical Intrabuilding and Interbuilding Distribution Networks.

    Science.gov (United States)

    Hull, Joseph A.

    Fiber optics communication technology is a potential competitive alternative to coaxial cable and shielded twisted pairlines as a wide-band communications medium. Pilot demonstrations by public institutions such as the health care delivery system can test the application of this new technology. Fiber optic networks may have the potential to be…

  10. Optical datacenter network employing slotted (TDMA) operation for dynamic resource allocation

    Science.gov (United States)

    Bakopoulos, P.; Tokas, K.; Spatharakis, C.; Patronas, I.; Landi, G.; Christodoulopoulos, K.; Capitani, M.; Kyriakos, A.; Aziz, M.; Reisis, D.; Varvarigos, E.; Zahavi, E.; Avramopoulos, H.

    2018-02-01

    The soaring traffic demands in datacenter networks (DCNs) are outpacing progresses in CMOS technology, challenging the bandwidth and energy scalability of currently established technologies. Optical switching is gaining traction as a promising path for sustaining the explosive growth of DCNs; however, its practical deployment necessitates extensive modifications to the network architecture and operation, tailored to the technological particularities of optical switches (i.e. no buffering, limitations in radix size and speed). European project NEPHELE is developing an optical network infrastructure that leverages optical switching within a software-defined networking (SDN) framework to overcome the bandwidth and energy scaling challenges of datacenter networks. An experimental validation of the NEPHELE data plane is reported based on commercial off-the-shelf optical components controlled by FPGA boards. To facilitate dynamic allocation of the network resources and perform collision-free routing in a lossless network environment, slotted operation is employed (i.e. using time-division multiple-access - TDMA). Error-free operation of the NEPHELE data plane is verified for 200 μs slots in various scenarios that involve communication between Ethernet hosts connected to custom-designed top-of-rack (ToR) switches, located in the same or in different datacenter pods. Control of the slotted data plane is obtained through an SDN framework comprising an OpenDaylight controller with appropriate add-ons. Communication between servers in the optical-ToR is demonstrated with various routing scenarios, concerning communication between hosts located in the same rack or in different racks, within the same or different datacenter pods. Error-free operation is confirmed for all evaluated scenarios, underpinning the feasibility of the NEPHELE architecture.

  11. Dynamic optical fiber delivery of Ka-band packet transmissions for wireless access networks

    DEFF Research Database (Denmark)

    Rodríguez Páez, Juan Sebastián; Madsen, Peter; Tafur Monroy, Idelfonso

    2017-01-01

    A Reconfigurable Radio Access Unit is presented and experimentally demonstrated. In the unit, an optical switching system is set to dynamically deliver different packets to different points in the network. The packets are transmitted wirelesslty on the Ka-band (26–40 GHz), achieving BER values...

  12. An absorptive single-pole four-throw switch using multiple-contact MEMS switches and its application to a monolithic millimeter-wave beam-forming network

    International Nuclear Information System (INIS)

    Lee, Sanghyo; Kim, Jong-Man; Kim, Yong-Kweon; Kwon, Youngwoo

    2009-01-01

    In this paper, a new absorptive single-pole four-throw (SP4T) switch based on multiple-contact switching is proposed and integrated with a Butler matrix to demonstrate a monolithic beam-forming network at millimeter waves (mm waves). In order to simplify the switching driving circuit and reduce the number of unit switches in an absorptive SP4T switch, the individual switches were replaced with long-span multiple-contact switches using stress-free single-crystalline-silicon MEMS technology. This approach improves the mechanical stability as well as the manufacturing yield, thereby allowing successful integration into a monolithic beam former. The fabricated absorptive SP4T MEMS switch shows insertion loss less than 1.3 dB, return losses better than 11 dB at 30 GHz and wideband isolation performance higher than 39 dB from 20 to 40 GHz. The absorptive SP4T MEMS switch is integrated with a 4 × 4 Butler matrix on a single chip to implement a monolithic beam-forming network, directing beam into four distinct angles. Array factors from the measured data show that the proposed absorptive SPnT MEMS switch can be effectively used for high-performance mm-wave beam-switching systems. This work corresponds to the first demonstration of a monolithic beam-forming network using switched beams

  13. Delay-Dependent Stability Criteria of Uncertain Periodic Switched Recurrent Neural Networks with Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Xing Yin

    2011-01-01

    uncertain periodic switched recurrent neural networks with time-varying delays. When uncertain discrete-time recurrent neural network is a periodic system, it is expressed as switched neural network for the finite switching state. Based on the switched quadratic Lyapunov functional approach (SQLF and free-weighting matrix approach (FWM, some linear matrix inequality criteria are found to guarantee the delay-dependent asymptotical stability of these systems. Two examples illustrate the exactness of the proposed criteria.

  14. Development of a switched integrator amplifier for high-accuracy optical measurements

    International Nuclear Information System (INIS)

    Mountford, John; Porrovecchio, Geiland; Smid, Marek; Smid, Radislav

    2008-01-01

    In the field of low flux optical measurements, the development and use of large area silicon detectors is becoming more frequent. The current/voltage conversion of their photocurrent presents a set of problems for traditional transimpedance amplifiers. The switched integration principle overcomes these limitations. We describe the development of a fully characterized current-voltage amplifier using the switched integrator technique. Two distinct systems have been developed in parallel at the United Kingdom's National Physical Laboratory (NPL) and Czech Metrology Institute (CMI) laboratories. We present the circuit theory and best practice in the design and construction of switched integrators. In conclusion the results achieved and future developments are discussed

  15. Development of a switched integrator amplifier for high-accuracy optical measurements.

    Science.gov (United States)

    Mountford, John; Porrovecchio, Geiland; Smid, Marek; Smid, Radislav

    2008-11-01

    In the field of low flux optical measurements, the development and use of large area silicon detectors is becoming more frequent. The current/voltage conversion of their photocurrent presents a set of problems for traditional transimpedance amplifiers. The switched integration principle overcomes these limitations. We describe the development of a fully characterized current-voltage amplifier using the switched integrator technique. Two distinct systems have been developed in parallel at the United Kingdom's National Physical Laboratory (NPL) and Czech Metrology Institute (CMI) laboratories. We present the circuit theory and best practice in the design and construction of switched integrators. In conclusion the results achieved and future developments are discussed.

  16. 2×2 polymeric electro-optic MZI switch using multimode interference couplers

    Science.gov (United States)

    Li, H. P.; Liao, J. K.; Tang, X. G.; Lu, R. G.; Liu, Y. Z.

    2009-11-01

    We present the design of a 2×2 photonic switch operating at 1.55-μm wavelength using electro-optic (EO) polymer waveguides. A Mach-Zehnder interferometer (MZI) is used to implement the proposed switch in which two identical 2×2 multimode interference (MMI) couplers are connected by two identical parallel single mode waveguides (two MZI arms). These two single-mode waveguides with electrodes allow modulating the phase difference between the two MZI arms based on the EO effect. In the proposed switch, the EO polymer, IPC-E/polysulfone, is used for the core layer of optical waveguides. UV15 and NOA61 are employed for the lower and upper cladding layers, respectively. The singlemode waveguide structure and 2×2 MMI coupler have been designed and analyzed for the EO switch. Device performance has been simulated using the beam propagation method. It is found that the switch performance is most sensitive to the MMI width and less sensitive to the MMI length. Optimized structure has been obtained for the 2×2 polymeric EO switch, which has a crosstalk level better than -25 dB and insertion loss lower than -1.8 dB. This performance makes the switch a potential candidate for practical use in photonic systems.

  17. Connection Management and Recovery Strategies under Epidemic Network Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2014-01-01

    The current trend in deploying automatic control plane solutions for increased flexibility in the optical transport layer leads to numerous advantages for both the operators and the customers, but also pose challenges related to the stability of the network and its ability to operate in a robust...... manner under attacks. This work proposes four policies for failure handling in a connection-oriented optical transport network, under Generalized MultiProtocol Label Switching control plane, and evaluates their performance under multiple correlated large-scale failures. We employ the Susceptible...... of their transport infrastructures. Applying proactive methods for avoiding areas where epidemic failures spread results in 50% less connections requiring recovery, which translates in improved quality of service to customers....

  18. Towards green high capacity optical networks

    Science.gov (United States)

    Glesk, I.; Mohd Warip, M. N.; Idris, S. K.; Osadola, T. B.; Andonovic, I.

    2011-09-01

    The demand for fast, secure, energy efficient high capacity networks is growing. It is fuelled by transmission bandwidth needs which will support among other things the rapid penetration of multimedia applications empowering smart consumer electronics and E-businesses. All the above trigger unparallel needs for networking solutions which must offer not only high-speed low-cost "on demand" mobile connectivity but should be ecologically friendly and have low carbon footprint. The first answer to address the bandwidth needs was deployment of fibre optic technologies into transport networks. After this it became quickly obvious that the inferior electronic bandwidth (if compared to optical fiber) will further keep its upper hand on maximum implementable serial data rates. A new solution was found by introducing parallelism into data transport in the form of Wavelength Division Multiplexing (WDM) which has helped dramatically to improve aggregate throughput of optical networks. However with these advancements a new bottleneck has emerged at fibre endpoints where data routers must process the incoming and outgoing traffic. Here, even with the massive and power hungry electronic parallelism routers today (still relying upon bandwidth limiting electronics) do not offer needed processing speeds networks demands. In this paper we will discuss some novel unconventional approaches to address network scalability leading to energy savings via advance optical signal processing. We will also investigate energy savings based on advanced network management through nodes hibernation proposed for Optical IP networks. The hibernation reduces the network overall power consumption by forming virtual network reconfigurations through selective nodes groupings and by links segmentations and partitionings.

  19. Broadband optically controlled switching effect in a microfluid-filled photonic bandgap fiber

    International Nuclear Information System (INIS)

    Guo, Junqi; Liu, Yan-ge; Wang, Zhi; Luo, Mingming; Huang, Wei; Liu, Xiaoqi; Han, Tingting

    2016-01-01

    Broadband optically controlled switching in a microfluid-filled photonic bandgap fiber (MF-PBGF) was observed and investigated. The MF-PBGF was formed by infusing a temperature-sensitive high-index fluid into all of the cladding holes of a microstructured optical fiber (MOF). The fiber was then side pumped with a 532 nm continuous wave laser. An extinction ratio of greater than 20 dB at most of the bandgap wavelengths (more than 200 nm) was obtained with a switching power of ∼147 mW. Theoretical and experimental investigations revealed that the effect originated from changes in the temperature gradient induced by heat absorption of the fiber coating with laser illumination. These investigations offer a new and simple approach to achieve wideband and flexible all-optical fiber switching devices without using any photosensitive materials. (paper)

  20. Energy-Efficiency in Optical Networks

    DEFF Research Database (Denmark)

    Saldaña Cercos, Silvia

    This thesis expands the state-of-the-art on the complex problem of implementing energy efficient optical networks. The main contribution of this Ph.D. thesis is providing a holistic approach in a multi-layered manner where different tools are used to tackle the urgent need of both estimating...... and optimizing power consumption in different network segments. An energy consumption analysis for a novel digital signal processing for signal slicing to reduce bandwidth requirements for passive optical networks is presented in this thesis. This scheme aims at re-using low bandwidth equipment to cope...... with parallel optics and WDM systems is reported. These results show the trade-off between increased capacity and both power consumption and system performance. In conclusion, an energy-efficient set of tools has been provided covering different aspects of the telecommunication network resulting in a cohesive...

  1. Efficient all-optical switching using slow light within a hollow fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Balic, Vlatko

    2009-01-01

    We demonstrate a fiber-optical switch that is activated at tiny energies corresponding to a few hundred optical photons per pulse. This is achieved by simultaneously confining both photons and a small laser-cooled ensemble of atoms inside the microscopic hollow core of a single-mode photonic-crys......-crystal fiber and using quantum optical techniques for generating slow light propagation and large nonlinear interaction between light beams.......We demonstrate a fiber-optical switch that is activated at tiny energies corresponding to a few hundred optical photons per pulse. This is achieved by simultaneously confining both photons and a small laser-cooled ensemble of atoms inside the microscopic hollow core of a single-mode photonic...

  2. Neural networks in continuous optical media

    International Nuclear Information System (INIS)

    Anderson, D.Z.

    1987-01-01

    The authors' interest is to see to what extent neural models can be implemented using continuous optical elements. Thus these optical networks represent a continuous distribution of neuronlike processors rather than a discrete collection. Most neural models have three characteristic features: interconnections; adaptivity; and nonlinearity. In their optical representation the interconnections are implemented with linear one- and two-port optical elements such as lenses and holograms. Real-time holographic media allow these interconnections to become adaptive. The nonlinearity is achieved with gain, for example, from two-beam coupling in photorefractive media or a pumped dye medium. Using these basic optical elements one can in principle construct continuous representations of a number of neural network models. The authors demonstrated two devices based on continuous optical elements: an associative memory which recalls an entire object when addressed with a partial object and a tracking novelty filter which identifies time-dependent features in an optical scene. These devices demonstrate the potential of distributed optical elements to implement more formal models of neural networks

  3. All optical OFDM transmission for passive optical networks

    Science.gov (United States)

    Kachare, Nitin; Ashik T., J.; Bai, K. Kalyani; Kumar, D. Sriram

    2017-06-01

    This paper demonstrates the idea of data transmission at a very higher rate (Tbits/s) through optical fibers in a passive optical network using the most efficient data transmission technique widely used in wireless communication that is orthogonal frequency division multiplexing. With an increase in internet users, data traffic has also increased significantly and the current dense wavelength division multiplexing (DWDM) systems may not support the next generation passive optical networks (PONs) requirements. The approach discussed in this paper allows to increase the downstream data rate per user and extend the standard single-mode fiber reach for future long-haul applications. All-optical OFDM is a promising solution for terabit per second capable single wavelength transmission, with high spectral efficiency and high tolerance to chromatic dispersion.

  4. Future optical communication networks beyond 160 Gbit/s based on OTDM

    Science.gov (United States)

    Prati, Giancarlo; Bogoni, Antonella; Poti, Luca

    2005-01-01

    The virtually unlimited bandwidth of optical fibers has caused a great increase in data transmission speed over the past decade and, hence, stimulated high-demand multimedia services such as distance learning, video-conferencing and peer to peer applications. For this reason data traffic is exceeding telephony traffic, and this trend is driving the convergence of telecommunications and computer communications. In this scenario Internet Protocol (IP) is becoming the dominant protocol for any traffic, shifting the attention of the network designers from a circuit switching approach to a packet switching approach. A role of paramount importance in packet switching networks is played by the router that must implement the functionalities to set up and maintain the inter-nodal communications. The main functionalities a router must implement are routing, forwarding, switching, synchronization, contention resolution, and buffering. Nowadays, opto-electronic conversion is still required at each network node to process the incoming signal before routing that to the right output port. However, when the single channel bit rate increases beyond electronic speed limit, Optical Time Division Multiplexing (OTDM) becomes a forced choice, and all-optical processing must be performed to extract the information from the incoming packet. In this paper enabling techniques for ultra-fast all-optical network will be addressed. First a 160 Gbit/s complete transmission system will be considered. As enabling technique, an overview for all-optical logics will be discussed and experimental results will be presented using a particular reconfigurable NOLM based on Self-Phase-Modulation (SPM) or Cross-Phase-Modulation (XPM). Finally, a rough experiment on label extraction, all-optical switching and packet forwarding is shown.

  5. Multicast traffic grooming in flexible optical WDM networks

    Science.gov (United States)

    Patel, Ankitkumar N.; Ji, Philip N.; Jue, Jason P.; Wang, Ting

    2012-12-01

    In Metropolitan Area Networks (MANs), point-to-multipoint applications, such as IPTV, video-on-demand, distance learning, and content distribution, can be efficiently supported through light-tree-based multicastcommunications instead of lightpath-based unicast-communications. The application of multicasting for such traffic is justified by its inherent benefits of reduced control and management overhead and elimination of redundant resource provisioning. Supporting such multicast traffic in Flexible optical WDM (FWDM) networks that can provision light-trees using optimum amount of spectrum within flexible channel spacing leads to higher wavelength and spectral efficiencies compared to the conventional ITU-T fixed grid networks. However, in spite of such flexibility, the residual channel capacity of stranded channels may not be utilized if the network does not offer channels with arbitrary line rates. Additionally, the spectrum allocated to guard bands used to isolate finer granularity channels remains unutilized. These limitations can be addressed by using traffic grooming in which low-rate multicast connections are aggregated and switched over high capacity light-trees. In this paper, we address the multicast traffic grooming problem in FWDM networks, and propose a novel auxiliary graph-based algorithm for the first time. The performance of multicast traffic grooming is evaluated in terms of spectral, cost, and energy efficiencies compared to lightpath-based transparent FWDM networks, lightpathbased traffic grooming-capable FWDM networks, multicast-enabled transparent FWDM networks, and multicast traffic grooming-capable fixed grid networks. Simulation results demonstrate that multicast traffic grooming in FWDM networks not only improves spectral efficiency, but also cost, and energy efficiencies compared to other multicast traffic provisioning approaches of FWDM and fixed grid networks.

  6. Co-ordination and Lock-in: Competition with Switching Costs and Network Effects

    OpenAIRE

    Joseph Farrell; Paul Klemperer

    2006-01-01

    Switching costs and network effects bind customers to vendors if products are incompatible, locking customers or even markets in to early choices. Lock-in hinders customers from changing suppliers in response to (predictable or unpredictable) changes in effciency, and gives vendors lucrative ex post market power-over the same buyer in the case of switching costs (or brand loyalty), or over others with network effects. Firms compete ex ante for this ex post power, using penetration pricing, in...

  7. Coordination and Lock-In: Competition with Switching Costs and Network Effects

    OpenAIRE

    Farrell, Joseph; Klemperer, Paul

    2006-01-01

    Switching costs and network effects bind customers to vendors if products are incompatible, locking customers or even markets in to early choices. Lock-in hinders customers from changing suppliers in response to (predictable or unpredictable) changes in efficiency, and gives vendors lucrative ex post market power—over the same buyer in the case of switching costs (or brand loyalty), or over others with network effects. Firms compete ex ante for this ex post power, using penetration ...

  8. Modelling switching-time effects in high-frequency power conditioning networks

    Science.gov (United States)

    Owen, H. A.; Sloane, T. H.; Rimer, B. H.; Wilson, T. G.

    1979-01-01

    Power transistor networks which switch large currents in highly inductive environments are beginning to find application in the hundred kilohertz switching frequency range. Recent developments in the fabrication of metal-oxide-semiconductor field-effect transistors in the power device category have enhanced the movement toward higher switching frequencies. Models for switching devices and of the circuits in which they are imbedded are required to properly characterize the mechanisms responsible for turning on and turning off effects. Easily interpreted results in the form of oscilloscope-like plots assist in understanding the effects of parametric studies using topology oriented computer-aided analysis methods.

  9. Towards all-optical label switching nodes with multicast

    NARCIS (Netherlands)

    Yan, N.

    2008-01-01

    Fiber optics has developed so rapidly during the last decades that it has be- come the backbone of our communication systems. Evolved from initially static single-channel point-to-point links, the current advanced optical backbone net- work consists mostly of wavelength-division multiplexed (WDM)

  10. Temporal dynamics of all-optical switching in Photonic Crystal Cavity

    DEFF Research Database (Denmark)

    Colman, Pierre; Heuck, Mikkel; Yu, Yi

    2014-01-01

    The temporal dynamics of all-optical switching has been investigated in a Photonic Crystal Cavity with a 150fs-40aJ/pulse resolution. This allowed observing for the first time effects like pulse reshaping, pulse delay and intra-cavity Four-Wave-Mixing.......The temporal dynamics of all-optical switching has been investigated in a Photonic Crystal Cavity with a 150fs-40aJ/pulse resolution. This allowed observing for the first time effects like pulse reshaping, pulse delay and intra-cavity Four-Wave-Mixing....

  11. High-speed electro-optic switch with -80 dB crosstalk

    Science.gov (United States)

    Pan, J. J.; Su, W. H.; Xu, J. Y.; Grove, C. H.

    1992-01-01

    Special device modeling, design and layout, and precision processing controls were employed to fabricate new balanced-bridge 2x2 and 4x4 switches on X-cut, Y-propagation LiNbO3 substrate using Ti indiffused optical waveguides. The best of these devices achieved extinction ratio and crosstalk isolation of better than 93 dB electrically (46.5 dB optically). The new switches demonstrate good reproducibility with electrical crosstalk less than -80 dB.

  12. Reconfigurable optical implementation of quantum complex networks

    Science.gov (United States)

    Nokkala, J.; Arzani, F.; Galve, F.; Zambrini, R.; Maniscalco, S.; Piilo, J.; Treps, N.; Parigi, V.

    2018-05-01

    Network theory has played a dominant role in understanding the structure of complex systems and their dynamics. Recently, quantum complex networks, i.e. collections of quantum systems arranged in a non-regular topology, have been theoretically explored leading to significant progress in a multitude of diverse contexts including, e.g., quantum transport, open quantum systems, quantum communication, extreme violation of local realism, and quantum gravity theories. Despite important progress in several quantum platforms, the implementation of complex networks with arbitrary topology in quantum experiments is still a demanding task, especially if we require both a significant size of the network and the capability of generating arbitrary topology—from regular to any kind of non-trivial structure—in a single setup. Here we propose an all optical and reconfigurable implementation of quantum complex networks. The experimental proposal is based on optical frequency combs, parametric processes, pulse shaping and multimode measurements allowing the arbitrary control of the number of the nodes (optical modes) and topology of the links (interactions between the modes) within the network. Moreover, we also show how to simulate quantum dynamics within the network combined with the ability to address its individual nodes. To demonstrate the versatility of these features, we discuss the implementation of two recently proposed probing techniques for quantum complex networks and structured environments.

  13. Performance evaluation of distributed wavelength assignment in WDM optical networks

    Science.gov (United States)

    Hashiguchi, Tomohiro; Wang, Xi; Morikawa, Hiroyuki; Aoyama, Tomonori

    2004-04-01

    In WDM wavelength routed networks, prior to a data transfer, a call setup procedure is required to reserve a wavelength path between the source-destination node pairs. A distributed approach to a connection setup can achieve a very high speed, while improving the reliability and reducing the implementation cost of the networks. However, along with many advantages, several major challenges have been posed by the distributed scheme in how the management and allocation of wavelength could be efficiently carried out. In this thesis, we apply a distributed wavelength assignment algorithm named priority based wavelength assignment (PWA) that was originally proposed for the use in burst switched optical networks to the problem of reserving wavelengths of path reservation protocols in the distributed control optical networks. Instead of assigning wavelengths randomly, this approach lets each node select the "safest" wavelengths based on the information of wavelength utilization history, thus unnecessary future contention is prevented. The simulation results presented in this paper show that the proposed protocol can enhance the performance of the system without introducing any apparent drawbacks.

  14. Moving Reflector Type Micro Optical Switch for High-Power Transfer in a MEMS-Based Safety and Arming System

    National Research Council Canada - National Science Library

    Cochran, Kevin R; Fan, Lawrence; Voe, Don L

    2003-01-01

    ...) system for use in underwater weapons. In this switch, an etched vertical sidewall reflector is electrostatically actuated in and out of the optical path between input and output optical fibers...

  15. Optical interconnection networks for high-performance computing systems

    International Nuclear Information System (INIS)

    Biberman, Aleksandr; Bergman, Keren

    2012-01-01

    Enabled by silicon photonic technology, optical interconnection networks have the potential to be a key disruptive technology in computing and communication industries. The enduring pursuit of performance gains in computing, combined with stringent power constraints, has fostered the ever-growing computational parallelism associated with chip multiprocessors, memory systems, high-performance computing systems and data centers. Sustaining these parallelism growths introduces unique challenges for on- and off-chip communications, shifting the focus toward novel and fundamentally different communication approaches. Chip-scale photonic interconnection networks, enabled by high-performance silicon photonic devices, offer unprecedented bandwidth scalability with reduced power consumption. We demonstrate that the silicon photonic platforms have already produced all the high-performance photonic devices required to realize these types of networks. Through extensive empirical characterization in much of our work, we demonstrate such feasibility of waveguides, modulators, switches and photodetectors. We also demonstrate systems that simultaneously combine many functionalities to achieve more complex building blocks. We propose novel silicon photonic devices, subsystems, network topologies and architectures to enable unprecedented performance of these photonic interconnection networks. Furthermore, the advantages of photonic interconnection networks extend far beyond the chip, offering advanced communication environments for memory systems, high-performance computing systems, and data centers. (review article)

  16. Design and optimization of all-optical networks

    Science.gov (United States)

    Xiao, Gaoxi

    1999-10-01

    available to support full wavelength conversion, the cost of the links can be significantly reduced. 4.In the fourth part, we consider all-optical wide area networks with multiple fibers per link. We design a node configuration for all-optical networks. We exploit the flexibility that, to establish a lightpath across a node, we can select any one of the available channels in the incoming link and any one of the available channels in the outgoing link. As a result, the proposed node configuration requires a small number of small optical switches while it can achieve nearly the same performance as the existing one. And there is no additional crosstalk other than the intrinsic crosstalk within each single-chip optical switch.* (Abstract shortened by UMI.) *Originally published in DAI Vol. 60, No. 2. Reprinted here with corrected author name.

  17. Network architecture in a converged optical + IP network

    Science.gov (United States)

    Wakim, Walid; Zottmann, Harald

    2012-01-01

    As demands on Provider Networks continue to grow at exponential rates, providers are forced to evaluate how to continue to grow the network while increasing service velocity, enhancing resiliency while decreasing the total cost of ownership (TCO). The bandwidth growth that networks are experiencing is in the form packet based multimedia services such as video, video conferencing, gaming, etc... mixed with Over the Top (OTT) content providers such as Netflix, and the customer's expectations that best effort is not enough you end up with a situation that forces the provider to analyze how to gain more out of the network with less cost. In this paper we will discuss changes in the network that are driving us to a tighter integration between packet and optical layers and how to improve on today's multi - layer inefficiencies to drive down network TCO and provide for a fully integrated and dynamic network that will decrease time to revenue.

  18. Transparent ceramic photo-optical semiconductor high power switches

    Science.gov (United States)

    Werne, Roger W.; Sullivan, James S.; Landingham, Richard L.

    2016-01-19

    A photoconductive semiconductor switch according to one embodiment includes a structure of sintered nanoparticles of a high band gap material exhibiting a lower electrical resistance when excited by light relative to an electrical resistance thereof when not exposed to the light. A method according to one embodiment includes creating a mixture comprising particles, at least one dopant, and at least one solvent; adding the mixture to a mold; forming a green structure in the mold; and sintering the green structure to form a transparent ceramic. Additional system, methods and products are also presented.

  19. A nonlinear plasmonic resonator for three-state all-optical switching

    KAUST Repository

    Amin, Muhammad

    2014-01-01

    A nonlinear plasmonic resonator design is proposed for three-state all-optical switching at frequencies including near infrared and lower red parts of the spectrum. The tri-stable response required for three-state operation is obtained by enhancing nonlinearities of a Kerr medium through multiple (higher order) plasmons excited on resonator\\'s metallic surfaces. Indeed, simulations demonstrate that exploitation of multiple plasmons equips the proposed resonator with a multi-band tri-stable response, which cannot be obtained using existing nonlinear plasmonic devices that make use of single mode Lorentzian resonances. Multi-band three-state optical switching that can be realized using the proposed resonator has potential applications in optical communications and computing. © 2014 Optical Society of America.

  20. A nonlinear plasmonic resonator for three-state all-optical switching

    KAUST Repository

    Amin, Muhammad; Farhat, Mohamed; Bagci, Hakan

    2014-01-01

    A nonlinear plasmonic resonator design is proposed for three-state all-optical switching at frequencies including near infrared and lower red parts of the spectrum. The tri-stable response required for three-state operation is obtained by enhancing nonlinearities of a Kerr medium through multiple (higher order) plasmons excited on resonator's metallic surfaces. Indeed, simulations demonstrate that exploitation of multiple plasmons equips the proposed resonator with a multi-band tri-stable response, which cannot be obtained using existing nonlinear plasmonic devices that make use of single mode Lorentzian resonances. Multi-band three-state optical switching that can be realized using the proposed resonator has potential applications in optical communications and computing. © 2014 Optical Society of America.

  1. Realization of all-optical switch and diode via Raman gain process using a Kerr field

    Science.gov (United States)

    Abbas, Muqaddar; Qamar, Sajid; Qamar, Shahid

    2016-08-01

    The idea of optical photonic crystal, which is generated using two counter-propagating fields, is revisited to study gain-assisted all-optical switch and diode using Kerr field. Two counter-propagating fields with relative detuning Δ ν generate standing-wave field pattern which interacts with a four-level atomic system. The standing-wave field pattern acts like a static photonic crystal for Δ ν =0 , however, it behaves as a moving photonic crystal for Δ ν \

  2. Preparation, optical properties and 1 Multiplication-Sign 2 polymeric thermo-optic switch of polyurethane-urea

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Fengxian, E-mail: fxqiuchem@163.com [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Cao, Zhijuan [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Cao, Guorong; Guan, Yijun; Shen, Qiang [Department of Physics, Jiangsu University, Zhenjiang 212013 (China); Wang, Qing; Yang, Dongya [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China)

    2012-08-15

    A polyurethane-urea (PUU) containing azo chromophore, polyether polyol (NJ-220) and isophorone diisocyanate (IPDI) was prepared. The structure, thermal property and mechanical properties of obtained PUU were characterized and measured by the UV-visible spectroscopy, Fourier transform infrared, Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The refractive index (n) of PUU was determined at different temperature and wavelength (532 nm, 650 nm and 850 nm) using attenuated total reflection (ATR) technique, and the thermo-optic coefficients (dn/dT) were -5.3643 Multiplication-Sign 10{sup -4} Degree-Sign C{sup -1}, -5.2500 Multiplication-Sign 10{sup -4} Degree-Sign C{sup -1} and -4.6071 Multiplication-Sign 10{sup -4} Degree-Sign C{sup -1}, respectively. Using the Charge Coupled Device (CCD) digital imaging devices, transmission loss of PUU was measured and the value was 0.659 dB cm{sup -1}. A 1 Multiplication-Sign 2 polymeric thermo-optic switch based on the thermo-optic effect of PUU film was proposed. With branching angle of 0.143 Degree-Sign and the finite difference beam propagation method (FD-BPM), the polymeric thermo-optic switch was simulated. The result showed that the power consumption of the thermo-optic switch could be only 0.72 mW, and the response time of the switch was about 3.0 ms. The obtained PUU has a significant improvement in reducing the power consumption and response time compared with those of the normal polymeric thermo-optic switches. -- Highlights: Black-Right-Pointing-Pointer Preparation and structural characterization of a novel azo polyurethane-urea (PUU). Black-Right-Pointing-Pointer The mechanical performance and thermal property of PUU film. Black-Right-Pointing-Pointer The thermo-optic property, transmission loss and dispersion property of PUU. Black-Right-Pointing-Pointer Proposed a new 1 Multiplication-Sign 2 polymeric thermo-optic switch.

  3. Research on optical access network remote management technology

    Science.gov (United States)

    Wang, Wayne; Zou, Chen; Luo, Wenyi

    2008-11-01

    This paper goal is to provide a framework for the remote configuration and management of services for PON (Passive Optical Network) access and fiber access. Also it defines how Auto-Configuration Servers (ACS) in the network can remotely configure, troubleshoot and manage a Passive Optical Network (PON) optical network termination (ONT) with layer 3 capabilities using the CPE WAN management protocol, TR-069.

  4. Reconfigurable optical interconnection network for multimode optical fiber sensor arrays

    Science.gov (United States)

    Chen, R. T.; Robinson, D.; Lu, H.; Wang, M. R.; Jannson, T.; Baumbick, R.

    1992-01-01

    A single-source, single-detector architecture has been developed to implement a reconfigurable optical interconnection network multimode optical fiber sensor arrays. The network was realized by integrating LiNbO3 electrooptic (EO) gratings working at the Raman Na regime and a massive fan-out waveguide hologram (WH) working at the Bragg regime onto a multimode glass waveguide. The glass waveguide utilized the whole substrate as a guiding medium. A 1-to-59 massive waveguide fan-out was demonstrated using a WH operating at 514 nm. Measured diffraction efficiency of 59 percent was experimentally confirmed. Reconfigurability of the interconnection was carried out by generating an EO grating through an externally applied electric field. Unlike conventional single-mode integrated optical devices, the guided mode demonstrated has an azimuthal symmetry in mode profile which is the same as that of a fiber mode.

  5. Physical impairment aware transparent optical networks

    Science.gov (United States)

    Antona, Jean-Christophe; Morea, Annalisa; Zami, Thierry; Leplingard, Florence

    2009-11-01

    As illustrated by optical fiber and optical amplification, optical telecommunications have appeared for the last ten years as one of the most promising candidates to increase the transmission capacities. More recently, the concept of optical transparency has been investigated and introduced: it consists of the optical routing of Wavelength Division Multiplexed (WDM) channels without systematic optoelectronic processing at nodes, as long as propagation impairments remain acceptable [1]. This allows achieving less power-consuming, more scalable and flexible networks, and today partial optical transparency has become a reality in deployed systems. However, because of the evolution of traffic features, optical networks are facing new challenges such as demand for higher transmitted capacity, further upgradeability, and more automation. Making all these evolutions compliant on the same current network infrastructure with a minimum of upgrades is one of the main issues for equipment vendors and operators. Hence, an automatic and efficient management of the network needs a control plan aware of the expected Quality of Transmission (QoT) of the connections to set-up with respect to numerous parameters such as: the services demanded by the customers in terms of protection/restoration; the modulation rate and format of the connection under test and also of its adjacent WDM channels; the engineering rules of the network elements traversed with an accurate knowledge of the associated physical impairments. Whatever the method and/or the technology used to collect this information, the issue about its accuracy is one of the main concerns of the network system vendors, because an inaccurate knowledge could yield a sub-optimal dimensioning and so additional costs when installing the network in the field. Previous studies [1], [2] illustrated the impact of this knowledge accuracy on the ability to predict the connection feasibility. After describing usual methods to build

  6. On the topology of optical transport networks

    International Nuclear Information System (INIS)

    Cardenas, J P; Santiago, A; Losada, J C; Benito, R M; Mouronte, M L

    2010-01-01

    Synchronous Digital Hierarchy (SDH) is the standard technology for information transmission in broadband optical networks. Unlike systems with unplanned growth, such as those of natural origin or the Internet network, the SDH systems are strictly planned as rings, meshes, stars or tree-branches structures designed to connect different equipments. In spite of that, we have found that the SDH network operated by Telefonica in Spain shares remarkable topological properties with other real complex networks as a product of its evolution since 1992. In fact, we have found power-law scaling in the degree distribution (N·P(k) = k -γ ) and small-world networks properties. The complexity found in SDH systems was reproduced by two models of complex networks, one of them considers real planning directives that take into account geographical and technological variables and the other one is based in the compatibility among SDH equipments.

  7. Ultra-fast all-optical plasmonic switching in near infra-red spectrum using a Kerr nonlinear ring resonator

    Science.gov (United States)

    Nurmohammadi, Tofiq; Abbasian, Karim; Yadipour, Reza

    2018-03-01

    In this paper, an all-optical plasmonic switch based on metal-insulator-metal (MIM) nanoplasmonic waveguide with a Kerr nonlinear ring resonator is introduced and studied. Two-dimensional simulations utilizing the finite-difference time-domain algorithm are used to demonstrate an apparent optical bistability and significant switching mechanisms (in enabled-low condition: T(ON/OFF) =21.9 and in enabled-high condition: T(ON/OFF) =24.9) of the signal light arisen by altering the pump-light intensity. The proposed all-optical switching demonstrates femtosecond-scale feedback time (90 fs) and then ultra-fast switching can be achieved. The offered all-optical switch may recognize potential significant applications in integrated optical circuits.

  8. Microsecond pulsed optical parametric oscillator pumped by a Q-switched fiber laser

    NARCIS (Netherlands)

    Klein, M.E.; Adel, P.; Auerbach, M.; Fallnich, C.; Gross, P.; Boller, Klaus J.

    2003-01-01

    We report on what is to our knowledge the first optical parametric oscillator (OPO) pumped by microsecond pulses from a wavelength-tunable solid-state laser. The singly resonant OPO (SRO) is based on a periodically poled LiNbO3 crystal and pumped with 2.1-ms-long pulses from an actively Q-switched

  9. High-power electro-optic switch technology based on novel transparent ceramic

    Science.gov (United States)

    Xue-Jiao, Zhang; Qing, Ye; Rong-Hui, Qu; Hai-wen, Cai

    2016-03-01

    A novel high-power polarization-independent electro-optic switch technology based on a reciprocal structure Sagnac interferometer and a transparent quadratic electro-optic ceramic is proposed and analyzed theoretically and experimentally. The electro-optic ceramic is used as a phase retarder for the clockwise and counter-clockwise polarized light, and their polarization directions are adjusted to their orthogonal positions by using two half-wave plates. The output light then becomes polarization-independent with respect to the polarization direction of the input light. The switch characteristics, including splitter ratios and polarization states, are theoretically analyzed and simulated in detail by the matrix multiplication method. An experimental setup is built to verify the analysis and experimental results. A new component ceramic is used and a non-polarizing cube beam splitter (NPBS) replaces the beam splitter (BS) to lower the ON/OFF voltage to 305 V and improve the extinction ratio by 2 dB. Finally, the laser-induced damage threshold for the proposed switch is measured and discussed. It is believed that potential applications of this novel polarization-independent electro-optic switch technology will be wide, especially for ultrafast high-power laser systems. Project supported by the National Natural Science Foundation of China (Grant Nos. 61137004, 61405218, and 61535014).

  10. High-power electro-optic switch technology based on novel transparent ceramic

    International Nuclear Information System (INIS)

    Zhang Xue-Jiao; Ye Qing; Qu Rong-Hui; Cai Hai-wen

    2016-01-01

    A novel high-power polarization-independent electro-optic switch technology based on a reciprocal structure Sagnac interferometer and a transparent quadratic electro-optic ceramic is proposed and analyzed theoretically and experimentally. The electro-optic ceramic is used as a phase retarder for the clockwise and counter-clockwise polarized light, and their polarization directions are adjusted to their orthogonal positions by using two half-wave plates. The output light then becomes polarization-independent with respect to the polarization direction of the input light. The switch characteristics, including splitter ratios and polarization states, are theoretically analyzed and simulated in detail by the matrix multiplication method. An experimental setup is built to verify the analysis and experimental results. A new component ceramic is used and a non-polarizing cube beam splitter (NPBS) replaces the beam splitter (BS) to lower the ON/OFF voltage to 305 V and improve the extinction ratio by 2 dB. Finally, the laser-induced damage threshold for the proposed switch is measured and discussed. It is believed that potential applications of this novel polarization-independent electro-optic switch technology will be wide, especially for ultrafast high-power laser systems. (paper)

  11. Optical switching properties of VO2 films driven by using WDM-aligned lasers

    International Nuclear Information System (INIS)

    Tsai, K.Y.; Wu, F.-H.; Shieh, H.-P.D.; Chin, T.-S.

    2006-01-01

    Vanadium dioxide (VO 2 ) film had been demonstrated a high speed IR shutter driven by total optical modulation. However, it usually required a higher power heating laser of high power and precise optical systems to cover the probe beam on the sample with a heating beam of larger area. A new optical system, simply composed of wavelength division multiplexing (WDM), fiber lens or convex lens system, and a glass sheet with VO 2 thin film on it, was easily assembled to utilize VO 2 film as an IR shutter, implying the possibility to highly miniaturize the VO 2 -based optical shutter. A permanent low-transmittance (PLT) region forms on the film within the probe beam, resulting in a decrease in average power of the probe beam. Another ring-type switching area (switching ring) forms around the PLT region, resulting in the transmittance switching of the probe beam synchronously with the heating signal. VO 2 films can be switched with the highest rate of a continuous square heating signal of 3 mW at 120 kHz. A heating pulse of 0.7 ns and 13 mW can be used to stimulate an IR pulse with fiber lens

  12. Design of an all-optical switch and arbitrary proportion of energy output beam splitter

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Qing-Hua, E-mail: lqhua@ncu.edu.cn [Department of Physics, Nanchang University, Nanchang 330031 (China); Zhang, Xuan; Chen, Shu-Wen; Hu, Ping; Yu, Tian-Bao [Department of Physics, Nanchang University, Nanchang 330031 (China); Huang, Yong-Zhen [The State Key Laboratory on Integrated Optoelectronics, Institute of Semiconductors, CAS, Beijing 100083 (China)

    2013-11-15

    Based on the Kerr effect of photonic crystal, we design a simple structure of all-optical switch, which can be controlled by the pump intensity. At the same time, the structure can also realize the free control of energy output. It has low insertion loss and crosstalk. Numerical simulation results embody its high efficiency.

  13. A 2D Rods-in-Air Square-Lattice Photonic Crystal Optical Switch

    Science.gov (United States)

    2009-03-01

    4] Tao Chu, Hirohito Yamada, Satomi Ishida, Yasuhiko Arakawa, Thermooptic switch based on photonic-crystal line-defect waveguides, IEEE Photon...Ishida, Yasuhiko Arakawa, Hiroyuki Fujita, Hiroshi Toshiyoshi, Design and fabrication on MEMS optical mod- ulators integrated with Phc waveguide, in

  14. All-optical switching using a new photonic crystal directional coupler

    Directory of Open Access Journals (Sweden)

    B. Vakili

    2015-07-01

    Full Text Available In this paper all-optical switching in a new photonic crystal directional coupler is performed.  The structure of the switch consists of a directional coupler and a separate path for a control signal called “control waveguide”. In contrast to the former reported structures in which the directional couplers are made by removing a row of rods entirely, the directional coupler in our optical switch is constructed by two reduced-radius line-defect waveguides separated by the control waveguide. Furthermore, in our case the background material has the nonlinear Kerr property. Therefore, in the structure of this work, no frequency overlap occurs between the control waveguide mode and the directional coupler modes. It is shown that such a condition provides a very good isolation between the control and the probe signals at the output ports. In the control waveguide, nonlinear Kerr effect causes the required refractive index change by the presence of a high power control (pump signal. Even and odd modes of the coupler are investigated by applying the distribution of the refractive index change in the nonlinear region of a super-cell so that a switching length of about 94 µm is obtained at the wavelength of 1.55 µm. Finally, all-optical switching of the 1.55 µm probe signal using a control signal at the wavelength of 1.3 µm, is simulated through the finite-difference time-domain method, where both signals are desirable in optical communication systems. A very high extinction ratio of 67 dB is achieved and the temporal characteristics of the switch are demonstrated.

  15. Lightpath restoration in SDN-based optical networks: Overview

    CSIR Research Space (South Africa)

    Nkosi, Mpho C

    2017-10-01

    Full Text Available Optical networks employ restoration methods to ensure efficient recovery of connections interrupted by network failures. Software Defined Networking (SDN) is emerging as the future network architectures and introduces new control planes...

  16. Optical networks for wideband sensor array

    Science.gov (United States)

    Sheng, Lin Horng

    2011-12-01

    This thesis presents the realization of novel systems for optical sensing networks with an array of long-period grating (LPG) sensors. As a launching point of the thesis, the motivation to implement optical sensing network in precisely catering LPG sensors is presented. It highlights the flexibility of the sensing network to act as the foundation in order to boost the application of the various LPG sensor design in biological and chemical sensing. After the thorough study on the various optical sensing networks, sub-carrier multiplexing (SCM) and optical time division multiplexing (OTDM) schemes are adopted in conjunction with tunable laser source (TLS) to facilitate simultaneous interrogation of the LPG sensors array. In fact, these systems are distinct to have the capability to accommodate wideband optical sensors. Specifically, the LPG sensors which is in 20nm bandwidth are identified to operate in these systems. The working principles of the systems are comprehensively elucidated in this thesis. It highlights the mathematical approach to quantify the experimental setup of the optical sensing network. Additionally, the system components of the designs are identified and methodically characterized so that the components well operate in the designed environment. A mockup has been setup to demonstrate the application in sensing of various liquid indices and analyse the response of the LPG sensors in order to evaluate the performance of the systems. Eventually, the resemblance of the demultiplexed spectral response to the pristine spectral response are quantified to have excellent agreement. Finally, the promising result consistency of the systems is verified through repeatability test.

  17. VO{sub 2}-like thermo-optical switching effect in one-dimensional nonlinear defective photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Juan, E-mail: juanzhang@staff.shu.edu.cn, E-mail: ywang@siom.ac.cn; Zhang, Rongjun [Key Laboratory of Specialty Fiber Optics and Optical Access Networks, School of Communication and Information Engineering, Shanghai University, Shanghai 200072 (China); Wang, Yang, E-mail: juanzhang@staff.shu.edu.cn, E-mail: ywang@siom.ac.cn [Key Laboratory of High Power Laser Materials, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2015-06-07

    A new approach to achieve VO{sub 2}-like thermo-optical switching in a one-dimensional photonic crystal by the combination of thermo-optical and optical Kerr effects was proposed and numerically demonstrated in this study. The switching temperature and the hysteresis width can be tuned in a wide temperature range. Steep transition, high optical contrast, and low pumping power can be achieved at the same time. This kind of one-dimensional photonic crystal-based bistable switch will be low-cost, easy-to-fabricate, and versatile in practical applications compared with traditional VO{sub 2}-type one.

  18. Extreme nonlinear terahertz electro-optics in diamond for ultrafast pulse switching

    Science.gov (United States)

    Shalaby, Mostafa; Vicario, Carlo; Hauri, Christoph P.

    2017-03-01

    Polarization switching of picosecond laser pulses is a fundamental concept in signal processing [C. Chen and G. Liu, Annu. Rev. Mater. Sci. 16, 203 (1986); V. R. Almeida et al., Nature 431, 1081 (2004); and A. A. P. Pohl et al., Photonics Sens. 3, 1 (2013)]. Conventional switching devices rely on the electro-optical Pockels effect and work at radio frequencies. The ensuing gating time of several nanoseconds is a bottleneck for faster switches which is set by the performance of state-of-the-art high-voltage electronics. Here we show that by substituting the electric field of several kV/cm provided by modern electronics by the MV/cm field of a single-cycle THz laser pulse, the electro-optical gating process can be driven orders of magnitude faster, at THz frequencies. In this context, we introduce diamond as an exceptional electro-optical material and demonstrate a pulse gating time as fast as 100 fs using sub-cycle THz-induced Kerr nonlinearity. We show that THz-induced switching in the insulator diamond is fully governed by the THz pulse shape. The presented THz-based electro-optical approach overcomes the bandwidth and switching speed limits of conventional MHz/GHz electronics and establishes the ultrafast electro-optical gating technology for the first time in the THz frequency range. We finally show that the presented THz polarization gating technique is applicable for advanced beam diagnostics. As a first example, we demonstrate tomographic reconstruction of a THz pulse in three dimensions.

  19. Scalable Optical-Fiber Communication Networks

    Science.gov (United States)

    Chow, Edward T.; Peterson, John C.

    1993-01-01

    Scalable arbitrary fiber extension network (SAFEnet) is conceptual fiber-optic communication network passing digital signals among variety of computers and input/output devices at rates from 200 Mb/s to more than 100 Gb/s. Intended for use with very-high-speed computers and other data-processing and communication systems in which message-passing delays must be kept short. Inherent flexibility makes it possible to match performance of network to computers by optimizing configuration of interconnections. In addition, interconnections made redundant to provide tolerance to faults.

  20. Polarization encoded all-optical quaternary successor with the help of SOA assisted Sagnac switch

    Science.gov (United States)

    Chattopadhyay, Tanay; Roy, Jitendra Nath

    2011-06-01

    The application of multi-valued (non-binary) signals can provide a considerable relief in transmission, storage and processing of large amount of information in digital signal processing. Optical multi-valued logical operation is an interesting challenge for future optical signal processing where we can expect much innovation. A novel all-optical quaternary successor (QSUC) circuit with the help of semiconductor optical amplifier (SOA)-assisted Sagnac switch is proposed and described. This circuit exploits the polarization properties of light. Different logical states are represented by different polarization state of light. Simulation result confirming described method is given in this paper. Proposed all-optical successor circuit can take an important and significant role in designing of all-optical quaternary universal inverter and modulo arithmetic unit (addition and multiplication).

  1. Fault discovery protocol for passive optical networks

    Science.gov (United States)

    Hajduczenia, Marek; Fonseca, Daniel; da Silva, Henrique J. A.; Monteiro, Paulo P.

    2007-06-01

    All existing flavors of passive optical networks (PONs) provide an attractive alternative to legacy copper-based access lines deployed between a central office (CO) of the service provider (SP) and a customer site. One of the most challenging tasks for PON network planners is the reduction of the overall cost of employing protection schemes for the optical fiber plant while maintaining a reasonable level of survivability and reducing the downtime, thus ensuring acceptable levels of quality of service (QoS) for end subscribers. The recently growing volume of Ethernet PONs deployment [Kramer, IEEE 802.3, CFI (2006)], connected with low-cost electronic and optical components used in the optical network unit (ONU) modules, results in the situation where remote detection of faulty/active subscriber modules becomes indispensable for proper operation of an EPON system. The problem of the remote detection of faulty ONUs in the system is addressed where the upstream channel is flooded with the cw transmission from one or more damaged ONUs and standard communication is severed, providing a solution that is applicable in any type of PON network, regardless of the operating protocol, physical structure, and data rate.

  2. Fiber optic configurations for local area networks

    Science.gov (United States)

    Nassehi, M. M.; Tobagi, F. A.; Marhic, M. E.

    1985-01-01

    A number of fiber optic configurations for a new class of demand assignment multiple-access local area networks requiring a physical ordering among stations are proposed. In such networks, the data transmission and linear-ordering functions may be distinguished and be provided by separate data and control subnetworks. The configurations proposed for the data subnetwork are based on the linear, star, and tree topologies. To provide the linear-ordering function, the control subnetwork must always have a linear unidirectional bus structure. Due to the reciprocity and excess loss of optical couplers, the number of stations that can be accommodated on a linear fiber optic bus is severely limited. Two techniques are proposed to overcome this limitation. For each of the data and control subnetwork configurations, the maximum number of stations as a function of the power margin, for both reciprocal and nonreciprocal couplers, is computed.

  3. Load balancing in integrated optical wireless networks

    DEFF Research Database (Denmark)

    Yan, Ying; Dittmann, Lars; Wong, S-W.

    2010-01-01

    In this paper, we tackle the load balancing problem in Integrated Optical Wireless Networks, where cell breathing technique is used to solve congestion by changing the coverage area of a fully loaded cell tower. Our objective is to design a load balancing mechanism which works closely...... with the integrated control scheme so as to maximize overall network throughput in the integrated network architecture. To the best of our knowledge no load balancing mechanisms, especially based on the Multi-Point Control Protocol (MPCP) defined in the IEEE 802.3ah, have been proposed so far. The major research...... issues are outlined and a cost function based optimization model is developed for power management. In particularly, two alternative feedback schemes are proposed to report wireless network status. Simulation results show that our proposed load balancing mechanism improves network performances....

  4. Path Diversity Media Streaming over Best Effort Packet Switched Networks

    Science.gov (United States)

    2003-01-01

    intolerable sounds of my violin practice, but my mom was always there to defend and encourage her young violinist. When I left my full-time job for graduate...information can be incomplete or inaccurate. For exam - ple, traceroute can only differentiate between routers and not switches. Two paths with completely

  5. Studi Migrasi Public Switched Telephone Network (Pstn) Menuju Jaringan Telekomunikasi Berbasis Paket Next Generation Network (Ngn) Dengan Teknologi Softswitch

    OpenAIRE

    Suseno, Andrias Danang; Najib, Warsun; Samiyono, -

    2009-01-01

    Public Switched Telephone Network (PSTN) adalah sistem telekomunikasi berbasis circuit-switched. Pada awalnya PSTN hanya menyediakan layanan voice. PSTN sekarang telah berkembang ke arah pelayanan komunikasi data yang didorong oleh berkembangnya dunia internet dengan Internet Protokol (IP)-nya. Telah muncul teknologi Voice over IP (VoIP) yang mampu melewatkan trafik voice pada jaringan data dengan mengubah voice menjadi paket. VoIP telah mendorong trend/kecenderungan terjadinya konvergensi an...

  6. Micro optical fiber display switch based on the magnetohydrodynamic (MHD) principle

    Science.gov (United States)

    Lian, Kun; Heng, Khee-Hang

    2001-09-01

    This paper reports on a research effort to design, microfabricate and test an optical fiber display switch based on magneto hydrodynamic (MHD) principal. The switch is driven by the Lorentz force and can be used to turn on/off the light. The SU-8 photoresist and UV light source were used for prototype fabrication in order to lower the cost. With a magnetic field supplied by an external permanent magnet, and a plus electrical current supplied across the two inert sidewall electrodes, the distributed body force generated will produce a pressure difference on the fluid mercury in the switch chamber. By change the direction of current flow, the mercury can turn on or cut off the light pass in less than 10 ms. The major advantages of a MHD-based micro-switch are that it does not contain any solid moving parts and power consumption is much smaller comparing to the relay type switches. This switch can be manufactured by molding gin batch production and may have potential applications in extremely bright traffic control,, high intensity advertising display, and communication.

  7. Data Transparent and Polarization Insensitive All-Optical Switch based on Fibers with Enhanced Nonlinearity

    Directory of Open Access Journals (Sweden)

    M. Komanec

    2014-09-01

    Full Text Available We have developed a data transparent optical packet switch prototype employing wavelength conversion based on four-wave mixing. The switch is composed of an electro-optical control unit and an all-optical switching segment. To achieve higher switching efficiencies, Ge-doped silica suspended-core and chalcogenide arsenicselenide single-mode fibers were experimentally evaluated and compared to conventional highly-nonlinear fiber. Improved connectorization technology has been developed for Ge-doped suspended-core fiber, where we achieved connection losses of 0.9 dB. For the arsenic-selenide fiber we present a novel solid joint technology, with connection losses of only 0.25 dB, which is the lowest value presented up-to-date. Conversion efficiency of -13.7 dB was obtained for the highly-nonlinear fiber, which is in perfect correlation with previously published results and thus verifies the functionality of the prototype. Conversion efficiency of -16.1 dB was obtained with arsenic-selenide fiber length reduced to five meters within simulations, based on measurement results with a 26 m long component. Employment of such a short arsenic-selenide fiber segment allows significant broadening of the wavelength conversion spectral range due to possible neglection of dispersion.

  8. De-optical-line-terminal hybrid access-aggregation optical network for time-sensitive services based on software-defined networking orchestration

    Science.gov (United States)

    Bai, Wei; Yang, Hui; Xiao, Hongyun; Yu, Ao; He, Linkuan; Zhang, Jie; Li, Zhen; Du, Yi

    2017-11-01

    With the increase in varieties of services in network, time-sensitive services (TSSs) appear and bring forward an impending need for delay performance. Ultralow-latency communication has become one of the important development goals for many scenarios in the coming 5G era (e.g., robotics and driverless cars). However, the conventional methods, which decrease delay by promoting the available resources and the network transmission speed, have limited effect; a new breakthrough for ultralow-latency communication is necessary. We propose a de-optical-line-terminal (De-OLT) hybrid access-aggregation optical network (DAON) for TSS based on software-defined networking (SDN) orchestration. In this network, low-latency all-optical communication based on optical burst switching can be achieved by removing OLT. For supporting this network and guaranteeing the quality of service for TSSs, we design SDN-driven control method and service provision method. Numerical results demonstrate the proposed DAON promotes network service efficiency and avoids traffic congestion.

  9. All-optical signal processing using InP photonic-crystal nanocavity switches

    DEFF Research Database (Denmark)

    Yu, Yi; Vukovic, Dragana; Heuck, Mikkel

    2014-01-01

    In this paper, we present recent progress in experimental characterization of InP photonic-crystal nanocavity switches. Pump-probe measurements on an InP PhC H0 cavity show large-contrast ultrafast switching at low pulse energy. At large pulse energies, a large resonance shift passing across...... for the joint effects of fast carrier diffusion, slow surface and bulk recombination. Utilizin g the simple InP PhC nanocavity structure, we successfully dem onstrate 10-Gb/s RZ- OOK all-optical modulation with low energy consumption....

  10. Spatial dynamics of picosecond CO2 laser pulses produced by optical switching in Ge

    International Nuclear Information System (INIS)

    Pogorelsky, I.; Fisher, A.S.; Veligdan, J.; Russell, P.

    1991-01-01

    The design, test and optimization of a picosecond CO 2 pulse-forming system are presented. The system switches a semiconductor's optical characteristics at 10 μm under the control of a synchronized 1.06-μm Nd:YAG picosecond laser pulse. An energy-efficient version of such a system using collimated beams is described. A simple, semi-empirical approach is used to simulate the switching process, specifically including the spatial distributions of the laser energy and phase, which are relevant for experiments in laser-driven electron acceleration. 11 refs., 7 figs

  11. Software defined networks reactive flow programming and load balance switching

    OpenAIRE

    Καλλιανιώτης, Νικόλαος; Kallianiotis, Nikolaos

    2017-01-01

    This project serves as a Master Thesis as the requirements of the master’s programme Master of Digital Communications and Networks. It proposes load balancing algorithms applied to Software-Defined Networks to achieve the best possible resource utilisation of each of the links present in a network. The open-sources Opendaylight project and Floodlight project are used as SDN controllers, and the network is emulated using Mininet software

  12. Adaptive approach to global synchronization of directed networks with fast switching topologies

    International Nuclear Information System (INIS)

    Qin Buzhi; Lu Xinbiao

    2010-01-01

    Global synchronization of directed networks with switching topologies is investigated. It is found that if there exists at least one directed spanning tree in the network with the fixed time-average topology and the time-average topology is achieved sufficiently fast, the network will reach global synchronization for appreciate coupling strength. Furthermore, this appreciate coupling strength may be obtained by local adaptive approach. A sufficient condition about the global synchronization is given. Numerical simulations verify the effectiveness of the adaptive strategy.

  13. Adaptive Asymptotical Synchronization for Stochastic Complex Networks with Time-Delay and Markovian Switching

    Directory of Open Access Journals (Sweden)

    Xueling Jiang

    2014-01-01

    Full Text Available The problem of adaptive asymptotical synchronization is discussed for the stochastic complex dynamical networks with time-delay and Markovian switching. By applying the stochastic analysis approach and the M-matrix method for stochastic complex networks, several sufficient conditions to ensure adaptive asymptotical synchronization for stochastic complex networks are derived. Through the adaptive feedback control techniques, some suitable parameters update laws are obtained. Simulation result is provided to substantiate the effectiveness and characteristics of the proposed approach.

  14. SNL evaluation of Gigabit Passive Optical Networks (GPON).

    Energy Technology Data Exchange (ETDEWEB)

    Heckart, David G.; Roybal, Glen B.; Walker, Betty R.; Pratt, Thomas Joseph; Gossage, Steven Allen; Trujillo, Sandra M.; Fischer, Bob; Brenkosh, Joseph Peter; Rudolfo, Gerald F.; Dirks, David H.; Schutt, James Alan

    2009-08-01

    Gigabit Passive Optical Networks (GPON) is a networking technology which offers the potential to provide significant cost savings to Sandia National Laboratories in the area of network operations. However, a large scale GPON deployment requires a significant investment in equipment and infrastructure. Before a large scale GPON system was acquired and built, a small GPON system manufactured by Motorola was acquired and tested. The testing performed was to determine the suitability of GPON for use at SNL. This report documents that testing. This report presents test results of GPON system consisting of Motorola and Juniper equipment. The GPON system was tested in areas of data throughput, video conferencing, VOIP, security, and operations and management. The GPON system performed well in almost all areas. GPON will not meet the needs of the low percentage of users requiring a true 1-10 Gbps network connection. GPON will also most likely not meet the need of some servers requiring dedicated throughput of 1-10 Gbps. Because of that, there will be some legacy network connections that must remain. If these legacy network connections can not be reduced to a bare minimum and possibly consolidated to a few locations, any cost savings gained by switching to GPON will be negated by maintaining two networks. A contract has been recently awarded for new GPON equipment with larger buffers. This equipment should improve performance and further reduce the need for legacy network connections. Because GPON has fewer components than a typical hierarchical network, it should be easier to manage. For the system tested, the management was performed by using the AXSVison client. Access to the client must be tightly controlled, because if client/server communications are compromised, security will be an issue. As with any network, the reliability of individual components will determine overall system reliability. There were no failures with the routers, OLT, or Sun Workstation Management

  15. Multicasting based optical inverse multiplexing in elastic optical network.

    Science.gov (United States)

    Guo, Bingli; Xu, Yingying; Zhu, Paikun; Zhong, Yucheng; Chen, Yuanxiang; Li, Juhao; Chen, Zhangyuan; He, Yongqi

    2014-06-16

    Optical multicasting based inverse multiplexing (IM) is introduced in spectrum allocation of elastic optical network to resolve the spectrum fragmentation problem, where superchannels could be split and fit into several discrete spectrum blocks in the intermediate node. We experimentally demonstrate it with a 1-to-7 optical superchannel multicasting module and selecting/coupling components. Also, simulation results show that, comparing with several emerging spectrum defragmentation solutions (e.g., spectrum conversion, split spectrum), IM could reduce blocking performance significantly but without adding too much system complexity as split spectrum. On the other hand, service fairness for traffic with different granularity of these schemes is investigated for the first time and it shows that IM performs better than spectrum conversion and almost as well as split spectrum, especially for smaller size traffic under light traffic intensity.

  16. Green provisioning of the traffic partition grooming in robust, reconfigurable and heterogeneous optical networks

    Science.gov (United States)

    Hou, Weigang; Yu, Yao; Song, Qingyang; Gong, Xiaoxue

    2013-01-01

    In recent years, various high-speed network architectures have been widespread deployed. Dense Wavelength Division Multiplexing (DWDM) has gained favor as a terabit solution. The optical circuit switching has also been provided for "sub-rate" aggregation. Such that, the granular types of demands tend to be diverse and must be evaluated. However, current dedicated optical networks do not offer sufficient flexibility to satisfy the requirements of demands with such wide range of granularities. The traffic grooming becomes a power-efficient one only when it does not utilize the aggregation of Coarse-Granularity (CG) demands. The waveband switching merely provides port-cost-effective connections for CG demands regardless of fine-granularity ones. Consequently, in this paper, we devise a heterogeneous grooming method called traffic partition grooming. It combines the power efficiency advantage of the traffic grooming under fine-granularity environment and the port savings advantage of the waveband switching under coarse-granularity environment to provide green provisioning. In addition, the optical virtual topology self-reconfigures along with various optimization objectives variation and has the robustness to determine the pre-unknown information. This paper is also the first work on investigating the issue of Robust, Reconfigurable and Heterogeneous Optical Networking (R2HON). The effective green provisioning and OPEX savings of our R2HON have been demonstrated by numerical simulations.

  17. Software-defined optical network for metro-scale geographically distributed data centers.

    Science.gov (United States)

    Samadi, Payman; Wen, Ke; Xu, Junjie; Bergman, Keren

    2016-05-30

    The emergence of cloud computing and big data has rapidly increased the deployment of small and mid-sized data centers. Enterprises and cloud providers require an agile network among these data centers to empower application reliability and flexible scalability. We present a software-defined inter data center network to enable on-demand scale out of data centers on a metro-scale optical network. The architecture consists of a combined space/wavelength switching platform and a Software-Defined Networking (SDN) control plane equipped with a wavelength and routing assignment module. It enables establishing transparent and bandwidth-selective connections from L2/L3 switches, on-demand. The architecture is evaluated in a testbed consisting of 3 data centers, 5-25 km apart. We successfully demonstrated end-to-end bulk data transfer and Virtual Machine (VM) migrations across data centers with less than 100 ms connection setup time and close to full link capacity utilization.

  18. Novel Ethernet Based Optical Local Area Networks for Computer Interconnection

    NARCIS (Netherlands)

    Radovanovic, Igor; van Etten, Wim; Taniman, R.O.; Kleinkiskamp, Ronny

    2003-01-01

    In this paper we present new optical local area networks for fiber-to-the-desk application. Presented networks are expected to bring a solution for having optical fibers all the way to computers. To bring the overall implementation costs down we have based our networks on short-wavelength optical

  19. Programming Nanoparticles in Multiscale: Optically Modulated Assembly and Phase Switching of Silicon Nanoparticle Array.

    Science.gov (United States)

    Wang, Letian; Rho, Yoonsoo; Shou, Wan; Hong, Sukjoon; Kato, Kimihiko; Eliceiri, Matthew; Shi, Meng; Grigoropoulos, Costas P; Pan, Heng; Carraro, Carlo; Qi, Dongfeng

    2018-03-27

    Manipulating and tuning nanoparticles by means of optical field interactions is of key interest for nanoscience and applications in electronics and photonics. We report scalable, direct, and optically modulated writing of nanoparticle patterns (size, number, and location) of high precision using a pulsed nanosecond laser. The complex nanoparticle arrangement is modulated by the laser pulse energy and polarization with the particle size ranging from 60 to 330 nm. Furthermore, we report fast cooling-rate induced phase switching of crystalline Si nanoparticles to the amorphous state. Such phase switching has usually been observed in compound phase change materials like GeSbTe. The ensuing modification of atomic structure leads to dielectric constant switching. Based on these effects, a multiscale laser-assisted method of fabricating Mie resonator arrays is proposed. The number of Mie resonators, as well as the resonance peaks and dielectric constants of selected resonators, can be programmed. The programmable light-matter interaction serves as a mechanism to fabricate optical metasurfaces, structural color, and multidimensional optical storage devices.

  20. Optical packet networks - conclusions from the IST DAVID project

    DEFF Research Database (Denmark)

    Dittmann, Lars

    2004-01-01

    This work outlines the result from the European research project DAVID working with optical packet switch solutions for both WAN and MAN. The project started July 2000 and has been completed successfully by the end of 2003.......This work outlines the result from the European research project DAVID working with optical packet switch solutions for both WAN and MAN. The project started July 2000 and has been completed successfully by the end of 2003....

  1. Free-space optics technology employed in an UMTS release 4 bearer independent core network access part

    Science.gov (United States)

    Bibac, Ionut

    2005-08-01

    The UMTS Bearer Independent Core Network program introduced the 3rd Generation Partnership Program Release 4 BICN architecture into the legacy UMTS TDM-switched network. BICN is the application of calI server archltecture for voice and circuit switched data, enabling the provisioning of traditional circuit-switched services using a packet-switched transport network. Today"s business climate has made it essential for service providers to develop a comprehensive networking strategy that means introduction of RCBICN networks. The R4-BICN solution to the evolution of the Core Network in UMTS will enable operators to significantly reduce the capital and operational costs of delivering both traditional voice sewices and new multimedia services. To build the optical backbone, which can support the third generation (3G) packetized infrastructure, the operators could choose a fibre connection, or they could retain the benefits of a wireless connectivity by using a FSO - Free Space Optical lmk, the only wireless technology available that is capable of achieving data rates up to 2.4 Gbit/s. FSO offers viable alternatives for both core transmission networks and for replacing microwaves links in NodeB - RNC access networks. The paper and presentation aim to demonstrate the manner in which FSO products and networks are employed into R4-BICN design solutions.

  2. Dynamic Optical Networks for Future Internet Environments

    Science.gov (United States)

    Matera, Francesco

    2014-05-01

    This article reports an overview on the evolution of the optical network scenario taking into account the exponential growth of connected devices, big data, and cloud computing that is driving a concrete transformation impacting the information and communication technology world. This hyper-connected scenario is deeply affecting relationships between individuals, enterprises, citizens, and public administrations, fostering innovative use cases in practically any environment and market, and introducing new opportunities and new challenges. The successful realization of this hyper-connected scenario depends on different elements of the ecosystem. In particular, it builds on connectivity and functionalities allowed by converged next-generation networks and their capacity to support and integrate with the Internet of Things, machine-to-machine, and cloud computing. This article aims at providing some hints of this scenario to contribute to analyze impacts on optical system and network issues and requirements. In particular, the role of the software-defined network is investigated by taking into account all scenarios regarding data centers, cloud computing, and machine-to-machine and trying to illustrate all the advantages that could be introduced by advanced optical communications.

  3. 1×4 Optical packet switching of variable length 640 Gbit/s data packets using in-band optical notch-filter labeling

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros; Kamchevska, Valerija; Galili, Michael

    2014-01-01

    We experimentally perform 1×4 optical packet switching of variable length 640 Gbit/s OTDM data packets using in-band notch-filter labeling with only 2.7-dB penalty. Up to 8 notches are employed to demonstrate scalability of the labeling scheme to 1×256 switching operation.......We experimentally perform 1×4 optical packet switching of variable length 640 Gbit/s OTDM data packets using in-band notch-filter labeling with only 2.7-dB penalty. Up to 8 notches are employed to demonstrate scalability of the labeling scheme to 1×256 switching operation....

  4. Cisco Router and Switch Forensics Investigating and Analyzing Malicious Network Activity

    CERN Document Server

    Liu, Dale

    2009-01-01

    Cisco IOS (the software that runs the vast majority of Cisco routers and all Cisco network switches) is the dominant routing platform on the Internet and corporate networks. This widespread distribution, as well as its architectural deficiencies, makes it a valuable target for hackers looking to attack a corporate or private network infrastructure. Compromised devices can disrupt stability, introduce malicious modification, and endanger all communication on the network. For security of the network and investigation of attacks, in-depth analysis and diagnostics are critical, but no book current

  5. Optical processing for future computer networks

    Science.gov (United States)

    Husain, A.; Haugen, P. R.; Hutcheson, L. D.; Warrior, J.; Murray, N.; Beatty, M.

    1986-01-01

    In the development of future data management systems, such as the NASA Space Station, a major problem represents the design and implementation of a high performance communication network which is self-correcting and repairing, flexible, and evolvable. To obtain the goal of designing such a network, it will be essential to incorporate distributed adaptive network control techniques. The present paper provides an outline of the functional and communication network requirements for the Space Station data management system. Attention is given to the mathematical representation of the operations being carried out to provide the required functionality at each layer of communication protocol on the model. The possible implementation of specific communication functions in optics is also considered.

  6. Default mode network abnormalities during state switching in attention deficit hyperactivity disorder.

    Science.gov (United States)

    Sidlauskaite, J; Sonuga-Barke, E; Roeyers, H; Wiersema, J R

    2016-02-01

    Individuals with attention deficit hyperactivity disorder (ADHD) display excess levels of default mode network (DMN) activity during goal-directed tasks, which are associated with attentional disturbances and performance decrements. One hypothesis is that this is due to attenuated down-regulation of this network during rest-to-task switching. A second related hypothesis is that it may be associated with right anterior insula (rAI) dysfunction - a region thought to control the actual state-switching process. These hypotheses were tested in the current fMRI study in which 19 adults with ADHD and 21 typically developing controls undertook a novel state-to-state switching paradigm. Advance cues signalled upcoming switches between rest and task periods and switch-related anticipatory modulation of DMN and rAI was measured. To examine whether rest-to-task switching impairments may be a specific example of a more general state regulation deficit, activity upon task-to-rest cues was also analysed. Against our hypotheses, we found that the process of down-regulating the DMN when preparing to switch from rest to task was unimpaired in ADHD and that there was no switch-specific deficit in rAI modulation. However, individuals with ADHD showed difficulties up-regulating the DMN when switching from task to rest. Rest-to-task DMN attenuation seems to be intact in adults with ADHD and thus appears unrelated to excess DMN activity observed during tasks. Instead, individuals with ADHD exhibit attenuated up-regulation of the DMN, hence suggesting disturbed re-initiation of a rest state.

  7. Survivable integrated grooming in multi-granularity optical networks

    Science.gov (United States)

    Wu, Jingjing; Guo, Lei; Wei, Xuetao; Liu, Yejun

    2012-05-01

    Survivability is an important issue to ensure the service continuity in optical network. At the same time, with the granularity of traffic demands ranging from sub-wavelength-level to wavelength-level, traffic demands need to be aggregated and carried over the network in order to utilize resources effectively. Therefore, multi-granularity grooming is proposed to save the cost and reduce the number of switching ports in Optical-Cross Connects (OXCs). However, current works mostly addressed the survivable wavelength or waveband grooming. Therefore, in this paper, we propose three heuristic algorithms called Multi-granularity Dedicated Protection Grooming (MDPG), Multi-granularity Shared Protection Grooming (MSPG) and Multi-granularity Mixed Protection Grooming (MMPG), respectively. All of them are performed based on the Survivable Multi-granularity Integrated Auxiliary Graph (SMIAG) that includes one Wavelength Integrated Auxiliary Graph (WIAG) for wavelength protection and one waveBand Integrated Auxiliary Graph (BIAG) for waveband protection. Numerical results show that MMPG has the lowest average port-cost, the best resource utilization ratio and the lowest blocking probability among these three algorithms. Compared with MDPG, MSPG has lower average port-cost, better resource utilization ratio and lower blocking probability.

  8. Optical fiber telecommunications systems and networks

    CERN Document Server

    Kaminow, Ivan; Willner, Alan E

    2013-01-01

    Optical Fiber Telecommunications VI (A&B) is the sixth in a series that has chronicled the progress in the R&D of lightwave communications since the early 1970s. Written by active authorities from academia and industry, this edition brings a fresh look to many essential topics, including devices, subsystems, systems and networks. A central theme is the enabling of high-bandwidth communications in a cost-effective manner for the development of customer applications. These volumes are an ideal reference for R&D engineers and managers, optical systems implementers, university researchers and s

  9. Controlled perturbation-induced switching in pulse-coupled oscillator networks

    International Nuclear Information System (INIS)

    Schittler Neves, Fabio; Timme, Marc

    2009-01-01

    Pulse-coupled systems such as spiking neural networks exhibit nontrivial invariant sets in the form of attracting yet unstable saddle periodic orbits where units are synchronized into groups. Heteroclinic connections between such orbits may in principle support switching processes in these networks and enable novel kinds of neural computations. For small networks of coupled oscillators, we here investigate under which conditions and how system symmetry enforces or forbids certain switching transitions that may be induced by perturbations. For networks of five oscillators, we derive explicit transition rules that for two cluster symmetries deviate from those known from oscillators coupled continuously in time. A third symmetry yields heteroclinic networks that consist of sets of all unstable attractors with that symmetry and the connections between them. Our results indicate that pulse-coupled systems can reliably generate well-defined sets of complex spatiotemporal patterns that conform to specific transition rules. We briefly discuss possible implications for computation with spiking neural systems.

  10. Controlled perturbation-induced switching in pulse-coupled oscillator networks

    Energy Technology Data Exchange (ETDEWEB)

    Schittler Neves, Fabio; Timme, Marc [Network Dynamics Group, Max Planck Institute for Dynamics and Self-Organization, Goettingen, D-37073 (Germany); Bernstein Center for Computational Neuroscience (BCCN), Goettingen (Germany)], E-mail: neves@nld.ds.mpg.de, E-mail: timme@nld.ds.mpg.de

    2009-08-28

    Pulse-coupled systems such as spiking neural networks exhibit nontrivial invariant sets in the form of attracting yet unstable saddle periodic orbits where units are synchronized into groups. Heteroclinic connections between such orbits may in principle support switching processes in these networks and enable novel kinds of neural computations. For small networks of coupled oscillators, we here investigate under which conditions and how system symmetry enforces or forbids certain switching transitions that may be induced by perturbations. For networks of five oscillators, we derive explicit transition rules that for two cluster symmetries deviate from those known from oscillators coupled continuously in time. A third symmetry yields heteroclinic networks that consist of sets of all unstable attractors with that symmetry and the connections between them. Our results indicate that pulse-coupled systems can reliably generate well-defined sets of complex spatiotemporal patterns that conform to specific transition rules. We briefly discuss possible implications for computation with spiking neural systems.

  11. Synchronization transmission of laser pattern signal within uncertain switched network

    Science.gov (United States)

    Lü, Ling; Li, Chengren; Li, Gang; Sun, Ao; Yan, Zhe; Rong, Tingting; Gao, Yan

    2017-06-01

    We propose a new technology for synchronization transmission of laser pattern signal within uncertain network with controllable topology. In synchronization process, the connection of dynamic network can vary at all time according to different demands. Especially, we construct the Lyapunov function of network through designing a special semi-positive definite function, and the synchronization transmission of laser pattern signal within uncertain network with controllable topology can be realized perfectly, which effectively avoids the complicated calculation for solving the second largest eignvalue of the coupling matrix of the dynamic network in order to obtain the network synchronization condition. At the same time, the uncertain parameters in dynamic equations belonging to network nodes can also be identified accurately via designing the identification laws of uncertain parameters. In addition, there are not any limitations for the synchronization target of network in the new technology, in other words, the target can either be a state variable signal of an arbitrary node within the network or an exterior signal.

  12. Towards energy aware optical networks and interconnects

    Science.gov (United States)

    Glesk, Ivan; Osadola, Tolulope; Idris, Siti

    2013-10-01

    In a today's world, information technology has been identified as one of the major factors driving economic prosperity. Datacenters businesses have been growing significantly in the past few years. The equipments in these datacenters need to be efficiently connected to each other and also to the outside world in order to enable effective exchange of information. This is why there is need for highly scalable, energy savvy and reliable network connectivity infrastructure that is capable of accommodating the large volume of data being exchanged at any time within the datacenter network and the outside network in general. These devices that can ensure such effective connectivity currently require large amount of energy in order to meet up with these increasing demands. In this paper, an overview of works being done towards realizing energy aware optical networks and interconnects for datacenters is presented. Also an OCDMA approach is discussed as potential multiple access technique for future optical network interconnections. We also presented some challenges that might inhibit effective implementation of the OCDMA multiplexing scheme.

  13. Green Network Planning Model for Optical Backbones

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Riaz, M. Tahir; Jensen, Michael

    2010-01-01

    on the environment in general. In network planning there are existing planning models focused on QoS provisioning, investment minimization or combinations of both and other parameters. But there is a lack of a model for designing green optical backbones. This paper presents novel ideas to be able to define......Communication networks are becoming more essential for our daily lives and critically important for industry and governments. The intense growth in the backbone traffic implies an increment of the power demands of the transmission systems. This power usage might have a significant negative effect...

  14. Experience with PACS in an ATM/Ethernet switched network environment.

    Science.gov (United States)

    Pelikan, E; Ganser, A; Kotter, E; Schrader, U; Timmermann, U

    1998-03-01

    Legacy local area network (LAN) technologies based on shared media concepts are not adequate for the growth of a large-scale picture archiving and communication system (PACS) in a client-server architecture. First, an asymmetric network load, due to the requests of a large number of PACS clients for only a few main servers, should be compensated by communication links to the servers with a higher bandwidth compared to the clients. Secondly, as the number of PACS nodes increases, the network throughout should not measurably cut production. These requirements can easily be fulfilled using switching technologies. Here asynchronous transfer mode (ATM) is clearly one of the hottest topics in networking because the ATM architecture provides integrated support for a variety of communication services, and it supports virtual networking. On the other hand, most of the imaging modalities are not yet ready for integration into a native ATM network. For a lot of nodes already joining an Ethernet, a cost-effective and pragmatic way to benefit from the switching concept would be a combined ATM/Ethernet switching environment. This incorporates an incremental migration strategy with the immediate benefits of high-speed, high-capacity ATM (for servers and high-sophisticated display workstations), while preserving elements of the existing network technologies. In addition, Ethernet switching instead of shared media Ethernet improves the performance considerably. The LAN emulation (LANE) specification by the ATM forum defines mechanisms that allow ATM networks to coexist with legacy systems using any data networking protocol. This paper points out the suitability of this network architecture in accordance with an appropriate system design.

  15. Active high-power RF pulse compression using optically switched resonant delay lines

    International Nuclear Information System (INIS)

    Tantawi, S.G.; Ruth, R.D.; Vlieks, A.E.

    1996-11-01

    The authors present the design and a proof of principle experimental results of an optically controlled high power rf pulse compression system. The design should, in principle, handle few hundreds of Megawatts of power at X-band. The system is based on the switched resonant delay line theory. It employs resonant delay lines as a means of storing rf energy. The coupling to the lines is optimized for maximum energy storage during the charging phase. To discharge the lines, a high power microwave switch increases the coupling to the lines just before the start of the output pulse. The high power microwave switch, required for this system, is realized using optical excitation of an electron-hole plasma layer on the surface of a pure silicon wafer. The switch is designed to operate in the TE 01 mode in a circular waveguide to avoid the edge effects present at the interface between the silicon wafer and the supporting waveguide; thus, enhancing its power handling capability

  16. Simulation and optimization of a polymer directional coupler electro-optic switch with push pull electrodes

    Science.gov (United States)

    Zheng, Chuan-Tao; Ma, Chun-Sheng; Yan, Xin; Wang, Xian-Yin; Zhang, Da-Ming

    2008-07-01

    Structural model and design technique are proposed for a polymer directional coupler electro-optic switch with rib waveguides and push-pull electrodes, of which the electric field distribution is analyzed by the conformal transforming method and image method. In order to get the minimum mode loss and the minimum switching voltage, the parameters of the waveguide and electrode are optimized, such as the core with, core thickness, buffer layer between the core and the electrode, coupling gap between the waveguides, electrode thickness, electrode width and electrode gap. Switching Characteristics are analyzed, which include the output power, insertion loss, and crosstalk. To realize normal switching function, the fabrication error, spectrum shift, and coupling loss between a single mode fiber (SMF) and the waveguide are discussed. Simulation results show that the coupling length is 3082 μm, push-pull switching voltage is 2.14 V, insertion loss is less than 1.17 dB, and crosstalk is less than -30 dB for the designed device.

  17. Q FUNCTION AWARE OPTICAL PACKET SWITCH WITH LOW PACKET LOSS RATE

    Directory of Open Access Journals (Sweden)

    OMPAL SINGH

    2017-03-01

    Full Text Available Optical packet switching (OPS is a very promising technology for the next generation data transfer due to the very large bandwidth of the optical fiber. The success of the OPS relies heavily on design of the node architecture which supports comparatively larger buffering capacity without detiorating signal quality too much and it should provide very low packet loss probability with reasonably low average delay. In this paper, a design analysis of low complexity OPS node architecture is discussed along-with its advantages. The presented architecture support both fixed and variable length packets. The packets are stored in a single piece of fiber using the WDM technology. Physical layer analysis presented in this paper is to obtain the Q function (Bit Error Rate. Finally, the Monte Carlo simulation is done to obtain the packet loss. The average delay performance of the switch and effect of Q values on packet loss rates are discussed.

  18. Heuristic approach to the passive optical network with fibre duct ...

    African Journals Online (AJOL)

    Integer programming, network flow optimisation, passive optical network, ... This paper uses concepts from network flow optimisation to incorporate fibre duct shar ... [4] studied the survivable constrained ConFL problem and solved a number of.

  19. Controlled Photon Switch Assisted by Coupled Quantum Dots

    Science.gov (United States)

    Luo, Ming-Xing; Ma, Song-Ya; Chen, Xiu-Bo; Wang, Xiaojun

    2015-01-01

    Quantum switch is a primitive element in quantum network communication. In contrast to previous switch schemes on one degree of freedom (DOF) of quantum systems, we consider controlled switches of photon system with two DOFs. These controlled photon switches are constructed by exploring the optical selection rules derived from the quantum-dot spins in one-sided optical microcavities. Several double controlled-NOT gate on different joint systems are greatly simplified with an auxiliary DOF of the controlling photon. The photon switches show that two DOFs of photons can be independently transmitted in quantum networks. This result reduces the quantum resources for quantum network communication. PMID:26095049

  20. Evolutionary prisoner's dilemma games on the network with punishment and opportunistic partner switching

    Science.gov (United States)

    Takesue, H.

    2018-02-01

    Punishment and partner switching are two well-studied mechanisms that support the evolution of cooperation. Observation of human behaviour suggests that the extent to which punishment is adopted depends on the usage of alternative mechanisms, including partner switching. In this study, we investigate the combined effect of punishment and partner switching in evolutionary prisoner's dilemma games conducted on a network. In the model, agents are located on the network and participate in the prisoner's dilemma games with punishment. In addition, they can opportunistically switch interaction partners to improve their payoff. Our Monte Carlo simulation showed that a large frequency of punishers is required to suppress defectors when the frequency of partner switching is low. In contrast, cooperation is the most abundant strategy when the frequency of partner switching is high regardless of the strength of punishment. Interestingly, cooperators become abundant not because they avoid the cost of inflicting punishment and earn a larger average payoff per game but rather because they have more numerous opportunities to be referred to as a role agent by defectors. Our results imply that the fluidity of social relationships has a profound effect on the adopted strategy in maintaining cooperation.

  1. Free space optical networks for ultra-broad band services

    CERN Document Server

    Kartalopoulos, Stamatios V

    2011-01-01

    "Free Space Optical Network is a next generation communication network which uses optical waves instead of microwaves, potentially offering faster communication with ultra band width, meaning more complex communication services can be simultaneously offered. This book describes the network concepts in simple language starting with point-to-point free space optics basics and discusses networking, interoperability with existing communication network, and security. An ideal resource for communication professionals just entering the free space optical communication field and graduate students majoring in optical communications"--Provided by publisher.

  2. Optical Multiple Access Network (OMAN) for advanced processing satellite applications

    Science.gov (United States)

    Mendez, Antonio J.; Gagliardi, Robert M.; Park, Eugene; Ivancic, William D.; Sherman, Bradley D.

    1991-01-01

    An OMAN breadboard for exploring advanced processing satellite circuit switch applications is introduced. Network architecture, hardware trade offs, and multiple user interference issues are presented. The breadboard test set up and experimental results are discussed.

  3. NEMESIS : A Multigigabit Optical Local Area Network

    OpenAIRE

    Popescu, Adrian; Akyildizapo, Ian

    1994-01-01

    A new architecture is developed for an integrated 20 Gbps fiber optic Local Area Network (LAN) that supports data rates up to 9.6 Gbps. The architecture does not follow the standard, vertically-oriented Open System Interconnection (OSI) layering approach of other LANs. Instead, a horizontally-oriented model is introduced for the communication process to open up the three fundamental bottlenecks, i.e., opto-electronic, service and processing bottlenecks, that occur in a multi-Gbps integrated c...

  4. Fault location algorithms for optical networks

    OpenAIRE

    Mas Machuca, Carmen; Thiran, Patrick

    2005-01-01

    Today, there is no doubt that optical networks are the solution to the explosion of Internet traffic that two decades ago we only dreamed about. They offer high capacity with the use of Wavelength Division Multiplexing (WDM) techniques among others. However, this increase of available capacity can be betrayed by the high quantity of information that can be lost when a failure occurs because not only one, but several channels will then be interrupted. Efficient fault detection and location mec...

  5. Thermal lens and all optical switching of new organometallic compound doped polyacrylamide gel

    Science.gov (United States)

    Badran, Hussain Ali

    In this work thermal lens spectrometry (TLS) is applied to investigate the thermo-optical properties of new organometallic compound containing azomethine group, Dichloro bis [2-(2-hydroxybenzylideneamino)-5-methylphenyl] telluride platinum(II), doped polyacrylamide gel using transistor-transistor logic (TTL) modulated cw 532 nm laser beam as an excitation beam modulated at 10 Hz frequency and probe beam wavelength 635 nm at 14 mW. The technique is applied to determine the thermal diffusivities, ds/dT and the linear thermal expansion coefficient of the sample. All-optical switching effects with low background and high stability are demonstrated.

  6. Dual branch transmit switch-and-stay diversity for underlay cognitive networks

    KAUST Repository

    Sayed, Mostafa M.; Abdallah, Mohamed M.; Alouini, Mohamed-Slim; Qaraqe, Khalid A.

    2011-01-01

    In this paper, we study applying dual branch transmit switch-and-stay combining (SSC) technique for underlay cognitive radio (UCR) networks. In UCR, the secondary user is allowed to share the spectrum with the primary (licensed) user under the condition that interference at the primary receiver is below a predetermined threshold. Assuming binary phaseshift keying (BPSK) modulation and Rayleigh fading channels, we develop a closed form expression for the average bit error rate (BER) of the secondary link as a function of the switching threshold. We then find a closed form expression for the optimal switching threshold in the sense of minimizing the average BER. For the sake of comparison we derive an expression for the average BER of the dual branch transmit selection combining (SC) technique. We finally investigate the effect of correlation between secondary and interference channels on the average BER and the associated optimal switching threshold. © 2011 IEEE.

  7. Dual branch transmit switch-and-stay diversity for underlay cognitive networks

    KAUST Repository

    Sayed, Mostafa M.

    2011-05-01

    In this paper, we study applying dual branch transmit switch-and-stay combining (SSC) technique for underlay cognitive radio (UCR) networks. In UCR, the secondary user is allowed to share the spectrum with the primary (licensed) user under the condition that interference at the primary receiver is below a predetermined threshold. Assuming binary phaseshift keying (BPSK) modulation and Rayleigh fading channels, we develop a closed form expression for the average bit error rate (BER) of the secondary link as a function of the switching threshold. We then find a closed form expression for the optimal switching threshold in the sense of minimizing the average BER. For the sake of comparison we derive an expression for the average BER of the dual branch transmit selection combining (SC) technique. We finally investigate the effect of correlation between secondary and interference channels on the average BER and the associated optimal switching threshold. © 2011 IEEE.

  8. A theoretical and experimental study of neuromorphic atomic switch networks for reservoir computing.

    Science.gov (United States)

    Sillin, Henry O; Aguilera, Renato; Shieh, Hsien-Hang; Avizienis, Audrius V; Aono, Masakazu; Stieg, Adam Z; Gimzewski, James K

    2013-09-27

    Atomic switch networks (ASNs) have been shown to generate network level dynamics that resemble those observed in biological neural networks. To facilitate understanding and control of these behaviors, we developed a numerical model based on the synapse-like properties of individual atomic switches and the random nature of the network wiring. We validated the model against various experimental results highlighting the possibility to functionalize the network plasticity and the differences between an atomic switch in isolation and its behaviors in a network. The effects of changing connectivity density on the nonlinear dynamics were examined as characterized by higher harmonic generation in response to AC inputs. To demonstrate their utility for computation, we subjected the simulated network to training within the framework of reservoir computing and showed initial evidence of the ASN acting as a reservoir which may be optimized for specific tasks by adjusting the input gain. The work presented represents steps in a unified approach to experimentation and theory of complex systems to make ASNs a uniquely scalable platform for neuromorphic computing.

  9. CERNET - A high-speed packet-switching network

    International Nuclear Information System (INIS)

    Gerard, J.M.

    1981-01-01

    A general mesh-structured high-speed computer network has been designed and built. This network provides communication between any pair of connected user computers over distances of upto 6 km and at line speeds of 1 to 5 Mbit/second. The network is composed of a communication subnet providing a datagram service, complemented by tasks in the connected machines to implement an end-to-end logical link protocol. Details are given of the overall structure as well as the specific modules of which the system is composed. (orig.)

  10. Optically controlled reconfigurable antenna for 5G future broadband cellular communication networks

    DEFF Research Database (Denmark)

    Costa, I.F. da; Spadoti, D. H.; Cerqueira Sodre Jr., Arismar

    2017-01-01

    This paper presents an optically controlled reconfigurable antenna for millimetre-wave frequency range. Silicon switches are used to control the optical reconfiguration, modifying the frequency response and radiation pattern of the antenna design. Therefore, the system can switch between the ligh......This paper presents an optically controlled reconfigurable antenna for millimetre-wave frequency range. Silicon switches are used to control the optical reconfiguration, modifying the frequency response and radiation pattern of the antenna design. Therefore, the system can switch between...

  11. 25-Gbit/s burst-mode optical receiver using high-speed avalanche photodiode for 100-Gbit/s optical packet switching.

    Science.gov (United States)

    Nada, Masahiro; Nakamura, Makoto; Matsuzaki, Hideaki

    2014-01-13

    25-Gbit/s error-free operation of an optical receiver is successfully demonstrated against burst-mode optical input signals without preambles. The receiver, with a high-sensitivity avalanche photodiode and burst-mode transimpedance amplifier, exhibits sufficient receiver sensitivity and an extremely quick response suitable for burst-mode operation in 100-Gbit/s optical packet switching.

  12. A Scheme to Optimize Flow Routing and Polling Switch Selection of Software Defined Networks.

    Directory of Open Access Journals (Sweden)

    Huan Chen

    Full Text Available This paper aims at minimizing the communication cost for collecting flow information in Software Defined Networks (SDN. Since flow-based information collecting method requires too much communication cost, and switch-based method proposed recently cannot benefit from controlling flow routing, jointly optimize flow routing and polling switch selection is proposed to reduce the communication cost. To this end, joint optimization problem is formulated as an Integer Linear Programming (ILP model firstly. Since the ILP model is intractable in large size network, we also design an optimal algorithm for the multi-rooted tree topology and an efficient heuristic algorithm for general topology. According to extensive simulations, it is found that our method can save up to 55.76% communication cost compared with the state-of-the-art switch-based scheme.

  13. A Scheme to Optimize Flow Routing and Polling Switch Selection of Software Defined Networks.

    Science.gov (United States)

    Chen, Huan; Li, Lemin; Ren, Jing; Wang, Yang; Zhao, Yangming; Wang, Xiong; Wang, Sheng; Xu, Shizhong

    2015-01-01

    This paper aims at minimizing the communication cost for collecting flow information in Software Defined Networks (SDN). Since flow-based information collecting method requires too much communication cost, and switch-based method proposed recently cannot benefit from controlling flow routing, jointly optimize flow routing and polling switch selection is proposed to reduce the communication cost. To this end, joint optimization problem is formulated as an Integer Linear Programming (ILP) model firstly. Since the ILP model is intractable in large size network, we also design an optimal algorithm for the multi-rooted tree topology and an efficient heuristic algorithm for general topology. According to extensive simulations, it is found that our method can save up to 55.76% communication cost compared with the state-of-the-art switch-based scheme.

  14. Controllability of switched singular mix-valued logical control networks with constraints

    Science.gov (United States)

    Deng, Lei; Gong, Mengmeng; Zhu, Peiyong

    2018-03-01

    The present paper investigates the controllability problem of switched singular mix-valued logical control networks (SSMLCNs) with constraints on states and controls. First, using the semi-tenser product (STP) of matrices, the SSMLCN is expressed in an algebraic form, based on which a necessary and sufficient condition is given for the uniqueness of solution of SSMLCNs. Second, a necessary and sufficient criteria is derived for the controllability of constrained SSMLCNs, by converting a constrained SSMLCN into a parallel constrained switched mix-valued logical control network. Third, an algorithm is presented to design a proper switching sequence and a control scheme which force a state to a reachable state. Finally, a numerical example is given to demonstrate the efficiency of the results obtained in this paper.

  15. Call for Papers: Photonics in Switching

    Science.gov (United States)

    Wosinska, Lena; Glick, Madeleine

    2006-04-01

    Call for Papers: Photonics in Switching Guest Editors: Lena Wosinska, Royal Institute of Technology (KTH) / ICT Sweden Madeleine Glick, Intel Research, Cambridge, UK Technologies based on DWDM systems allow data transmission with bit rates of Tbit/s on a single fiber. To facilitate this enormous transmission volume, high-capacity and high-speed network nodes become inevitable in the optical network. Wideband switching, WDM switching, optical burst switching (OBS), and optical packet switching (OPS) are promising technologies for harnessing the bandwidth of WDM optical fiber networks in a highly flexible and efficient manner. As a number of key optical component technologies approach maturity, photonics in switching is becoming an increasingly attractive and practical solution for the next-generation of optical networks. The scope of this special issue is focused on the technology and architecture of optical switching nodes, including the architectural and algorithmic aspects of high-speed optical networks. Scope of Submission The scope of the papers includes, but is not limited to, the following topics: WDM node architectures Novel device technologies enabling photonics in switching, such as optical switch fabrics, optical memory, and wavelength conversion Routing protocols WDM switching and routing Quality of service Performance measurement and evaluation Next-generation optical networks: architecture, signaling, and control Traffic measurement and field trials Optical burst and packet switching OBS/OPS node architectures Burst/Packet scheduling and routing algorithms Contention resolution/avoidance strategies Services and applications for OBS/OPS (e.g., grid networks, storage-area networks, etc.) Burst assembly and ingress traffic shaping Hybrid OBS/TDM or OBS/wavelength routing Manuscript Submission To submit to this special issue, follow the normal procedure for submission to JON and select ``Photonics in Switching' in the features indicator of the online

  16. Argonne National Lab deploys Force10 networks' massively dense ethernet switch for supercomputing cluster

    CERN Multimedia

    2003-01-01

    "Force10 Networks, Inc. today announced that Argonne National Laboratory (Argonne, IL) has successfully deployed Force10 E-Series switch/routers to connect to the TeraGrid, the world's largest supercomputing grid, sponsored by the National Science Foundation (NSF)" (1/2 page).

  17. Attractor switching in neuron networks and Spatiotemporal filters for motion processing

    NARCIS (Netherlands)

    Subramanian, Easwara Naga

    2008-01-01

    From a broader perspective, we address two important questions, viz., (a) what kind of mechanism would enable a neuronal network to switch between various tasks or stored patterns? (b) what are the properties of neurons that are used by the visual system in early motion detection? To address (a) we

  18. Confinement and diffusion modulate bistability and stochastic switching in a reaction network with positive feedback

    International Nuclear Information System (INIS)

    Mlynarczyk, Paul J.; Pullen, Robert H.; Abel, Steven M.

    2016-01-01

    Positive feedback is a common feature in signal transduction networks and can lead to phenomena such as bistability and signal propagation by domain growth. Physical features of the cellular environment, such as spatial confinement and the mobility of proteins, play important but inadequately understood roles in shaping the behavior of signaling networks. Here, we use stochastic, spatially resolved kinetic Monte Carlo simulations to explore a positive feedback network as a function of system size, system shape, and mobility of molecules. We show that these physical properties can markedly alter characteristics of bistability and stochastic switching when compared with well-mixed simulations. Notably, systems of equal volume but different shapes can exhibit qualitatively different behaviors under otherwise identical conditions. We show that stochastic switching to a state maintained by positive feedback occurs by cluster formation and growth. Additionally, the frequency at which switching occurs depends nontrivially on the diffusion coefficient, which can promote or suppress switching relative to the well-mixed limit. Taken together, the results provide a framework for understanding how confinement and protein mobility influence emergent features of the positive feedback network by modulating molecular concentrations, diffusion-influenced rate parameters, and spatiotemporal correlations between molecules

  19. Global Robust Stability of Switched Interval Neural Networks with Discrete and Distributed Time-Varying Delays of Neural Type

    Directory of Open Access Journals (Sweden)

    Huaiqin Wu

    2012-01-01

    Full Text Available By combing the theories of the switched systems and the interval neural networks, the mathematics model of the switched interval neural networks with discrete and distributed time-varying delays of neural type is presented. A set of the interval parameter uncertainty neural networks with discrete and distributed time-varying delays of neural type are used as the individual subsystem, and an arbitrary switching rule is assumed to coordinate the switching between these networks. By applying the augmented Lyapunov-Krasovskii functional approach and linear matrix inequality (LMI techniques, a delay-dependent criterion is achieved to ensure to such switched interval neural networks to be globally asymptotically robustly stable in terms of LMIs. The unknown gain matrix is determined by solving this delay-dependent LMIs. Finally, an illustrative example is given to demonstrate the validity of the theoretical results.

  20. Architecture and design of optical path networks utilizing waveband virtual links

    Science.gov (United States)

    Ito, Yusaku; Mori, Yojiro; Hasegawa, Hiroshi; Sato, Ken-ichi

    2016-02-01

    We propose a novel optical network architecture that uses waveband virtual links, each of which can carry several optical paths, to directly bridge distant node pairs. Future photonic networks should not only transparently cover extended areas but also expand fiber capacity. However, the traversal of many ROADM nodes impairs the optical signal due to spectrum narrowing. To suppress the degradation, the bandwidth of guard bands needs to be increased, which degrades fiber frequency utilization. Waveband granular switching allows us to apply broader pass-band filtering at ROADMs and to insert sufficient guard bands between wavebands with minimum frequency utilization offset. The scheme resolves the severe spectrum narrowing effect. Moreover, the guard band between optical channels in a waveband can be minimized, which increases the number of paths that can be accommodated per fiber. In the network, wavelength path granular routing is done without utilizing waveband virtual links, and it still suffers from spectrum narrowing. A novel network design algorithm that can bound the spectrum narrowing effect by limiting the number of hops (traversed nodes that need wavelength path level routing) is proposed in this paper. This algorithm dynamically changes the waveband virtual link configuration according to the traffic distribution variation, where optical paths that need many node hops are effectively carried by virtual links. Numerical experiments demonstrate that the number of necessary fibers is reduced by 23% compared with conventional optical path networks.

  1. Spatial Soliton Interactions for Photonic Switching. Part I

    Science.gov (United States)

    2000-03-07

    Communications Networks • ’ 1.2.2 Digital Optical Computing and Processing 6 1.3 Requirements for Digital Switching and Logic Devices 7 1.3.1 Switching...high-speed optical communications networks. 1.2.2 Digital Optical Computing and Processing Determining what role optics should play in general... and Processing , vol. 2, pp. 57-61, January .1992. V. F Zakharov and A. B. Shabat. "Exact theory of two-dimensional self-focusing and one- dimensional

  2. High-power subnanosecond operation of a bistable optically controlled semiconductor switch (BOSS)

    International Nuclear Information System (INIS)

    Stoudt, D.C.; Richardson, M.A.; Demske, D.L.; Roush, R.A.; Eure, K.W.

    1994-01-01

    Recent high-power, subnanosecond-switching results of the Bistable Optically controlled Semiconductor Switch (BOSS) are presented. The process of persistent photoconductivity followed by photo-quenching have been demonstrated at megawatt power levels in copper-compensated, silicon-doped, semi-insulating gallium arsenide. These processes allow a switch to be developed that can be closed by the application of one laser pulse and opened by the application of a second laser pulse with a wavelength equal to twice that of the first laser. Switch closure is primarily achieved by elevating electrons from a deep copper center which has been diffused into the material. The opening phase is a two-step process which relies initially on the absorption of the 2-μm laser causing electrons to be elevated from the valance band back into the copper center, and finally on the recombination of electrons in the conduction band with boles in the valance band. The second step requires a sufficient concentration of recombination centers (RC) in the material for opening to occur in the subnanosecond regime. These RC's are generated in the bulk GaAs material by fast-neutron irradiation (∼ 1 MeV) at a fluence of about 3 x 10 15 cm -2 . High-power switching results which demonstrate that the BOSS switch can be opened in the subnanosecond regime are presented for the first time. Neutron-irradiated BOSS devices have been opened against a rising electric field of about 20 kV/cm (10 kV) in a time less than one nanosecond. Kilovolt electrical pulses have been generated with a FWHM of roughly 250 picoseconds

  3. Giant quadratic electro-optical effect during polarization switching in ultrathin ferroelectric polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Blinov, L. M., E-mail: lev39blinov@gmail.com; Lazarev, V V; Palto, S P; Yudin, S G [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2012-04-15

    The low-frequency quadratic electro-optical effect with a maximum electro-optical coefficient of g = 8 Multiplication-Sign 10{sup -19} m{sup 2}/V{sup 2} (i.e., four orders of magnitude greater than the standard high-frequency value) has been studied in thin films of ferroelectric polymer PVDF(70%)-TrFE(30%). The observed effect is related to the process of spontaneous polarization switching, during which the electron oscillators of C-F and C-H dipole groups rotate to become parallel to the applied field. As a result, the ellipsoid of the refractive index exhibits narrowing in the direction perpendicular to the field. The field dependence of the electro-optical coefficient g correlates with that of the apparent dielectric permittivity, which can be introduced under the condition of ferroelectric polarization switching. The observed electro-optical effect strongly decreases when the frequency increases up to several hundred hertz. The temperature dependence of the effect exhibits clearly pronounced hysteresis in the region of the ferroelectric phase transition.

  4. Simulation and Evaluation of Ethernet Passive Optical Network

    Directory of Open Access Journals (Sweden)

    Salah A. Jaro Alabady

    2013-05-01

    Full Text Available      This paper studies simulation and evaluation of Ethernet Passive Optical Network (EPON system, IEEE802.3ah based OPTISM 3.6 simulation program. The simulation program is used in this paper to build a typical ethernet passive optical network, and to evaluate the network performance when using the (1580, 1625 nm wavelength instead of (1310, 1490 nm that used in Optical Line Terminal (OLT and Optical Network Units (ONU's in system architecture of Ethernet passive optical network at different bit rate and different fiber optic length. The results showed enhancement in network performance by increase the number of nodes (subscribers connected to the network, increase the transmission distance, reduces the received power and reduces the Bit Error Rate (BER.   

  5. High speed switching for computer and communication networks

    NARCIS (Netherlands)

    Dorren, H.J.S.

    2014-01-01

    The role of data centers and computers are vital for the future of our data-centric society. Historically the performance of data-centers is increasing with a factor 100-1000 every ten years and as a result of this the capacity of the data-center communication network has to scale accordingly. This

  6. Phase-controlled all-optical switching based on coherent population oscillation in a two-level system

    International Nuclear Information System (INIS)

    Liao, Ping; Yu, Song; Luo, Bin; Shen, Jing; Gu, Wanyi; Guo, Hong

    2011-01-01

    We theoretically propose a scheme of phase-controlled all-optical switching due to the effect of degenerate four-wave mixing (FWM) and coherent population oscillation (CPO) in a two-level system driven by a strong coupling field and two weak symmetrically detuned fields. The results show that the phase of the FWM field can be utilized to switch between constructive and destructive interference, which can lead to the transmission or attenuation of the probe field and thus switch the field on or off. We also find the intensity of the coupling field and the propagation distance have great influence on the performance of the switching. In our scheme, due to the quick response in semiconductor systems, a fast all-optical switching can be realized at low light level. -- Highlights: ► We study a new all-optical switching based on coherent population oscillation. ► The phase of the FWM field can be utilized to switch the probe field on or off. ► A fast and low-light-level switching can be realized in semiconductors.

  7. Cognitive, Heterogeneous and Reconfigurable Optical Networks: The CHRON Project

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Borkowski, Robert; de Miguel, Ignacio

    2014-01-01

    . The incorporation of cognitive techniques can help to optimize a network by employing mechanisms that can observe, act, learn and improve network performance, taking into account end-to-end goals. The EU project CHRON: Cognitive Heterogeneous Reconfigurable Optical Network proposes a strategy to efficiently control...... the network by implementing cognition. In this paper we present a survey of different techniques developed throughout the course of the project to apply cognition in future optical networks....

  8. All-optical switching in Sagnac loop mirror containing an ytterbium-doped fiber and fiber Bragg grating.

    Science.gov (United States)

    Zang, Zhigang

    2013-08-10

    A configuration of all-optical switching based on a Signac loop mirror that incorporates an ytterbium-doped fiber and uniform fiber Bragg grating (FBG) is proposed in this paper. It is found that the transmission spectrum of this structure is the narrow splitting of the reflection spectrum of the FBG. The shift of this ultranarrow transmission spectrum is very sensitive to the intensity of the pump power. Thus, the threshold switching power can be greatly reduced by shifting such narrow transmission spectrum. Compared with the single FBG, the threshold switching power of this configuration is reduced by 4 orders of magnitude. In addition, the results indicate that this optical switching has a high extinction ratio of 20 dB and a ultrafast response time of 3 ns. The operation regime and switching performance under the cross-phase modulation cases are also investigated.

  9. CATO: a CAD tool for intelligent design of optical networks and interconnects

    Science.gov (United States)

    Chlamtac, Imrich; Ciesielski, Maciej; Fumagalli, Andrea F.; Ruszczyk, Chester; Wedzinga, Gosse

    1997-10-01

    Increasing communication speed requirements have created a great interest in very high speed optical and all-optical networks and interconnects. The design of these optical systems is a highly complex task, requiring the simultaneous optimization of various parts of the system, ranging from optical components' characteristics to access protocol techniques. Currently there are no computer aided design (CAD) tools on the market to support the interrelated design of all parts of optical communication systems, thus the designer has to rely on costly and time consuming testbed evaluations. The objective of the CATO (CAD tool for optical networks and interconnects) project is to develop a prototype of an intelligent CAD tool for the specification, design, simulation and optimization of optical communication networks. CATO allows the user to build an abstract, possible incomplete, model of the system, and determine its expected performance. Based on design constraints provided by the user, CATO will automatically complete an optimum design, using mathematical programming techniques, intelligent search methods and artificial intelligence (AI). Initial design and testing of a CATO prototype (CATO-1) has been completed recently. The objective was to prove the feasibility of combining AI techniques, simulation techniques, an optical device library and a graphical user interface into a flexible CAD tool for obtaining optimal communication network designs in terms of system cost and performance. CATO-1 is an experimental tool for designing packet-switching wavelength division multiplexing all-optical communication systems using a LAN/MAN ring topology as the underlying network. The two specific AI algorithms incorporated are simulated annealing and a genetic algorithm. CATO-1 finds the optimal number of transceivers for each network node, using an objective function that includes the cost of the devices and the overall system performance.

  10. Cavity electromagnetically induced transparency and all-optical switching using ion Coulomb crystals

    DEFF Research Database (Denmark)

    Albert, Magnus; Dantan, Aurelien Romain; Drewsen, Michael

    2011-01-01

    The control of one light field by another, ultimately at the single photon level1, 2, 3, 4, 5, 6, 7, is a challenging task that has numerous interesting applications within nonlinear optics4, 5 and quantum information science6, 7, 8. This type of control can only be achieved through highly...... nonlinear interactions, such as those based on electromagnetic induced transparency (EIT)2, 3, 4, 5, 6, 9, 10, 11, 12. Here, we demonstrate for the first time EIT as well as all-optical EIT-based light switching using ion Coulomb crystals situated in an optical cavity. Changes from essentially full...... milestones for future realizations of quantum information processing devices, such as high-efficiency quantum memories8, 13, 14, single-photon transistors15, 16 and single-photon gates4, 6, 9....

  11. Scaling architecture-on-demand based optical networks

    NARCIS (Netherlands)

    Meyer, Hugo; Sancho, Jose Carlos; Mrdakovic, Milica; Peng, Shuping; Simeonidou, Dimitra; Miao, Wang; Calabretta, Nicola

    2016-01-01

    This paper analyzes methodologies that allow scaling properly Architecture-On-Demand (AoD) based optical networks. As Data Centers and HPC systems are growing in size and complexity, optical networks seem to be the way to scale the bandwidth of current network infrastructures. To scale the number of

  12. Survivable resource orchestration for optically interconnected data center networks.

    Science.gov (United States)

    Zhang, Qiong; She, Qingya; Zhu, Yi; Wang, Xi; Palacharla, Paparao; Sekiya, Motoyoshi

    2014-01-13

    We propose resource orchestration schemes in overlay networks enabled by optical network virtualization. Based on the information from underlying optical networks, our proposed schemes provision the fewest data centers to guarantee K-connect survivability, thus maintaining resource availability for cloud applications under any failure.

  13. A compact plasmonic MOS-based 2×2 electro-optic switch

    Directory of Open Access Journals (Sweden)

    Ye Chenran

    2015-01-01

    Full Text Available We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, indium-tin-oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 (7 dB for the CROSS (BAR state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with silicon-on-insulator platforms for low-cost manufacturing.

  14. PCBM : P3HT polymer composites for photonic crystal all-optical switching applications

    International Nuclear Information System (INIS)

    Li Zhiqiang; Hu Xiaoyong; Zhang Jiaxiang; Yang Hong; Gong Qihuang

    2010-01-01

    An all-optical switching with an operating pump intensity of 1 MW cm -2 is realized in a one-dimensional nonlinear organic photonic crystal made of poly(3-hexylthiophene) doped with 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)C 61 , fabricated by focused ion-beam etching. The femtosecond pump and probe method is adopted to measure the transmittance changes of the probe laser based on the photonic bandgap shift induced by the pump laser. Under resonant excitation, a large nonlinear refractive index of the order of 10 -9 cm 2 W -1 is obtained for the polymer composite. A switching time of 58.9 ps is maintained due to intermolecular charge transfer and exciton-exciton annihilation.

  15. PCBM : P3HT polymer composites for photonic crystal all-optical switching applications

    Energy Technology Data Exchange (ETDEWEB)

    Li Zhiqiang; Hu Xiaoyong; Zhang Jiaxiang; Yang Hong; Gong Qihuang, E-mail: xiaoyonghu@pku.edu.c, E-mail: qhgong@pku.edu.c [State Key Laboratory for Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871 (China)

    2010-09-29

    An all-optical switching with an operating pump intensity of 1 MW cm{sup -2} is realized in a one-dimensional nonlinear organic photonic crystal made of poly(3-hexylthiophene) doped with 1-(3-methoxycarbonyl)propyl-1-phenyl-(6,6)C{sub 61}, fabricated by focused ion-beam etching. The femtosecond pump and probe method is adopted to measure the transmittance changes of the probe laser based on the photonic bandgap shift induced by the pump laser. Under resonant excitation, a large nonlinear refractive index of the order of 10{sup -9} cm{sup 2} W{sup -1} is obtained for the polymer composite. A switching time of 58.9 ps is maintained due to intermolecular charge transfer and exciton-exciton annihilation.

  16. Study on spin filtering and switching action in a double-triangular network chain

    Science.gov (United States)

    Zhang, Yongmei

    2018-04-01

    Spin transport properties of a double-triangular quantum network with local magnetic moment on backbones and magnetic flux penetrating the network plane are studied. Numerical simulation results show that such a quantum network will be a good candidate for spin filter and spin switch. Local dispersion and density of states are considered in the framework of tight-binding approximation. Transmission coefficients are calculated by the method of transfer matrix. Spin transmission is regulated by substrate magnetic moment and magnetic flux piercing those triangles. Experimental realization of such theoretical research will be conducive to designing of new spintronic devices.

  17. Securing optical code-division multiple-access networks with a postswitching coding scheme of signature reconfiguration

    Science.gov (United States)

    Huang, Jen-Fa; Meng, Sheng-Hui; Lin, Ying-Chen

    2014-11-01

    The optical code-division multiple-access (OCDMA) technique is considered a good candidate for providing optical layer security. An enhanced OCDMA network security mechanism with a pseudonoise (PN) random digital signals type of maximal-length sequence (M-sequence) code switching to protect against eavesdropping is presented. Signature codes unique to individual OCDMA-network users are reconfigured according to the register state of the controlling electrical shift registers. Examples of signature reconfiguration following state switching of the controlling shift register for both the network user and the eavesdropper are numerically illustrated. Dynamically changing the PN state of the shift register to reconfigure the user signature sequence is shown; this hinders eavesdroppers' efforts to decode correct data sequences. The proposed scheme increases the probability of eavesdroppers committing errors in decoding and thereby substantially enhances the degree of an OCDMA network's confidentiality.

  18. A liquid lens switching-based motionless variable fiber-optic delay line

    Science.gov (United States)

    Khwaja, Tariq Shamim; Reza, Syed Azer; Sheikh, Mumtaz

    2018-05-01

    We present a Variable Fiber-Optic Delay Line (VFODL) module capable of imparting long variable delays by switching an input optical/RF signal between Single Mode Fiber (SMF) patch cords of different lengths through a pair of Electronically Controlled Tunable Lenses (ECTLs) resulting in a polarization-independent operation. Depending on intended application, the lengths of the SMFs can be chosen accordingly to achieve the desired VFODL operation dynamic range. If so desired, the state of the input signal polarization can be preserved with the use of commercially available polarization-independent ECTLs along with polarization-maintaining SMFs (PM-SMFs), resulting in an output polarization that is identical to the input. An ECTL-based design also improves power consumption and repeatability. The delay switching mechanism is electronically-controlled, involves no bulk moving parts, and can be fully-automated. The VFODL module is compact due to the use of small optical components and SMFs that can be packaged compactly.

  19. SONEP: A Software-Defined Optical Network Emulation Platform

    DEFF Research Database (Denmark)

    Azodolmolky, Siamak; Petersen, Martin Nordal; Fagertun, Anna Manolova

    2014-01-01

    Network emulation has been one of the tools of choice for conducting experiments on commodity hardware. In the absence of an easy to use optical network test-bed, researchers can significantly benefit from the availability of a flexible/programmable optical network emulation platform. Exploiting...... the lightweight system virtualization, which is recently supported in modern operating systems, in this work we present the architecture of a Software-Defined Network (SDN) emulation platform for transport optical networks and investigate its usage in a use-case scenario. To the best of our knowledge......, this is for the first time that an SDN-based emulation platform is proposed for modeling and performance evaluation of optical networks. Coupled with recent trend of extension of SDN towards transport (optical) networks, the presented tool can facilitate the evaluation of innovative idea before actual implementations...

  20. Building SDN-Based Agricultural Vehicular Sensor Networks Based on Extended Open vSwitch.

    Science.gov (United States)

    Huang, Tao; Yan, Siyu; Yang, Fan; Pan, Tian; Liu, Jiang

    2016-01-19

    Software-defined vehicular sensor networks in agriculture, such as autonomous vehicle navigation based on wireless multi-sensor networks, can lead to more efficient precision agriculture. In SDN-based vehicle sensor networks, the data plane is simplified and becomes more efficient by introducing a centralized controller. However, in a wireless environment, the main controller node may leave the sensor network due to the dynamic topology change or the unstable wireless signal, leaving the rest of network devices without control, e.g., a sensor node as a switch may forward packets according to stale rules until the controller updates the flow table entries. To solve this problem, this paper proposes a novel SDN-based vehicular sensor networks architecture which can minimize the performance penalty of controller connection loss. We achieve this by designing a connection state detection and self-learning mechanism. We build prototypes based on extended Open vSwitch and Ryu. The experimental results show that the recovery time from controller connection loss is under 100 ms and it keeps rule updating in real time with a stable throughput. This architecture enhances the survivability and stability of SDN-based vehicular sensor networks in precision agriculture.

  1. Building SDN-Based Agricultural Vehicular Sensor Networks Based on Extended Open vSwitch

    Directory of Open Access Journals (Sweden)

    Tao Huang

    2016-01-01

    Full Text Available Software-defined vehicular sensor networks in agriculture, such as autonomous vehicle navigation based on wireless multi-sensor networks, can lead to more efficient precision agriculture. In SDN-based vehicle sensor networks, the data plane is simplified and becomes more efficient by introducing a centralized controller. However, in a wireless environment, the main controller node may leave the sensor network due to the dynamic topology change or the unstable wireless signal, leaving the rest of network devices without control, e.g., a sensor node as a switch may forward packets according to stale rules until the controller updates the flow table entries. To solve this problem, this paper proposes a novel SDN-based vehicular sensor networks architecture which can minimize the performance penalty of controller connection loss. We achieve this by designing a connection state detection and self-learning mechanism. We build prototypes based on extended Open vSwitch and Ryu. The experimental results show that the recovery time from controller connection loss is under 100 ms and it keeps rule updating in real time with a stable throughput. This architecture enhances the survivability and stability of SDN-based vehicular sensor networks in precision agriculture.

  2. Building SDN-Based Agricultural Vehicular Sensor Networks Based on Extended Open vSwitch

    Science.gov (United States)

    Huang, Tao; Yan, Siyu; Yang, Fan; Pan, Tian; Liu, Jiang

    2016-01-01

    Software-defined vehicular sensor networks in agriculture, such as autonomous vehicle navigation based on wireless multi-sensor networks, can lead to more efficient precision agriculture. In SDN-based vehicle sensor networks, the data plane is simplified and becomes more efficient by introducing a centralized controller. However, in a wireless environment, the main controller node may leave the sensor network due to the dynamic topology change or the unstable wireless signal, leaving the rest of network devices without control, e.g., a sensor node as a switch may forward packets according to stale rules until the controller updates the flow table entries. To solve this problem, this paper proposes a novel SDN-based vehicular sensor networks architecture which can minimize the performance penalty of controller connection loss. We achieve this by designing a connection state detection and self-learning mechanism. We build prototypes based on extended Open vSwitch and Ryu. The experimental results show that the recovery time from controller connection loss is under 100 ms and it keeps rule updating in real time with a stable throughput. This architecture enhances the survivability and stability of SDN-based vehicular sensor networks in precision agriculture. PMID:26797616

  3. Shape-Memory Hydrogels: Evolution of Structural Principles To Enable Shape Switching of Hydrophilic Polymer Networks.

    Science.gov (United States)

    Löwenberg, Candy; Balk, Maria; Wischke, Christian; Behl, Marc; Lendlein, Andreas

    2017-04-18

    The ability of hydrophilic chain segments in polymer networks to strongly interact with water allows the volumetric expansion of the material and formation of a hydrogel. When polymer chain segments undergo reversible hydration depending on environmental conditions, smart hydrogels can be realized, which are able to shrink/swell and thus alter their volume on demand. In contrast, implementing the capacity of hydrogels to switch their shape rather than volume demands more sophisticated chemical approaches and structural concepts. In this Account, the principles of hydrogel network design, incorporation of molecular switches, and hydrogel microstructures are summarized that enable a spatially directed actuation of hydrogels by a shape-memory effect (SME) without major volume alteration. The SME involves an elastic deformation (programming) of samples, which are temporarily fixed by reversible covalent or physical cross-links resulting in a temporary shape. The material can reverse to the original shape when these molecular switches are affected by application of a suitable stimulus. Hydrophobic shape-memory polymers (SMPs), which are established with complex functions including multiple or reversible shape-switching, may provide inspiration for the molecular architecture of shape-memory hydrogels (SMHs), but cannot be identically copied in the world of hydrophilic soft materials. For instance, fixation of the temporary shape requires cross-links to be formed also in an aqueous environment, which may not be realized, for example, by crystalline domains from the hydrophilic main chains as these may dissolve in presence of water. Accordingly, dual-shape hydrogels have evolved, where, for example, hydrophobic crystallizable side chains have been linked into hydrophilic polymer networks to act as temperature-sensitive temporary cross-links. By incorporating a second type of such side chains, triple-shape hydrogels can be realized. Considering the typically given light

  4. Cross layer optimization for cloud-based radio over optical fiber networks

    Science.gov (United States)

    Shao, Sujie; Guo, Shaoyong; Qiu, Xuesong; Yang, Hui; Meng, Luoming

    2016-07-01

    To adapt the 5G communication, the cloud radio access network is a paradigm introduced by operators which aggregates all base stations computational resources into a cloud BBU pool. The interaction between RRH and BBU or resource schedule among BBUs in cloud have become more frequent and complex with the development of system scale and user requirement. It can promote the networking demand among RRHs and BBUs, and force to form elastic optical fiber switching and networking. In such network, multiple stratum resources of radio, optical and BBU processing unit have interweaved with each other. In this paper, we propose a novel multiple stratum optimization (MSO) architecture for cloud-based radio over optical fiber networks (C-RoFN) with software defined networking. Additionally, a global evaluation strategy (GES) is introduced in the proposed architecture. MSO can enhance the responsiveness to end-to-end user demands and globally optimize radio frequency, optical spectrum and BBU processing resources effectively to maximize radio coverage. The feasibility and efficiency of the proposed architecture with GES strategy are experimentally verified on OpenFlow-enabled testbed in terms of resource occupation and path provisioning latency.

  5. Detection and localization of crosstalk in an all-optical network

    International Nuclear Information System (INIS)

    Jedidi, Ahmed; Abid, Mohamed; Rejeb, Ridha

    2011-01-01

    The all-optical network (AON) has been considered as promising technology for next-generation optical networks. AONs are attractive because they promise very high rates, flexible switching and broad application support. However, AONs are susceptible to malicious attacks as the signals remain in the optical domain within the network and are difficult to monitor closely. One of the serious problems with AONs is the fact that optical crosstalk is additive, and thus the aggregate effect of crosstalk over a whole network may be more nefarious than a single point of crosstalk. Crosstalk attacks can spread rapidly through the network, causing additional awkward failures and triggering multiple undesirable alarms. Therefore, these attacks must be detected and identified at any point in the network where they may occur. This results in the continuous monitoring and identification of the impairments becoming challenging in the event of transmission failures. This paper proposes a novel approach for detecting and localizing crosstalk in AONs, offering the benefit of relaxing the high cost and management complexity

  6. Optical switching and detection of 640 Gb/s OTDM data packets transmitted over 50 km of fibre

    NARCIS (Netherlands)

    Gomez-Agis, F.; Hu, H.; Luo, J.; Mulvad, H.C.H.; Galili, M.; Calabretta, N.; Oxenløwe, L.K.; Dorren, H.J.S.; Jeppesen, P.

    2011-01-01

    We demonstrate 1×4 optical-packet switching with error-free transmission of 640 Gb/s single-wavelength OTDM data-packets including instantaneous clock extraction and short pulse generation for optical time-demultiplexing based on a cavity-less pulse source.

  7. New value added to network services through software-defined optical core networking

    Science.gov (United States)

    Yamada, Akiko; Nakatsugawa, Keiichi; Yamashita, Shinji; Soumiya, Toshio

    2016-02-01

    If an optical core network can be handled flexibly, it can be used not only as network infrastructure but also as a temporary broadband resource when customers have to transfer a large volume of data quickly, which will in turn lead to new WAN services. We propose "software-defined optical core networking", which achieves flexible optical network control, meaning it virtualizes optical transport network/wavelength-division multiplexing resources and controls them with resources from other layers, such as Ether/MPLS. We developed a testbed system and verified that users could request broadband resources easily, and our controller could quickly set up an optical channel data unit path for the request.

  8. Design of energy efficient optical networks with software enabled integrated control plane

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Yan, Ying; Dittmann, Lars

    2015-01-01

    energy consumption by proposing a new integrated control plane structure utilising Software Defined Networking technologies. The integrated control plane increases the efficiencies of exchanging control information across different network domains, while introducing new possibilities to the routing...... methods and the control over quality of service (QoS). The structure is defined as an overlay generalised multi-protocol label switching (GMPLS) control model. With the defined structure, the integrated control plane is able to gather information from different domains (i.e. optical core network......'s) routing behaviours. With the flexibility of the routing structure, results show that the energy efficiency of the network can be improved without compromising the QoS for delay/blocking sensitive services....

  9. A microcontroller-based compensated optical proximity detector employing the switching-mode synchronous detection technique

    International Nuclear Information System (INIS)

    Rakshit, Anjan; Chatterjee, Amitava

    2012-01-01

    This paper describes the development of a microcontroller-based optical proximity detector that can provide a low-cost yet powerful obstacle-sensing mechanism for mobile robots. The system is developed with the switching-mode synchronous detection technique to provide satisfactory performance over a wide range of operating conditions and is developed with the facility of externally setting a threshold, for reliable operation. The system is dynamically compensated against ambient illumination variations. Experimental studies demonstrate how the minimum distance of activation can be varied with different choices of thresholds. (paper)

  10. Traffic-aware Elastic Optical Networks to leverage Energy Savings

    DEFF Research Database (Denmark)

    Turus, Ioan; Fagertun, Anna Manolova; Dittmann, Lars

    2014-01-01

    Because of the static nature of the deployed optical networks, large energy wastage is experienced today in production networks such as Telecom networks . With power-adaptive optical interfaces and suitable grooming procedures, we propose the design of more energy efficient transport networks....... Optical network reconfigurations are performed by GMPLS node controllers according to monitored traffic information. The investigated energy reduction strategies are simulated on two large scale transport networks (DT17 and COST37). The results show that the energy savings obtained by these strategies......-Europea n COST37 network, for both symbol-rate and modulation format adaptations significant savings are obtained . Mixed adaptation (jointly performing symbol-rate and modulation format adaptations) used together with optical grooming allows up to 4 4 % and 4 7 % power savings in DT17 and COST37 networks...

  11. Photonics in switching: enabling technologies and subsystem design

    DEFF Research Database (Denmark)

    Vlachos, K.; Raffaelli, C.; Aleksic, S.

    2009-01-01

    This paper describes recent research activities and results in the area of photonic switching carried out within the framework of the EU-funded e-Photon/ONe + network of excellence, Virtual Department on Optical Switching. Technology aspects of photonics in switching and, in particular, recent...

  12. Potential energy landscape and robustness of a gene regulatory network: toggle switch.

    Directory of Open Access Journals (Sweden)

    Keun-Young Kim

    2007-03-01

    Full Text Available Finding a multidimensional potential landscape is the key for addressing important global issues, such as the robustness of cellular networks. We have uncovered the underlying potential energy landscape of a simple gene regulatory network: a toggle switch. This was realized by explicitly constructing the steady state probability of the gene switch in the protein concentration space in the presence of the intrinsic statistical fluctuations due to the small number of proteins in the cell. We explored the global phase space for the system. We found that the protein synthesis rate and the unbinding rate of proteins to the gene were small relative to the protein degradation rate; the gene switch is monostable with only one stable basin of attraction. When both the protein synthesis rate and the unbinding rate of proteins to the gene are large compared with the protein degradation rate, two global basins of attraction emerge for a toggle switch. These basins correspond to the biologically stable functional states. The potential energy barrier between the two basins determines the time scale of conversion from one to the other. We found as the protein synthesis rate and protein unbinding rate to the gene relative to the protein degradation rate became larger, the potential energy barrier became larger. This also corresponded to systems with less noise or the fluctuations on the protein numbers. It leads to the robustness of the biological basins of the gene switches. The technique used here is general and can be applied to explore the potential energy landscape of the gene networks.

  13. Resource management research in Passive Optical Networks (PON)

    OpenAIRE

    Garfias Hernández, Paola

    2013-01-01

    Next Generation Access Networks (NGAN) are the new step forward to deliver broadband services and to facilitate the integration of different technologies. It is plausible to assume that, from a technological standpoint, the Future Internet will be composed of long-range high-speed optical networks; a number of wireless networks at the edge; and, in between, several access technologies, among which, the Passive Optical Networks (xPON) are very likely to succeed, due to their simplicity, low-co...

  14. Introduction of Spectrally and Spatially Flexible Optical Networks

    DEFF Research Database (Denmark)

    Xia, Tiejun J.; Fevrier, Herve; Wang, Ting

    2015-01-01

    Given the introduction of coherent 100G systems has provided enough fiber capacity to meet data traffic growth in the near term, enhancing network efficiency will be service providers' high priority. Adding flexibility at the optical layer is a key step to increasing network efficiency, and both...... spectral and spatial functionality will be considered in next generation optical networks along with advanced network management to effectively harness the new capabilities....

  15. Software-Programmed Optical Networking with Integrated NFV Service Provisioning

    DEFF Research Database (Denmark)

    Mehmeri, Victor; Wang, Xi; Basu, Shrutarshi

    2017-01-01

    We showcase demonstrations of “program & compile” styled optical networking as well as open platforms & standards based NFV service provisioning using a proof-of-concept implementation of the Software-Programmed Networking Operating System (SPN OS).......We showcase demonstrations of “program & compile” styled optical networking as well as open platforms & standards based NFV service provisioning using a proof-of-concept implementation of the Software-Programmed Networking Operating System (SPN OS)....

  16. Fault Detection for Wireless Networked Control Systems with Stochastic Switching Topology and Time Delay

    Directory of Open Access Journals (Sweden)

    Pengfei Guo

    2014-01-01

    Full Text Available This paper deals with the fault detection problem for a class of discrete-time wireless networked control systems described by switching topology with uncertainties and disturbances. System states of each individual node are affected not only by its own measurements, but also by other nodes’ measurements according to a certain network topology. As the topology of system can be switched in a stochastic way, we aim to design H∞ fault detection observers for nodes in the dynamic time-delay systems. By using the Lyapunov method and stochastic analysis techniques, sufficient conditions are acquired to guarantee the existence of the filters satisfying the H∞ performance constraint, and observer gains are derived by solving linear matrix inequalities. Finally, an illustrated example is provided to verify the effectiveness of the theoretical results.

  17. A Time-Varied Probabilistic ON/OFF Switching Algorithm for Cellular Networks

    KAUST Repository

    Rached, Nadhir B.; Ghazzai, Hakim; Kadri, Abdullah; Alouini, Mohamed-Slim

    2018-01-01

    In this letter, we develop a time-varied probabilistic on/off switching planning method for cellular networks to reduce their energy consumption. It consists in a risk-aware optimization approach that takes into consideration the randomness of the user profile associated with each base station (BS). The proposed approach jointly determines (i) the instants of time at which the current active BS configuration must be updated due to an increase or decrease of the network traffic load, and (ii) the set of minimum BSs to be activated to serve the networks’ subscribers. Probabilistic metrics modeling the traffic profile variation are developed to trigger this dynamic on/off switching operation. Selected simulation results are then performed to validate the proposed algorithm for different system parameters.

  18. A Time-Varied Probabilistic ON/OFF Switching Algorithm for Cellular Networks

    KAUST Repository

    Rached, Nadhir B.

    2018-01-11

    In this letter, we develop a time-varied probabilistic on/off switching planning method for cellular networks to reduce their energy consumption. It consists in a risk-aware optimization approach that takes into consideration the randomness of the user profile associated with each base station (BS). The proposed approach jointly determines (i) the instants of time at which the current active BS configuration must be updated due to an increase or decrease of the network traffic load, and (ii) the set of minimum BSs to be activated to serve the networks’ subscribers. Probabilistic metrics modeling the traffic profile variation are developed to trigger this dynamic on/off switching operation. Selected simulation results are then performed to validate the proposed algorithm for different system parameters.

  19. Guaranteed cost control of mobile sensor networks with Markov switching topologies.

    Science.gov (United States)

    Zhao, Yuan; Guo, Ge; Ding, Lei

    2015-09-01

    This paper investigates the consensus seeking problem of mobile sensor networks (MSNs) with random switching topologies. The network communication topologies are composed of a set of directed graphs (or digraph) with a spanning tree. The switching of topologies is governed by a Markov chain. The consensus seeking problem is addressed by introducing a global topology-aware linear quadratic (LQ) cost as the performance measure. By state transformation, the consensus problem is transformed to the stabilization of a Markovian jump system with guaranteed cost. A sufficient condition for global mean-square consensus is derived in the context of stochastic stability analysis of Markovian jump systems. A computational algorithm is given to synchronously calculate both the sub-optimal consensus controller gains and the sub-minimum upper bound of the cost. The effectiveness of the proposed design method is illustrated by three numerical examples. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  20. Fibre and components induced limitations in high capacity optical networks

    DEFF Research Database (Denmark)

    Peucheret, Christophe

    2003-01-01

    The design of future all-optical networks relies on the knowledge of the physical layer transport properties. In this thesis, we focus on two types of system impairments: those induced by the non-ideal transfer functions of optical filters to be found in network elements such as optical add...... design in order to maximise the spectral efficiency in a four add-drop node ring network. The concept of "normalised transmission sections" is introduced in order to ease the dimensioning of transparent domains in future all-optical networks. Normalised sections based on standard single mode fibre (SMF......-drop multiplexers (OADM) and optical cross-connects (OXC), as well as those due to the interaction of group-velocity dispersion, optical fibre non-linearities and accumulation of amplifier noise in the transmission path. The dispersion of fibre optics components is shown to limit their cascadability. Dispersion...