WorldWideScience

Sample records for gmpls optical router

  1. 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.

  2. Wavelength-Converter Saving Span Restoration in GMPLS Controlled WDM Optical Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Buron, Jakob Due; Andriolli, N.

    2006-01-01

    We present two label preference schemes to reduce wavelength-conversion during restoration path setup in GMPLS controlled optical networks exploiting span restoration. The amount of required wavelength-conversions can be reduced up to 34 percent.......We present two label preference schemes to reduce wavelength-conversion during restoration path setup in GMPLS controlled optical networks exploiting span restoration. The amount of required wavelength-conversions can be reduced up to 34 percent....

  3. 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...

  4. Blocking Reduction of Span Restoration Requests in GMPLS Controlled WDM Optical Networks

    DEFF Research Database (Denmark)

    Buron, Jakob Due; Ruepp, Sarah Renée; Andriolli, N.

    2006-01-01

    The proposed label preference scheme reduces blocking of span restoration requests in GMPLS optical networks with limited wavelength conversion. By minimizing resource contention and conversion usage, it increases recovery percentage and reduces control plane load.......The proposed label preference scheme reduces blocking of span restoration requests in GMPLS optical networks with limited wavelength conversion. By minimizing resource contention and conversion usage, it increases recovery percentage and reduces control plane load....

  5. Energy-Aware Routing Optimization in Dynamic GMPLS Controlled Optical Networks

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Ricciardi, Sergio; Fagertun, Anna Manolova

    2012-01-01

    In this paper, routing optimizations based on energy sources are proposed in dynamic GMPLS controlled optical networks. The influences of re-routing and load balancing factors on the algorithm are evaluated, with a focus on different re-routing thresholds. Results from dynamic network simulations...

  6. 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.

  7. Four-port mode-selective silicon optical router for on-chip optical interconnect.

    Science.gov (United States)

    Jia, Hao; Zhou, Ting; Fu, Xin; Ding, Jianfeng; Zhang, Lei; Yang, Lin

    2018-04-16

    We propose and demonstrate a four-port mode-selective optical router on a silicon-on-insulator platform. The passive routing property ensures that the router consumes no power to establish the optical links. For each port, input signals with different modes are selectively routed to the target ports through the pre-designed architecture. In general, the device intrinsically supports broadcasting of multiplexed signals from one port to the other three ports through mode division multiplexing. In some applications, the input signal from one port would only be sent to another port as in reconfigurable optical routers. The prototype is constructed by mode multiplexers/de-multiplexers and single-mode interconnect waveguides between them. The insertion losses for all optical links are lower than 8.0 dB, and the largest optical crosstalk values are lower than -18.7 dB and -22.0 dB for the broadcasting and port-to-port routing modes, respectively, at the wavelength range of 1525-1565 nm. In order to verify the routing functionality, a 40-Gbps bidirectional data transmission experiment is performed. The device offers a promising building block for passive routing by utilizing the dimension of the modes.

  8. Resource-efficient linear-optical quantum router

    Czech Academy of Sciences Publication Activity Database

    Lemr, K.; Bartkiewicz, K.; Černoch, A.; Soubusta, Jan

    2013-01-01

    Roč. 87, č. 6 (2013), "062333-1"-"062333-7" ISSN 1050-2947 Institutional research plan: CEZ:AV0Z10100522 Keywords : quantum router * signal qubit * quantum communications Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.991, year: 2013

  9. An Experiment of GMPLS-Based Dispersion Compensation Control over In-Field Fibers

    Science.gov (United States)

    Seno, Shoichiro; Horiuchi, Eiichi; Yoshida, Sota; Sugihara, Takashi; Onohara, Kiyoshi; Kamei, Misato; Baba, Yoshimasa; Kubo, Kazuo; Mizuochi, Takashi

    As ROADMs (Reconfigurable Optical Add/Drop Multiplexers) are becoming widely used in metro/core networks, distributed control of wavelength paths by extended GMPLS (Generalized MultiProtocol Label Switching) protocols has attracted much attention. For the automatic establishment of an arbitrary wavelength path satisfying dynamic traffic demands over a ROADM or WXC (Wavelength Cross Connect)-based network, precise determination of chromatic dispersion over the path and optimized assignment of dispersion compensation capabilities at related nodes are essential. This paper reports an experiment over in-field fibers where GMPLS-based control was applied for the automatic discovery of chromatic dispersion, path computation, and wavelength path establishment with dynamic adjustment of variable dispersion compensation. The GMPLS-based control scheme, which the authors called GMPLS-Plus, extended GMPLS's distributed control architecture with attributes for automatic discovery, advertisement, and signaling of chromatic dispersion. In this experiment, wavelength paths with distances of 24km and 360km were successfully established and error-free data transmission was verified. The experiment also confirmed path restoration with dynamic compensation adjustment upon fiber failure.

  10. Deflection routing scheme for GMPLS-based OBS networks

    DEFF Research Database (Denmark)

    Eid, Arafat; Mahmood, Waqar; Alomar, Anwar

    2010-01-01

    Integrating the Generalized Multi-Protocol Label Switching (GMPLS) framework into an Optical Burst Switching (OBS) Control Plane is a promising solution to alleviating most of OBS performance and design issues. However, implementing the already proposed OBS deflection routing schemes is not appli...

  11. The fiber optics router apply to the control system of HIRFL-CSR

    International Nuclear Information System (INIS)

    Zhang Shuocheng; Wang Dan; Jing Lan; Qiao Weimin; Ma Yunhai

    2006-01-01

    The authors introduced a kind of Fiber Optic Router that we had designed specially applies to the engineering HIRFL-CSR (Heavy Ion Research Facility in Lanzhou). Including design principle, operational principle, and hardware construction, field of application. The router has standard communication interface such as RS232, RS485, Ethernet and Optics; setup of an optical communication network is simplified. It solved problems such as communication disturb. The requirements of control in the national great science engineering HIRFL-CSR are fulfilled. (authors)

  12. Linear-optical programmable quantum router

    Czech Academy of Sciences Publication Activity Database

    Lemr, K.; Černoch, Antonín

    2013-01-01

    Roč. 300, JUL (2013), s. 282-285 ISSN 0030-4018 R&D Projects: GA ČR GAP205/12/0382 Institutional research plan: CEZ:AV0Z10100522 Keywords : quantum router * quantum information processing * photon pairs * quantum communications * programmable phase gate Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.542, year: 2013 http://ac.els-cdn.com/S0030401813002563/1-s2.0-S0030401813002563-main.pdf?_tid=d1f7d17a-66e9-11e3-aa5e-00000aab0f6c&acdnat=1387264198_99aef4d40cf81f69

  13. Multi-functional quantum router using hybrid opto-electromechanics

    Science.gov (United States)

    Ma, Peng-Cheng; Yan, Lei-Lei; Chen, Gui-Bin; Li, Xiao-Wei; Liu, Shu-Jing; Zhan, You-Bang

    2018-03-01

    Quantum routers engineered with multiple frequency bands play a key role in quantum networks. We propose an experimentally accessible scheme for a multi-functional quantum router, using photon-phonon conversion in a hybrid opto-electromechanical system. Our proposed device functions as a bidirectional, tunable multi-channel quantum router, and demonstrates the possibility to route single optical photons bidirectionally and simultaneously to three different output ports, by adjusting the microwave power. Further, the device also behaves as an interswitching unit for microwave and optical photons, yielding probabilistic routing of microwave (optical) signals to optical (microwave) outports. With respect to potential application, we verify the insignificant influence from vacuum and thermal noises in the performance of the router under cryogenic conditions.

  14. 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.

  15. RS485 optical router for HIRFL-CSR

    International Nuclear Information System (INIS)

    Zhang Shuocheng; Wang Dan; Jing Lan; Qiao Weimin

    2007-01-01

    A communication equipment-RS485 optical router has been developed to satisfy requirements of control system communication network of HIRFL-CSR (Heavy Ion Research Facility at Lanzhou-Cooling Storage Ring). The equipment is compatible with multiple communication protocols, such as Ethernet, RS232 and RS485 standard. It can be used to setup the RS485 communication network quickly and connected to the Ethernet easily. The fiber optical interface is introduced to facilitate the connection with the network of industrial Fiber Optics Communication (FOC), which expands the application field of the equipment in a large extent. This paper introduces the details of the equipment, including the design of the circuit and software, features of the equipment and how it works in the whole control system network. Its application in the HIRFL-CSR control system shows that the equipment is in accordance with the general requirement of automatic control communication system. It could also be used in other industrial automatic control fields. (authors)

  16. Complementary Walsh-Hadamard coded optical CDMA coder/decoders structured over arrayed-waveguide grating routers

    Science.gov (United States)

    Huang, Jen-Fa; Yang, Chao-Chin; Tseng, Shin-Pin

    2004-01-01

    In this paper, an optical code-division multiple-access (OCDMA) system with complementary Walsh-Hadamard coded optical encoder/decoder configuration structured over arrayed-waveguide grating (AWG) routers is examined. In the proposed system, each network user requires only two AWG routers to accomplish spectral encoding and decoding for complementary keying, thus, resulting a simpler and low cost system. Performance of the proposed system is analyzed by taking the effect of phase-induced intensity noise into account. The result indicates that the established system not only preserves the capability of suppressing multiple-access interference (MAI), but also improves bit-error-rate performance as compared to the conventional coders employing simple on-off keying.

  17. Increasing Restorability for Local-to-Egress Restoration in GMPLS Controlled Networks with Limited Wavelength Conversion

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Buron, Jakob Due; Andriolli, N.

    2006-01-01

    We study the performance of the local-to-egress restoration method in GMPLS controlled optical networks, when a limited number of wavelength converters are available. We evaluate the recovery percentage for a converter-saving label assignment scheme and compare its performance to a simple scheme...

  18. A design for an internet router with a digital optical data plane

    Science.gov (United States)

    Touch, Joe; Bannister, Joseph; Suryaputra, Stephen; Willner, Alan E.

    2013-12-01

    This paper presents a complete design for an optical Internet router based on decomposing the steps required for IP packet forwarding. Implementations of hopcount decrement and header matching are integrated with a simulation-based approach to variable-length packet merging that avoids recirculation, resulting in an all-optical data plane. A method for IPv4 checksum computation is introduced, and this and previously designed components are extended from binary to higher-density (multiple bits per symbol) encodings. The implications of this design are considered, including the potential for chip-level and system integration, as well as the requirements of basic optical processing components.

  19. PERANGKAT LUNAK SEMI HOT STANDBY ROUTER PROTOCOL PADA PC ROUTER BERBASIS LINUX

    Directory of Open Access Journals (Sweden)

    Nur Aini Rakhmawati

    2005-01-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Router memegang peranan penting dalam sebuah jaringan. Jika router mengalami suatu masalah dapat berakibat terhambatnya lalu lintas data dalam suatu jaringan. Untuk mengatasi masalah sebuah router, Cisco mengembangkan suatu sistem Hot Standby Router Protocol (HSRP. Namun HSRP ini belum dimiliki oleh router komputer. Padahal harga komputer lebih murah daripada router hardware. Semi HSRP merupakan suatu metode yang diimplementasikan pada router komputer dengan keterbatasan yang dimiliki oleh sebuah komputer dimana sebuahrouter komputer tidak dapat mengirimkan pesan resign yang mengijikan router lain untuk menggantikannyaketika router komputer ini mengalami kegagalan. Dalam semi HSRP dibentuk suatu kelompok router yang memiliki subnet yang sama pada masing-masing interfacenya.Pada masing-masing router dijalankan aplikasi yang berfungsi untuk mengatur jalannya mekanisme HSRP. Aplikasi ini memungkinkan router-router tersebut dapat berhubungan untuk mengetahui apakah ada masalah yang terjadi pada router utama yang berfungsi untuk meneruskan data klien dengan menggunakan alamat virtual IP dan MAC. Dalam berhubungan router-router tersebut menggunakan komunikasi broadcast. Ketika router utama mengalami kegagalan maka

  20. Restoration in multi-domain GMPLS-based networks

    DEFF Research Database (Denmark)

    Manolova, Anna; Ruepp, Sarah Renée; Dittmann, Lars

    2011-01-01

    In this paper, we evaluate the efficiency of using restoration mechanisms in a dynamic multi-domain GMPLS network. Major challenges and solutions are introduced and two well-known restoration schemes (End-to-End and Local-to-End) are evaluated. Additionally, new restoration mechanisms are introdu......In this paper, we evaluate the efficiency of using restoration mechanisms in a dynamic multi-domain GMPLS network. Major challenges and solutions are introduced and two well-known restoration schemes (End-to-End and Local-to-End) are evaluated. Additionally, new restoration mechanisms...... are introduced: one based on the position of a failed link, called Location-Based, and another based on minimizing the additional resources consumed during restoration, called Shortest-New. A complete set of simulations in different network scenarios show where each mechanism is more efficient in terms, such as...

  1. A Design for an Internet Router with a Digital Optical Data Plane

    Directory of Open Access Journals (Sweden)

    Joe Touch

    2017-02-01

    Full Text Available This paper presents a complete design for an optical Internet router based on the component steps required for Internet protocol (IP packet forwarding. Implementations of hop count decrement and header matching are integrated with a simulation-based approach to variable-length packet traffic merging that avoids recirculation, demonstrating an approach for an all-optical data plane. A method for IPv4 checksum computation is introduced, and this and previously designed components are extended from binary to higher-density (multiple bits per symbol encodings. The implications of this design are considered, including the potential for chip-level and system integration, as well as the requirements of basic optical processing components.

  2. Guide to Cisco Routers Configuration Becoming a Router Geek

    CERN Document Server

    Alani, Mohammed M

    2012-01-01

    This work provides a guide to the configuration of Cisco routers, from tasks for beginners to advanced operations. A collection of detailed "how-to" instructions are presented, which will be of use to all professionals and students who engage with Cisco routers in the field or in the lab. The guide starts with the simple step-by-step task of connecting the router and performing basic configuration, before building up to complex and sensitive operations such as router IOS upgrade and Site-to-Site VPNs.

  3. Final Report - Dynamic Path Scheduling through Extensions to Generalized Multiprotocol Label Switching (GMPLS)

    Energy Technology Data Exchange (ETDEWEB)

    Principal Investigator: Dr. Abdella Battou

    2009-05-22

    The major accomplishments of the project are the successful software implementation of the Phase I scheduling algorithms for GMPLS Label Switched Paths (LSPs) and the extension of the IETF Path Computation Element (PCE) Protocol to support scheduling extensions. In performing this work, we have demonstrated the theoretical work of Phase I, analyzed key issues, and made relevant extensions. Regarding the software implementation, we developed a proof of concept prototype as part of our Algorithm Evaluation System (AES). This implementation uses the Linux operating system to provide software portability and will be the foundation for our commercial software. To demonstrate proof of concept, we have implemented LSP scheduling algorithms to support two of the key GMPLS switching technologies (Lambda and Packet) and support both Fixed Path (FP) and Switched Path (SP) routing. We chose Lambda and Packet because we felt it was essential to include both circuit and packet switching technologies as well as to address all-optical switching in the study. As conceptualized in Phase I, the FP algorithms use a traditional approach where the LSP uses the same physical path for the entire service duration while the innovative SP algorithms allow the physical path to vary during the service duration. As part of this study, we have used the AES to conduct a performance analysis using metro size networks (up to 32 nodes) that showed that these algorithms are suitable for commercial implementation. Our results showed that the CPU time required to compute an LSP schedule was small compared to expected inter-arrival time between LSP requests. Also, when the network size increased from 7 to 15 to 32 nodes with 10, 26, and 56 TE links, the CPU processing time showed excellent scaling properties. When Fixed Path and Switched Path routing were compared, SP provided only modestly better performance with respect to LSP completion rate, service duration, path length, and start time deviation

  4. Analysis of a time-lens based optical frame synchronizer and retimer for 10G Ethernet aiming at a Tb/s optical router/switch design

    DEFF Research Database (Denmark)

    Laguardia Areal, Janaina; Hu, Hao; Peucheret, Christophe

    2010-01-01

    This paper analyzes experimentally and by numerical simulations an optical frame retimer and synchronizer unit for 10 Gbit/s Ethernet input frames. The unit is envisaged to be applied in the design of an optically transparent router for Optical Time Division Multiplexed (OTDM) links, aggregating...... traffic from several 10 Gbit/s Ethernet (10 GE) links. The scheme is based on time-lenses implemented through a combination of a sinusoidally driven optical phase modulation and linear dispersion. Our analysis extracts the operation range of the scheme used for synchronization and retiming in the context...

  5. Epidemic Propagation of Control Plane Failures in GMPLS Controlled Optical Transport Networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Fagertun, Anna Manolova

    2013-01-01

    In this paper, we investigate the behaviour of a dataplane-decoupled GMPLS control plane, when it is affected by failures that spread in the network in an epidemic manner. In particular, we consider network nodes to be either fully functional, or having a failed control plane, or having both...... a failed control and data plane. Through large-scale network simulation, we evaluate the effect of epidemically spreading control plane failures in terms of blocked connections requests and the amount of stranded capacity due to a dysfunctional control plane. Furthermore, we investigate the effect...... of the epidemic and the epidemic spreading intensity. In particular, networks with long epidemic durations do not necessarily result in worst performance in terms of blocked requests and capacity. Also epidemic scenarios, resulting in worst impact on the network availability does not necessarily result in worst...

  6. Location-based restoration mechanism for multi-domain GMPLS networks

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Calle, Eusibi; Ruepp, Sarah Renée

    2009-01-01

    In this paper we propose and evaluate the efficiency of a location-based restoration mechanism in a dynamic multi-domain GMPLS network. We focus on inter-domain link failures and utilize the correlation between the actual position of a failed link along the path with the applied restoration...

  7. Advanced router architectures

    CERN Document Server

    Kloth, Axel K

    2005-01-01

    Routers, switches, and transmission equipment form the backbone of the Internet, yet many users and service technicians do not understand how these nodes really work.Advanced Router Architectures addresses how components of advanced routers work together and how they are integrated with each other. This book provides the background behind why these building blocks perform certain functions, and how the function is implemented in general use. It offers an introduction to the subject matter that is intended to trigger deeper interest from the reader. The book explains, for example, why traffic m

  8. QoS Enabled Resource Allocation Over an UPnP-QoS - GMPLS Controlled Edge

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Sköldström, Pontus; Gavler, Anders

    2011-01-01

    This paper focuses on the problem of coherent resource allocation within home and access networks. The interdomain QoS signaling discussed here enables the initiation of the QoS provisioning in the home and access from the end device in users home. The home network considered in this paper is UPn......P-QoS enabled while the access network is GMPLS based. We propose and implement an interface between aforementioned network segments allowing for end-to-end QoS establishment. We present the QoS parameters and mechanisms in both UPnP-QoS and GMPLS and how they can be matched to create a coherent Qo...

  9. Mobile Router Developed and Tested

    Science.gov (United States)

    Ivancic, William D.

    2002-01-01

    The NASA Glenn Research Center, under a NASA Space Act Agreement with Cisco Systems, has been performing joint networking research to apply Internet-based technologies and protocols to space-based communications. As a result of this research, NASA performed stringent performance testing of the mobile router, including the interaction of routing and the transport-level protocol. In addition, Cisco Systems developed the mobile router for both commercial and Government markets. The code has become part of the Cisco Systems Internetworking Operating System (IOS) as of release 12.2 (4) T--which will make this capability available to the community at large. The mobile router is software code that resides in a network router and enables entire networks to roam while maintaining connectivity to the Internet. This router code is pertinent to a myriad of applications for both Government and commercial sectors, including the "wireless battlefield." NASA and the Department of Defense will utilize this technology for near-planetary observation and sensing spacecraft. It is also a key enabling technology for aviation-based information applications. Mobile routing will make it possible for information such as weather, air traffic control, voice, and video to be transmitted to aircraft using Internet-based protocols. This technology shows great promise in reducing congested airways and mitigating aviation disasters due to bad weather. The mobile router can also be incorporated into emergency vehicles (such as ambulances and life-flight aircraft) to provide real-time connectivity back to the hospital and health-care experts, enabling the timely application of emergency care. Commercial applications include entertainment services, Internet protocol (IP) telephone, and Internet connectivity for cruise ships, commercial shipping, tour buses, aircraft, and eventually cars. A mobile router, which is based on mobile IP, allows hosts (mobile nodes) to seamlessly "roam" among various IP

  10. Quality of Service Control Based on Virtual Private Network Services in a Wide Area Gigabit Ethernet Optical Test Bed

    Science.gov (United States)

    Rea, Luca; Pompei, Sergio; Valenti, Alessandro; Matera, Francesco; Zema, Cristiano; Settembre, Marina

    We report an experimental investigation about the Virtual Private LAN Service technique to guarantee the quality of service in the metro/core network and also in the presence of access bandwidth bottleneck. We also show how the virtual private network can be set up for answering to a user request in a very fast way. The tests were performed in a GMPLS test bed with GbE core routers linked with long (tens of kilometers) GbE G.652 fiber links.

  11. OSPF-TE Extensions for Green Routing in Optical Networks

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Ricciardi, S.; Fagertun, Anna Manolova

    2012-01-01

    This paper proposes extensions to the OSPF-TE protocol to enable green routing in GMPLS-controlled optical networks. Simulation results show a remarkable reduction in CO2 emissions by preferring network elements powered by green energy sources in the connection routing.......This paper proposes extensions to the OSPF-TE protocol to enable green routing in GMPLS-controlled optical networks. Simulation results show a remarkable reduction in CO2 emissions by preferring network elements powered by green energy sources in the connection routing....

  12. Router Agent Technology for Policy-Based Network Management

    Science.gov (United States)

    Chow, Edward T.; Sudhir, Gurusham; Chang, Hsin-Ping; James, Mark; Liu, Yih-Chiao J.; Chiang, Winston

    2011-01-01

    This innovation can be run as a standalone network application on any computer in a networked environment. This design can be configured to control one or more routers (one instance per router), and can also be configured to listen to a policy server over the network to receive new policies based on the policy- based network management technology. The Router Agent Technology transforms the received policies into suitable Access Control List syntax for the routers it is configured to control. It commits the newly generated access control lists to the routers and provides feedback regarding any errors that were faced. The innovation also automatically generates a time-stamped log file regarding all updates to the router it is configured to control. This technology, once installed on a local network computer and started, is autonomous because it has the capability to keep listening to new policies from the policy server, transforming those policies to router-compliant access lists, and committing those access lists to a specified interface on the specified router on the network with any error feedback regarding commitment process. The stand-alone application is named RouterAgent and is currently realized as a fully functional (version 1) implementation for the Windows operating system and for CISCO routers.

  13. 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.

  14. Traffic engineering and regenerator placement in GMPLS networks with restoration

    Science.gov (United States)

    Yetginer, Emre; Karasan, Ezhan

    2002-07-01

    In this paper we study regenerator placement and traffic engineering of restorable paths in Generalized Multipro-tocol Label Switching (GMPLS) networks. Regenerators are necessary in optical networks due to transmission impairments. We study a network architecture where there are regenerators at selected nodes and we propose two heuristic algorithms for the regenerator placement problem. Performances of these algorithms in terms of required number of regenerators and computational complexity are evaluated. In this network architecture with sparse regeneration, offline computation of working and restoration paths is studied with bandwidth reservation and path rerouting as the restoration scheme. We study two approaches for selecting working and restoration paths from a set of candidate paths and formulate each method as an Integer Linear Programming (ILP) prob-lem. Traffic uncertainty model is developed in order to compare these methods based on their robustness with respect to changing traffic patterns. Traffic engineering methods are compared based on number of additional demands due to traffic uncertainty that can be carried. Regenerator placement algorithms are also evaluated from a traffic engineering point of view.

  15. Exploring crosstalk noise generated in the N-port router used in the WDM-based ONoC

    Science.gov (United States)

    Zhang, Zhendong; Xie, Yiyuan; Song, Tingting; He, Chao; Li, Jiachao; Liu, Yong

    2017-07-01

    Compared with optical network-on-chip (ONoC) with single wavelength, ONoC adopting wavelength division multiplexing (WDM) technology possesses a very prominent advantage-higher bandwidth. Therefore, WDM-based ONoC has been considered one of the most promising ways to relieve the rapidly increasing traffic load in communication systems. A WDM-based router, as the core equipment of WDM-based ONoC, is influenced by crosstalk noise, especially the nonlinear crosstalk noise generated by the four-wave mixing effect. Thus, to explore the performance of the N-port nonblocking optical router using WDM, we propose a universal analytic model to analyze the transmission loss, crosstalk noise, optical signal-to-noise ratio (OSNR), and bit error ratio (BER). The research results show that crosstalk noise varies along with signals at different wavelengths in the same channel. For signals with the same wavelength, the noises generated in the different transmission paths are obviously different from each other. For research of transmission loss, OSNR, and BER, similar results can be obtained. Based on the eye diagrams, we can learn that crosstalk noise will cause signal distortion to a certain extent. With this model, capability of this kind of multiport optical router using WDM can be understood conveniently.

  16. Spacewire Routers Implemented with FPGA Technology

    Science.gov (United States)

    Habinc, Sandi; Isomaki, Marko

    2011-08-01

    Routers are an integral part of SpaceWire networks. Aeroflex Gaisler has developed a highly configurable SpaceWire router VHDL IP core to meet the needs for technology independent router designs. The main design goals have been configurability, technology independence, support of the standard and expandability. The IP core being technologically independent allows it to be used in both ASIC and FPGA technology. The latter is now being used to produce versatile standard products that can reach the market faster than for example an ASIC based product.

  17. Next Generation to Connect the Wi-Fi with IEEE Cloud Router

    OpenAIRE

    Kaur, Ramandeep

    2014-01-01

    The Wi-Fi has many features for internet access. There are many Wi-Fi technologies are used with the help of router. He latest router is AC router, it is also known as 802.11AC router with many benefits include speed, band etc. Ac router offers the ultimate performance and excellent bandwidth with antennas compare of N router (802.11N router).It is also upgrade the previous technology network. The wireless communication devices are upgrade time to time. Ac router is beneficial for HD videos...

  18. A Comparative Evaluation of Algorithms in the Implementation of an Ultra-Secure Router-to-Router Key Exchange System

    Directory of Open Access Journals (Sweden)

    Nishaal J. Parmar

    2017-01-01

    Full Text Available This paper presents a comparative evaluation of possible encryption algorithms for use in a self-contained, ultra-secure router-to-router communication system, first proposed by El Rifai and Verma. The original proposal utilizes a discrete logarithm-based encryption solution, which will be compared in this paper to RSA, AES, and ECC encryption algorithms. RSA certificates are widely used within the industry but require a trusted key generation and distribution architecture. AES and ECC provide advantages in key length, processing requirements, and storage space, also maintaining an arbitrarily high level of security. This paper modifies each of the four algorithms for use within the self-contained router-to-router environment system and then compares them in terms of features offered, storage space and data transmission needed, encryption/decryption efficiency, and key generation requirements.

  19. Adaptación del uso de routers CISCO en prácticas de laboratorio a routers Open-Source

    OpenAIRE

    Egea Chueca, Héctor

    2011-01-01

    En este proyecto fin de carrera se comprueba en qué medida una solución de router open-source, puede sustituir a routers CISCO en un entorno de laboratorio. Se podrá ver algunos de los servicios de los que dispone el sistema Vyatta en su versión gratuita, comprobando que puede realizar muchas de las funciones de los routers CISCO. Para ello, primero se hará una comparación de las diferentes opciones que existen a la hora de elegir un open-source routing, explicando qué es, cómo...

  20. Analysis Of Default Passwords In Routers Against Brute-Force Attack

    Directory of Open Access Journals (Sweden)

    Mohammed Farik

    2015-08-01

    Full Text Available Abstract Password authentication is the main means of access control on network routers and router manufacturers provide a default password for initial login to the router. While there has been many publications regarding the minimum requirements of a good password how widely the manufacturers themselves are adhering to the minimum standards and whether these passwords can withstand brute-force attack are not widely known. The novelty of this research is that this is the first time default passwords have been analyzed and documented from such a large variety of router models to reveal password strengths or weaknesses against brute-force attacks. Firstly individual default router password of each model was collected tabulated and tested using password strength meter for entropy. Then descriptive statistical analysis was performed on the tabulated data. The analysis revealed quantitatively how strong or weak default passwords are against brute-force attacks. The results of this research give router security researchers router manufacturers router administrators a useful guide on the strengths and weaknesses of passwords that follow similar patterns.

  1. Accounting for PMD Temporal Correlation During Lightpath Set Up in Transparent Optical Networks

    DEFF Research Database (Denmark)

    Sambo, Nicola; Secondini, Marco; Andriolli, Nicola

    2010-01-01

    stochastic characteristics. Moreover, PMD depends on time-variant factors, such as the temperature and the fiber stress. When implementing a dynamic GMPLS-controlled transparent optical network, the GMPLS protocol suite must take into account physical impairment information in order to establish lightpaths......In transparent optical networks, the signal transmission is degraded by optical layer physical impairments. Therefore, lightpaths may be blocked due to unacceptable quality of transmission (QoT). Among physical impairments, polarization mode dispersion (PMD) is a detrimental effect which has...... that PTC scheme significantly reduces the lightpath blocking probability with respect to the classical scheme. Moreover, PTC demonstrates that, by considering PMD temporal correlation, the transparency domain size can be increased, since paths that would be rejected by a classical model can be actually...

  2. ALPHA: Proposal of Mapping QoS Parameters between UPnP Home Network and GMPLS Access

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy; Sköldström, Pontus; Gavler, Anders

    2011-01-01

    This paper is treating the interdomain QoS signaling between the home and access domains with a focus on applying it for providing QoS between a UPnP-QoS based home network and GMPLS based access network. The work presented here is defining a possible approach for an interface between UPn...

  3. 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

  4. Auto-Configuration of Cisco Routers with Application Software

    National Research Council Canada - National Science Library

    Prado, Alexandre

    2003-01-01

    .... These parameters are dynamic, so they must be uploaded into the Cisco routers to take effect. The focus is on determining the most efficient way of communicating between the Cisco routers and the SAAM system...

  5. Security Engine Management of Router based on Security Policy

    OpenAIRE

    Su Hyung Jo; Ki Young Kim; Sang Ho Lee

    2007-01-01

    Security management has changed from the management of security equipments and useful interface to manager. It analyzes the whole security conditions of network and preserves the network services from attacks. Secure router technology has security functions, such as intrusion detection, IPsec(IP Security) and access control, are applied to legacy router for secure networking. It controls an unauthorized router access and detects an illegal network intrusion. This paper re...

  6. Router Designs for an Asynchronous Time-Division-Multiplexed Network-on-Chip

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia; Sparsø, Jens; Sørensen, Rasmus Bo

    2013-01-01

    In this paper we explore the design of an asynchronous router for a time-division-multiplexed (TDM) network-on-chip (NOC) that is being developed for a multi-processor platform for hard real-time systems. TDM inherently requires a common time reference, and existing TDM-based NOC designs are either....... This adds hardware complexity and increases area and power consumption. We propose to use asynchronous routers in order to achieve a simpler, more robust and globally-asynchronous NOC, and this represents an unexplored point in the design space. The paper presents a range of alternative router designs. All...... routers have been synthesized for a 65nm CMOS technology, and the paper reports post-layout figures for area, speed and energy and compares the asynchronous designs with an existing mesochronous clocked router. The results show that an asynchronous router is 2 times smaller, marginally slower...

  7. On the efficiency of BGP-TE extensions for GMPLS multi-domain routing

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée; Buron, Jakob Due

    2009-01-01

    This paper evaluates the efficiency of set of modifications to the border gateway protocol (BGP) which aim at providing flexible traffic engineering (TE) across multiple GMPLS domains. A short overview and analysis of existing proposals for BGP-TE extensions is presented. Based on that, three...... modifications are proposed for support of multi-domain TE: an end-to-end path-specific TE attribute, a border node attribute and a behavioral modification of the protocol. Via analysis and extensive simulations we show that the proposed enhancements successfully improve the most significant BGP drawbacks...

  8. AC Power Local Network with Multiple Power Routers

    Directory of Open Access Journals (Sweden)

    Ryo Takahashi

    2013-12-01

    Full Text Available Controlling power flow and achieving appropriate matching between power sources and loads according to the quality of energy is expected to be one of the approaches to reduce wasted energy consumption. A power router, proposed recently, has the capability of realizing circuit switching in a power distribution network. This study focuses on the feasibility of an AC power routing network system composed of multiple power routers. To evaluate the feasibility, we experimentally confirm the circuit switching operation of the parallel and series configurations of the power routers, so that the network system can be designed by the combination of parallel and series configurations.

  9. Stochastic Stability in Internet Router Congestion Games

    Science.gov (United States)

    Chung, Christine; Pyrga, Evangelia

    Congestion control at bottleneck routers on the internet is a long standing problem. Many policies have been proposed for effective ways to drop packets from the queues of these routers so that network endpoints will be inclined to share router capacity fairly and minimize the overflow of packets trying to enter the queues. We study just how effective some of these queuing policies are when each network endpoint is a self-interested player with no information about the other players’ actions or preferences. By employing the adaptive learning model of evolutionary game theory, we study policies such as Droptail, RED, and the greedy-flow-punishing policy proposed by Gao et al. [10] to find the stochastically stable states: the states of the system that will be reached in the long run.

  10. Switch/router architectures shared-bus and shared-memory based systems

    CERN Document Server

    Aweya, James

    2018-01-01

    A practicing engineer's inclusive review of communication systems based on shared-bus and shared-memory switch/router architectures. This book delves into the inner workings of router and switch design in a comprehensive manner that is accessible to a broad audience. It begins by describing the role of switch/routers in a network, then moves on to the functional composition of a switch/router. A comparison of centralized versus distributed design of the architecture is also presented. The author discusses use of bus versus shared-memory for communication within a design, and also covers Quality of Service (QoS) mechanisms and configuration tools. Written in a simple style and language to allow readers to easily understand and appreciate the material presented, Switch/Router Architectures: Shared-Bus and Shared-Memory Based Systems discusses the design of multilayer switches—starting with the basic concepts and on to the basic architectures. It describes the evolution of multilayer switch designs and highli...

  11. Analisis Kinerja Local Area Network Menggunakan Router.

    OpenAIRE

    Hutahaean, Yosua

    2012-01-01

    Perangkat internetworking menawarkan komunikasi di antara segmen Local Area Network (LAN). Ada empat tipe utama perangkat internetworking ini: repeater, bridge, router, dan gateway. Perangkat ini dibedakan atas dasar system lapisan Open System Interconnection (OSI) yang digunakan, berfungsi sebagai media komunikasi dari LAN ke LAN. Pada Tugas Akhir ini penulis tertarik untuk membahas analisis kinerja Local Area Network (LAN) menggunakan Router yang menggunakan sistem antrian M/M/1 dimana j...

  12. 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.

  13. Analysis Of Default Passwords In Routers Against Brute-Force Attack

    OpenAIRE

    Mohammed Farik; ABM Shawkat Ali

    2015-01-01

    Abstract Password authentication is the main means of access control on network routers and router manufacturers provide a default password for initial login to the router. While there has been many publications regarding the minimum requirements of a good password how widely the manufacturers themselves are adhering to the minimum standards and whether these passwords can withstand brute-force attack are not widely known. The novelty of this research is that this is the first time default...

  14. Multiport power router and its impact on future smart grids

    Science.gov (United States)

    Kado, Yuichi; Shichijo, Daiki; Wada, Keiji; Iwatsuki, Katsumi

    2016-07-01

    We propose a Y configuration power router as a unit cell to easily construct a power delivery system that can meet many types of user requirements. The Y configuration power router controls the direction and magnitude of power flows between three ports regardless of DC or AC. We constructed a prototype three-way isolated DC/DC converter that is the core unit of the Y configuration power router. The electrical insulation between three ports assures safety and reliability for power network systems. We then tested the operation of power flow control. The experimental results revealed that our methodology based on a governing equation was appropriate to control the power flow of the three-way DC/DC converter. In addition, a distribution network composed of power routers had the ability to easily enable interchanges of electrical power between autonomous microgrid cells. We also explored the requirements for communication between energy routers to achieve dynamic adjustments of energy flows in a coordinated manner and their impact on resilient power grid systems.

  15. Multi-port power router and its impact on resilient power grid systems

    Science.gov (United States)

    Kado, Yuichi; Iwatsuki, Katsumi; Wada, Keiji

    2016-02-01

    We propose a Y-configuration power router as a unit cell to easily construct a power delivery system that can meet many types of user requirements. The Y-configuration power router controls the direction and magnitude of power flow among three ports regardless of DC and AC. We constructed a prototype three-way isolated DC/DC converter that is the core unit of the Y-configuration power router and tested the power flow control operation. Experimental results revealed that our methodology based on the governing equation was appropriate for the power flow control of the three-way DC/DC converter. In addition, the hexagonal distribution network composed of the power routers has the ability to easily interchange electric power between autonomous microgrid cells. We also explored the requirements for communication between energy routers to achieve dynamic adjustments of energy flow in a coordinated manner and its impact on resilient power grid systems.

  16. VR-Cluster: Dynamic Migration for Resource Fragmentation Problem in Virtual Router Platform

    Directory of Open Access Journals (Sweden)

    Xianming Gao

    2016-01-01

    Full Text Available Network virtualization technology is regarded as one of gradual schemes to network architecture evolution. With the development of network functions virtualization, operators make lots of effort to achieve router virtualization by using general servers. In order to ensure high performance, virtual router platform usually adopts a cluster of general servers, which can be also regarded as a special cloud computing environment. However, due to frequent creation and deletion of router instances, it may generate lots of resource fragmentation to prevent platform from establishing new router instances. In order to solve “resource fragmentation problem,” we firstly propose VR-Cluster, which introduces two extra function planes including switching plane and resource management plane. Switching plane is mainly used to support seamless migration of router instances without packet loss; resource management plane can dynamically move router instances from one server to another server by using VR-mapping algorithms. Besides, three VR-mapping algorithms including first-fit mapping algorithm, best-fit mapping algorithm, and worst-fit mapping algorithm are proposed based on VR-Cluster. At last, we establish VR-Cluster protosystem by using general X86 servers, evaluate its migration time, and further analyze advantages and disadvantages of our proposed VR-mapping algorithms to solve resource fragmentation problem.

  17. Analisis Perancangan PC (Personal Computer Router Proxy Untuk Menggabungkan Tiga Jalur Koneksi Di Indospeed

    Directory of Open Access Journals (Sweden)

    Bangun Harizal

    2012-05-01

    Full Text Available Router very important for computer network. To get the router can buy a router products but can also design your own using personal computers. Mikrotik is one of the router manufacturer that provides products in the form of hardware or software. If you want to pay less to design a router can use operating system Ubuntu. This operating system is open source and provided free of charge by the manufacturer. If you want to design a router with this OS can make use of personal computers are often used in homes or offices. Merging the performance of both types of routers can also be usedto cover the lack of one another. With the proxy on a local network then the use of bandwidth can be saved. Becausethere are several websites cached and stored therein if the same website is accessed by other users, the router transmits only from the proxy to the computerwhich make the request.

  18. Microsoft Windows 2000 Router Configuration Guide

    National Research Council Canada - National Science Library

    Richburg, Florence

    2001-01-01

    The purpose of this guide is to provide technical guidance to network administrators of small to medium size networks in the configuration and integration of Microsoft Windows 2000 Server Router features...

  19. Algorithm To Ensure And Enforce Brute-Force Attack-Resilient Password In Routers

    OpenAIRE

    Mohammed Farik; ABM Shawkat Ali

    2015-01-01

    Abstract Issues of weak login passwords arising from default passwords in wired and wireless routers has been a concern for more than a decade. In this research we develop and test an algorithm to ensure and enforce passwords in routers that are resistant to brute-force attack. A comparative analysis is performed to show the improved strengths of passwords derived via this algorithm. Implementation of this algorithm in routers will ensure setup of brute-force attack resistant passwords.

  20. Oilfield automation with MRD-310 industrial 3G router

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2010-01-15

    The SAM Well Manager is the most advanced technological solution for high precision monitoring and control of rod-pumping wells. It was developed by Lufkin-Automation to optimize pump performance and reliability. The company was formed by the merger of Delta X and Nabla Corporations, which are currently part of the oil field division, offering analysis, security and control solutions for rod pumping wells. The SAM Well Manager product is equipped with the Westermo MRD-310 3G router. It has been used in pilot projects in remote and harsh environments in Europe and Asia. The MRD-310 router has a very high level of connectivity and provides support for GSM, GPRS, 3G UMTS, HSDPA and HSUPA. It also supports IPSec encrypted VPN tunnels which is a requirement for safety critical applications that use unsecure public networks. In addition, the MRD-310 provides a serial interface and serial to IP conversion, which is required for connection to the controller. The router is used to analyze pump flow and calculate service and maintenance requirements before the event of mechanical failure. Energy consumption can also be optimized. This installation of the SAM Well Manager with MRD-310 industrial 3G router in several applications has demonstrated the potential for significant cost savings. 2 figs.

  1. Modelling of plug and play interface for energy router based on IEC61850

    Science.gov (United States)

    Shi, Y. F.; Yang, F.; Gan, L.; He, H. L.

    2017-11-01

    Under the background of the “Internet Plus”, as the energy internet infrastructure equipment, energy router will be widely developed. The IEC61850 standard is the only universal standard in the field of power system automation which realizes the standardization of engineering operation of intelligent substation. To eliminate the lack of International unified standard for communication of energy router, this paper proposes to apply IEC61850 to plug and play interface and establishes the plug and play interface information model and information transfer services. This paper provides a research approach for the establishment of energy router communication standards, and promotes the development of energy router.

  2. Specification and Validation of an Edge Router Discovery Protocol for Mobile Ad Hoc Networks

    DEFF Research Database (Denmark)

    Kristensen, Lars Michael; Jensen, Kurt

    2004-01-01

    We present an industrial project at Ericsson Telebit A/S where Coloured Petri Nets (CP-nets or CPNs) have been used for the design and specification of an edge router discovery protocol for mobile ad-hoc networks. The Edge Router Discovery Protocol (ERDP) supports an edge router in a stationary...

  3. Algorithm To Ensure And Enforce Brute-Force Attack-Resilient Password In Routers

    Directory of Open Access Journals (Sweden)

    Mohammed Farik

    2015-08-01

    Full Text Available Abstract Issues of weak login passwords arising from default passwords in wired and wireless routers has been a concern for more than a decade. In this research we develop and test an algorithm to ensure and enforce passwords in routers that are resistant to brute-force attack. A comparative analysis is performed to show the improved strengths of passwords derived via this algorithm. Implementation of this algorithm in routers will ensure setup of brute-force attack resistant passwords.

  4. Method of sharing mobile unit state information between base station routers

    NARCIS (Netherlands)

    Bosch, H.G.P.; Mullender, Sape J.; Polakos, Paul Anthony; Rajkumar, Ajay; Sundaram, Ganapathy S.

    2007-01-01

    The present invention provides a method of operating a first base station router. The method may include transmitting state information associated with at least one inactive mobile unit to at least one second base station router. The state information is usable to initiate an active session with the

  5. Method of sharing mobile unit state information between base station routers

    NARCIS (Netherlands)

    Bosch, H.G.P.; Mullender, Sape J.; Polakos, Paul Anthony; Rajkumar, Ajay; Sundaram, Ganapathy S.

    2010-01-01

    The present invention provides a method of operating a first base station router. The method may include transmitting state information associated with at least one inactive mobile unit to at least one second base station router. The state information is usable to initiate an active session with the

  6. Complex Ornament Machining Process on a CNC Router

    Directory of Open Access Journals (Sweden)

    Camelia COŞEREANU

    2014-03-01

    Full Text Available The paper investigates the CNC routering possibilities for three species of wood, namely ash (Fraxinus Excelsior, lime wood (Tilia cordata and fir wood (Abies Alba, in order to obtain right surfaces of Art Nouveau sculptured ornaments. Given the complexity of the CNC tool path for getting wavy shapes of Art Nouveau decorations, the choice of processing parameters for each processed species of wood requires a laborious research work to correlate these parameters. Two Art Nouveau ornaments are proposed for the investigation. They are CNC routered using two types of cutting tools. The processed parameters namely the spindle speed, feed speed and depth of cut were the three variables of the machining process for the three species of wood, which were combined so, to provide good surface finish as a quality attribute. There were totally forty six variants of combining the processing parameter which were applied for CNC routering the samples made of the three species of wood. At the end, an optimum combination of the processed parameters is recommended for each species of wood.

  7. An Overview of Optical Network Bandwidth and Fault Management

    Directory of Open Access Journals (Sweden)

    J.A. Zubairi

    2010-09-01

    Full Text Available This paper discusses the optical network management issues and identifies potential areas for focused research. A general outline of the main components in optical network management is given and specific problems in GMPLS based model are explained. Later, protection and restoration issues are discussed in the broader context of fault management and the tools developed for fault detection are listed. Optical networks need efficient and reliable protection schemes that restore the communications quickly on the occurrence of faults without causing failure of real-time applications using the network. A holistic approach is required that provides mechanisms for fault detection, rapid restoration and reversion in case of fault resolution. Since the role of SDH/SONET is diminishing, the modern optical networks are poised towards the IP-centric model where high performance IP-MPLS routers manage a core intelligent network of IP over WDM. Fault management schemes are developed for both the IP layer and the WDM layer. Faults can be detected and repaired locally and also through centralized network controller. A hybrid approach works best in detecting the faults where the domain controller verifies the established LSPs in addition to the link tests at the node level. On detecting a fault, rapid restoration can perform localized routing of traffic away from the affected port and link. The traffic may be directed to pre-assigned backup paths that are established as shared or dedicated resources. We examine the protection issues in detail including the choice of layer for protection, implementing protection or restoration, backup path routing, backup resource efficiency, subpath protection, QoS traffic survival and multilayer protection triggers and alarm propagation. The complete protection cycle is described and mechanisms incorporated into RSVP-TE and other protocols for detecting and recording path errors are outlined. In addition, MPLS testbed

  8. HARDWARE IMPLEMENTATION OF PIPELINE BASED ROUTER DESIGN FOR ON-CHIP NETWORK

    Directory of Open Access Journals (Sweden)

    U. Saravanakumar

    2012-12-01

    Full Text Available As the feature size is continuously decreasing and integration density is increasing, interconnections have become a dominating factor in determining the overall quality of a chip. Due to the limited scalability of system bus, it cannot meet the requirement of current System-on-Chip (SoC implementations where only a limited number of functional units can be supported. Long global wires also cause many design problems, such as routing congestion, noise coupling, and difficult timing closure. Network-on-Chip (NoC architectures have been proposed to be an alternative to solve the above problems by using a packet-based communication network. In this paper, the Circuit-Switched (CS Router was designed and analysed the various parameters such as power, timing and area. The CS router has taken more number of cycles to transfer the data from source to destination. So the pipelining concept was implemented by adding registers in the CS router architecture. The proposed architecture increases the speed of operation and reduces the critical path of the circuit. The router has been implemented using Verilog HDL. The parameters area, power and timing were calculated in 130 nm CMOS technology using Synopsys tool with nominal operating voltage of 1V and packet size is 39 bits. Finally power, area and time of these two routers have been analysed and compared.

  9. Virtual Private Lan Services Over IP/MPLS Networks and Router Configurations

    Directory of Open Access Journals (Sweden)

    Pınar KIRCI

    2015-06-01

    Full Text Available The rising number of users and ever growing traffic rates over the networks reveal the need of higher bandwidth and transmission rates. At every packet transmission process, routers need to route the packets by looking at the routing tables, this fact leads to an increase at the load of the routers and at the amount of time consumed during the processes. Today, users need high level security, faster data transmission and easy managed network structures because of the increasing technology usage. MPLS network structures can provide these requirements with their QoS feature. In our work, at first a topology structure is constructed with the routers that are used in Alcatel-Lucent laboratories. OSPF (Open Shortest Path First routing protocol and MPLS (Multiprotocol Label Switching technologies are used over the topology. Afterwards, E-pipe (Ethernet Pipe and VPLS (Virtual private LAN services configurations are performed over the routers. To illustrate the current network data traffic, three tests are performed in the study. Routers’ configurations are performed by Secure-CRT and still developing i-Gen software. With i-Gen, many routers’ configurations can be performed with a user friendly interface. Instead of performing the configurations one by one with Secure CRT, the user can perform the routers’ configurations easily by entering the needed values for the system with i-Gen software. So, with the new and developing i-Gen software, the users’ workload is minimized and streamlined. In our work, Secure-CRT software which is mostly preferred for router configurations at Windows operating system and i-Gen software which is developed by Alcatel-Lucent are considered. Both of the router configuration softwares are worked on and gained results are expounded. Consequently, instead of using time consuming Secure-CRT software, with utilizing new developed i-Gen software, the users’ work load is minimized.

  10. Discovery of IPV6 Router Interface Addresses via Heuristic Methods

    Science.gov (United States)

    2015-09-01

    NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS DISCOVERY OF IPV6 ROUTER INTERFACE ADDRESSES VIA HEURISTIC METHODS by Matthew D. Gray September...AND SUBTITLE DISCOVERY OF IPV6 ROUTER INTERFACE ADDRESSES VIA HEURISTIC METHODS 5. FUNDING NUMBERS CNS-1111445 6. AUTHOR(S) Matthew D. Gray 7...Internet Assigned Numbers Authority, there is continued pressure for widespread IPv6 adoption. Because the IPv6 address space is orders of magnitude

  11. Interconnecting Microgrids via the Energy Router with Smart Energy Management

    Directory of Open Access Journals (Sweden)

    Yingshu Liu

    2017-08-01

    Full Text Available A novel and flexible interconnecting framework for microgrids and corresponding energy management strategies are presented, in response to the situation of increasing renewable-energy penetration and the need to alleviate dependency on energy storage equipment. The key idea is to establish complementary energy exchange between adjacent microgrids through a multiport electrical energy router, according to the consideration that adjacent microgrids may differ substantially in terms of their patterns of energy production and consumption, which can be utilized to compensate for each other’s instant energy deficit. Based on multiport bidirectional voltage source converters (VSCs and a shared direct current (DC power line, the energy router serves as an energy hub, and enables flexible energy flow among the adjacent microgrids and the main grid. The analytical model is established for the whole system, including the energy router, the interconnected microgrids and the main grid. Various operational modes of the interconnected microgrids, facilitated by the energy router, are analyzed, and the corresponding control strategies are developed. Simulations are carried out on the Matlab/Simulink platform, and the results have demonstrated the validity and reliability of the idea for microgrid interconnection as well as the corresponding control strategies for flexible energy flow.

  12. 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...

  13. A Performance Analytical Strategy for Network-on-Chip Router with Input Buffer Architecture

    Directory of Open Access Journals (Sweden)

    WANG, J.

    2012-11-01

    Full Text Available In this paper, a performance analytical strategy is proposed for Network-on-Chip router with input buffer architecture. First, an analytical model is developed based on semi-Markov process. For the non-work-conserving router with small buffer size, the model can be used to analyze the schedule delay and the average service time for each buffer when given the related parameters. Then, the packet average delay in router is calculated by using the model. Finally, we validate the effectiveness of our strategy by simulation. By comparing our analytical results to simulation results, we show that our strategy successfully captures the Network-on-Chip router performance and it performs better than the state-of-art technology. Therefore, our strategy can be used as an efficiency performance analytical tool for Network-on-Chip design.

  14. Enabling IP Header Compression in COTS Routers via Frame Relay on a Simplex Link

    Science.gov (United States)

    Nguyen, Sam P.; Pang, Jackson; Clare, Loren P.; Cheng, Michael K.

    2010-01-01

    NASA is moving toward a networkcentric communications architecture and, in particular, is building toward use of Internet Protocol (IP) in space. The use of IP is motivated by its ubiquitous application in many communications networks and in available commercial off-the-shelf (COTS) technology. The Constellation Program intends to fit two or more voice (over IP) channels on both the forward link to, and the return link from, the Orion Crew Exploration Vehicle (CEV) during all mission phases. Efficient bandwidth utilization of the links is key for voice applications. In Voice over IP (VoIP), the IP packets are limited to small sizes to keep voice latency at a minimum. The common voice codec used in VoIP is G.729. This new algorithm produces voice audio at 8 kbps and in packets of 10-milliseconds duration. Constellation has designed the VoIP communications stack to use the combination of IP/UDP/RTP protocols where IP carries a 20-byte header, UDP (User Datagram Protocol) carries an 8-byte header, and RTP (Real Time Transport Protocol) carries a 12-byte header. The protocol headers total 40 bytes and are equal in length to a 40-byte G.729 payload, doubling the VoIP latency. Since much of the IP/UDP/RTP header information does not change from IP packet to IP packet, IP/UDP/RTP header compression can avoid transmission of much redundant data as well as reduce VoIP latency. The benefits of IP header compression are more pronounced at low data rate links such as the forward and return links during CEV launch. IP/UDP/RTP header compression codecs are well supported by many COTS routers. A common interface to the COTS routers is through frame relay. However, enabling IP header compression over frame relay, according to industry standard (Frame Relay IP Header Compression Agreement FRF.20), requires a duplex link and negotiations between the compressor router and the decompressor router. In Constellation, each forward to and return link from the CEV in space is treated

  15. Experimental verification of a very low crosstalk wavelength router construction using arrayed-waveguide grating multi/demultiplexers

    DEFF Research Database (Denmark)

    Liu, Fenghai; Pedersen, Rune Johan Skullerud; Peucheret, Christophe

    1999-01-01

    A very low crosstalk N×N wavelength router construction based on 1×N AWG multi/demultiplexers has been proposed. The peak crosstalk level of -53 dB is measured in such an 8×8 wavelength router and the power penalty from the router is negligible. Rather large wavelength routing networks can be built...

  16. Argo: A Time-Elastic Time-Division-Multiplexed NOC using Asynchronous Routers

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia; Sparsø, Jens

    2014-01-01

    are either synchronous or mesochronous. We use asynchronous routers to achieve a simpler, smaller, and more robust, self-timed design. Our design exploits the fact that pipelined asynchronous circuits also behave as ripple FIFOs. Thus, it avoids the need for explicit synchronization FIFOs between the routers......In this paper we explore the use of asynchronous routers in a time-division-multiplexed (TDM) network-on-chip (NOC), Argo, that is being developed for a multi-processor platform for hard real-time systems. TDM inherently requires a common time reference, and existing TDM-based NOC designs...... delays derived from a 65nm CMOS implementation, a worstcase analysis shows that a typical design can tolerate a skew of 1-5 cycles (depending on FIFO depths and NI clock frequency). Simulation results of a 2 x 2 NOC confirm this....

  17. FPGA Based Low Power Router Design Using High Speed Transeceiver Logic IO Standard

    DEFF Research Database (Denmark)

    Thind, Vandana; Hussain, Dil muhammed Akbar

    2015-01-01

    and information. Router is main component of computer networks is an intelligent device uses to transfer data packets between various computer networks. Router must consume low power to perform its work in an efficient manner. To achieve the same the work has been done to make a FPGA based low power design using...

  18. Sistem Pencegahan UDP DNS Flood Dengan Filter Firewall Pada Router Mikrotik

    Directory of Open Access Journals (Sweden)

    Doni Aprilianto

    2017-05-01

    Full Text Available Serangan terhadap server jaringan dapat terjadi kapan saja,  jenis serangan yang dapat menyebabkan efek yang signifikan pada sebuah router adalah UDP-Flooding. UDP (User Datagram Protocol-Flooding adalah jenis serangan yang memanfaatkan protokol UDP dengan mengurangi sambungan (connectionless untuk menyerang target. Dalam analisis ini menggunakan metode penelitian deskriptif untuk memperoleh data secara langsung dengan melakukan teknik flooding serta teknik pencegahannya terhadap server yang telah dirancang. Dengan menggunakan Filter Rules yang telah dibuat, packet yang melalui port DNS selain IP Address yang telah di allow jika mencoba melakukan request atau flood DNS ke IP Public ISP pada router mikrotik, maka packet tersebut akan langsung di drop oleh pengaturan rules tersebut. kesimpulan yang dapat diambil yaitu penerapan filter firewall pada router mikrotik dapat mengurangi jumlah paket data UDP yang dikirimkan oleh attacker melalui port DNS sebanyak 60% dari jumlah paket yang masuk jika tanpa firewall.

  19. Proposal for a transmon-based quantum router

    NARCIS (Netherlands)

    Sala, Arnau; Blaauboer, M.

    2016-01-01

    We propose an implementation of a quantum router for microwave photons in a superconducting qubit architecture consisting of a transmon qubit, SQUIDs and a nonlinear capacitor. We model and analyze the dynamics of operation of the quantum switch using quantum Langevin equations in a scattering

  20. 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).

  1. Design and Test of a Signal Packet Router Prototype for the ATLAS NSW sTGC Detector

    CERN Document Server

    Hu, Xueye; The ATLAS collaboration

    2016-01-01

    Abstract– The New Small Wheel (NSW) small-strip thin-gap chambers (sTGC) detector will be installed in Large Hadron Collider (LHC) during ATLAS Phase-I upgrade. For sTGC detector, it requires very high-speed electronic triggering of signal events. On detecting a signal peak, sTGC front-end trigger logic will send out serialized track information on twinax fast serial copper wires to the signal packet Router on the periphery of the new small wheel. The signal packet Router boards handle all incoming traffic from the TDS chips (4.8 Gbps), serving as a very fast switching-yard between incoming active TDS signals and a limited number of optoelectronic outputs. There are several design requirements on router: radiation-hard (9kRad), high-speed serial link and low fixed latency in FPGA (field-programmable gate array) data processing. To meet those requirements, a router prototype has been developed for demonstration purpose. The components used in router prototype have been tested in radiation environment to m...

  2. 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.

  3. Infinite Queue Management via Cascade Control for Industrial Routers in Smart Grid IP Networks

    Directory of Open Access Journals (Sweden)

    Ku-Hwan Kim

    2016-01-01

    Full Text Available Smart grid applications experience an extremely wide range of communication delay. Data flows of those applications are normally aggregated at industrial network routers in substations, form infinite (long queues termed bufferbloat issue, and might damage the operation of transmission control protocol. The default queue management scheme, DropTail, in such routers just drops packets if queue is full while the others in literature are mostly based on one-loop feedback control where an optimal point of performance between queue length and drop rate is limited. In this paper, we study the problem of managing a long queue of industrial router at substation under heterogeneous smart grid networks. Specifically, we propose an enqueue-dequeue dropping cascade control using a two-loop design method to control both window size and queue length. Moreover, our proposal can be easily implemented into router firmware with provided discrete expressions. Finally, our simulation results are presented to validate the possible benefits that can be gained from cascade control and compare the existing queue management methods as well.

  4. 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...

  5. 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...

  6. Dynamic Mobile IP routers in ad hoc networks

    NARCIS (Netherlands)

    Kock, B.A.; Schmidt, J.R.

    2005-01-01

    This paper describes a concept combining mobile IP and ad hoc routing to create a robust mobile network. In this network all nodes are mobile and globally and locally reachable under the same IP address. Essential for implementing this network are the dynamic mobile IP routers. They act as gateways

  7. Enabling Research Network Connectivity to Clouds with Virtual Router Technology

    Science.gov (United States)

    Seuster, R.; Casteels, K.; Leavett-Brown, CR; Paterson, M.; Sobie, RJ

    2017-10-01

    The use of opportunistic cloud resources by HEP experiments has significantly increased over the past few years. Clouds that are owned or managed by the HEP community are connected to the LHCONE network or the research network with global access to HEP computing resources. Private clouds, such as those supported by non-HEP research funds are generally connected to the international research network; however, commercial clouds are either not connected to the research network or only connect to research sites within their national boundaries. Since research network connectivity is a requirement for HEP applications, we need to find a solution that provides a high-speed connection. We are studying a solution with a virtual router that will address the use case when a commercial cloud has research network connectivity in a limited region. In this situation, we host a virtual router in our HEP site and require that all traffic from the commercial site transit through the virtual router. Although this may increase the network path and also the load on the HEP site, it is a workable solution that would enable the use of the remote cloud for low I/O applications. We are exploring some simple open-source solutions. In this paper, we present the results of our studies and how it will benefit our use of private and public clouds for HEP computing.

  8. Infinite Queue Management via Cascade Control for Industrial Routers in Smart Grid IP Networks

    OpenAIRE

    Kim, Ku-Hwan; To, Hoang-Linh; Hwang, Won-Joo; Lee, Jung-Tae

    2016-01-01

    Smart grid applications experience an extremely wide range of communication delay. Data flows of those applications are normally aggregated at industrial network routers in substations, form infinite (long) queues termed bufferbloat issue, and might damage the operation of transmission control protocol. The default queue management scheme, DropTail, in such routers just drops packets if queue is full while the others in literature are mostly based on one-loop feedback control where an optimal...

  9. Sate-of-the-art IP switching router architecture using SFQ technology

    International Nuclear Information System (INIS)

    Miyaho, N.; Miyahara, K.; Yamazaki, A.

    2006-01-01

    Taking the recent trend of rapid IP traffic increasing and QoS in the Internet into account, we propose an innovative IP router architecture from the viewpoint of minimum switching delay, switching capacity, QoS assurance for the next generation Internet services. We examined the IP router performance using superconductivity device simulator (WinS) assuming the future-generation Nb junction process and confirmed more than 300 GHz clock operation. For the evaluation of a novel IP switch architecture, we effectively apply the SFQ circuits using Josephson junctions to an extremely restricted function block in the switching node and a conventional semiconductor technology is also applied for the rest parts of the other function blocks inside it

  10. Analisa Link Balancing dan Failover 2 Provider Menggunakan Border Gateway Protocol (BGP Pada Router Cisco 7606s

    Directory of Open Access Journals (Sweden)

    Darmawan Darmawan

    2017-12-01

    Full Text Available Sistem link balancing dan failover merupakan salah satu cara yang dapat digunakan untuk membagi beban traffic dari client pada beberapa koneksi internet, dapat sebagai backup/failover ketika salah satu koneksi internet mengalami gangguan. Pada perancangan sistem ini digunakan 4 buah router, yaitu terdiri dari satu router cisco 7606s yang berfungsi sebagai main gateway yang mengatur sistem failover dan link balancing menuju ke 2 buah router mikrotik RB951G 2HND sebagai jalur kedua ISP dan router mikrotik CCR1036-12G-4S sebagai gateway dari FTP server. Tiap router tersebut memiliki Autonomus System Number yang berbeda yang saling berkomunikasi menggunakan routing Border Gateway Protocol (BGP. Dari hasil pengujian penggunaan link balancing dengan besar bandwidth 10 mb/s, didapatkan throughput 794 KB/s, sedangkan yang tidak menggunakan link balancing dengan bandwidth sebesar 20 mb/s, didapatkan nilai throughput hanya 136 KB/s. Penggunaan link balancing dapat memanfaatkan besar bandwidth yang ada dan meningkatkan throughput, dibandingkan tidak menggunkan link balancing. Pada pengujian delay, menggunakan link balancing hanya delay 1.24 ms, sedangkan tidak menggunakan metode link balancing mencapai 8.19 ms. Nilai latency didapatkan 12 ms untuk menggunakan link balancing sedangkan tidak menggunkan metode link balancing mencapai 1896 ms.

  11. Design and Implementation of 3 Axis CNC Router for Computer Aided Manufacturing Courses

    Directory of Open Access Journals (Sweden)

    Aktan Mehmet Emin

    2016-01-01

    Full Text Available In this paper, it is intended to make the mechanical design of 3 axis Computer Numerical Control (CNC router with linear joints, production of electronic control interface cards and drivers and manufacturing of CNC router system which is a combination of mechanics and electronics. At the same time, interface program has been prepared to control router via USB. The router was developed for educational purpose. In some vocational schools and universities, Computer Aided Manufacturing (CAM courses are though rather theoretical. This situation cause ineffective and temporary learning. Moreover, students at schools which have the opportunity to apply for these systems can face with various dangerous accidents. Because of this situation, these students start to get knowledge about this system for the first time. For the first steps of CNC education, using smaller and less dangerous systems will be easier. A new concept CNC machine and its user interface suitable and profitable for education have been completely designed and realized during this study. To test the validity of the hypothesis which the benefits that may exist on the educational life, enhanced traditional education method with the contribution of the designed machine has been practiced on CAM course students for a semester. At the end of the semester, the new method applied students were more successful in the rate of 27.36 percent both in terms of verbal comprehension and exam grades.

  12. [Making a low cost IPSec router on Linux and the assessment for practical use].

    Science.gov (United States)

    Amiki, M; Horio, M

    2001-09-01

    We installed Linux and FreeS/WAN on a PC/AT compatible machine to make an IPSec router. We measured the time of ping/ftp, only in the university, between the university and the external network. Between the university and the external network (the Internet), there were no differences. Therefore, we concluded that CPU load was not remarkable at low speed networks, because packets exchanged via the Internet are small, or compressions of VPN are more effective than encoding and decoding. On the other hand, in the university, the IPSec router performed down about 20-30% compared with normal IP communication, but this is not a serious problem for practical use. Recently, VPN machines are becoming cheaper, but they do not function sufficiently to create a fundamental VPN environment. Therefore, if one wants a fundamental VPN environment at a low cost, we believe you should select a VPN router on Linux.

  13. Cisco ASM Router

    CERN Multimedia

    2001-01-01

    One of the two "ASM/2-32EM" boxes installed in 1988, from "Cisco Systems Inc." - then an unknown 20-employee company in Menlo Park, California (USA). This is one of the first two Cisco boxes to appear in Switzerland, and possibly Europe. The 220v power supply was a special modification made for use at CERN. They supported IP address filtering, which seemed just what CERN needed to help protect the new Cray XMP-48 super computer from network hackers. The two ASM boxes were both routers and terminal servers. They protected a secure private Ethernet segment used by the Cray project, as well as providing secure terminal connections to that segment, including CERN's first dialback terminal service, which allowed Cray and CERN system analysts to work on the machine from home, using another Cisco feature called TACACS. (Kindly offered by B. Segal who discovered this company while at a Usenix Conference in Phoenix, Arizona in June 1987.)

  14. 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.

  15. Junction Temperature Aware Energy Efficient Router Design on FPGA

    DEFF Research Database (Denmark)

    Thind, Vandana; Sharma, Shivani; Minwer, M H

    2015-01-01

    Energy, Power and efficiency are very much related to each other. To make any system efficient, Power consumed by it must be minimized or we can say that power dissipation should be less. In our research we tried to make a energy efficient router design on FPGA by varying junction temperature...

  16. The Three-Phase Power Router and Its Operation with Matrix Converter toward Smart-Grid Applications

    Directory of Open Access Journals (Sweden)

    Alexandros Kordonis

    2015-04-01

    Full Text Available A power router has been recently developed for both AC and DC applications that has the potential for smart-grid applications. This study focuses on three-phase power switching through the development of an experimental setup which consists of a three-phase direct AC/AC matrix converter with a power router attached to its output. Various experimental switching scenarios with the loads connected to different input sources were investigated. The crescent introduction of decentralized power generators throughout the power-grid obligates us to take measurements for a better distribution and management of the power. Power routers and matrix converters have great potential to succeed this goal with the help of power electronics devices. In this paper, a novel experimental three-phase power switching was achieved and the advantages of this operation are presented, such as on-demand and constant power supply at the desired loads.

  17. Fidget with Widgets: CNC Activity Introduces the Flatbed Router

    Science.gov (United States)

    Tryon, Daniel V.

    2006-01-01

    The computer numerical control (CNC) flatbed router is a powerful tool and a must-have piece of equipment for any technology education program in which students will produce a product--whether it involves Manufacturing, Materials Processing, or any of the vast array of Project Lead the Way courses. This article describes an activity--producing a…

  18. Analysis and Implementation of an Open Programmable Router Based on Forwarding and Control Element Separation

    Institute of Scientific and Technical Information of China (English)

    Wei-Ming Wang; Li-Gang Dong; Bin Zhuge

    2008-01-01

    A router architecture based upon ForCES (Forwarding and Control Element Separation), which is being standardized by IETF ForCES working group, gains its competitive advantage over traditional router architectures in flexibility, programmability, and cost-effectiveness. In this paper, design and implementation of a ForCES-based router (ForTER) is illustrated. Firstly, the implementation architecture of ForTER is discussed. Then, a layered software model,which well illustrates ForCES features, is proposed. Based on the model, design and implementation of Control Element (CE) and Forwarding Element (FE) in ForTER are introduced in detail. Moreover, security for ForTER is considered and an algorithm to prevent DoS attacks is presented. Lastly, experiments of ForTER are illustrated for routing and running routing protocols, network management, DoS attack prevention, etc. The experimental results show the feasibility of the ForTER design. Consequently, the ForTER implementation basically testifies the feasibility of ForCES architecture and some IETF ForCES specifications.

  19. Evaluación del tiempo de recuperación de fallas para LSP L1VPN sobre redes GMPLS

    Directory of Open Access Journals (Sweden)

    Octavio Salcedo

    2012-12-01

    Full Text Available Nowadays network failure is a common problem that is caused, to certain extent, by various factors such as the number of devices involved in a link, the quality of these devices, their geographical location, and environmental conditions among others. There is a great deal of factors influencing network failure occurrence, which indicates that, whether expected or not, failure will always be present. However, the issue is not about having or avoiding failure but about how quickly can a network recover and restore its services. The present paper addresses the point of failure-recovery time of an L1VPN over GMPLS technology, where failure can be automatically overcome through routing protocols by redirecting packets to alternate routes.

  20. Performance Evaluation of Software Routers with VPN Features

    Directory of Open Access Journals (Sweden)

    H. Redžović

    2017-11-01

    Full Text Available This paper presents implementation and analysis of the VPN software router which is based on Quagga and strongSwan open-source software tools. We validated the functionalities of strongSwan and Quagga in realistic environment which include scenarios with link failures. Also, we measured and analyzed the performance of encryption and hash algorithms supported by strongSwan software, in order to advise an optimal VPN configuration that provides the best performance.

  1. A Router Architecture for Connection-Oriented Service Guarantees in the MANGO Clockless Network-on-Chip

    DEFF Research Database (Denmark)

    Bjerregaard, Tobias; Sparsø, Jens

    2005-01-01

    On-chip networks for future system-on-chip designs need simple, high performance implementations. In order to promote system-level integrity, guaranteed services (GS) need to be provided. We propose a network-on-chip (NoC) router architecture to support this, and demonstrate with a CMOS standard...... cell design. Our implementation is based on clockless circuit techniques, and thus inherently supports a modular, GALS-oriented design flow. Our router exploits virtual channels to provide connection-oriented GS, as well as connection-less best-effort (BE) routing. The architecture is highly flexible...

  2. Proposal for the award of a contract for the supply of Cabletron gigabit routers

    CERN Document Server

    2000-01-01

    This document concerns the award of a contract for the supply of Cabletron gigabit routers. Following a call for tenders (IT-2870/IT) sent on 14 July 2000 to 13 firms in three Member States, CERN received, by the closing date, tenders from four firms in one Member State. The Finance Committee is invited to agree to the negotiation of a contract with ACN (CH), the lowest bidder, for the supply of Cabletron gigabit routers for a total amount of 1 887 000 Swiss francs, not subject to revision. The firm has indicated the following distribution by country of the contract value covered by this adjudication proposal: IE-100%.

  3. Analyzing Capabilities of Commercial and Open-Source Routers to Implement Atomic BGP

    Directory of Open Access Journals (Sweden)

    A. Cvjetić

    2010-06-01

    Full Text Available The paper analyzes implementations of BGP protocol on commercial and open-source routers and presents how some existing BGP extensions and routing table isolation mechanisms may be used to solve issues found in standard BGP implementation.

  4. Span Restoration in Optical Networks with Limited Wavelength Conversion

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Buron, Jakob Due; Andriolli, N

    2007-01-01

    Next generation optical networks provide functionalities to dynamically provision and recover connections, while emerging technologies allow for the conversion between wavelengths. These devices are however expensive and hence it is likely that only few are deployed throughout the network...... converter-saving wavelength assignment in GMPLS networks. The converter saving property of the Suggested Vector is particularly desirable in span restoration, where the pre-failure path stubs have to be merged to the restoration path at the failure-adjacent nodes. In order to avoid wavelength conversion....... Furthermore, we describe different scenarios to extend the suggested vector wavelength assignment scheme to multi-domain networks with focus on span restoration....

  5. Internet optical infrastructure issues on monitoring and failure restoration

    CERN Document Server

    Tapolcai, János; Babarczi, Péter; Rónyai, Lajos

    2015-01-01

    This book covers the issues of monitoring, failure localization, and restoration in the Internet optical backbone, and focuses on the progress of state-of-the-art in both industry standard and academic research. The authors summarize, categorize, and analyze the developed technology in the context of Internet fault management and failure recovery under the Generalized Multi-Protocol Label Switching (GMPLS), via both aspects of network operations and theories. Examines monitoring, failure localization, and failure restoration in the Internet backbone Includes problem formulations based on combinatorial group testing and topology coding Covers state-of-the-art development for the Internet backbone fault management and failure recovery

  6. IP- -: A Reduced Internet Protocol for Optical Packet Networking

    Science.gov (United States)

    Ohta, Masataka; Fujikawa, Kenji

    IP- - is proposed as an Internet Protocol suitable for optical packet networking. As optical routers require much faster control than electric ones and lack of optical buffers other than those by fiber delay lines requires fixed time control, Internet Protocols must be at least as simple as IPv4 and much simpler than IPv6. IP- - also addresses issues of IP address space exhaustion and IP routing table explosion.

  7. Desain dan Implementasi Sistem Kendali CNC Router Menggunakan PC untuk Flame Cutting Machine

    Directory of Open Access Journals (Sweden)

    Roni Permana Saputra

    2012-03-01

    Full Text Available This paper focuses on design of router control systems based on computer numerical control (CNC using personal computer (PC implemented in flame cutting machine (FCM. NC-Code entered into the computer translated to be a command signal sent by the PC to a microcontroller to control the end effector’s movement alongthe X and Y axis simultaneously based on linear and circular interpolations calculation on the PC. This control system is implemented on FCM by connecting the output control of the microcontroller with the driver actuator of the FCM in the form of a DC motor. The obtained result is in the form of a CNC router control system prototype to be implemented in the FCM which is capable to perform linear interpolation and circular interpolation. 

  8. An IPv6 routing lookup algorithm using weight-balanced tree based on prefix value for virtual router

    Science.gov (United States)

    Chen, Lingjiang; Zhou, Shuguang; Zhang, Qiaoduo; Li, Fenghua

    2016-10-01

    Virtual router enables the coexistence of different networks on the same physical facility and has lately attracted a great deal of attention from researchers. As the number of IPv6 addresses is rapidly increasing in virtual routers, designing an efficient IPv6 routing lookup algorithm is of great importance. In this paper, we present an IPv6 lookup algorithm called weight-balanced tree (WBT). WBT merges Forwarding Information Bases (FIBs) of virtual routers into one spanning tree, and compresses the space cost. WBT's average time complexity and the worst case time complexity of lookup and update process are both O(logN) and space complexity is O(cN) where N is the size of routing table and c is a constant. Experiments show that WBT helps reduce more than 80% Static Random Access Memory (SRAM) cost in comparison to those separation schemes. WBT also achieves the least average search depth comparing with other homogeneous algorithms.

  9. Acousto-optic resonant coupling of three spatial modes in an optical fiber.

    Science.gov (United States)

    Park, Hee Su; Song, Kwang Yong

    2014-01-27

    A fiber-optic analogue to an externally driven three-level quantum state is demonstrated by acousto-optic coupling of the spatial modes in a few-mode fiber. Under the condition analogous to electromagnetically induced transparency, a narrow-bandwidth transmission within an absorption band for the fundamental mode is demonstrated. The presented structure is an efficient converter between the fundamental mode and the higher-order modes that cannot be easily addressed by previous techniques, therefore can play a significant role in the next-generation space-division multiplexing communications as an arbitrarily mode-selectable router.

  10. Increased Microleakage of Amalgam Restorations after Exposure to 2.4 Ghz Radiofrequency Electromagnetic Fields from Common Wi-Fi Routers

    Directory of Open Access Journals (Sweden)

    Mortazavi SMJ

    2017-09-01

    Full Text Available Statement of Problem: Previous studies have shown that exposure of dental amalgam fillings to MRI and mobile phones can increase microleakage of amalgam restorations. Objectives: The aim of this study was to evaluate the effects of exposure to radiofrequency radiation emitted from indoor Wi-Fi access devices on microleakage of amalgam restorations. Materials and Methods: Standard class V cavities were prepared on the buccal surfaces of 69 extracted human premolar teeth. The samples were divided into two exposure groups and one non-exposed control group of 23 teeth each. The specimens in the experimental groups were exposed to a radiofrequency (RF radiation emitted from a commercial 2.4 GHz Wi Fi router. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. Teeth samples in the first exposure group (group A were exposed to RF for 3 days while the second exposure group (group B was exposed for 6 days. Then the teeth were sectioned and scored for microleakage under a stereomicroscope. Results: The score of microleakage was significantly higher in the exposure group A compared to that of the control group. However, the score of microleakage was not significantly different between the exposure group B and control group. Furthermore, the scores of microleakage was signifi-cantly higher in the exposure group A than that of the exposure group B. Conclusions: Exposure of patients with amalgam restorations to radiofre-quency waves emitted from commercial Wi-Fi routers can lead to in-creased microleakage of amalgam restorations.

  11. SEMTAP (Serpentine End Match TApe program): The Easy Way to Program Your Numerically Controlled Router for the Production of SEM Joints

    Science.gov (United States)

    Ronald E. Coleman

    1977-01-01

    SEMTAP (Serpentine End Match TApe Program) is an easy and inexpensive method of programing a numerically controlled router for the manufacture of SEM (Serpentine End Matching) joints. The SEMTAP computer program allows the user to issue commands that will accurately direct a numerically controlled router along any SEM path. The user need not be a computer programer to...

  12. Analytical Study of different types Of network failure detection and possible remedies

    Science.gov (United States)

    Saxena, Shikha; Chandra, Somnath

    2012-07-01

    Faults in a network have various causes,such as the failure of one or more routers, fiber-cuts, failure of physical elements at the optical layer, or extraneous causes like power outages. These faults are usually detected as failures of a set of dependent logical entities and the links affected by the failed components. A reliable control plane plays a crucial role in creating high-level services in the next-generation transport network based on the Generalized Multiprotocol Label Switching (GMPLS) or Automatically Switched Optical Networks (ASON) model. In this paper, approaches to control-plane survivability, based on protection and restoration mechanisms, are examined. Procedures for the control plane state recovery are also discussed, including link and node failure recovery and the concepts of monitoring paths (MPs) and monitoring cycles (MCs) for unique localization of shared risk linked group (SRLG) failures in all-optical networks. An SRLG failure is a failure of multiple links due to a failure of a common resource. MCs (MPs) start and end at same (distinct) monitoring location(s). They are constructed such that any SRLG failure results in the failure of a unique combination of paths and cycles. We derive necessary and sufficient conditions on the set of MCs and MPs needed for localizing an SRLG failure in an arbitrary graph. Procedure of Protection and Restoration of the SRLG failure by backup re-provisioning algorithm have also been discussed.

  13. 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

  14. Waveguide-type optical circuits for recognition of optical 8QAM-coded label

    Science.gov (United States)

    Surenkhorol, Tumendemberel; Kishikawa, Hiroki; Goto, Nobuo; Gonchigsumlaa, Khishigjargal

    2017-10-01

    Optical signal processing is expected to be applied in network nodes. In photonic routers, label recognition is one of the important functions. We have studied different kinds of label recognition methods so far for on-off keying, binary phase-shift keying, quadrature phase-shift keying, and 16 quadrature amplitude modulation-coded labels. We propose a method based on waveguide circuits to recognize an optical eight quadrature amplitude modulation (8QAM)-coded label by simple passive optical signal processing. The recognition of the proposed method is theoretically analyzed and numerically simulated by the finite difference beam propagation method. The noise tolerance is discussed, and bit-error rate against optical signal-to-noise ratio is evaluated. The scalability of the proposed method is also discussed theoretically for two-symbol length 8QAM-coded labels.

  15. 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.

  16. Generalized fiber Fourier optics.

    Science.gov (United States)

    Cincotti, Gabriella

    2011-06-15

    A twofold generalization of the optical schemes that perform the discrete Fourier transform (DFT) is given: new passive planar architectures are presented where the 2 × 2 3 dB couplers are replaced by M × M hybrids, reducing the number of required connections and phase shifters. Furthermore, the planar implementation of the discrete fractional Fourier transform (DFrFT) is also described, with a waveguide grating router (WGR) configuration and a properly modified slab coupler.

  17. Optical RAM-enabled cache memory and optical routing for chip multiprocessors: technologies and architectures

    Science.gov (United States)

    Pleros, Nikos; Maniotis, Pavlos; Alexoudi, Theonitsa; Fitsios, Dimitris; Vagionas, Christos; Papaioannou, Sotiris; Vyrsokinos, K.; Kanellos, George T.

    2014-03-01

    The processor-memory performance gap, commonly referred to as "Memory Wall" problem, owes to the speed mismatch between processor and electronic RAM clock frequencies, forcing current Chip Multiprocessor (CMP) configurations to consume more than 50% of the chip real-estate for caching purposes. In this article, we present our recent work spanning from Si-based integrated optical RAM cell architectures up to complete optical cache memory architectures for Chip Multiprocessor configurations. Moreover, we discuss on e/o router subsystems with up to Tb/s routing capacity for cache interconnection purposes within CMP configurations, currently pursued within the FP7 PhoxTrot project.

  18. Smart meters and routers radiofrequency disturbances study with pacemakers and implantable cardiac defibrillators.

    Science.gov (United States)

    Ostiguy, Geneviève; Black, Tom; Bluteau, Louis-Jean; Dupont, Louis; Dyrda, Katia; Girard, Guillaume; Nguyen, Duc-Hai; Plante, Michel; Thibault, Bernard

    2013-11-01

    There is no scientific literature that examines radiofrequency (RF) interference from Smart Meters with cardiac implantable electronic devices (CIEDs). The objective of this in vitro study was to assess any potential interference with Medtronic CIEDs (Medtronic Inc., Minneapolis, MN, USA). In the Quebec testing, five models of Medtronic CIEDs were placed in an acrylic cylinder filled with a saline solution and faced a Landis+Gyr Smart Meter or Router (Landis+Gyr AG, Zug, Switzerland). The distance between CIEDs and the meter casing or router antenna was 10 cm. The Meter's normal operating conditions were modified to artificially set the number of impulsions at an abnormally high level (one, two, and three impulses per second). Each scenario was repeated one to five times, for 1 minute each. In the U.S. testing, 6 cm and 15 cm (∼2.25' and ∼6') separated the six models of Medtronic CIEDs from the Schlumberger Smart Meter (Itron Inc., Liberty Lake, WA, USA), which generally sent out a 96-bit Standard Consumption Message over 3 seconds. The transmission varied in frequencies along with the interval between cycles. A total of 6,966 RF transmissions were completed during the 34 tests conducted in Quebec. In the United States, the CIED was exposed to the meter for 10 minutes to provide a minimum of 200 completed RF transmissions. No interference was observed in worst-case scenarios (testing of meters and CIEDs at their performance limits). Landis+Gyr Smart Meters/Routers and Schlumberger Smart Meters do not interfere with the functioning of the Medtronic CIEDs tested, when placed, respectively, 10 cm and 6 cm and 15 cm apart. ©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.

  19. 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....

  20. 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...

  1. Arquitectura y prestaciones de un router de conmutación de paquetes ópticos para las futuras redes de Internet

    Directory of Open Access Journals (Sweden)

    Gustavo Puerto Leguizamón

    2010-01-01

    Full Text Available En este artículo se describe la arquitectura, funcionamiento y prestaciones de un prototipo de router de conmutación de paquetes ópticos con intercambio de etiqueta y con capacidad para procesar dos canales independientes. Además se describen los principales subsistemas usados en la arquitectura del router óptico de conmutación de paquetes en el cual se transportan 10Gb/s NRZ de carga de datos junto con 155Mb/s NRZ de etiqueta codificada en SCM sobre una subportadora de RF de 18GHz.

  2. A Multilevel Congestion-Based Global Router

    Directory of Open Access Journals (Sweden)

    Logan Rakai

    2009-01-01

    Full Text Available Routing in nanometer nodes creates an elevated level of importance for low-congestion routing. At the same time, advances in mathematical programming have increased the power to solve complex problems, such as the routing problem. Hence, new routing methods need to be developed that can combine advanced mathematical programming and modeling techniques to provide low-congestion solutions. In this paper, a hierarchical mathematical programming-based global routing technique that considers congestion is proposed. The main contributions presented in this paper include (i implementation of congestion estimation based on actual routing solutions versus purely probabilistic techniques, (ii development of a congestion-based hierarchy for solving the global routing problem, and (iii generation of a robust framework for solving the routing problem using mathematical programming techniques. Experimental results illustrate that the proposed global router is capable of reducing congestion and overflow by as much as 36% compared to the state-of-the-art mathematical programming models.

  3. GMPLS control plane extensions in support of flex-grid enabled elastic optical networks

    DEFF Research Database (Denmark)

    Turus, Ioan; Fagertun, Anna Manolova; Dittmann, Lars

    2013-01-01

    of generalized labels format and enable enhancements for the wavelength selection procedures. OSPF-TE enables the creation of spectrum databases based on novel LSA sub-TLV attributes capable of advertising spectrum status. Based on the implemented extensions, we propose and evaluate advanced distributed spectrum...... allocation schemes and strategies for dynamic routing algorithms in support of flex-grid optical networks....

  4. PI Stabilization for Congestion Control of AQM Routers with Tuning Parameter Optimization

    Directory of Open Access Journals (Sweden)

    S. Chebli

    2016-09-01

    Full Text Available In this paper, we consider the problem of stabilizing network using a new proportional- integral (PI based congestion controller in active queue management (AQM router; with appropriate model approximation in the first order delay systems, we seek a stability region of the controller by using the Hermite- Biehler theorem, which isapplicable to quasipolynomials. A Genetic Algorithm technique is employed to derive optimal or near optimal PI controller parameters.

  5. Wavelength converter placement in optical networks with dynamic traffic

    DEFF Research Database (Denmark)

    Buron, Jakob Due; Ruepp, Sarah Renée; Wessing, Henrik

    2008-01-01

    We evaluate the connection provisioning performance of GMPLS-controlled wavelength routed networks under dynamic traffic load and using three different wavelength converter placement heuristics. Results show that a simple uniform placement heuristic matches the performance of complex heuristics...

  6. On the Design of Energy Efficient Optical Networks with Software Defined Networking Control Across Core and Access Networks

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Yan, Ying; Dittmann, Lars

    2013-01-01

    This paper presents a Software Defined Networking (SDN) control plane based on an overlay GMPLS control model. The SDN control platform manages optical core networks (WDM/DWDM networks) and the associated access networks (GPON networks), which makes it possible to gather global information...... and enable wider areas' energy efficiency networking. The energy related information of the networks and the types of the traffic flows are collected and utilized for the end-to-end QoS provision. Dynamic network simulation results show that by applying different routing algorithms according to the type...... of traffic in the core networks, the energy efficiency of the network is improved without compromising the quality of service....

  7. 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

  8. 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

  9. End to End Inter-domain Quality of Service Provisioning

    DEFF Research Database (Denmark)

    Brewka, Lukasz Jerzy

    This thesis addresses selected topics of Quality of Service (QoS) provisioning in heterogeneous data networks that construct the communication environment of today's Internet. In the vast range of protocols available in different domains of network infrastructures, a few chosen ones are discussed......, the general UPnPQoS performance was assessed analytically and confirmed by simulations results. The results validate the usability of UPnP-QoS, but some open issues in the specication were identified. As a result of addressing mentioned shortcomings of UPnP-QoS, a few pre-emption algorithms for home gateway...... and discuss also access Passive Optical Network (PON) technologies, a GMPLS controlled Ten Gigabit Passive Optical Network (XGPON) was proposed. This part of the thesis introduces the possibility of managing the XG-PON by the GMPLS suite, showing again that this protocol suite is a good candidate...

  10. 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...

  11. Multi-link faults localization and restoration based on fuzzy fault set for dynamic optical networks.

    Science.gov (United States)

    Zhao, Yongli; Li, Xin; Li, Huadong; Wang, Xinbo; Zhang, Jie; Huang, Shanguo

    2013-01-28

    Based on a distributed method of bit-error-rate (BER) monitoring, a novel multi-link faults restoration algorithm is proposed for dynamic optical networks. The concept of fuzzy fault set (FFS) is first introduced for multi-link faults localization, which includes all possible optical equipment or fiber links with a membership describing the possibility of faults. Such a set is characterized by a membership function which assigns each object a grade of membership ranging from zero to one. OSPF protocol extension is designed for the BER information flooding in the network. The BER information can be correlated to link faults through FFS. Based on the BER information and FFS, multi-link faults localization mechanism and restoration algorithm are implemented and experimentally demonstrated on a GMPLS enabled optical network testbed with 40 wavelengths in each fiber link. Experimental results show that the novel localization mechanism has better performance compared with the extended limited perimeter vector matching (LVM) protocol and the restoration algorithm can improve the restoration success rate under multi-link faults scenario.

  12. Design and evaluation of FDDI fiber optics networkfor Ethernets, VAX's and Ingraph work stations

    Science.gov (United States)

    Wernicki, M. Chris

    1992-09-01

    The purpose of this project is to design and evaluate the FDDI Fiber Optics Network for Ethernets, VAX's, and Ingraph work stations. From the KSC Headquarters communication requirement, it would be necessary to develop the FDDI network based on IEEE Standards outlined in the ANSI X3T9.5, Standard 802.3 and 802.5 topology - direct link via intermediate concentrator and bridge/router access. This analysis should examine the major factors that influence the operating conditions of the Headquarters Fiber plant. These factors would include, but are not limited to the interconnecting devices such as repeaters, bridges, routers and many other relevant or significant FDDI characteristics. This analysis is needed to gain a better understanding of overall FDDI performance.

  13. Design and evaluation of FDDI fiber optics networkfor Ethernets, VAX's and Ingraph work stations

    Science.gov (United States)

    Wernicki, M. Chris

    1992-01-01

    The purpose of this project is to design and evaluate the FDDI Fiber Optics Network for Ethernets, VAX's, and Ingraph work stations. From the KSC Headquarters communication requirement, it would be necessary to develop the FDDI network based on IEEE Standards outlined in the ANSI X3T9.5, Standard 802.3 and 802.5 topology - direct link via intermediate concentrator and bridge/router access. This analysis should examine the major factors that influence the operating conditions of the Headquarters Fiber plant. These factors would include, but are not limited to the interconnecting devices such as repeaters, bridges, routers and many other relevant or significant FDDI characteristics. This analysis is needed to gain a better understanding of overall FDDI performance.

  14. 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).

  15. 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.

  16. THE EXAMINATION OF THE PERFORMANCE FACTORS ON NG-DWDM SYSTEMS WITH ROADM STRUCTURE

    OpenAIRE

    Yücel, Murat; Özduman, Yusuf

    2016-01-01

    Nowadays, the new technologies provide high capacity by using 100 Gb/s channels. These systems are useful, practical, and flexible by using Optical Transport Networks (OTN) and Reconfigurable Optical Add Drop Multiplexers (ROADMs) structures. These new features supply new protection mechanisms over switching on Wavelength Selective Switching (WSS) layer, and Automatically Switching Optical Network (ASON) that is the Generalized Multiprotocol Label Switching (GMPLS) based software runs on the ...

  17. 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.

  18. Performance Enhancement of Optical CDMA by Differential-Phase Method for Radio-over-Fiber Transmissions

    Directory of Open Access Journals (Sweden)

    Hsu-Chih Cheng

    2013-01-01

    Full Text Available The study proposes the differential-phase optical code-division multiple-access (OCDMA network for radio-over-fiber (RoF transmissions, and the characteristics are numerically analyzed. The network coder/decoders (codecs are structured on the basis of arrayed-waveguide-grating (AWG routers with complementary Walsh-Hadamard (CWH signature codes. In the proposed system, the network requires only two AWG routers to accomplish spectral encoding of radio base station (RBS and decoding of control station for the complementary keying, thus resulting in a simpler and low cost system. Performance analyses are evaluated with the dominant noise of phase-induced intensity noise (PIIN in spectral code OCDMA network. By the proposed AWG-based OCDMA with the differential-phase scheme, it is possible to establish interference-free and low crosstalk beat noise RoF systems.

  19. Integration of QoS provisioning in home and access networks

    DEFF Research Database (Denmark)

    Popov, Mikhail; Gavler, A.; Sköldström, P.

    2010-01-01

    Approaches for QoS provisioning using UPnP for home networks and GMPLS for access networks are described. A solution for interworking the UPnP and the GMPLS at the residential gateway is proposed.......Approaches for QoS provisioning using UPnP for home networks and GMPLS for access networks are described. A solution for interworking the UPnP and the GMPLS at the residential gateway is proposed....

  20. ANALISIS PENGARUH KONFIGURASI EIGRP EQUAL DAN UNEQUAL COST LOAD BALANCING TERHADAP KINERJA ROUTER

    Directory of Open Access Journals (Sweden)

    Dian Bagus Saptonugroho

    2015-04-01

    Full Text Available Routing protocol is tasked with finding the best route to send the packet. Assessed using the metric. If there is more than one route with the same metric value, Routing Information Path (RIP, Open Shortest Path First (OSPF, and Enhanched Interior Gateway Routing Protocol (EIGRP support equal cost load balancing to send packets to the destination. If there is more than one route with a different metric values, EIGRP can do unequal cost load balancing. Research needs to be conducted to determine the effect of the configuration of EIGRP equal and unequal cost load balancing on the performance of the router which can be used as a proof-of-concept testing that is part of the project design document on a network. Research networks using EIGRP as the routing protocol. After the equal and unequal load balancing is enabled by configuring the variance, CEF, per-destination load balancing, per-packet load balancing, or traffic sharing and analyzing its effect on the neighbor table, topology table, routing table, the data transmission, survivability, convergence, throughput, and utilization. This study used an emulator GNS3 as Cisco 2691 Router with Cisco IOS version 12:24 (25 c and advanced enterprise-adventerprisek9 image c2691-mz.124-25c.bin, and OPNET Modeler 14.5 for simulation. The results of the study can be used as a proof-of-concept testing in the design document for later use as contemplated in the manufacture of plan implementation and verification plan.

  1. Proposal to endorse the award of a contract for the supply of a juniper T320 network router

    CERN Document Server

    2003-01-01

    This document concerns the award of a contract for the supply of a JUNIPER T320 Network Router. The Finance Committee is invited to endorse the CERN Management's decision to negotiate a contract with QWEST COMMUNICATION (USA) for the supply of a JUNIPER T320 Network Router for a total amount not exceeding 265 000 US dollars (350 000 Swiss francs). The Finance Committee is also requested to approve the negotiation of a maintenance contract for a value not exceeding 50 000 US dollars (66 000 Swiss francs) for three years and the option to purchase additional network interfaces for a value not exceeding 100 000 US dollars (132 000 Swiss francs) bringing the total amount to 415 000 US dollars (548 000 Swiss francs), not subject to revision. CERN's contribution will not exceed 90 000 Swiss francs. The amounts in Swiss francs have been calculated using the present rate of exchange. The firm has indicated the following distribution by country of the contract value covered by this adjudication proposal: CA - 100%.

  2. Tunable optical nonreciprocity and a phonon-photon router in an optomechanical system with coupled mechanical and optical modes

    Science.gov (United States)

    Li, Guolong; Xiao, Xiao; Li, Yong; Wang, Xiaoguang

    2018-02-01

    We propose a multimode optomechanical system to realize tunable optical nonreciprocity that has the prospect of making an optical diode for information technology. The proposed model consists of two subsystems, each of which contains two optical cavities, injected with a classical field and a quantum signal via a 50:50 beam splitter, and a mechanical oscillator, coupled to both cavities via optomechanical coupling. Meanwhile two cavities and an oscillator in a subsystem are respectively coupled to their corresponding cavities and an oscillator in the other subsystem. Our scheme yields nonreciprocal effects at different frequencies with opposite directions, but each effective linear optomechanical coupling can be controlled by an independent classical one-frequency pump. With this setup one is able to apply quantum states with large fluctuations, which extends the scope of applicable quantum states, and exploit the independence of paths. Moreover, the optimal frequencies for nonreciprocal effects can be controlled by adjusting the relevant parameters. We also exhibit the path switching of two directions, from a mechanical input to two optical output channels, via tuning the signal frequency. In experiment, the considered scheme can be tuned to reach small damping rates of the oscillators relative to those of the cavities, which is more practical and requires less power than in previous schemes.

  3. 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...

  4. Prioritizing connection requests in GMPLS-controlled optical networks

    DEFF Research Database (Denmark)

    Ruepp, Sarah Renée; Koster, A.; Andriolli, N.

    2009-01-01

    We prioritize bidirectional connection requests by combining dynamic connection provisioning with off-line optimization. Results show that the proposed approach decreases wavelength-converter usage, thereby allowing operators to reduce blocking-probably under bulk connection assignment or network...

  5. Survivability Strategies for Epidemic Failures in Heterogeneous Networks

    DEFF Research Database (Denmark)

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

    2013-01-01

    Nowadays, transport networks, carry extremely large amounts of network traffic, and are widely spread across multiple geographical locations. As a result, any possible connectivity failure could directly impact the service delivery of a vast amount of users. Therefore, the network should be able...... protection, path restoration) X[1]X. Hence, assuming sufficient resources, network resilience can be achieved when a single failure occur (e.g. fiber cut). However, when it comes to simultaneous failures such as cascading and epidemic failures, the available solutions are expensive X[2]X. For Generalized...... the network X[6]X[7]X. This paper evaluates the reliability of a GMPLS transport network under epidemic failure scenarios. Thus, the aim is to increase the fault tolerance of the GMPLS technology when simultaneous failures occur impacting a large number of network nodes across an optical transport network...

  6. Dynamic traffic grooming with Spectrum Engineering (TG-SE) in flexible grid optical networks

    Science.gov (United States)

    Yu, Xiaosong; Zhao, Yongli; Zhang, Jiawei; Wang, Jianping; Zhang, Guoying; Chen, Xue; Zhang, Jie

    2015-12-01

    Flexible grid has emerged as an evolutionary technology to satisfy the ever increasing demand for higher spectrum efficiency and operational flexibility. To optimize the spectrum resource utilization, this paper introduces the concept of Spectrum Engineering in flex-grid optical networks. The sliceable optical transponder has been proposed to offload IP traffic to the optical layer and reduce the number of IP router ports and transponders. We discuss the impact of sliceable transponder in traffic grooming and propose several traffic-grooming schemes with Spectrum Engineering (TG-SE). Our results show that there is a tradeoff among different traffic grooming policies, which should be adopted based on the network operator's objectives. The proposed traffic grooming with Spectrum Engineering schemes can reduce OPEX as well as increase spectrum efficiency by efficiently utilizing the bandwidth variability and capability of sliceable optical transponders.

  7. 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.

  8. WDM Optical Access Network for Full-Duplex and Reconfigurable Capacity Assignment Based on PolMUX Technique

    Directory of Open Access Journals (Sweden)

    Jose Mora

    2014-12-01

    Full Text Available We present a novel bidirectional WDM-based optical access network featuring reconfigurable capacity assignment. The architecture relies on the PolMUX technique allowing a compact, flexible, and bandwidth-efficient router in addition to source-free ONUs and color-less ONUs for cost/complexity minimization. Moreover, the centralized architecture contemplates remote management and control of polarization. High-quality transmission of digital signals is demonstrated through different routing scenarios where all channels are dynamically assigned in both downlink and uplink directions.

  9. CWDM for very-short-reach and optical-backplane interconnections

    Science.gov (United States)

    Laha, Michael J.

    2002-06-01

    Course Wavelength Division Multiplexing (CWDM) provides access to next generation optical interconnect data rates by utilizing conventional electro-optical components that are widely available in the market today. This is achieved through the use of CWDM multiplexers and demultiplexers that integrate commodity type active components, lasers and photodiodes, into small optical subassemblies. In contrast to dense wavelength division multiplexing (DWDM), in which multiple serial data streams are combined to create aggregate data pipes perhaps 100s of gigabits wide, CWDM uses multiple laser sources contained in one module to create a serial equivalent data stream. For example, four 2.5 Gb/s lasers are multiplexed to create a 10 Gb/s data pipe. The advantages of CWDM over traditional serial optical interconnects include lower module power consumption, smaller packaging, and a superior electrical interface. This discussion will detail the concept of CWDM and design parameters that are considered when productizing a CWDM module into an industry standard optical interconnect. Additionally, a scalable parallel CWDM hybrid architecture will be described that allows the transport of large amounts of data from rack to rack in an economical fashion. This particular solution is targeted at solving optical backplane bottleneck problems predicted for the next generation terabit and petabit routers.

  10. Integrated Optical Content Addressable Memories (CAM and Optical Random Access Memories (RAM for Ultra-Fast Address Look-Up Operations

    Directory of Open Access Journals (Sweden)

    Christos Vagionas

    2017-07-01

    Full Text Available Electronic Content Addressable Memories (CAM implement Address Look-Up (AL table functionalities of network routers; however, they typically operate in the MHz regime, turning AL into a critical network bottleneck. In this communication, we demonstrate the first steps towards developing optical CAM alternatives to enable a re-engineering of AL memories. Firstly, we report on the photonic integration of Semiconductor Optical Amplifier-Mach Zehnder Interferometer (SOA-MZI-based optical Flip-Flop and Random Access Memories on a monolithic InP platform, capable of storing the binary prefix-address data-bits and the outgoing port information for next hop routing, respectively. Subsequently the first optical Binary CAM cell (B-CAM is experimentally demonstrated, comprising an InP Flip-Flop and a SOA-MZI Exclusive OR (XOR gate for fast search operations through an XOR-based bit comparison, yielding an error-free 10 Gb/s operation. This is later extended via physical layer simulations in an optical Ternary-CAM (T-CAM cell and a 4-bit Matchline (ML configuration, supporting a third state of the “logical X” value towards wildcard bits of network subnet masks. The proposed functional CAM and Random Access Memories (RAM sub-circuits may facilitate light-based Address Look-Up tables supporting search operations at 10 Gb/s and beyond, paving the way towards minimizing the disparity with the frantic optical transmission linerates, and fast re-configurability through multiple simultaneous Wavelength Division Multiplexed (WDM memory access requests.

  11. An infrastructure with a unified control plane to integrate IP into optical metro networks to provide flexible and intelligent bandwidth on demand for cloud computing

    Science.gov (United States)

    Yang, Wei; Hall, Trevor

    2012-12-01

    The Internet is entering an era of cloud computing to provide more cost effective, eco-friendly and reliable services to consumer and business users and the nature of the Internet traffic will undertake a fundamental transformation. Consequently, the current Internet will no longer suffice for serving cloud traffic in metro areas. This work proposes an infrastructure with a unified control plane that integrates simple packet aggregation technology with optical express through the interoperation between IP routers and electrical traffic controllers in optical metro networks. The proposed infrastructure provides flexible, intelligent, and eco-friendly bandwidth on demand for cloud computing in metro areas.

  12. Optical Microresonators Theory, Fabrication, and Applications

    CERN Document Server

    Heebner, John; Ibrahim, Tarek

    2008-01-01

    This book explains why microresonators came to be important components in the photonic toolbox. While functionally similar to the Fabry-Perot, microring resonators offer a planar nature which is naturally compatible with monolithic microfabrication technologies. In these chapters lie the principles required to characterize, design, construct, and implement microresonators as lasers, amplifiers, sensors, filters, demultiplexers, switches, routers, and logic gates. Additionally, much like quantum dots and photonic crystals, it will be shown how microresonators offer an alternative method for creating engineerable materials with designer linear and nonlinear responses tailored for advanced functionalities operating at ultrafast speeds and compact scales. This is the first detailed text on the theory, fabrication, and applications of optical microresonators, and will be found useful by both graduate students and researchers. With an emphasis on building intuition with distilled equations and graphical illustratio...

  13. Optical Backplane Based on Ring-Resonators: Scalability and Performance Analysis for 10 Gb/s OOK-NRZ

    Directory of Open Access Journals (Sweden)

    Giuseppe Rizzelli

    2014-05-01

    Full Text Available The use of architectures that implement optical switching without any need of optoelectronic conversion allows us to overcome the limits imposed by today’s electronic backplane, such as power consumption and dissipation, as well as power supply and footprint requirements. We propose a ring-resonator based optical backplane for router line-card interconnection. In particular we investigate how the scalability of the architecture is affected by the following parameters: number of line cards, switching-element round-trip losses, frequency drifting due to thermal variations, and waveguide-crossing effects. Moreover, to quantify the signal distortions introduced by filtering operations, the bit error rate for the different parameter conditions are shown in case of an on-off keying non-return-to-zero (OOK-NRZ input signal at 10 Gb/s.

  14. Nonlinearity effect of electro-optical modulator response in double spread CDMA radio-over-fiber transmissions

    Science.gov (United States)

    Huang, Jen-Fa; Yen, Chih-Ta; Li, Tzung-Yen

    2008-07-01

    This study presents a double-spread code-division multiple-access (CDMA) scheme for radio-over-fiber (RoF) transmissions. The network coder/decoders (codecs) are implemented using arrayed-waveguide grating (AWG) routers coded with maximal-length sequence ( M-sequence) codes. The effects of phase-induced intensity noise (PIIN) and multiple-access interference (MAI) on the system performance are evaluated numerically for different values of the optical modulation index (OMI) during the nonlinear electro-optical modulator (EOM) response. At low OMI optical device noise is dominant, but at high OMI nonlinear effect becomes significant. Numerical result shows that the system performance is highly sensitive to the OMI. Therefore, specifying an appropriate value of the OMI is essential in optimizing the system performance. The influence of the degree of polarization (DOP) in the system is also discussed. By employing the scrambler in front of the balanced photo-detector, the system performance can be enhanced. The high-performance, low-cost characteristics of the double-spread CDMA render the scheme an ideal solution for radio-CDMA wireless system cascaded with optical CDMA network.

  15. The Exposure Duration and Distance Effects of Microwave Radiation from Wireless Routers on Sperm Parameters of Wistar Rats

    Directory of Open Access Journals (Sweden)

    S Safari

    2015-12-01

    Full Text Available Background & aim: As a communication technology, Wi-Fi allows electronic devices such as laptops to exchange data or connect to a network resource such as the Internet via a wireless network access point  using 2.4 GHz microwave radiation. However, with the exponential development of wireless communication technology, the public concern regarding the safety of this technology has increased rapidly. The main goal of this study was to assess the bio effects of duration of exposure of an animal model to 2.4 GHz microwave radiation emitted from a common Wi-Fi router on sperm quality. Method: In the present experimental study, 84 male Wistar rats were used. The mice were randomly divided based on the duration of exposure to microwave radiation and distance to the modem into seven groups of 12. Group II rats were exposed to 2.4 GHz microwave radiation for 2 hours per day in term of 7 days at a distance of 30 cm from the router. The rats in this group were allowed to live for 53 days then sacrificed and semen samples analyzed. Rats in all the groups except group II, were sacrificed 30 min to 1 hr.After exposure. To analyze the results, The Mann-Whitney and Kruskal-Wallis tests were used. Result: The average sperm with normal morphology, testes weight and number of spermatogonial cells after exposure to microwave radiation decreased. With increasing exposure time and reduce the distance to the modem, testis weight and the number of spermatogonia cells significantly reduced. Conclusion: Beams of microwave radiation from Wi-Fi modems leads to sperm morphological changes and weight loss of testicular spermatogonia. With increasing exposure time and reduce the distance to the modem, testis weight and the number of spermatogonia cells significantly reduced.

  16. 06 Chapter 6

    African Journals Online (AJOL)

    Nathan

    fiber optic cable links and by wireless (radio) antennae. Access to the Internet .... 1. Lucent Orinoco Central Office Router w/2.4GHz. Wireless. 3. 381,920.00 1,145,760.00. 2. Lucent Orinoco Remote Outdoor Router w/2.4. Ghz Wireless Card. 12. 353,500.00 ... making it quite secure, and it is inherently safer than coaxial cable ...

  17. Network Performance Improvement under Epidemic Failures in Optical Transport Networks

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    In this paper we investigate epidemic failure spreading in large- scale GMPLS-controlled transport networks. By evaluating the effect of the epidemic failure spreading on the network, we design several strategies for cost-effective network performance improvement via differentiated repair times....... First we identify the most vulnerable and the most strategic nodes in the network. Then, via extensive simulations we show that strategic placement of resources for improved failure recovery has better performance than randomly assigning lower repair times among the network nodes. Our OPNET simulation...... model can be used during the network planning process for facilitating cost- effective network survivability design....

  18. 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

  19. 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.

  20. Polarization diversity scheme on spectral polarization coding optical code-division multiple-access network

    Science.gov (United States)

    Yen, Chih-Ta; Huang, Jen-Fa; Chang, Yao-Tang; Chen, Bo-Hau

    2010-12-01

    We present an experiment demonstrating the spectral-polarization coding optical code-division multiple-access system introduced with a nonideal state of polarization (SOP) matching conditions. In the proposed system, the encoding and double balanced-detection processes are implemented using a polarization-diversity scheme. Because of the quasiorthogonality of Hadamard codes combining with array waveguide grating routers and a polarization beam splitter, the proposed codec pair can encode-decode multiple code words of Hadamard code while retaining the ability for multiple-access interference cancellation. The experimental results demonstrate that when the system is maintained with an orthogonal SOP for each user, an effective reduction in the phase-induced intensity noise is obtained. The analytical SNR values are found to overstate the experimental results by around 2 dB when the received effective power is large. This is mainly limited by insertion losses of components and a nonflattened optical light source. Furthermore, the matching conditions can be improved by decreasing nonideal influences.

  1. On the impact of fiber-delay-lines (FDL) in an all-optical network (AON) bottleneck without wavelength conversion

    Science.gov (United States)

    Argibay-Losada, Pablo Jesus; Sahin, Gokhan

    2014-08-01

    Random access memories (RAM) are fundamental in conventional electronic switches and routers to manage short-term congestion and to decrease data loss probabilities. Switches in all-optical networks (AONs), however, do not have access to optical RAM, and therefore are prone to much higher loss levels than their electronic counterparts. Fiber-delay-lines (FDLs), able to delay an optical data packet a fixed amount of time, have been proposed in the literature as a means to alleviate those high loss levels. However, they are extremely bulky to manage, so their usage introduces a trade-off between practicality and performance in the design and operation of the AON. In this paper we study the influence that FDLs have in the performance of flows crossing an all-optical switch that acts as their bottleneck. We show how extremely low numbers of FDLs (e.g., 1 or 2) can help in reducing losses by several orders of magnitude in several illustrative scenarios with high aggregation levels. Our results therefore suggest that FDLs can be a practical means of dealing with congestion in AONs in the absence of optical RAM buffers or of suitable data interchange protocols specifically designed for AONs.

  2. 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.

  3. Distributed Sharing of Functionalities and Resources in Survivable GMPLS-controlled WSONs

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Cerutti, I.; Muñoz, R.

    2012-01-01

    Sharing of functionalities and sharing of network resources are effective solutions for improving the cost-effectiveness of wavelength-switched optical networks (WSONs). Such cost-effectiveness should be pursued together with the objective of ensuring the requested level of performance at the phy...

  4. High capacity fiber optic sensor networks using hybrid multiplexing techniques and their applications

    Science.gov (United States)

    Sun, Qizhen; Li, Xiaolei; Zhang, Manliang; Liu, Qi; Liu, Hai; Liu, Deming

    2013-12-01

    Fiber optic sensor network is the development trend of fiber senor technologies and industries. In this paper, I will discuss recent research progress on high capacity fiber sensor networks with hybrid multiplexing techniques and their applications in the fields of security monitoring, environment monitoring, Smart eHome, etc. Firstly, I will present the architecture of hybrid multiplexing sensor passive optical network (HSPON), and the key technologies for integrated access and intelligent management of massive fiber sensor units. Two typical hybrid WDM/TDM fiber sensor networks for perimeter intrusion monitor and cultural relics security are introduced. Secondly, we propose the concept of "Microstructure-Optical X Domin Refecltor (M-OXDR)" for fiber sensor network expansion. By fabricating smart micro-structures with the ability of multidimensional encoded and low insertion loss along the fiber, the fiber sensor network of simple structure and huge capacity more than one thousand could be achieved. Assisted by the WDM/TDM and WDM/FDM decoding methods respectively, we built the verification systems for long-haul and real-time temperature sensing. Finally, I will show the high capacity and flexible fiber sensor network with IPv6 protocol based hybrid fiber/wireless access. By developing the fiber optic sensor with embedded IPv6 protocol conversion module and IPv6 router, huge amounts of fiber optic sensor nodes can be uniquely addressed. Meanwhile, various sensing information could be integrated and accessed to the Next Generation Internet.

  5. Performance Evaluation of Resilience using Service Relocation for GMPLS Networks

    DEFF Research Database (Denmark)

    Wessing, Henrik; Herrmann, Sven; Ruepp, Sarah Renée

    2015-01-01

    Cloud computing today represents an ever increasing part of the data exchanged over the Internet. This influences the core network, where the special properties of cloud based services can be leveraged to increase the network efficiency. This paper explores the concept of relocation for the backup...... path when providing resiliency to cloud services in the network. The control plane of a GMPLSenabled optical network is simulated, thus evaluating the proposed Path Computation Element architecture for service relocation. The results show that for increased offered traffic in the network, the overall...

  6. Realization of OSW/AWG-based bipolar wavelength time optical CDMA for wired wireless transmissions

    Science.gov (United States)

    Yen, Chih-Ta; Huang, Jen-Fa

    2009-01-01

    This study proposes a novel radio-over-fiber (RoF) system using two-dimensional (2-D) optical code-division multiple-access (OCDMA) scheme using pseudorandom (PN) codes for the time-spreading and wavelength-hopping ( t-spreading/ λ-hopping) codes. The 2-D system is implemented using optical switches (OSWs) and arrayed-waveguide grating (AWG) routers. By constructing 2-D codes using bipolar PN codes rather than unipolar codes provides a significant increase in the maximum permissible number of active radio base stations (RBSs). In general, the phase-induced intensity noise (PIIN) generated at high optical intensities significantly degrades the performance of a conventional multi-wavelength scheme. However, the OSW-based time-spreading method employed in the current 2-D OCDMA scheme effectively suppresses the PIIN effect. Additionally, multiple-access interference (MAI) is suppressed by the use of a wavelength/time balanced detector structure in the network receivers. The numerical evaluation results demonstrate that under PIIN- and MAI-limited conditions, the proposed system outperforms a conventional multi-wavelength OCDMA scheme by using the spectral spreading scheme to suppress beating noise. Especially, the t-spreading encoder/decoder (codec) groups share the same wavelength codec and the overall complexity is reduced and system network becomes more compact.

  7. Multicast routing for wavelength-routed WDM networks with dynamic membership

    Science.gov (United States)

    Huang, Nen-Fu; Liu, Te-Lung; Wang, Yao-Tzung; Li, Bo

    2000-09-01

    Future broadband networks must support integrated services and offer flexible bandwidth usage. In our previous work, we explore the optical link control layer on the top of optical layer that enables the possibility of bandwidth on-demand service directly over wavelength division multiplexed (WDM) networks. Today, more and more applications and services such as video-conferencing software and Virtual LAN service require multicast support over the underlying networks. Currently, it is difficult to provide wavelength multicast over the optical switches without optical/electronic conversions although the conversion takes extra cost. In this paper, based on the proposed wavelength router architecture (equipped with ATM switches to offer O/E and E/O conversions when necessary), a dynamic multicast routing algorithm is proposed to furnish multicast services over WDM networks. The goal is to joint a new group member into the multicast tree so that the cost, including the link cost and the optical/electronic conversion cost, is kept as less as possible. The effectiveness of the proposed wavelength router architecture as well as the dynamic multicast algorithm is evaluated by simulation.

  8. Evaluation of the Protective Role of Vitamin C on the Metabolic and Enzymatic Activities of the Liver in the Male Rats After Exposure to 2.45 GHz Of Wi-Fi Routers

    Directory of Open Access Journals (Sweden)

    Shekoohi-Shooli F.

    2016-09-01

    Full Text Available Background: The use of devices emitted microwave radiation such as mobile phones, wireless fidelity (Wi-Fi routers, etc. is increased rapidly. It has caused a great concern; the researchers should identify its effects on people’s health. We evaluated the protective role of Vitamin C on the metabolic and enzymatic activities of the liver after exposure to Wi-Fi routers. Material and Methods: 70 male Wistar rats weighing 200-250 g were randomly divided into 7 groups (10 rats in each group.The first stage one –day test: Group A (received vitamin C 250 mg/kg/day orally together with 8- hour/day Wi-Fi exposure. Group B (exposed to Wi-Fi radiation. Group C (received vitamin C. Group D or Control (was neither exposed to radiation of Wi-Fi modem nor did receive vitamin C. The second phase of experiment had done for five consecutive days. It involved Group E (received vitamin C, Group F (exposed to Wi-Fi radiation, Group G (received vitamin C together with Wi-Fi radiation. The distance between animals’ restrainers was 20 cm away from the router antenna. Finally, blood samples were collected and assayed the level of hepatic enzymes including alkaline phosphatase(ALP, alanine amino transferase(ALT aspartate amino transferase (ASL, gamma glutamyl transferase (GGT and the concentration of Blood Glucose, Cholesterol , Triglyceride(TG,High density lipoprotein (HDLand low density lipoprotein (LDL. Results: Data obtained from the One day test showed an increase in concentration of blood glucose, decrease in Triglyceride level and GGT factor (P<0.05, however no observed significant difference on the Cholesterol , HDL , LDL level and hepatic enzymes activities in compare to control group. Groups of the five-day test showed reduction in the amount of blood glucose, elevation of cholesterol level and LDL relative to control group(P<0.05. Conclusion: WiFi exposure may exert alternations on the metabolic parameters and hepatic enzymes activities through stress

  9. Future High Capacity Backbone Networks

    DEFF Research Database (Denmark)

    Wang, Jiayuan

    are proposed. The work focuses on energy efficient routing algorithms in a dynamic optical core network environment, with Generalized MultiProtocol Label Switching (GMPLS) as the control plane. Energy ef- ficient routing algorithms for energy savings and CO2 savings are proposed, and their performance...... aiming for reducing the dynamic part of the energy consumption of the network may increase the fixed part of the energy consumption meanwhile. In the second half of the thesis, the conflict between energy efficiency and Quality of Service (QoS) is addressed by introducing a novel software defined......This thesis - Future High Capacity Backbone Networks - deals with the energy efficiency problems associated with the development of future optical networks. In the first half of the thesis, novel approaches for using multiple/single alternative energy sources for improving energy efficiency...

  10. Development of High-Speed, Low-fixed Latency Serial Links for the Router of ATLAS NSW sTGC Detector

    CERN Document Server

    Hu, Xueye; The ATLAS collaboration

    2014-01-01

    The ATLAS experiment at the Large Hadron Collider (LHC) needs to be upgraded in order to cope with the increased luminosity and particle rates expected for the High Luminosity LHC (HL­LHC) running. Part of the phase­1 upgrade, to be done in the 2018/19 shutdown, is the replacement of the present muon forward detector (wheel) by a new detector, the so called New Small Wheel (NSW). The NSW detector consists of two detector technologies and the work here is on the small­strip Thin­Gap Chambers (sTGC). For sTGC, it requires very high­speed electronic triggering of signal events. The data must be quickly digitized, serialized, and transmitted off­detector for computer processing. The serialized data is sent to the trigger processor through a routing system that serves as a switchyard for all active signals. Design requirements on the router are low latency and stable/predictable data transfer timing with high­speed serial links (4.8 Gbps). We describe a 4.8 Gbps (maximum 6.6 Gbps) serial link structure base...

  11. The SIP express router: An open source SIP platform: Presentation held at EVOLUTE - seamlEss multimedia serVices Over alL IP-based infrastrUcTurEs Workshop, 10. November 2003, Guildford, UK

    OpenAIRE

    Rebahi, Y.; Sisalem, D.; Kuthan, J.; Pelinescu-Oncicul, A.; Iancu, B.; Janak, J.; Mierla, D.C.

    2003-01-01

    The session initiation protocol (SIP) is constantly gaining in popularity and acceptance as the signaling protocol for next generation multimedia communication. This paper describes a scalable and reliable open source SIP platform called the SIP Express Router (SER). SER does not only support basic SIP features but also advanced features such as messaging and presence, translation between SIP and SMS or Jabber as well as full featured application programming interfaces. In this paper we will ...

  12. Dynamic routing and spectrum assignment based on multilayer virtual topology and ant colony optimization in elastic software-defined optical networks

    Science.gov (United States)

    Wang, Fu; Liu, Bo; Zhang, Lijia; Zhang, Qi; Tian, Qinghua; Tian, Feng; Rao, Lan; Xin, Xiangjun

    2017-07-01

    Elastic software-defined optical networks greatly improve the flexibility of the optical switching network while it has brought challenges to the routing and spectrum assignment (RSA). A multilayer virtual topology model is proposed to solve RSA problems. Two RSA algorithms based on the virtual topology are proposed, which are the ant colony optimization (ACO) algorithm of minimum consecutiveness loss and the ACO algorithm of maximum spectrum consecutiveness. Due to the computing power of the control layer in the software-defined network, the routing algorithm avoids the frequent link-state information between routers. Based on the effect of the spectrum consecutiveness loss on the pheromone in the ACO, the path and spectrum of the minimal impact on the network are selected for the service request. The proposed algorithms have been compared with other algorithms. The results show that the proposed algorithms can reduce the blocking rate by at least 5% and perform better in spectrum efficiency. Moreover, the proposed algorithms can effectively decrease spectrum fragmentation and enhance available spectrum consecutiveness.

  13. 100G Ethernet in the wild - first experiences

    Science.gov (United States)

    Hoeft, Bruno; Stoy, Robert; Schröder, Frank; Reymund, Aurelie; Niederberger, Ralf; Mextorf, Olaf; Werner, Sabine

    2011-12-01

    A 100 Gigabit Testbed was established in a collaboration of 6 partners. Three industry partners have contributed the fiber infrastructure, the DWDM equipment, as well as the required routers. 447 kilometer was the distance of the wide area testbed established in collaboration with the German NREN DFN between Karlsruhe Institute of Technology and Forschungszentrum Jülich Before starting, DFN assured the quality of the fiber infrastructure, the operation of the DWDM systems at both locations, as well as the connection of the routers to this WAN link with a bandwidth of 100GE. 12*10GE interfaces were available at each site for connecting the local testnodes to the routers. A monitoring and measurement framework was installed for recording the most important IP network performance metrics, among them the One Way Delay (OWD) and its Variation, Packet Loss and Packet Reordering. The delay measurements were conducted between the GPS time synchronized Hades[1]measurement nodes at each location. Additionally all relevant counters at the routers have been recorded using a SNMP based Network Manangement Station and supplemented special command line interface output gathering and parsing scripts. The interfaces statistics were stored in 60 second intervals. The aim of the testbed was to demonstrate a failure-free transmission of one or more IP datastreams over 100GE during the whole period of 4 weeks.This included the evaluation of the 100 Gbit/s optical transmission system, the 100GE interfaces between the routers and the optical system, and the evaluation of a sustained 100GE transmission as well as the evaluation of the use of 100GE in a production like environment. The evaluation included a circulated (in a routing loop) tunable load between 1 and 100 Gbit/s, measurement of transmission quality of TCP and UDP datastreams between the endsystems, measurements of one way latency, a ramping up data transmission from approx. 8 Gbit/s up to 96 Gbit/s.

  14. 100G Ethernet in the wild-first experiences

    International Nuclear Information System (INIS)

    Hoeft, Bruno; Reymund, Aurelie; Stoy, Robert; Schröder, Frank; Niederberger, Ralf; Mextorf, Olaf; Werner, Sabine

    2011-01-01

    A 100 Gigabit Testbed was established in a collaboration of 6 partners. Three industry partners have contributed the fiber infrastructure, the DWDM equipment, as well as the required routers. 447 kilometer was the distance of the wide area testbed established in collaboration with the German NREN DFN between Karlsruhe Institute of Technology and Forschungszentrum Julich Before starting, DFN assured the quality of the fiber infrastructure, the operation of the DWDM systems at both locations, as well as the connection of the routers to this WAN link with a bandwidth of 100GE. 12*10GE interfaces were available at each site for connecting the local testnodes to the routers. A monitoring and measurement framework was installed for recording the most important IP network performance metrics, among them the One Way Delay (OWD) and its Variation, Packet Loss and Packet Reordering. The delay measurements were conducted between the GPS time synchronized Hades [1] measurement nodes at each location. Additionally all relevant counters at the routers have been recorded using a SNMP based Network Manangement Station and supplemented special command line interface output gathering and parsing scripts. The interfaces statistics were stored in 60 second intervals. The aim of the testbed was to demonstrate a failure-free transmission of one or more IP datastreams over 100GE during the whole period of 4 weeks.This included the evaluation of the 100 Gbit/s optical transmission system, the 100GE interfaces between the routers and the optical system, and the evaluation of a sustained 100GE transmission as well as the evaluation of the use of 100GE in a production like environment. The evaluation included a circulated (in a routing loop) tunable load between 1 and 100 Gbit/s, measurement of transmission quality of TCP and UDP datastreams between the endsystems, measurements of one way latency, a ramping up data transmission from approx. 8 Gbit/s up to 96 Gbit/s.

  15. PHASAR-based WDM-devices: principles, design and applications

    NARCIS (Netherlands)

    Smit, M.K.; Dam, van C.

    1996-01-01

    Wavelength multiplexers, demultiplexers and routers based on optical phased arrays play a key role in multiwavelength telecommunication links and networks. In this paper, a detailed description of phased-array operation and design is presented and an overview is given of the most important

  16. A Kohonen neural network controlled all-optical router system

    NARCIS (Netherlands)

    Frietman, E.E.E.; Hill, M.T.; Khoe, G.D.

    2001-01-01

    The internet is composed of thousands of networks, linking millions of users at academic, industrial and governmental institutions all over the world, offering opportunities to collaborate and to share resources, such as documents, software and data. The ever-increasing number of users confronts the

  17. Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli.

    Science.gov (United States)

    Taheri, M; Mortazavi, S M J; Moradi, M; Mansouri, S; Hatam, G R; Nouri, F

    2017-01-01

    Mobile phones and Wi-Fi radiofrequency radiation are among the main sources of the exposure of the general population to radiofrequency electromagnetic fields (RF-EMF). Previous studies have shown that exposure of microorganisms to RF-EMFs can be associated with a wide spectrum of changes ranged from the modified bacterial growth to the alterations of the pattern of antibiotic resistance. Our laboratory at the nonionizing department of the Ionizing and Non-ionizing Radiation Protection Research Center has performed experiments on the health effects of exposure to animal models and humans to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons, magnetic resonance imaging, and Helmholtz coils. On the other hand, we have previously studied different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. In this study, we assessed if the exposure to 900 MHz GSM mobile phone radiation and 2.4 GHz radiofrequency radiation emitted from common Wi-Fi routers alters the susceptibility of microorganisms to different antibiotics. The pure cultures of Listeria monocytogenes and Escherichia coli were exposed to RF-EMFs generated either by a GSM 900 MHz mobile phone simulator and a common 2.4 GHz Wi-Fi router. It is also shown that exposure to RF-EMFs within a narrow level of irradiation (an exposure window) makes microorganisms resistant to antibiotics. This adaptive phenomenon and its potential threats to human health should be further investigated in future experiments. Altogether, the findings of this study showed that exposure to Wi-Fi and RF simulator radiation can significantly alter the inhibition zone diameters and growth rate for L monocytogenes and E coli. These findings may have implications for the management of serious infectious diseases.

  18. Optical CDMA with Embedded Spectral-Polarization Coding over Double Balanced Differential-Detector

    Science.gov (United States)

    Huang, Jen-Fa; Yen, Chih-Ta; Chen, Bo-Hau

    A spectral-polarization coding (SPC) optical code-division multiple-access (OCDMA) configuration structured over arrayed-waveguide grating (AWG) router is proposed. The polarization-division double balanced detector is adopted to execute difference detection and enhances system performance. The signal-to-noise ratio (SNR) is derived by taking the effect of PIIN into account. The result indicates that there would be up to 9-dB SNR improvement than the conventional spectral-amplitude coding (SAC) structures with Walsh-Hadamard codes. Mathematical deriving results of the SNR demonstrate the system embedded with the orthogonal state of polarization (SOP) will suppress effectively phase-induced intensity noise (PIIN). In addition, we will analyze the relations about bit error rate (BER) vs. the number of active users under the different encoding schemes and compare them with our proposed scheme. The BER vs. the effective power under the different encoding scheme with the same number of simultaneous active user conditions are also revealed. Finally, the polarization-matched factor and the difference between simulated and experimental values are discussed.

  19. Design of Active Queue Management for Robust Control on Access Router for Heterogeneous Networks

    Directory of Open Access Journals (Sweden)

    Åhlund Christer

    2011-01-01

    Full Text Available The Internet architecture is a packet switching technology that allows dynamic sharing of bandwidth among different flows with in an IP network. Packets are stored and forwarded from one node to the next until reaching their destination. Major issues in this integration are congestion control and how to meet different quality of service requirements associated with various services. In other words streaming media quality degrades with increased packet delay and jitter caused by network congestion. To mitigate the impact of network congestion, various techniques have been used to improve multimedia quality and one of those techniques is Active Queue Management (AQM. Access routers require a buffer to hold packets during times of congestion. A large buffer can absorb the bursty arrivals, and this tends to increase the link utilizations but results in higher queuing delays. Traffic burstiness has a considerable negative impact on network performance. AQM is now considered an effective congestion control mechanism for enhancing transport protocol performance over wireless links. In order to have good link utilization, it is necessary for queues to adapt to varying traffic loads. This paper considers a particular scheme which is called Adaptive AQM (AAQM and studies its performance in the presence of feedback delays and its ability to maintain a small queue length as well as its robustness in the presence of traffic burstiness. The paper also presents a method based on the well-known Markov Modulated Poisson Process (MPP to capture traffic burstiness and buffer occupancy. To demonstrate the generality of the presented method, an analytic model is described and verified by extensive simulations of different adaptive AQM algorithms. The analysis and simulations show that AAQM outperforms the other AQMs with respect to responsiveness and robustness.

  20. 顺序控制

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    On a roll: Burke E. Porter introduces customer-configurable roll test software.Ontology-based state space model generation for automatic design of sequence control program.Operational fault diagnosis of manufacturing systems.Packet sequence control algorithm in an optical packet router with shared buffers.Panel-Mounted Controller with integrated Display and Operation Functions.

  1. 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...

  2. Energy-efficient multicast traffic grooming strategy based on light-tree splitting for elastic optical networks

    Science.gov (United States)

    Liu, Huanlin; Yin, Yarui; Chen, Yong

    2017-07-01

    In order to address the problem of optimizing the spectrum resources and power consumption in elastic optical networks (EONs), we investigate the potential gains by jointly employing the light-tree splitting and traffic grooming for multicast requests. An energy-efficient multicast traffic grooming strategy based on light-tree splitting (EED-MTGS-LS) is proposed in this paper. Firstly, we design a traffic pre-processing mechanism to decide the multicast requests' routing order, which considers the request's bandwidth requirement and physical hops synthetically. Then, by dividing a light-tree to some sub-light-trees and grooming the request to these sub-light-trees, the light-tree sharing ratios of multicast requests can be improved. What's more, a priority scheduling vector is constructed, which aims to improve the success rate of spectrum assignment for grooming requests. Finally, a grooming strategy is designed to optimize the total power consumption by reducing the use of transponders and IP routers during routing. Simulation results show that the proposed strategy can significantly improve the spectrum utilization and save the power consumption.

  3. ANALISIS DAN IMPLEMENTASI MIKROTIK ROUTER BOARD RB450G UNTUK MANAJEMEN JARINGAN (STUDI KASUS : BADAN PENGKAJIAN DAN PENERAPAN TEKNOLOGI SUB BALAI BESAR TEKNOLOGI ENERGI (B2TE-BPPT SERPONG

    Directory of Open Access Journals (Sweden)

    Rahmat Rizkiyanto

    2015-09-01

    Full Text Available The importance of a management of the network in B2TE and optimize use of existing network devices. During this time, the network system that is running can’t be managed properly. There are still problems, especially related to topology, traffic network system, bandwidth, access rights, and the login process. On the basis of these, carried out an analysis and implementation of development using Network Development Live Cycle (NDLC with activity analysis, design, prototype simulation, implementation, monitoring, and management. Development method is applied to solve problems that occur. Data collection methods used are the methods of observation and interviews with the B2TE and do a similar study. To resolve issues related to topology, topology implemented using the router board. For traffic network system, load balancing system implemented by the method of Per Connection Classifier (PCC. Queue tree with Hierarcial Token Bucket (HTB method and Per Connection Queue (PCQ and hotspot system is applied to solve problems related to bandwidth and permissions. Single sign-on system (SSO with Open LDAP and RADIUS functioned to minimize the use of username and password during the login process. From the test results of the implemented system, the selection router board it is appropriate to handle the problem topology. Load balancing with the PCC method, queue tree with HTB and PCQ methods and systems hotspot capable of answering traffic problems on the issue of network systems, bandwidth, and permissions. While the system SSO is capable of handling problems login process. For further development, it is expected that the system has been running for bandwidth management rule can be added to separate the local and international bandwidth. Then, for security, made ​​the policy in terms of access to the IP address and port. In terms of permissions, can be applied to the scheduling of access to certain sites. For the development of SSO, can be applied SSO

  4. IPv6 and IPsec Tests of a Space-Based Asset, the Cisco Router in Low Earth Orbit (CLEO)

    Science.gov (United States)

    Ivancic, William; Stewart, David; Wood, Lloyd; Jackson, Chris; Northam, James; Wilhelm, James

    2008-01-01

    This report documents the design of network infrastructure to support testing and demonstrating network-centric operations and command and control of space-based assets, using IPv6 and IPsec. These tests were performed using the Cisco router in Low Earth Orbit (CLEO), an experimental payload onboard the United Kingdom--Disaster Monitoring Constellation (UK-DMC) satellite built and operated by Surrey Satellite Technology Ltd (SSTL). On Thursday, 29 March 2007, NASA Glenn Research Center, Cisco Systems and SSTL performed the first configuration and demonstration of IPsec and IPv6 onboard a satellite in low Earth orbit. IPv6 is the next generation of the Internet Protocol (IP), designed to improve on the popular IPv4 that built the Internet, while IPsec is the protocol used to secure communication across IP networks. This demonstration was made possible in part by NASA s Earth Science Technology Office (ESTO) and shows that new commercial technologies such as mobile networking, IPv6 and IPsec can be used for commercial, military and government space applications. This has direct application to NASA s Vision for Space Exploration. The success of CLEO has paved the way for new spacebased Internet technologies, such as the planned Internet Routing In Space (IRIS) payload at geostationary orbit, which will be a U.S. Department of Defense Joint Capability Technology Demonstration. This is a sanitized report for public distribution. All real addressing has been changed to psueco addressing.

  5. Electromagnetically induced two-dimensional grating assisted by incoherent pump

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yu-Yuan; Liu, Zhuan-Zhuan; Wan, Ren-Gang, E-mail: wrg@snnu.edu.cn

    2017-04-25

    We propose a scheme for realizing electromagnetically induced two-dimensional grating in a double-Λ system driven simultaneously by a coherent field and an incoherent pump field. In such an atomic configuration, the absorption is suppressed owing to the incoherent pumping process and the probe can be even amplified, while the refractivity is mainly attributed to the dynamically induced coherence. With the help of a standing-wave pattern coherent field, we obtain periodically modulated refractive index without or with gain, and therefore phase grating or gain-phase grating which diffracts a probe light into high-order direction efficiently can be formed in the medium via appropriate manipulation of the system parameters. The diffraction efficiency attainable by the present gratings can be controlled by tuning the coherent field intensity or the interaction length. Hence, the two-dimensional grating can be utilized as all-optical splitter or router in optical networking and communication. - Highlights: • Two-dimensional grating is coherently induced in four-level atoms. • Phase and gain-phase gratings are obtained assisted by incoherent pump. • The diffraction power is improved due to the enhanced refraction modulation. • The gratings can be utilized as multi-channel all-optical splitter and router.

  6. Advantages of Intelligent SDH/SONET Networks

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Advantages of Intelligent SDH/SONET Networks. GMPLS simplifies network management, thus reducing operating expenses (“staff”) and minimizing errors. Same benefits as computerization of banking, accounts, etc. Auto-discovery simplifies equipment installation ...

  7. Single-photon manipulation in Nanophotonic Circuits

    DEFF Research Database (Denmark)

    Hansen, Sofie Lindskov

    Quantum dots in photonic nanostructures has long been known to be a very powerful and versatile solid-state platform for conducting quantum optics experiments. The present PhD thesis describes experimental demonstrations of single-photon generation and subsequent manipulation all realized...... on a gallium arsenide platform. This platform offers near-unity coupling between embedded single-photon emitters and a photonic mode, as well as the ability to suppress decoherence mechanisms, making it highly suited for quantum information applications. In this thesis we show how a single-photon router can...... be realized on a chip with embedded quantum dots. This allows for on-chip generation and manipulation of single photons. The router consists of an on-chip interferometer where the phase difference between the arms of the interferometer is controlled electrically. The response time of the device...

  8. An energy-aware engineered control plane for wavelength-routed networks

    DEFF Research Database (Denmark)

    Ricciardi, Sergio; Wang, Jiayuan; Palmieri, Francesco

    2015-01-01

    ' operational expenditures. To face this problem, we propose a single-stage routing and wavelength assignment scheme, based on several network engineering extensions to the Generalised Multi-Protocol Label Switching (GMPLS) control plane protocols, mainly Open Shortest Path First, with new composed metrics...

  9. HARM processing techniques for MEMS and MOEMS devices using bonded SOI substrates and DRIE

    Science.gov (United States)

    Gormley, Colin; Boyle, Anne; Srigengan, Viji; Blackstone, Scott C.

    2000-08-01

    Silicon-on-Insulator (SOI) MEMS devices (1) are rapidly gaining popularity in realizing numerous solutions for MEMS, especially in the optical and inertia application fields. BCO recently developed a DRIE trench etch, utilizing the Bosch process, and refill process for high voltage dielectric isolation integrated circuits on thick SOI substrates. In this paper we present our most recently developed DRIE processes for MEMS and MOEMS devices. These advanced etch techniques are initially described and their integration with silicon bonding demonstrated. This has enabled process flows that are currently being utilized to develop optical router and filter products for fiber optics telecommunications and high precision accelerometers.

  10. 1997 NRL Review

    Science.gov (United States)

    1997-04-01

    She is on the editorial boards of the Journal of Biomedical Optics, Genetic Engineering, and Applied Biochemistry & Biotechnology. DAVID A. STENGER...Discussion: Onion routers are similar to site concerned about traffic analysis should control Chaum MIXES [2], which also reorder and change an onion...the way for the complete auto- 2. D. Chaum , "Untraceable Electronic Mail, mation of the routing process. Return Addresses, and Digital Pseudonyms

  11. Transport Network Technologies – Study and Testing

    DEFF Research Database (Denmark)

    Bozorgebrahimi, K.; Channegowda, M.; Colmenero, A.

    Following on from the theoretical research into Carrier Class Transport Network Technologies (CCTNTs) documented in DJ1.1.1, this report describes the extensive testing performed by JRA1 Task 1. The tests covered EoMPLS, Ethernet OAM, Synchronous Ethernet, PBB-TE, MPLS-TP, OTN and GMPLS...

  12. ESTIMATION OF BURSTS LENGTH AND DESIGN OF A FIBER DELAY LINE BASED OBS ROUTER

    Directory of Open Access Journals (Sweden)

    RICHA AWASTHI

    2017-03-01

    Full Text Available The demand for higher bandwidth is increasing day by day and this ever growing demand cannot be catered to with current electronic technology. Thus new communication technology like optical communication needs to be used. In the similar context OBS (optical burst switching is considered as next generation data transfer technology. In OBS information is transmitted in forms of optical bursts of variable lengths. However, contention among the bursts is a major problem in OBS system, and for contention resolution defection routing is mostly preferred. However, deflection routing increases delay. In this paper, it is shown that the arrival of very large bursts is rare event, and for moderate burst length the buffering of contending burst can provide very effective solution. However, in case of arrival of large bursts deflection can be used.

  13. The OBS control plane

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée

    2010-01-01

    . The applicability analysis carried out here focuses on the actual feasibility of the integration and the potential trade-offs which appear when two contradicting principles are combined. Taking advantage of the flexibility of the GMPLS control plane does not seem to be as easy and as straightforward as expected...

  14. Controllable azimuthons of four-wave mixing and their applications

    International Nuclear Information System (INIS)

    Wang, R M; Che, J L; Wang, X P; Lan, H Y; Wu, Z K; Zhang, Y Q; Zhang, Y P

    2014-01-01

    We report controllable azimuthons of four-wave mixing (FWM), which can be modulated by several parameters in experiment. The spot number, splitting depth, rotation angular velocity and direction of such azimuthons can be controlled by the frequency and intensity of the FWM signal or the dressing field through the cross-phase modulation due to atomic coherence. The intensity gain of the azimuthons can be modulated by frequency detuning through quantum parametric amplification. The quantum correlated FWM vortex is observed in experiment. We also discuss the applications of such controllable azimuthons in all-optical circulators, multiplexers (demultiplexers), routers, cross-connects and optical amplifiers. (paper)

  15. Extending the Performance of Hybrid NoCs beyond the Limitations of Network Heterogeneity

    Directory of Open Access Journals (Sweden)

    Michael Opoku Agyeman

    2017-04-01

    Full Text Available To meet the performance and scalability demands of the fast-paced technological growth towards exascale and big data processing with the performance bottleneck of conventional metal-based interconnects (wireline, alternative interconnect fabrics, such as inhomogeneous three-dimensional integrated network-on-chip (3D NoC and hybrid wired-wireless network-on-chip (WiNoC, have emanated as a cost-effective solution for emerging system-on-chip (SoC design. However, these interconnects trade off optimized performance for cost by restricting the number of area and power hungry 3D routers and wireless nodes. Moreover, the non-uniform distributed traffic in a chip multiprocessor (CMP demands an on-chip communication infrastructure that can avoid congestion under high traffic conditions while possessing minimal pipeline delay at low-load conditions. To this end, in this paper, we propose a low-latency adaptive router with a low-complexity single-cycle bypassing mechanism to alleviate the performance degradation due to the slow 2D routers in such emerging hybrid NoCs. The proposed router transmits a flit using dimension-ordered routing (DoR in the bypass datapath at low-loads. When the output port required for intra-dimension bypassing is not available, the packet is routed adaptively to avoid congestion. The router also has a simplified virtual channel allocation (VA scheme that yields a non-speculative low-latency pipeline. By combining the low-complexity bypassing technique with adaptive routing, the proposed router is able to balance the traffic in hybrid NoCs to achieve low-latency communication under various traffic loads. Simulation shows that the proposed router can reduce applications’ execution time by an average of 16.9% compared to low-latency routers, such as SWIFT. By reducing the latency between 2D routers (or wired nodes and 3D routers (or wireless nodes, the proposed router can improve the performance efficiency in terms of average

  16. The European BOOM project :silicon photonics for high-capacity optical packet routers

    NARCIS (Netherlands)

    Stampoulidis, L.; Vyrsokinos, K.; Voigt, K.; Zimmermann, L.; Gomez-Agis, F.; Dorren, H.J.S.; Sheng, Z.; Thourhout, Van D.; Moerl, L.; Kreissl, J.; Sedighi, B.; Scheytt, J.C.; Pagano, A.; Riccardi, E.

    2010-01-01

    During the past years, monolithic integration in InP has been the driving force for the realization of integrated photonic routing systems. The advent of silicon as a basis for cost-effective integration and its potential blend with III–V material is now opening exciting opportunities for the

  17. Slow light brings faster communications

    International Nuclear Information System (INIS)

    Gauthier, D.

    2006-01-01

    Two teams of researchers have managed to significantly reduce the speed of light in an optical fibre, which could open the door to all-optical routers for telecommunications, as Daniel Gauthier explains. Optical engineers around the globe are working hard to meet the ever-growing demand for higher-speed information networks, and the latest systems being developed operate at rates close to 160 GB per second - which is over 100 times quicker than the fastest broadband services currently available and a world away from the 56 kb per second dial-up connections of the early years of the Internet. Paradoxically, it seems that making light travel slower rather than faster might be the best way to meet these high-speed challenges. (U.K.)

  18. Sharing cost in social community networks

    DEFF Research Database (Denmark)

    Pal, Ranjan; Elango, Divya; Wardana, Satya Ardhy

    2012-01-01

    their deployment in a residential locality. Our proposed mechanism accounts for heterogeneous user preferences towards different router features and comes up with the optimal (feature-set, user costs) router blueprint that satisfies each user in a locality, in turn motivating them to buy routers and thereby improve......Wireless social community networks (WSCNs) is an emerging technology that operate in the unlicensed spectrum and have been created as an alternative to cellular wireless networks for providing low-cost, high speed wireless data access in urban areas. WSCNs is an upcoming idea that is starting...... reflect their slow progress in capturing the WiFi router market. In this paper, we look at a router design and cost sharing problem in WSCNs to improve deployment. We devise a simple to implement, successful, budget-balanced, ex-post efficient, and individually rational auction-based mechanism...

  19. WiFi networks and malware epidemiology.

    Science.gov (United States)

    Hu, Hao; Myers, Steven; Colizza, Vittoria; Vespignani, Alessandro

    2009-02-03

    In densely populated urban areas WiFi routers form a tightly interconnected proximity network that can be exploited as a substrate for the spreading of malware able to launch massive fraudulent attacks. In this article, we consider several scenarios for the deployment of malware that spreads over the wireless channel of major urban areas in the US. We develop an epidemiological model that takes into consideration prevalent security flaws on these routers. The spread of such a contagion is simulated on real-world data for georeferenced wireless routers. We uncover a major weakness of WiFi networks in that most of the simulated scenarios show tens of thousands of routers infected in as little as 2 weeks, with the majority of the infections occurring in the first 24-48 h. We indicate possible containment and prevention measures and provide computational estimates for the rate of encrypted routers that would stop the spreading of the epidemics by placing the system below the percolation threshold.

  20. WiFi networks and malware epidemiology

    Science.gov (United States)

    Hu, Hao; Myers, Steven; Colizza, Vittoria; Vespignani, Alessandro

    2009-01-01

    In densely populated urban areas WiFi routers form a tightly interconnected proximity network that can be exploited as a substrate for the spreading of malware able to launch massive fraudulent attacks. In this article, we consider several scenarios for the deployment of malware that spreads over the wireless channel of major urban areas in the US. We develop an epidemiological model that takes into consideration prevalent security flaws on these routers. The spread of such a contagion is simulated on real-world data for georeferenced wireless routers. We uncover a major weakness of WiFi networks in that most of the simulated scenarios show tens of thousands of routers infected in as little as 2 weeks, with the majority of the infections occurring in the first 24–48 h. We indicate possible containment and prevention measures and provide computational estimates for the rate of encrypted routers that would stop the spreading of the epidemics by placing the system below the percolation threshold. PMID:19171909

  1. Optics/Optical Diagnostics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

  2. Spare a Little Change? Towards a 5-Nines Internet in 250 Lines of Code

    Science.gov (United States)

    2011-05-01

    before I could do so myself. Max Poletto, my first manager at Meraki , allowed me to pursue a similar approach in my development work there. It was my...For example, Cisco , the dominant vendor of IP routers used in ISP networks, offers “Nonstop Forwarding with Stateful Switchover” []. With this...keeping a router up-to-date, assuming the historical re- lease schedule for Cisco IOS, and assuming that customers are moved to a temporary router

  3. IP Traceback through modified Probabilistic Packet Marking algorithm using Chinese Remainder Theorem

    Directory of Open Access Journals (Sweden)

    Y. Bhavani

    2015-06-01

    Full Text Available Probabilistic Packet Marking algorithm suggests a methodology to identify all the participated routers of the attack path by probabilistically marking the packets. In this approach, these marked packets contain partial information regarding the routers of the attack path. At receiver, to get the complete information of every router, it requires more number of marked packets and hence more combinations and more false positives. To overcome this drawback we have presented a novel idea in finding the exact IP address of the routers in the attack path by applying Chinese Remainder Theorem. The result of our implementation reveals that our idea requires less number of marked packets and takes no time in constructing the attack path. The same idea is true even in the case of multiple attackers.

  4. New organic materials for optics: optical storage and nonlinear optics

    International Nuclear Information System (INIS)

    Gan, F.

    1996-01-01

    New organic materials have received considerable attention recently, due to their easy preparation and different variety. The most application fields in optics are optical storage and nonlinear optics. In optical storage the organic dyes have been used for example, in record able and erasable compact disks (CD-R, CD-E) nonlinear optical effects, such as nonlinear optical absorption, second and third order optical absorption, second and third order optical nonlinearities, can be applied for making optical limiters, optical modulators, as well as laser second and third harmonic generations. Due to high value of optical absorption and optical nonlinearity organic materials are always used as thin films in optical integration. In this paper the new experimental results have been presented, and future development has been also discussed. (author)

  5. Application of Mobile-ip to Space and Aeronautical Networks

    Science.gov (United States)

    Leung, Kent; Shell, Dan; Ivancic, William D.; Stewart, David H.; Bell, Terry L.; Kachmar, Brian A.

    2001-01-01

    The National Aeronautics and Space Administration (NASA) is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AAT-F), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This paper describes mobile-ip and mobile routers--in particular, the features, capabilities, and initial performance of the mobile router are presented. The application of mobile-router technology to NASA's space and aeronautics programs is also discussed.

  6. Routers in Internetworks

    Indian Academy of Sciences (India)

    senior engineer-software in the Broadband ... The Internet has changed the way humans work like never before. Millions of ... Managing millions of hosts at the same time is tedious to say the least. .... Since TCP and UDP deal directly with the end hosts, they ..... mobile computers running from home/small business environ-.

  7. Self-Organization of Internet Paths

    NARCIS (Netherlands)

    Kleiberg, T.; Van Mieghem, P.

    2009-01-01

    The Internet consists of a constantly evolving complex hierarchical architecture where routers are grouped into autonomous systems (ASes) that interconnect to provide global connectivity. Routing is generally performed in a decentralized fashion, where each router determines the route to the

  8. 78 FR 43953 - Self-Regulatory Organizations; Chicago Board Options Exchange, Incorporated; Notice of Filing and...

    Science.gov (United States)

    2013-07-22

    ... or dealer that executes orders internally by trading as principal or crossing orders as agent. \\4... may determine to utilize a Routing Intermediary that employs ``smart router'' functionality which... to use its smart router functionality to determine the destination options exchange(s) (trading...

  9. 78 FR 43956 - Self-Regulatory Organizations; C2 Options Exchange, Incorporated; Notice of Filing and Immediate...

    Science.gov (United States)

    2013-07-22

    ... executes orders internally by trading as principal or crossing orders as agent. \\4\\ For a more detailed... Routing Intermediary that employs ``smart router'' functionality which, generally, is functionality that... from a PULSe workstation, a user may direct a Routing Intermediary to use its smart router...

  10. Optical Communication over Plastic Optical Fibers Integrated Optical Receiver Technology

    CERN Document Server

    Atef, Mohamed

    2013-01-01

    This book presents high-performance data transmission over plastic optical fibers (POF) using integrated optical receivers having good properties with multilevel modulation, i.e. a higher sensitivity and higher data rate transmission over a longer plastic optical fiber length. Integrated optical receivers and transmitters with high linearity are introduced for multilevel communication. For binary high-data rate transmission over plastic optical fibers, an innovative receiver containing an equalizer is described leading also to a high performance of a plastic optical fiber link. The cheap standard PMMA SI-POF (step-index plastic optical fiber) has the lowest bandwidth and the highest attenuation among multimode fibers. This small bandwidth limits the maximum data rate which can be transmitted through plastic optical fibers. To overcome the problem of the plastic optical fibers high transmission loss, very sensitive receivers must be used to increase the transmitted length over POF. The plastic optical fiber li...

  11. Ethernet over SDH (EoS): Summary

    Indian Academy of Sciences (India)

    Cost effective way to support data customers. Use of integrated Ethernet eliminates the need for costly WAN interfaces (E1/E3/STM-1) on routers connecting to SDH/SONET; WAN bandwidth can be provided directly from customers' Ethernet switches, potentially eliminating routers at customer sites ...

  12. Rising Trend: Complex and sophisticated attack methods

    Indian Academy of Sciences (India)

    Stux, DuQu, Nitro, Luckycat, Exploit Kits, FLAME. ADSL/SoHo Router Compromise. Botnets of compromised ADSL/SoHo Routers; User Redirection via malicious DNS entry. Web Application attacks. SQL Injection, RFI etc. More and more Webshells. More utility to hackers; Increasing complexity and evading mechanisms.

  13. ReNoC: A Network-on-Chip Architecture with Reconfigurable Topology

    DEFF Research Database (Denmark)

    Stensgaard, Mikkel Bystrup; Sparsø, Jens

    2008-01-01

    links and direct links between IP-blocks. The configurability is inserted as a layer between routers and links, and the architecture can therefore be used in combination with existing NoC routers, making it a general architecture. The topology is configured using energy-efficient topology switches based...

  14. 76 FR 33686 - Proposed Extension of Part 4 of the Commission's Rules Regarding Outage Reporting to...

    Science.gov (United States)

    2011-06-09

    ... failure of core routers, network servers, SIP proxy servers, Serving General Packet Radio Service (GPRS..., Exchange Point, core router, root name server, ISP-operated DNS server, or DHCP server) that it owns... Commission. ACTION: Notice of proposed rulemaking. SUMMARY: The purpose of this document is to seek comment...

  15. The theoretical and numerical models of the novel and fast tunable semiconductor ring laser

    Science.gov (United States)

    Zhu, Jiangbo; Zhang, Junwen; Chi, Nan; Yu, Siyuan

    2011-01-01

    Fast wavelength-tunable semiconductor lasers will be the key components in future optical packet switching networks. Especially, they are of great importance in the optical network nodes: transmitters, optical wavelength-routers, etc. In this paper, a new scheme of a next-generation fast tunable ring laser was given. Tunable lasers in this design have better wavelength tunability compared with others, for they are switched faster in wavelength and simpler to control with the injecting light from an external distributed Bragg-reflector(DBR). Then some discussion of the waveguide material system and coupler design of the ring laser were given. And we also derived the multimode rate equations corresponding to this scheme by analyzing some characteristics of the semiconductor ring cavity, directionality, nonlinear mode competition, optical injection locking, etc. We did MatLab simulation based on the new rate equations to research the process of mode competition and wavelength switching in the laser, and achieved the basic functions of a tunable laser. Finally some discussion of the impact of several key parameters was given.

  16. Integrated circuit and method of arbitration in a network on an integrated circuit.

    NARCIS (Netherlands)

    2011-01-01

    The invention relates to an integrated circuit and to a method of arbitration in a network on an integrated circuit. According to the invention, a method of arbitration in a network on an integrated circuit is provided, the network comprising a router unit, the router unit comprising a first input

  17. Access Agent Improving The Performance Of Access Control Lists

    Directory of Open Access Journals (Sweden)

    Thelis R. S.

    2015-08-01

    Full Text Available The main focus of the proposed research is maintaining the security of a network. Extranet is a popular network among most of the organizations where network access is provided to a selected group of outliers. Limiting access to an extranet can be carried out using Access Control Lists ACLs method. However handling the workload of ACLs is an onerous task for the router. The purpose of the proposed research is to improve the performance and to solidify the security of the ACLs used in a small organization. Using a high performance computer as a dedicated device to share and handle the router workload is suggested in order to increase the performance of the router when handling ACLs. Methods of detecting and directing sensitive data is also discussed in this paper. A framework is provided to help increase the efficiency of the ACLs in an organization network using the above mentioned procedures thus helping the organizations ACLs performance to be improved to be more secure and the system to perform faster. Inbuilt methods of Windows platform or Software for open source platforms can be used to make a computer function as a router. Extended ACL features allow the determining of the type of packets flowing through the router. Combining these mechanisms allows the ACLs to be improved and perform in a more efficient manner.

  18. Field trials of 100G and beyond: an operator's point of view

    Science.gov (United States)

    Vorbeck, S.; Schneiders, M.; Weiershausen, W.; Mayer, H.; Schippel, A.; Wagner, P.; Ehrhardt, A.; Braun, R.; Breuer, D.; Drafz, U.; Fritzsche, D.

    2011-01-01

    In this article we present a summary of the latest 100 Gbps field trials in the network of Deutsche Telekom AG with industry partners. We cover a brown field approach as alien wavelength on existing systems, a green field high speed overlay network approach and a high speed interface router-router coupling.

  19. Applied optics and optical design

    CERN Document Server

    Conrady, Alexander Eugen

    1957-01-01

    ""For the optical engineer it is an indispensable work."" - Journal, Optical Society of America""As a practical guide this book has no rival."" - Transactions, Optical Society""A noteworthy contribution,"" - Nature (London)Part I covers all ordinary ray-tracing methods, together with the complete theory of primary aberrations and as much of higher aberration as is needed for the design of telescopes, low-power microscopes and simple optical systems. Chapters: Fundamental Equations, Spherical Aberration, Physical Aspect of Optical Images, Chromatic Aberration, Design of Achromatic Object-Glass

  20. Preventing Active Timing Attacks in Low-Latency Anonymous Communication

    Science.gov (United States)

    2010-04-26

    measured routers with the modifiers “Exit”, “Fast”, “Running”, “Stable”, and “Valid”. The routers also had to be non- hibernating and could not have exit...Tor client was a custom client written in Java . Packet traces were recorded using tcpdump. The timestamps on these were used to determine the timing of

  1. 75 FR 18925 - Program for Allocation of Regulatory Responsibilities Pursuant to Rule 17d-2; Notice of Filing of...

    Science.gov (United States)

    2010-04-13

    ... Plan from interested persons. \\1\\ 15 U.S.C. 78q(d). \\2\\ 17 CFR 240.17d-2. I. Introduction Section 19(g... complaints. 10. Advertising. FINRA shall assume responsibility to review the advertising of Inbound Router... advertising of Inbound Router Members shall be subject only to compliance with appropriate FINRA Rules and...

  2. An ICMP-Based Mobility Management Approach Suitable for Protocol Deployment Limitation

    Directory of Open Access Journals (Sweden)

    Jeng-Yueng Chen

    2009-01-01

    Full Text Available Mobility management is one of the important tasks on wireless networks. Many approaches have been proposed in the past, but none of them have been widely deployed so far. Mobile IP (MIP and Route Optimization (ROMIP, respectively, suffer from triangular routing problem and binding cache supporting upon each node on the entire Internet. One step toward a solution is the Mobile Routing Table (MRT, which enables edge routers to take over address binding. However, this approach demands that all the edge routers on the Internet support MRT, resulting in protocol deployment difficulties. To address this problem and to offset the limitation of the original MRT approach, we propose two different schemes, an ICMP echo scheme and an ICMP destination-unreachable scheme. These two schemes work with the MRT to efficiently find MRT-enabled routers that greatly reduce the number of triangular routes. In this paper, we analyze and compare the standard MIP and the proposed approaches. Simulation results have shown that the proposed approaches reduce transmission delay, with only a few routers supporting MRT.

  3. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  4. Light Optics for Optical Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Andorf, Matthew [NICADD, DeKalb; Lebedev, Valeri [Fermilab; Piot, Philippe [NICADD, DeKalb; Ruan, Jinhao [Fermilab

    2016-06-01

    In Optical Stochastic Cooling (OSC) radiation generated by a particle in a "pickup" undulator is amplified and transported to a downstream "kicker" undulator where it interacts with the same particle which radiated it. Fermilab plans to carry out both passive (no optical amplifier) and active (optical amplifier) tests of OSC at the Integrable Optics Test Accelerator (IOTA) currently in construction*. The performace of the optical system is analyzed with simulations in Synchrotron Radiation Workshop (SRW) accounting for the specific temporal and spectral properties of undulator radiation and being augmented to include dispersion of lens material.

  5. Optical materials

    International Nuclear Information System (INIS)

    Poker, D.B.; Ortiz, C.

    1989-01-01

    This book reports on: Diamond films, Synthesis of optical materials, Structure related optical properties, Radiation effects in optical materials, Characterization of optical materials, Deposition of optical thin films, and Optical fibers and waveguides

  6. 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

  7. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  8. Routing protocol extension for resilient GMPLS multi-domain networks

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée; Romeral, Ricardo

    2010-01-01

    This paper evaluates the performance of multi-domain networks under the Generalized Multi-Protocol Label Switching control framework in case of a single inter-domain link failure. We propose and evaluate a routing protocol extension for the Border Gateway Protocol, which allows domains to obtain...... two Autonomous System disjoint paths and use them efficiently under failure conditions. Three main applications for the protocol extension are illustrated: reducing traffic loss on existing connections by xploiting pre-selected backup paths derived with our proposal, applying multi-domain restoration...... as survivability mechanism in case of single link failure, and employing proper failure notification mechanisms for routing of future connection requests under routing protocol re-convergence. Via simulations we illustrate the benefits of utilizing the proposed routing protocol extension for networks employing...

  9. Optic neuritis

    Science.gov (United States)

    Retro-bulbar neuritis; Multiple sclerosis - optic neuritis; Optic nerve - optic neuritis ... The exact cause of optic neuritis is unknown. The optic nerve carries visual information from your eye to the brain. The nerve can swell when ...

  10. Semiconductor optical amplifier-based all-optical gates for high-speed optical processing

    DEFF Research Database (Denmark)

    Stubkjær, Kristian

    2000-01-01

    Semiconductor optical amplifiers are useful building blocks for all-optical gates as wavelength converters and OTDM demultiplexers. The paper reviews the progress from simple gates using cross-gain modulation and four-wave mixing to the integrated interferometric gates using cross-phase modulation....... These gates are very efficient for high-speed signal processing and open up interesting new areas, such as all-optical regeneration and high-speed all-optical logic functions...

  11. Bio-Optics and Bio-Inspired Optical Materials.

    Science.gov (United States)

    Tadepalli, Sirimuvva; Slocik, Joseph M; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

    2017-10-25

    Through the use of the limited materials palette, optimally designed micro- and nanostructures, and tightly regulated processes, nature demonstrates exquisite control of light-matter interactions at various length scales. In fact, control of light-matter interactions is an important element in the evolutionary arms race and has led to highly engineered optical materials and systems. In this review, we present a detailed summary of various optical effects found in nature with a particular emphasis on the materials and optical design aspects responsible for their optical functionality. Using several representative examples, we discuss various optical phenomena, including absorption and transparency, diffraction, interference, reflection and antireflection, scattering, light harvesting, wave guiding and lensing, camouflage, and bioluminescence, that are responsible for the unique optical properties of materials and structures found in nature and biology. Great strides in understanding the design principles adapted by nature have led to a tremendous progress in realizing biomimetic and bioinspired optical materials and photonic devices. We discuss the various micro- and nanofabrication techniques that have been employed for realizing advanced biomimetic optical structures.

  12. A Cluster- Based Secure Active Network Environment

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-lin; ZHOU Jing-yang; DAI Han; LU Sang-lu; CHEN Gui-hai

    2005-01-01

    We introduce a cluster-based secure active network environment (CSANE) which separates the processing of IP packets from that of active packets in active routers. In this environment, the active code authorized or trusted by privileged users is executed in the secure execution environment (EE) of the active router, while others are executed in the secure EE of the nodes in the distributed shared memory (DSM) cluster. With the supports of a multi-process Java virtual machine and KeyNote, untrusted active packets are controlled to securely consume resource. The DSM consistency management makes that active packets can be parallelly processed in the DSM cluster as if they were processed one by one in ANTS (Active Network Transport System). We demonstrate that CSANE has good security and scalability, but imposing little changes on traditional routers.

  13. Monolithically integrated quantum dot optical modulator with Semiconductor optical amplifier for short-range optical communications

    Science.gov (United States)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-04-01

    A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed. Broadband QD optical gain material was used to achieve Gbps-order high-speed optical data transmission, and an optical gain change as high as approximately 6-7 dB was obtained with a low OGM voltage of 2.0 V. Loss of optical power due to insertion of the device was also effectively compensated for by the SOA section. Furthermore, it was confirmed that the QD-OGM/SOA device helped achieve 6.0-Gbps error-free optical data transmission over a 2.0-km-long photonic crystal fiber. We also successfully demonstrated generation of Gbps-order, high-speed, and error-free optical signals in the >5.5-THz broadband optical frequency bandwidth larger than the C-band. These results suggest that the developed monolithically integrated QD-OGM/SOA device will be an advantageous and compact means of increasing the usable optical frequency channels for short-reach communications.

  14. Engineering Optics

    CERN Document Server

    Iizuka, Keigo

    2008-01-01

    Engineering Optics is a book for students who want to apply their knowledge of optics to engineering problems, as well as for engineering students who want to acquire the basic principles of optics. It covers such important topics as optical signal processing, holography, tomography, holographic radars, fiber optical communication, electro- and acousto-optic devices, and integrated optics (including optical bistability). As a basis for understanding these topics, the first few chapters give easy-to-follow explanations of diffraction theory, Fourier transforms, and geometrical optics. Practical examples, such as the video disk, the Fresnel zone plate, and many more, appear throughout the text, together with numerous solved exercises. There is an entirely new section in this updated edition on 3-D imaging.

  15. Reconfigurable optical-to-optical frequency conversion method and apparatus

    Science.gov (United States)

    Zortman, William A.; Lentine, Anthony L.

    2017-04-18

    A photonic device is provided for impressing a modulation pattern on an optical carrier. The device includes a unit in which a photodetector and an optical microresonator are monolithically integrated. The device further includes an optical waveguide evanescently coupled to the optical microresonator and having at least an upstream portion configured to carry at least one optical carrier toward the microresonator. The optical microresonator is tunable so as to resonate with the optical carrier frequency. The optical microresonator and the photodetector are mutually coupled such that in operation, charge carriers photogenerated in the photodetector are injected into the microresonator, where the photocurrent changes the resonant conditions. In some embodiments the device is operable as an optical-to-optical frequency converter. In other embodiments the device is operable as an oscillator.

  16. Magneto-Optic Field Coupling in Optical Fiber Bragg Gratings

    Science.gov (United States)

    Carman, Gregory P. (Inventor); Mohanchandra, Panduranga K. (Inventor); Emmons, Michael C. (Inventor); Richards, William Lance (Inventor)

    2016-01-01

    The invention is a magneto-optic coupled magnetic sensor that comprises a standard optical fiber Bragg grating system. The system includes an optical fiber with at least one Bragg grating therein. The optical fiber has at least an inner core and a cladding that surrounds the inner core. The optical fiber is part of an optical system that includes an interrogation device that provides a light wave through the optical fiber and a system to determine the change in the index of refraction of the optical fiber. The cladding of the optical fiber comprises at least a portion of which is made up of ferromagnetic particles so that the ferromagnetic particles are subject to the light wave provided by the interrogation system. When a magnetic field is present, the ferromagnetic particles change the optical properties of the sensor directly.

  17. Multifocal visual evoked potential in optic neuritis, ischemic optic neuropathy and compressive optic neuropathy

    Science.gov (United States)

    Jayaraman, Manju; Gandhi, Rashmin Anilkumar; Ravi, Priya; Sen, Parveen

    2014-01-01

    Purpose: To investigate the effect of optic neuritis (ON), ischemic optic neuropathy (ION) and compressive optic neuropathy (CON) on multifocal visual evoked potential (mfVEP) amplitudes and latencies, and to compare the parameters among three optic nerve disorders. Materials and Methods: mfVEP was recorded for 71 eyes of controls and 48 eyes of optic nerve disorders with subgroups of optic neuritis (ON, n = 21 eyes), ischemic optic neuropathy (ION, n = 14 eyes), and compressive optic neuropathy (CON, n = 13 eyes). The size of defect in mfVEP amplitude probability plots and relative latency plots were analyzed. The pattern of the defect in amplitude probability plot was classified according to the visual field profile of optic neuritis treatment trail (ONTT). Results: Median of mfVEP amplitude (log SNR) averaged across 60 sectors were reduced in ON (0.17 (0.13-0.33)), ION (0.14 (0.12-0.21)) and CON (0.21 (0.14-0.30)) when compared to controls. The median mfVEP relative latencies compared to controls were significantly prolonged in ON and CON group of 10.53 (2.62-15.50) ms and 5.73 (2.67-14.14) ms respectively compared to ION group (2.06 (-4.09-13.02)). The common mfVEP amplitude defects observed in probability plots were diffuse pattern in ON, inferior altitudinal defect in ION and temporal hemianopia in CON eyes. Conclusions: Optic nerve disorders cause reduction in mfVEP amplitudes. The extent of delayed latency noted in ischemic optic neuropathy was significantly lesser compared to subjects with optic neuritis and compressive optic neuropathy. mfVEP amplitudes can be used to objectively assess the topography of the visual field defect. PMID:24088641

  18. Enhancing network performance under single link failure with AS-disjoint BGP extension

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Romeral, S.; Ruepp, Sarah Renée

    2009-01-01

    In this paper we propose an enhancement of the BGP protocol for obtaining AS-disjoint paths in GMPLS multi-domain networks. We evaluate the benefits of having AS-disjoint paths under single inter-domain link failure for two main applications: routing of future connection requests during routing...... protocol re-convergence and applying multi-domain restoration as survivability mechanism in case of a single link failure. The proposed BGP modification is a simple and effective solution for disjoint path selection in connection-oriented multi-domain networks. Our results show that applying the proper...

  19. Optical near-fields & nearfield optics

    OpenAIRE

    Meixner, Alfred J; Leiderer, Paul

    2014-01-01

    Optical methods provide exceedingly powerful tools in science and technology for measuring, analyzing and manipulating, from optical microscopy and spectroscopy to the characterization of ultrafast processes by femtosecond pulses and the modification of materials by intense laser radiation. However, when it comes to applications in the nanometer-regime, the conventional optical techniques suffer from the resolution limit – formulated by Ernst Abbe one and a half centuries ago – that light can...

  20. Aberration correction in photoemission microscopy and applications in photonics and plasmonics

    Energy Technology Data Exchange (ETDEWEB)

    Koenenkamp, Rolf [Portland State Univ., Portland, OR (United States)

    2017-09-28

    We report on the design, assembly, operation and application of an aberration-corrected photoemission electron microscope. The instrument used novel hyperbolic mirror-correctors with two and three electrodes that allowed simultaneous correction of spherical and chromatic aberrations. A spatial resolution of 5.4nm was obtained with this instrument in 2009, and 4.7nm in subsequent years. New imaging methodology was introduced involving interferometric imaging of light diffraction. This methodology was applied in nano-photonics and in the characterization of surface-plasmon polaritons. Photonic crystals and waveguides, optical antennas and new plasmonic devices such as routers, localizers and filters were designed and demonstrated using the new capabilities offered by the microscope.

  1. 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)

  2. 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.

  3. Progress in nano-electro optics characterization of nano-optical materials and optical near-field interactions

    CERN Document Server

    Ohtsu, Motoichi

    2005-01-01

    This volume focuses on the characterization of nano-optical materials and optical-near field interactions. It begins with the techniques for characterizing the magneto-optical Kerr effect and continues with methods to determine structural and optical properties in high-quality quantum wires with high spatial uniformity. Further topics include: near-field luminescence mapping in InGaN/GaN single quantum well structures in order to interpret the recombination mechanism in InGaN-based nano-structures; and theoretical treatment of the optical near field and optical near-field interactions, providing the basis for investigating the signal transport and associated dissipation in nano-optical devices. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

  4. 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...

  5. 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

  6. Feasibility of Optical Instruments Based on Multiaperture Optics.

    Science.gov (United States)

    1984-10-16

    system may be configured. The optical elements may be nonimaging concentrators (light horns), the field of view (FOV) of which may be controlled by a...RD-RI58 868 FEASIBILITY OF OPTICAL INSTRUMENTS BASED ON i/I MULTIAPERTURE OPTICS (U) FLORIDA UNIV GAINESVILLE DEPT OF NUCLEAR ENGINEERING SCIENCES J D...d Subtitle) 5. TYPE OF REPORT & PERIOD COVERED ’ 0 Feasibility of Optical Instruments Based on Final Report * CD Multiaperature Optics 615/83 to 9/30

  7. Nonlinear optics

    International Nuclear Information System (INIS)

    Boyd, R.W.

    1992-01-01

    Nonlinear optics is the study of the interaction of intense laser light with matter. This book is a textbook on nonlinear optics at the level of a beginning graduate student. The intent of the book is to provide an introduction to the field of nonlinear optics that stresses fundamental concepts and that enables the student to go on to perform independent research in this field. This book covers the areas of nonlinear optics, quantum optics, quantum electronics, laser physics, electrooptics, and modern optics

  8. Physical optics

    International Nuclear Information System (INIS)

    Kim Il Gon; Lee, Seong Su; Jang, Gi Wan

    2012-07-01

    This book indicates physical optics with properties and transmission of light, mathematical expression of wave like harmonic wave and cylindrical wave, electromagnetic theory and light, transmission of light with Fermat principle and Fresnel equation, geometrical optics I, geometrical optics II, optical instrument such as stops, glasses and camera, polarized light like double refraction by polarized light, interference, interference by multiple reflections, diffraction, solid optics, crystal optics such as Faraday rotation and Kerr effect and measurement of light. Each chapter has an exercise.

  9. Physical optics

    Energy Technology Data Exchange (ETDEWEB)

    Kim Il Gon; Lee, Seong Su; Jang, Gi Wan

    2012-07-15

    This book indicates physical optics with properties and transmission of light, mathematical expression of wave like harmonic wave and cylindrical wave, electromagnetic theory and light, transmission of light with Fermat principle and Fresnel equation, geometrical optics I, geometrical optics II, optical instrument such as stops, glasses and camera, polarized light like double refraction by polarized light, interference, interference by multiple reflections, diffraction, solid optics, crystal optics such as Faraday rotation and Kerr effect and measurement of light. Each chapter has an exercise.

  10. Design and Implementation of Mobile Car with Wireless Video Monitoring System Based on STC89C52

    Directory of Open Access Journals (Sweden)

    Yang Hong

    2014-05-01

    Full Text Available With the rapid development of wireless networks and image acquisition technology, wireless video transmission technology has been widely applied in various communication systems. The traditional video monitoring technology is restricted by some conditions such as layout, environmental, the relatively large volume, cost, and so on. In view of this problem, this paper proposes a method that the mobile car can be equipped with wireless video monitoring system. The mobile car which has some functions such as detection, video acquisition and wireless data transmission is developed based on STC89C52 Micro Control Unit (MCU and WiFi router. Firstly, information such as image, temperature and humidity is processed by the MCU and communicated with the router, and then returned by the WiFi router to the host computer phone. Secondly, control information issued by the host computer phone is received by WiFi router and sent to the MCU, and then the MCU sends relevant instructions. Lastly, the wireless transmission of video images and the remote control of the car are realized. The results prove that the system has some features such as simple operation, high stability, fast response, low cost, strong flexibility, widely application, and so on. The system has certain practical value and popularization value.

  11. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  12. Electron optics

    CERN Document Server

    Grivet, Pierre; Bertein, F; Castaing, R; Gauzit, M; Septier, Albert L

    1972-01-01

    Electron Optics, Second English Edition, Part I: Optics is a 10-chapter book that begins by elucidating the fundamental features and basic techniques of electron optics, as well as the distribution of potential and field in electrostatic lenses. This book then explains the field distribution in magnetic lenses; the optical properties of electrostatic and magnetic lenses; and the similarities and differences between glass optics and electron optics. Subsequent chapters focus on lens defects; some electrostatic lenses and triode guns; and magnetic lens models. The strong focusing lenses and pris

  13. A Technique for Presenting a Deceptive Dynamic Network Topology

    Science.gov (United States)

    2013-03-01

    more complicated network topologies in our experiments. We used a Watts- Strogatz [35] model to generate a synthetic topology for experimentation due...generated Watts- Strogatz model except for the intelligent router and the web server. The actual router used does not impact the results of our experiment...library for the Python [43] programming language. NetworkX provides two features useful for this experiment. It was used to generate a Watts- Strogatz model

  14. An Enhancing Security Research of Tor Anonymous Communication to Against DDos Attacks

    OpenAIRE

    Feng Tao; Zhao Ming-Tao

    2017-01-01

    Tor (The Second Onion Router) is modified by the first generation onion router and known as the most prevalent anonymous communication system. According to the advantage of low latency, high confidentiality of transmission content, high security of communication channels and et al., Tor is widely used in anonymous Web browsing, instant message and so on. However, the vulnerability and blemish of Tor affect system security. An identity and Signcryption-based concurrent signature scheme was use...

  15. Magneto-optic and electro-optic modulators

    International Nuclear Information System (INIS)

    Hutchinson, D.P.; Ma, C.H.; Price, T.R.; Staats, P.A.; Sluis, K.L.V.

    1982-01-01

    An important aspect of the Faraday rotation diagnostic for tokamak plasma measurement has been the development of suitable polarization modulators for submillimeter wavelength. The problems are to obtain high optical transmission and fast modulation frequencies. In ORNL, the authors have developed both a magneto-optic and an electro-optic submillimeter-wave modulators. These devices have been operated at modulation frequency of approximately 100 kHz, and both have high transmission. The original magneto-optic modulator consists of a 3 mm thick by 1.4 cm diameter 2-111 ferrite disk mounted at the center of an air core coil. Recently, a new ferrite modulator has been tested, which allows a much higher modulation frequency than the original device. A laboratory set-up designed to simulate a plasma heterodyne interferometer/polarimeter experiment has been used to determine the modulator characteristics. A mechanical polarization rotor was used to simulate the rotation by plasma. The transmission of the ferrite disk was 80 % at a wavelength of 0.447 mm. The authors have also performed preliminary measurement on an electro-optic modulator first demonstrated by Fetterman at Lincoln Laboratory, U.S. This device is a classical electro-optic modulator using a cryogenically cooled (4.2 K) LiTaO 3 crystal. Experiments are underway to determine the electro-optic properties of the crystal over the temperature range from 4.2 K to 77 K and over the range of wavelength from 0.118 mm to 0.447 mm. (Wakatsuki, Y.)

  16. Atomic optics. The optics of the year 2000?

    International Nuclear Information System (INIS)

    Guzman, Angela M.

    1998-01-01

    In atom optics the roles of light and matter are exchanged with respect to those of conventional optics. Atom optics makes possible the manipulation of atoms with lasers. This review deals with foundations and recent developments on atom optics: laser cooling and trapping, optical lattices, Bose-Einstein Condensation (BEC), and the atom laser. Main features of BEC and theoretical models for generation of a coherent atomic beam are described, indicating the technological challenges involved in their implementation. Special attention is devoted to the model of Guzman et al. perspectives and possible applications are mentioned

  17. Magneto-optic and electro-optic modulators

    International Nuclear Information System (INIS)

    Hutchinson, D.P.; Ma, C.H.; Price, T.R.; Staats, P.A.; Vander Sluis, K.L.

    1982-01-01

    An important aspect of the Faraday rotation diagnostic for tokamak plasma measurements has been the development of suitable polarization modulators for submillimeter wavelengths. The problems are to obtain high optical transmission and fast modulation frequencies. At ORNL we have developed both a magneto-optic and an electro-optic submillimeter-wave modulators. These devices have been operated at modulation frequencies of approximately 100 kHz and both have high transmission

  18. International Symposium on Optics and its Applications (OPTICS-2011)

    Science.gov (United States)

    Bhattacherjee, Aranya B.; Calvo, Maria L.; Kazaryan, Eduard M.; Papoyan, Aram V.; Sarkisyan, Hayk A.

    2012-03-01

    OPTICS Logo PREFACE The papers selected for this volume were reported at the International Symposium 'Optics and its applications' (OPTICS-2011, Yerevan & Ashtarak, Armenia, September 5-9, 2011), http://www.ipr.sci.am/optics2011/. The Symposium was organized by the SPIE Armenian Student Chapter and major Armenian R&D organizations, universities and industrial companies working in the field of basic and applied optics: Institute for Physical Research of the National Academy of Sciences of Armenia, Yerevan State University, Russian-Armenian (Slavonic) University, and LT-PYRKAL Closed Joint Stock Company. OPTICS-2011 was primarily intended to support and promote the involvement of students and young scientists in various fields of modern optics, giving them the possibility to attend invited talks by prominent scientists and to present and discuss their own results. Furthermore, the Symposium allowed foreign participants from 14 countries to become acquainted with the achievements of optical science and technology in Armenia, which became a full member of the International Commission for Optics (ICO) in 2011. To follow this concept, the Symposium sessions were held in various host institutions. The creative and friendly ambience established at OPTICS-2011 promoted further international collaboration in the field and motivated many students to take up research in optics and photonics as a career. This volume of Journal of Physics: Conference Series covers thematic sections of the Symposium (both oral and poster), which represent the main fields of interest in optics for Armenian scientists: quantum optics & information, laser spectroscopy, optical properties of nanostructures, photonics & fiber optics, and optics of liquid crystals. Such wide coverage is consistent with the general scope of the Symposium, allowing all the students involved in optics to present, discuss and publish their recent results, and for those who are making their first steps in science to choose

  19. Optical Computing

    OpenAIRE

    Woods, Damien; Naughton, Thomas J.

    2008-01-01

    We consider optical computers that encode data using images and compute by transforming such images. We give an overview of a number of such optical computing architectures, including descriptions of the type of hardware commonly used in optical computing, as well as some of the computational efficiencies of optical devices. We go on to discuss optical computing from the point of view of computational complexity theory, with the aim of putting some old, and some very recent, re...

  20. Fibre-optic communications

    CERN Document Server

    Lecoy, Pierre

    2010-01-01

    This book describes in a comprehensive manner the components and systems of fiber optic communications and networks. The first section explains the theory of multimode and single-mode fibers, then the technological features, including manufacturing, cabling, and connecting. The second section describes the various components (passive and active optical components, integrated optics, opto-electronic transmitters and receivers, and optical amplifiers) used in fiber optic systems. Finally, the optical transmission system design is explained, and applications to optical networks and fiber optic se

  1. FIBER OPTICS: Fibre optics: Forty years later

    Science.gov (United States)

    Dianov, Evgenii M.

    2010-01-01

    This paper presents a brief overview of the state of the art in fibre optics and its main applications: optical fibre communications, fibre lasers and fibre sensors for various physical property measurements. The future of fibre optics and the status of this important area of the modern technology in Russia are discussed.

  2. Digital optical processing of optical communications: towards an Optical Turing Machine

    Science.gov (United States)

    Touch, Joe; Cao, Yinwen; Ziyadi, Morteza; Almaiman, Ahmed; Mohajerin-Ariaei, Amirhossein; Willner, Alan E.

    2017-01-01

    Optical computing is needed to support Tb/s in-network processing in a way that unifies communication and computation using a single data representation that supports in-transit network packet processing, security, and big data filtering. Support for optical computation of this sort requires leveraging the native properties of optical wave mixing to enable computation and switching for programmability. As a consequence, data must be encoded digitally as phase (M-PSK), semantics-preserving regeneration is the key to high-order computation, and data processing at Tb/s rates requires mixing. Experiments have demonstrated viable approaches to phase squeezing and power restoration. This work led our team to develop the first serial, optical Internet hop-count decrement, and to design and simulate optical circuits for calculating the Internet checksum and multiplexing Internet packets. The current exploration focuses on limited-lookback computational models to reduce the need for permanent storage and hybrid nanophotonic circuits that combine phase-aligned comb sources, non-linear mixing, and switching on the same substrate to avoid the macroscopic effects that hamper benchtop prototypes.

  3. Digital optical processing of optical communications: towards an Optical Turing Machine

    Directory of Open Access Journals (Sweden)

    Touch Joe

    2017-01-01

    Full Text Available Optical computing is needed to support Tb/s in-network processing in a way that unifies communication and computation using a single data representation that supports in-transit network packet processing, security, and big data filtering. Support for optical computation of this sort requires leveraging the native properties of optical wave mixing to enable computation and switching for programmability. As a consequence, data must be encoded digitally as phase (M-PSK, semantics-preserving regeneration is the key to high-order computation, and data processing at Tb/s rates requires mixing. Experiments have demonstrated viable approaches to phase squeezing and power restoration. This work led our team to develop the first serial, optical Internet hop-count decrement, and to design and simulate optical circuits for calculating the Internet checksum and multiplexing Internet packets. The current exploration focuses on limited-lookback computational models to reduce the need for permanent storage and hybrid nanophotonic circuits that combine phase-aligned comb sources, non-linear mixing, and switching on the same substrate to avoid the macroscopic effects that hamper benchtop prototypes.

  4. Realization of an optical interferometer based on holographic optics ...

    Indian Academy of Sciences (India)

    The paper describes a simple and cost effective method for the realization of an optical interferometer based on holographic optics, which use minimal bulk optical components. The optical arrangement in the proposed method involves a very simple alignment procedure and inexpensive holographic recording material is ...

  5. Controlling lightwave in Riemann space by merging geometrical optics with transformation optics.

    Science.gov (United States)

    Liu, Yichao; Sun, Fei; He, Sailing

    2018-01-11

    In geometrical optical design, we only need to choose a suitable combination of lenses, prims, and mirrors to design an optical path. It is a simple and classic method for engineers. However, people cannot design fantastical optical devices such as invisibility cloaks, optical wormholes, etc. by geometrical optics. Transformation optics has paved the way for these complicated designs. However, controlling the propagation of light by transformation optics is not a direct design process like geometrical optics. In this study, a novel mixed method for optical design is proposed which has both the simplicity of classic geometrical optics and the flexibility of transformation optics. This mixed method overcomes the limitations of classic optical design; at the same time, it gives intuitive guidance for optical design by transformation optics. Three novel optical devices with fantastic functions have been designed using this mixed method, including asymmetrical transmissions, bidirectional focusing, and bidirectional cloaking. These optical devices cannot be implemented by classic optics alone and are also too complicated to be designed by pure transformation optics. Numerical simulations based on both the ray tracing method and full-wave simulation method are carried out to verify the performance of these three optical devices.

  6. Through the Wormhole: Tracking Invisible MPLS Tunnels

    OpenAIRE

    Vanaubel, Yves; Mérindol, Pascal; Pansiot, Jean-Jacques; Donnet, Benoît

    2017-01-01

    For years, Internet topology research has been conducted through active measurement. For instance, CAIDA builds router level topologies on top of IP level traces obtained with traceroute. The resulting graphs contain a significant amount of nodes with a very large degree, often exceeding the actual number of interfaces of a router. Although this property may result from inaccurate alias resolution, we believe that opaque MPLS clouds made of invisible tunnels are the main cause. Using Layer-2...

  7. Lathe tool bit and holder for machining fiberglass materials

    Science.gov (United States)

    Winn, L. E. (Inventor)

    1972-01-01

    A lathe tool and holder combination for machining resin impregnated fiberglass cloth laminates is described. The tool holder and tool bit combination is designed to accommodate a conventional carbide-tipped, round shank router bit as the cutting medium, and provides an infinite number of cutting angles in order to produce a true and smooth surface in the fiberglass material workpiece with every pass of the tool bit. The technique utilizes damaged router bits which ordinarily would be discarded.

  8. Analysis of DDoS Attack Effect and Protection Scheme in Wireless Mobile Ad-hoc Network

    OpenAIRE

    Ramratan Ahirwal; Leeladhar Mahour

    2012-01-01

    In Wireless mobile Ad Hoc Networks (MANET) every node functions as transmitter, router and data sink is network without infrastructure. Detecting malicious nodes in an open ad-hoc network in whichparticipating nodes have no previous security associations presents a number of challenges not faced by traditional wired networks. Traffic monitoring in wired networks is usually performed at switches,routers and gateways, but an ad-hoc network does not have these types of network elements where the...

  9. Cloud Computing Implementation Organizational Success in the Department of Defense

    Science.gov (United States)

    2014-03-27

    researchers after the first pass responses were received using Cohen’s Kappa (Equation 1) (Cohen, 1960). The recruitment of a second researcher was...those feeds to Tier 1 ISPs who send them onto many other ISPs. Your ISP serves them through your Motorola Surfboard to your Cisco Router to your Dell...Surfboard to your Cisco Router to your Dell Laptop, running Microsoft Windows for playback in a Google Chrome browser. Netflix only ‘owns’ a very

  10. Optical fibres

    CERN Document Server

    Geisler, J; Boutruche, J P

    1986-01-01

    Optical Fibers covers numerous research works on the significant advances in optical fibers, with particular emphasis on their application.This text is composed of three parts encompassing 15 chapters. The first part deals with the manufacture of optical fibers and the materials used in their production. The second part describes optical-fiber connectors, terminals and branches. The third part is concerned with the major optoelectronic components encountered in optical-communication systems.This book will be of value to research scientists, engineers, and patent workers.

  11. Nonlinear optics

    CERN Document Server

    Boyd, Robert W

    2013-01-01

    Nonlinear Optics is an advanced textbook for courses dealing with nonlinear optics, quantum electronics, laser physics, contemporary and quantum optics, and electrooptics. Its pedagogical emphasis is on fundamentals rather than particular, transitory applications. As a result, this textbook will have lasting appeal to a wide audience of electrical engineering, physics, and optics students, as well as those in related fields such as materials science and chemistry.Key Features* The origin of optical nonlinearities, including dependence on the polarization of light* A detailed treatment of the q

  12. The efficiency of buffer

    Directory of Open Access Journals (Sweden)

    Ahmed Aldammas

    2016-04-01

    This paper proposes an internal router architecture, for on chip communication, implementing flow-control mechanism for congestion avoidance with QoS consideration. It describes the internal functions of this router for optimal output flit scheduling and its capability to apply per-class service for inbound flows. The paper focuses mainly on the description and performance analysis of two proposed schemes for data flow control that can be used with the proposed router architecture. The results shown in this paper prove that the application of these proposed schemes in NoC achieves an interesting enhancement in the measured end to end QoS. We carried out an extensive comparison of the proposed solutions with the existing schemes published in the literature to show that the proposed solution outperforms these, maintaining an interesting tradeoff with the hardware characteristics when designed with 45 nm integration technology.

  13. Optical Observations of X-ray Bright, Optically Normal Galaxies

    Science.gov (United States)

    Sadun, Alberto C.; Aryan, N. S.; Ghosh, K. K.

    2007-05-01

    X-ray bright, optically normal galaxies (XBONGs) are galaxies that seem to have normal spectra and morphology, but are relatively bright x-ray sources. The large ratio of the x-ray to optical emission suggests that some activity, similar to that of active galactic nuclei (AGN), is occurring. Since the galaxies do not show any obvious sign of nuclear activity in their optical spectra, one possible explanation is that these galaxies do not have an optically thick accretion disk at small radii, as previously assumed. Previous data for NGC 7626 classifies it as an XBONG, and so we are studying optical features of this galaxy in order to determine better its features. After confirming an x-ray jet, we are now comparing this to optical features that we have found, including warped dust lanes and a possible optical jet.

  14. All-optical microwave signal processing based on optical phase modulation

    Science.gov (United States)

    Zeng, Fei

    This thesis presents a theoretical and experimental study of optical phase modulation and its applications in all-optical microwave signal processing, which include all-optical microwave filtering, all-optical microwave mixing, optical code-division multiple-access (CDMA) coding, and ultrawideband (UWB) signal generation. All-optical microwave signal processing can be considered as the use of opto-electronic devices and systems to process microwave signals in the optical domain, which provides several significant advantages such as low loss, low dispersion, light weight, high time bandwidth products, and immunity to electromagnetic interference. In conventional approaches, the intensity of an optical carrier is modulated by a microwave signal based on direct modulation or external modulation. The intensity-modulated optical signal is then fed to a photonic circuit or system to achieve specific signal processing functionalities. The microwave signal being processed is usually obtained based on direct detection, i.e., an opto-electronic conversion by use of a photodiode. In this thesis, the research efforts are focused on the optical phase modulation and its applications in all-optical microwave signal processing. To avoid using coherent detection which is complicated and costly, simple and effective phase modulation to intensity modulation (PM-IM) conversion schemes are pursued. Based on a theoretical study of optical phase modulation, two approaches to achieving PM-IM conversions are proposed. In the first approach, the use of chromatic dispersion induced by a dispersive device to alter the phase relationships among the sidebands and the optical carrier of a phase-modulated optical signal to realize PM-IM conversion is investigated. In the second approach, instead of using a dispersive device, the PM-IM conversion is realized based on optical frequency discrimination implemented using an optical filter. We show that the proposed PM-IM conversion schemes can be

  15. Optical interconnects

    CERN Document Server

    Chen, Ray T

    2006-01-01

    This book describes fully embedded board level optical interconnect in detail including the fabrication of the thin-film VCSEL array, its characterization, thermal management, the fabrication of optical interconnection layer, and the integration of devices on a flexible waveguide film. All the optical components are buried within electrical PCB layers in a fully embedded board level optical interconnect. Therefore, we can save foot prints on the top real estate of the PCB and relieve packaging difficulty reduced by separating fabrication processes. To realize fully embedded board level optical

  16. Optics for dummies

    CERN Document Server

    Duree, Galen C

    2011-01-01

    The easy way to shed light on Optics In general terms, optics is the science of light. More specifically, optics is a branch of physics that describes the behavior and properties of light?including visible, infrared, and ultraviolet?and the interaction of light with matter. Optics For Dummies gives you an approachable introduction to optical science, methods, and applications. You'll get plain-English explanations of the nature of light and optical effects; reflection, refraction, and diffraction; color dispersion; optical devices, industrial, medical, and military applicatio

  17. Atmospheric free-space coherent optical communications with adaptive optics

    Science.gov (United States)

    Ting, Chueh; Zhang, Chengyu; Yang, Zikai

    2017-02-01

    Free-space coherent optical communications have a potential application to offer last mile bottleneck solution in future local area networks (LAN) because of their information carrier, information security and license-free status. Coherent optical communication systems using orthogonal frequency division multiplexing (OFDM) digital modulation are successfully demonstrated in a long-haul tens Giga bits via optical fiber, but they are not yet available in free space due to atmospheric turbulence-induced channel fading. Adaptive optics is recognized as a promising technology to mitigate the effects of atmospheric turbulence in free-space optics. In this paper, a free-space coherent optical communication system using an OFDM digital modulation scheme and adaptive optics (FSO OFDM AO) is proposed, a Gamma-Gamma distribution statistical channel fading model for the FSO OFDM AO system is examined, and FSO OFDM AO system performance is evaluated in terms of bit error rate (BER) versus various propagation distances.

  18. Monolithically integrated quantum dot optical modulator with semiconductor optical amplifier for thousand and original band optical communication

    Science.gov (United States)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Matsumoto, Atsushi; Kawanishi, Tetsuya

    2016-04-01

    A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed with T-band (1.0 µm waveband) and O-band (1.3 µm waveband) QD optical gain materials for Gbps-order, high-speed optical data generation. The insertion loss due to coupling between the device and the optical fiber was effectively compensated for by the SOA section. It was also confirmed that the monolithic QD-OGM/SOA device enabled >4.8 Gbps optical data generation with a clear eye opening in the T-band. Furthermore, we successfully demonstrated error-free 4.8 Gbps optical data transmissions in each of the six wavelength channels over a 10-km-long photonic crystal fiber using the monolithic QD-OGM/SOA device in multiple O-band wavelength channels, which were generated by the single QD gain chip. These results suggest that the monolithic QD-OGM/SOA device will be advantageous in ultra-broadband optical frequency systems that utilize the T+O-band for short- and medium-range optical communications.

  19. Integrating optical, mechanical, and test software (with applications to freeform optics)

    Science.gov (United States)

    Genberg, Victor; Michels, Gregory; Myer, Brian

    2017-10-01

    Optical systems must perform under environmental conditions including thermal and mechanical loading. To predict the performance in the field, integrated analysis combining optical and mechanical software is required. Freeform and conformal optics offer many new opportunities for optical design. The unconventional geometries can lead to unconventional, and therefore unintuitive, mechanical behavior. Finite element (FE) analysis offers the ability to predict the deformations of freeform optics under various environments and load conditions. To understand the impact on optical performance, the deformations must be brought into optical analysis codes. This paper discusses several issues related to the integrated optomechanical analysis of freeform optics.

  20. The efficacy of centralized flow rate control in 802.11-based wireless mesh networks

    KAUST Repository

    Jamshaid, K.

    2013-06-13

    Commodity WiFi-based wireless mesh networks (WMNs) can be used to provide last mile Internet access. These networks exhibit extreme unfairness with backlogged traffic sources. Current solutions propose distributed source-rate control algorithms requiring link-layer or transport-layer changes on all mesh nodes. This is often infeasible in large practical deployments. In wireline networks, router-assisted rate control techniques have been proposed for use alongside end-to-end mechanisms. We wish to evaluate the feasibility of establishing similar centralized control via gateways in WMNs. In this paper, we focus on the efficacy of this control rather than the specifics of the controller design mechanism. We answer the question: Given sources that react predictably to congestion notification, can we enforce a desired rate allocation through a single centralized controller? The answer is not obvious because flows experience varying contention levels, and transmissions are scheduled by a node using imperfect local knowledge. We find that common router-assisted flow control schemes used in wired networks fail in WMNs because they assume that (1) links are independent, and (2) router queue buildups are sufficient for detecting congestion. We show that non-work-conserving, rate-based centralized scheduling can effectively enforce rate allocation. It can achieve results comparable to source rate limiting, without requiring any modifications to mesh routers or client devices. 2013 Jamshaid et al.; licensee Springer.

  1. Metamaterials for light rays: ray optics without wave-optical analog in the ray-optics limit

    International Nuclear Information System (INIS)

    Hamilton, Alasdair C; Courtial, Johannes

    2009-01-01

    Volumes of sub-wavelength electromagnetic elements can act like homogeneous materials: metamaterials. In analogy, sheets of optical elements such as prisms can act ray-optically like homogeneous sheet materials. In this sense, such sheets can be considered to be metamaterials for light rays (METATOYs). METATOYs realize new and unusual transformations of the directions of transmitted light rays. We study here, in the ray-optics and scalar-wave limits, the wave-optical analog of such transformations, and we show that such an analog does not always exist. Perhaps, this is the reason why many of the ray-optical possibilities offered by METATOYs have never before been considered.

  2. Wave-optics modeling of the optical-transport line for passive optical stochastic cooling

    Science.gov (United States)

    Andorf, M. B.; Lebedev, V. A.; Piot, P.; Ruan, J.

    2018-03-01

    Optical stochastic cooling (OSC) is expected to enable fast cooling of dense particle beams. Transition from microwave to optical frequencies enables an achievement of stochastic cooling rates which are orders of magnitude higher than ones achievable with the classical microwave based stochastic cooling systems. A subsystemcritical to the OSC scheme is the focusing optics used to image radiation from the upstream "pickup" undulator to the downstream "kicker" undulator. In this paper, we present simulation results using wave-optics calculation carried out with the SYNCHROTRON RADIATION WORKSHOP (SRW). Our simulations are performed in support to a proof-of-principle experiment planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab. The calculations provide an estimate of the energy kick received by a 100-MeV electron as it propagates in the kicker undulator and interacts with the electromagnetic pulse it radiated at an earlier time while traveling through the pickup undulator.

  3. Photonic layer security in fiber-optic networks and optical OFDM transmission

    Science.gov (United States)

    Wang, Zhenxing

    Currently the Internet is experiencing an explosive growth in the world. Such growth leads to an increased data transmission rate demand in fiber-optical networks. Optical orthogonal frequency multiplexing (OFDM) is considered as a promising solution to achieve data rate beyond 100Gb/s per wavelength channel. In the meanwhile, because of extensive data transmission and sharing, data security has become an important problem and receives considerable attention in current research literature. This thesis focuses on data security issues at the physical layer of optical networks involving code-division multiple access (CDMA) systems and steganography methods. The thesis also covers several implementation issues in optical OFDM transmission. Optical CDMA is regarded as a good candidate to provide photonic layer security in multi-access channels. In this thesis we provide a systematic analysis of the security performance of incoherent optical CDMA codes. Based on the analysis, we proposed and experimentally demonstrated several methods to improve the security performance of the optical CDMA systems, such as applying all-optical encryption, and code hopping using nonlinear wavelength conversion. Moreover, we demonstrate that the use of wireless CDMA codes in optical systems can enhance the security in one single-user end-to-end optical channel. Optical steganography is another method to provide photonic data security and involves hiding the existence of data transmissions. In the thesis, we demonstrate that an optical steganography channel can exist in phase modulated public channels as well as traditional on-off-keying (OOK) modulated channels, without data synchronization. We also demonstrate an optical steganography system with enhanced security by utilizing temporal phase modulation techniques. Additionally, as one type of an overlay channel, the optical steganography technology can carry the sensor data collected by wireless sensor network on top of public optical

  4. Fluidic optics

    Science.gov (United States)

    Whitesides, George M.; Tang, Sindy K. Y.

    2006-09-01

    Fluidic optics is a new class of optical system with real-time tunability and reconfigurability enabled by the introduction of fluidic components into the optical path. We describe the design, fabrication, operation of a number of fluidic optical systems, and focus on three devices, liquid-core/liquid-cladding (L2) waveguides, microfluidic dye lasers, and diffraction gratings based on flowing, crystalline lattices of bubbles, to demonstrate the integration of microfluidics and optics. We fabricate these devices in poly(dimethylsiloxane) (PDMS) with soft-lithographic techniques. They are simple to construct, and readily integrable with microanalytical or lab-on-a-chip systems.

  5. Atom optics

    International Nuclear Information System (INIS)

    Balykin, V. I.; Jhe, W.

    1999-01-01

    Atom optics, in analogy to neutron and electron optics, deals with the realization of as a traditional elements, such as lenes, mirrors, beam splitters and atom interferometers, as well as a new 'dissipative' elements such as a slower and a cooler, which have no analogy in an another types of optics. Atom optics made the development of atom interferometer with high sensitivity for measurement of acceleration and rotational possible. The practical interest in atom optics lies in the opportunities to create atom microprobe with atom-size resolution and minimum damage of investigated objects. (Cho, G. S.)

  6. Tunable laser optics

    CERN Document Server

    Duarte, FJ

    2015-01-01

    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

  7. Strategies for P2P connectivity in reconfigurable converged wired/wireless access networks.

    Science.gov (United States)

    Puerto, Gustavo; Mora, José; Ortega, Beatriz; Capmany, José

    2010-12-06

    This paper presents different strategies to define the architecture of a Radio-Over-Fiber (RoF) Access networks enabling Peer-to-Peer (P2P) functionalities. The architectures fully exploit the flexibility of a wavelength router based on the feedback configuration of an Arrayed Waveguide Grating (AWG) and an optical switch to broadcast P2P services among diverse infrastructures featuring dynamic channel allocation and enabling an optical platform for 3G and beyond wireless backhaul requirements. The first architecture incorporates a tunable laser to generate a dedicated wavelength for P2P purposes and the second architecture takes advantage of reused wavelengths to enable the P2P connectivity among Optical Network Units (ONUs) or Base Stations (BS). While these two approaches allow the P2P connectivity in a one at a time basis (1:1), the third architecture enables the broadcasting of P2P sessions among different ONUs or BSs at the same time (1:M). Experimental assessment of the proposed architecture shows approximately 0.6% Error Vector Magnitude (EVM) degradation for wireless services and 1 dB penalty in average for 1 x 10(-12) Bit Error Rate (BER) for wired baseband services.

  8. Magnetic-field-dependent slow light in strontium atom-cavity system

    Science.gov (United States)

    Liu, Zeng-Xing; Wang, Bao; Kong, Cui; Xiong, Hao; Wu, Ying

    2018-03-01

    Realizing and controlling a long-lived slow light is of fundamental importance in physics and may find applications in quantum router and quantum information processing. In this work, we propose a feasible scheme to realize the slow light in a strontium atom-cavity system, in which the value of group delay can be continuously adjusted within a range of different Zeeman splittings and vacuum Rabi frequencies by varying the applied static magnetic field and the atom number instead of a strong coherent field. In our scheme, the major limitations of the slow-light structure, namely, dispersion and loss, can be effectively resolved, and so our scheme may help to achieve the practical application of slow light relevant to the optical communication network.

  9. Optical interference coatings for optics and photonics [Invited].

    Science.gov (United States)

    Lee, Cheng-Chung

    2013-01-01

    Optical interference coatings play as an important role in the progress in optics and photonics. In this article we give a minireview of the evolution of optical interference coatings from the theory, the design, to the manufacture. Some interesting but challenging topics for the future are also discussed.

  10. Ray-optics analysis of inhomogeneous optically anisotropic media

    NARCIS (Netherlands)

    Sluijter, M.

    2010-01-01

    When the optical behavior of light in a medium depends on the direction in which light is traveling, the medium is called optically anisotropic. Light is an electromagnetic wave and in this thesis, we discuss the electromagnetic theory on optical anisotropy. We do this with the assumption that the

  11. Highly Reliable PON Optical Splitters for Optical Access Networks in Outside Environments

    Science.gov (United States)

    Watanabe, Hiroshi; Araki, Noriyuki; Fujimoto, Hisashi

    Broadband optical access services are spreading throughout the world, and the number of fiber to the home (FTTH) subscribers is increasing rapidly. Telecom operators are constructing passive optical networks (PONs) to provide optical access services. Externally installed optical splitters for PONs are very important passive devices in optical access networks, and they must provide satisfactory performance as outdoor plant over long periods. Therefore, we calculate the failure rate of optical access networks and assign a failure rate to the optical splitters in optical access networks. The maximum cumulative failure rate of 1 × 8 optical splitters was calculated as 0.025 for an optical access fiber length of 2.1km and a 20-year operating lifetime. We examined planar lightwave circuit (PLC) type optical splitters for use as outside plant in terms of their optical characteristics and environmental reliability. We confirmed that PLC type optical splitters have sufficient optical performance for a PON splitter and sufficient reliability as outside plant in accordance with ITU-T standard values. We estimated the lifetimes of three kinds of PLC type optical splitters by using accelerated aging tests. The estimated failure rate of these splitters installed in optical access networks was below the target value for the cumulative failure rate, and we confirmed that they have sufficient reliability to maintain the quality of the network service. We developed 1 × 8 optical splitter modules with plug and socket type optical connectors and optical fiber cords for optical aerial closures designed for use as outside plant. These technologies make it easy to install optical splitters in an aerial optical closure. The optical splitter modules have sufficient optical performance levels for PONs because the insertion loss at the commercially used wavelengths of 1.31 and 1.55µm is less than the criterion established by ITU-T Recommendation G.671 for optical splitters. We performed a

  12. SAVAH: Source Address Validation with Host Identity Protocol

    Science.gov (United States)

    Kuptsov, Dmitriy; Gurtov, Andrei

    Explosive growth of the Internet and lack of mechanisms that validate the authenticity of a packet source produced serious security and accounting issues. In this paper, we propose validating source addresses in LAN using Host Identity Protocol (HIP) deployed in a first-hop router. Compared to alternative solutions such as CGA, our approach is suitable both for IPv4 and IPv6. We have implemented SAVAH in Wi-Fi access points and evaluated its overhead for clients and the first-hop router.

  13. Allocating resources between network nodes for providing a network node function

    OpenAIRE

    Strijkers, R.J.; Meulenhoff, P.J.

    2014-01-01

    The invention provides a method wherein a first network node advertises available resources that a second network node may use to offload network node functions transparently to the first network node. Examples of the first network node are a client device (e.g. PC, notebook, tablet, smart phone), a server (e.g. application server, a proxy server, cloud location, router). Examples of the second network node are an application server, a cloud location or a router. The available resources may b...

  14. Optical XOR gate

    Science.gov (United States)

    Vawter, G. Allen

    2013-11-12

    An optical XOR gate is formed as a photonic integrated circuit (PIC) from two sets of optical waveguide devices on a substrate, with each set of the optical waveguide devices including an electroabsorption modulator electrically connected in series with a waveguide photodetector. The optical XOR gate utilizes two digital optical inputs to generate an XOR function digital optical output. The optical XOR gate can be formed from III-V compound semiconductor layers which are epitaxially deposited on a III-V compound semiconductor substrate, and operates at a wavelength in the range of 0.8-2.0 .mu.m.

  15. Fiber optic connector

    Science.gov (United States)

    Rajic, Slobodan; Muhs, Jeffrey D.

    1996-01-01

    A fiber optic connector and method for connecting composite materials within which optical fibers are imbedded. The fiber optic connector includes a capillary tube for receiving optical fibers at opposing ends. The method involves inserting a first optical fiber into the capillary tube and imbedding the unit in the end of a softened composite material. The capillary tube is injected with a coupling medium which subsequently solidifies. The composite material is machined to a desired configuration. An external optical fiber is then inserted into the capillary tube after fluidizing the coupling medium, whereby the optical fibers are coupled.

  16. Wave-Optics Modeling of the Optical-Transport Line for Passive Optical Stochastic Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Andorf, M. B. [NICADD, DeKalb; Lebedev, V. A. [Fermilab; Piot, P. [Fermilab; Ruan, J. [Fermilab

    2018-03-01

    Optical stochastic cooling (OSC) is expected to enable fast cooling of dense particle beams. Transition from microwave to optical frequencies enables an achievement of stochastic cooling rates which are orders of magnitude higher than ones achievable with the classical microwave based stochastic cooling systems. A subsytem critical to the OSC scheme is the focusing optics used to image radiation from the upstream "pickup" undulator to the downstream "kicker" undulator. In this paper, we present simulation results using wave-optics calculation carried out with the {\\sc Synchrotron Radiation Workshop} (SRW). Our simulations are performed in support to a proof-of-principle experiment planned at the Integrable Optics Test Accelerator (IOTA) at Fermilab. The calculations provide an estimate of the energy kick received by a 100-MeV electron as it propagates in the kicker undulator and interacts with the electromagnetic pulse it radiated at an earlier time while traveling through the pickup undulator.

  17. Two mode optical fiber in space optics communication

    Science.gov (United States)

    Hampl, Martin

    2017-11-01

    In our contribution we propose to use of a two-mode optical fiber as a primary source in a transmitting optical head instead of the laser diode. The distribution of the optical intensity and the complex degree of the coherence on the output aperture of the lens that is irradiated by a step-index weakly guiding optical fiber is investigated. In our treatment we take into account weakly guided modes with polarization corrections to the propagation constant and unified theory of second order coherence and polarization of electromagnetic beams.

  18. Stiffness of RBC optical confinement affected by optical clearing

    Science.gov (United States)

    Grishin, Oleg V.; Fedosov, Ivan V.; Tuchin, Valery V.

    2017-03-01

    In vivo optical trapping is a novel applied direction of an optical manipulation, which enables one to noninvasive measurement of mechanical properties of cells and tissues in living animals directly. But an application area of this direction is limited because strong scattering of many biological tissues. An optical clearing enables one to decrease the scattering and therefore increase a depth of light penetration, decrease a distortion of light beam, improve a resolution in imaging applications. Now novel methods had appeared for a measurement an optical clearing degree at a cellular level. But these methods aren't applicable in vivo. In this paper we present novel measurement method of estimate of the optical clearing, which are based on a measurement of optical trap stiffness. Our method may be applicable in vivo.

  19. Quantum Optics

    CERN Document Server

    Walls, D F

    2007-01-01

    Quantum Optics gives a comprehensive coverage of developments in quantum optics over the past years. In the early chapters the formalism of quantum optics is elucidated and the main techniques are introduced. These are applied in the later chapters to problems such as squeezed states of light, resonance fluorescence, laser theory, quantum theory of four-wave mixing, quantum non-demolition measurements, Bell's inequalities, and atom optics. Experimental results are used to illustrate the theory throughout. This yields the most comprehensive and up-to-date coverage of experiment and theory in quantum optics in any textbook. More than 40 exercises helps readers test their understanding and provide practice in quantitative problem solving.

  20. Energy-Efficient High-Performance Routers

    Science.gov (United States)

    2012-02-01

    procedures described in Sections III- B2b and III-B2d. If the update is an insert, then a new vertex is added to the priority graph. All rules overlapping with...discussed (Section III- B2b ), then we describe the creation of LTCAM1 entries using the process of carving (Section III-B2c). Next we describe partial port

  1. Router for internet of things

    OpenAIRE

    Čižius, Ovidijus

    2016-01-01

    The Internet of Things (IoT) is a globally growing technology based on internet information architecture is designed to facilitate the exchange of goods and services to manage the home devices more convenient way. IoT is the development of information technology infrastructure to ensure the safe and reliable transfer of data between objects. IoT - daily-used items, such as cars, refrigerators, air conditioners, umbrellas and others. There are not necessary a high technology to produce mention...

  2. Optical-domain Compensation for Coupling between Optical Fiber Conjugate Vortex Modes

    DEFF Research Database (Denmark)

    Lyubopytov, Vladimir S.; Tatarczak, Anna; Lu, Xiaofeng

    2016-01-01

    We demonstrate for the first time optical-domain compensation for coupling between conjugate vortex modes in optical fibers. We introduce a novel method for reconstructing the complex propagation matrix of the optical fiber with straightforward implementation.......We demonstrate for the first time optical-domain compensation for coupling between conjugate vortex modes in optical fibers. We introduce a novel method for reconstructing the complex propagation matrix of the optical fiber with straightforward implementation....

  3. Wideband optical vector network analyzer based on optical single-sideband modulation and optical frequency comb.

    Science.gov (United States)

    Xue, Min; Pan, Shilong; He, Chao; Guo, Ronghui; Zhao, Yongjiu

    2013-11-15

    A novel approach to increase the measurement range of the optical vector network analyzer (OVNA) based on optical single-sideband (OSSB) modulation is proposed and experimentally demonstrated. In the proposed system, each comb line in an optical frequency comb (OFC) is selected by an optical filter and used as the optical carrier for the OSSB-based OVNA. The frequency responses of an optical device-under-test (ODUT) are thus measured channel by channel. Because the comb lines in the OFC have fixed frequency spacing, by fitting the responses measured in all channels together, the magnitude and phase responses of the ODUT can be accurately achieved in a large range. A proof-of-concept experiment is performed. A measurement range of 105 GHz and a resolution of 1 MHz is achieved when a five-comb-line OFC with a frequency spacing of 20 GHz is applied to measure the magnitude and phase responses of a fiber Bragg grating.

  4. MultiPaths Revisited - A novel approach using OpenFlow-enabled devices

    CERN Document Server

    Al-Shabibi, Ali; Martin, Brian

    2011-06-11

    This thesis presents novel approaches enhancing the performance of computer networks using multipaths. Our enhancements take the form of congestion-aware routing protocols. We present three protocols called MultiRoute, Step-Route, and finally PathRoute. Each of these protocols leverage both local and remote congestion statistics and build different representations (or views) of the network congestion by using an innovative representation of congestion for router-router links. These congestion statistics are then distributed via an aggregation protocol to other routers in the network. For many years, multipath routing protocols have only been used in simple situations, such as Link Aggregation and/or networks where paths of equal cost (and therefore equal delay) exist. But, paths of unequal costs are often discarded to the benefit of shortest path only routing because it is known that paths of unequal length present different delays and therefore cause out of order packets which cause catastrophic network per...

  5. Transnasal Endoscopic Optic Nerve Decompression in Post Traumatic Optic Neuropathy.

    Science.gov (United States)

    Gupta, Devang; Gadodia, Monica

    2018-03-01

    To quantify the successful outcome in patients following optic nerve decompression in post traumatic unilateral optic neuropathy in form of improvement in visual acuity. A prospective study was carried out over a period of 5 years (January 2011 to June 2016) at civil hospital Ahmedabad. Total 20 patients were selected with optic neuropathy including patients with direct and indirect trauma to unilateral optic nerve, not responding to conservative management, leading to optic neuropathy and subsequent impairment in vision and blindness. Decompression was done via Transnasal-Ethmo-sphenoidal route and outcome was assessed in form of post-operative visual acuity improvement at 1 month, 6 months and 1 year follow up. After surgical decompression complete recovery of visual acuity was achieved in 16 (80%) patients and partial recovery in 4 (20%). Endoscopic transnasal approach is beneficial in traumatic optic neuropathy not responding to steroid therapy and can prevent permanent disability if earlier intervention is done prior to irreversible damage to the nerve. Endoscopic optic nerve surgery can decompress the traumatic and oedematous optic nerve with proper exposure of orbital apex and optic canal without any major intracranial, intraorbital and transnasal complications.

  6. Peptide Integrated Optics.

    Science.gov (United States)

    Handelman, Amir; Lapshina, Nadezda; Apter, Boris; Rosenman, Gil

    2018-02-01

    Bio-nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light-guiding components. In this work, an advanced concept of integrated bio-optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding. Developed new technology combining bottom-up controlled deposition of peptide planar wafers of a large area and top-down focus ion beam lithography provides direct fabrication of peptide optical integrated circuits. Finding a deep modification of peptide optical properties by reconformation of biological secondary structure from native phase to β-sheet architecture is followed by the appearance of visible fluorescence and unexpected transition from a native passive optical waveguiding to an active one. Original biocompatibility, switchable regimes of waveguiding, and multifunctional nonlinear optical properties make these new peptide planar optical materials attractive for application in emerging technology of lab-on-biochips, combining biomedical photonic and electronic circuits toward medical diagnosis, light-activated therapy, and health monitoring. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 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....

  8. Viscous optical clearing agent for in vivo optical imaging

    Science.gov (United States)

    Deng, Zijian; Jing, Lijia; Wu, Ning; lv, Pengyu; Jiang, Xiaoyun; Ren, Qiushi; Li, Changhui

    2014-07-01

    By allowing more photons to reach deeper tissue, the optical clearing agent (OCA) has gained increasing attention in various optical imaging modalities. However, commonly used OCAs have high fluidity, limiting their applications in in vivo studies with oblique, uneven, or moving surfaces. In this work, we reported an OCA with high viscosity. We measured the properties of this viscous OCA, and tested its successful performances in the imaging of a living animal's skin with two optical imaging modalities: photoacoustic microscopy and optical coherence tomography. Our results demonstrated that the viscous OCA has a great potential in the study of different turbid tissues using various optical imaging modalities.

  9. ADVANTAGES OF DIFFRACTIVE OPTICAL ELEMENTS APPLICATION IN SIMPLE OPTICAL IMAGING SYSTEMS

    Directory of Open Access Journals (Sweden)

    N. D. Zoric

    2015-01-01

    Full Text Available The paper deals with the influence of diffractive optical elements on the optical aberrations. The correction of optical aberrations was investigated in the simple optical systems with one and two lenses (singlet and doublet. The advantages of diffractive optical elements are their ability to generate arbitrary complex wave fronts from a piece of optical material that is essentially flat. The optical systems consisting of the standard surfaces were designed and optimized by using the same starting points. Further, the diffractive and aspheric surfaces were introduced into the developed systems. The resulting hybrid systems were optimized. To compare the complicity of the development of narrow field systems and wide field optical systems, the optimization has been done separately for these two types of the instruments. The optical systems were designed by using special Optical Design Software. Тhe characteristics of designed diffractive surfaces were controlled in Software DIFSYS 2.30. Due to the application of diffractive optical elements the longitudinal chromatic aberration was 5 times reduced for the narrow field systems. The absolute value of Seidel coefficient related to the spherical aberration was reduced in the range of 0.03. Considering that diffractive optical elements have the known disadvantages, like possible parasitic diffraction orders and probable decrease of the transmission, we also developed and analyzed the optical systems with combined aspheric and diffractive surfaces. A combination of the aspheric and diffractive surfaces in the optical disk system of the disk reading lens, gave cutting down of the longitudinal color aberrations almost 15 times on-axis, comparing to the lens consisting of the aspherical and standard surfaces. All of the designed diffractive optical elements possess the parameters within the fabrication limits.

  10. Fiber optic based optical tomography sensor for monitoring plasma uniformity

    International Nuclear Information System (INIS)

    Benck, Eric C.; Etemadi, Kasra

    2001-01-01

    A new type of fiber optic based optical tomography sensor has been developed for in situ monitoring of plasma uniformity. Optical tomography inverts optical emission measurements into the actual plasma distribution without assuming radial symmetry. The new sensor is designed to operate with only two small windows and acquire the necessary data in less than a second. Optical tomography is being tested on an ICP-GEC RF plasma source. Variations in plasma uniformity are measured as a function of different plasma conditions

  11. Optical trapping of a spherically symmetric sphere in the ray-optics regime: a model for optical tweezers upon cells

    International Nuclear Information System (INIS)

    Chang Yiren; Hsu Long; Chi Sien

    2006-01-01

    Since their invention in 1986, optical tweezers have become a popular manipulation and force measurement tool in cellular and molecular biology. However, until recently there has not been a sophisticated model for optical tweezers on trapping cells in the ray-optics regime. We present a model for optical tweezers to calculate the optical force upon a spherically symmetric multilayer sphere representing a common biological cell. A numerical simulation of this model shows that not only is the magnitude of the optical force upon a Chinese hamster ovary cell significantly three times smaller than that upon a polystyrene bead of the same size, but the distribution of the optical force upon a cell is also much different from that upon a uniform particle, and there is a 30% difference in the optical trapping stiffness of these two cases. Furthermore, under a small variant condition for the refractive indices of any adjacent layers of the sphere, this model provides a simple approximation to calculate the optical force and the stiffness of an optical tweezers system

  12. Blood cleaner on-chip design for artificial human kidney manipulation

    Directory of Open Access Journals (Sweden)

    Suwanpayak N

    2011-05-01

    Full Text Available N Suwanpayak1, MA Jalil2, MS Aziz3, FD Ismail3, J Ali3, PP Yupapin11Nanoscale Science and Engineering Research Alliance (N'SERA, Advanced Research Center for Photonics, Faculty of Science, King Mongkut's Institute of Technology, Ladkrabang, Bangkok, Thailand; 2Ibnu Sina Institute of Fundamental Science Studies (IIS, 3Institute of Advanced Photonics Science, Nanotechnology Research Alliance, Universiti Teknologi Malaysia, Johor Bahru, MalaysiaAbstract: A novel design of a blood cleaner on-chip using an optical waveguide known as a PANDA ring resonator is proposed. By controlling some suitable parameters, the optical vortices (gradient optical fields/wells can be generated and used to form the trapping tools in the same way as optical tweezers. In operation, the trapping force is formed by the combination between the gradient field and scattering photons by using the intense optical vortices generated within the PANDA ring resonator. This can be used for blood waste trapping and moves dynamically within the blood cleaner on-chip system (artificial kidney, and is performed within the wavelength routers. Finally, the blood quality test is exploited by the external probe before sending to the destination. The advantage of the proposed kidney on-chip system is that the unwanted substances can be trapped and filtered from the artificial kidney, which can be available for blood cleaning applications.Keywords: optical trapping, blood dialysis, blood cleaner, human kidney manipulation

  13. Applied optics

    International Nuclear Information System (INIS)

    Orszag, A.; Antonetti, A.

    1988-01-01

    The 1988 progress report, of the Applied Optics laboratory, of the (Polytechnic School, France), is presented. The optical fiber activities are focused on the development of an optical gyrometer, containing a resonance cavity. The following domains are included, in the research program: the infrared laser physics, the laser sources, the semiconductor physics, the multiple-photon ionization and the nonlinear optics. Investigations on the biomedical, the biological and biophysical domains are carried out. The published papers and the congress communications are listed [fr

  14. Optic Nerve Pit

    Science.gov (United States)

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Optic Nerve Pit What is optic nerve pit? An optic nerve pit is a ... may be seen in both eyes. How is optic pit diagnosed? If the pit is not affecting ...

  15. Ultrafast all-optical signal processing using semiconductor optical amplifiers

    NARCIS (Netherlands)

    Li, Z.

    2007-01-01

    As the bit rate of one wavelength channel and the number of channels keep increasing in the telecommunication networks thanks to the advancement of optical transmission technologies, switching is experiencing the transition from the electrical domain to the optical domain. All-optical signal

  16. Fibre Optic Gyroscope Developments Using Integrated Optic Components

    Science.gov (United States)

    Minford, W. J.; DePaula, R. M.

    1988-09-01

    The sensing of rotation using counterpropagating optical beams in a fiber loop (the SAGNAC effect) has gone through extensive developments and demonstrations since first proved feasible by Vali and Shorthilll in 1976. The interferometric fiber gyroscope minimum configuration2 which uses a common input-output port and single-mode filter was developed to provide the extreme high stability necessary to reach the sensitivities at low rotation rates attainable with current state-of-the-art detectors. The simplicity and performance of this configuration has led to its acceptance and wide-spread use. In order to increase the mechanical stability of this system, all single-mode fiber components are employed and a further advancement to integrated optics has enabled most of the optical functions to be placed on a single mass-producible substrate. Recent improvements in the components (eg polarization maintaining fiber and low coherence sources) have further enhanced the performance of the minimum configuration gyro. This presentation focused on the impact of LiNbO3 integrated optic components on gyroscope developments. The use of Ti-indiffused LiNbO3 waveguide optical circuits in interferometric fiber optic gyroscopes has taken two directions: to utilize only the phase modulator, or to combine many of the minimum configuration optical functions on the electro-optic substrate. The high-bandwidth phase modulator is the driving force for using LiNbO3 waveguide devices. This device allows both biasing the gyro for maximum sensitivity and closing the loop via frequency shifting, for example, thus increasing the dynamic range of the gyro and the linearity of the scale factor. Efforts to implement most of the minimum configuration optical functions onto a single LiNbO3 substrate have been led by Thomson CSF.3 They have demonstrated an interferometric gyroscope with excellent performance using a LiNbO3 optical circuit containing a Y-splitter, phase modulator, and surface

  17. 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.

  18. 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.

  19. Problems of Aero-optics and Adaptive Optical Systems: Analytical Review

    Directory of Open Access Journals (Sweden)

    Yu. I. Shanin

    2017-01-01

    Full Text Available The analytical review gives the basic concepts of the aero-optics problem arising from the radiation propagation in the region of the boundary layers of a laser installation carrier aircraft. Estimates the radiation wave front distortions at its propagation in the near and far field. Presents main calculation approaches and methods to solve the gas-dynamic and optical problems in propagating laser radiation. Conducts a detailed analysis of the flows and their generating optical aberrations introduced by the aircraft turret (a projection platform of the on-board laser. Considers the effect of various factors (shock wave, difference in wall and flow temperatures on the flow pattern and the optical aberrations. Provides research data on the aero-optics obtained in the flying laboratory directly while in flight. Briefly considers the experimental research methods, diagnostic equipment, and synthesis of results while studying the aero-optics problem. Discusses some methods for mitigating the aerodynamic effects on the light propagation under flight conditions. Presents data about the passive, active, and hybrid effects on the flow in the boundary layers in order to reduce aberrations through improving the flow aerodynamics.The paper considers operation of adaptive optical systems under conditions of aero-optical distortions. Presents the study results concerning the reduction of the aero-optics effect on the characteristics of radiation in far field. Gives some research results regarding the effect on the efficiency of the adaptive system of a laser beam jitter and a time delay in the feedback signal transmission, which occur under application conditions. Provides data on adaptive correction of aero-optical wave fronts of radiation. Considers some application aspects in control systems of the on-board adaptive optics of adaptive filtration as a way to improve the efficiency of adaptive optical systems. The project in mind is to use obtained results

  20. Unusual suicide by electric saw: A case report

    Directory of Open Access Journals (Sweden)

    M. Zribi

    2015-09-01

    Full Text Available Suicide by power saws (bland, chain, circular or router saw are an extreme exception. A few case reports are published in forensic literature regarding it. We report the case of a 30-year-old carpenter found dead lying on the floor next to a router saw in his carpenter workshop, with two gaping and deep wounds in his head. We summarize the findings of the death scene examination, the forensic autopsy, and the world literature concerning suicide committed with power saws.

  1. An Approach to Active Queue Management in Computer Network

    OpenAIRE

    Asimkiran Dandapat

    2016-01-01

    Active queue management is a key technique for reducing the packet drop rate in the internet. This packet dropping mechanism is used in a router to minimize congestion when the packets are dropped before queue gets full. In this paper a new framework of Active queue management namely MYRED is proposed. The goal of this new scheme is to improve the performance of AQM by keeping router queue length optimized. In RED packets are marked or dropped with a statistical probability before packet buff...

  2. Optical computing, optical memory, and SBIRs at Foster-Miller

    Science.gov (United States)

    Domash, Lawrence H.

    1994-03-01

    A desktop design and manufacturing system for binary diffractive elements, MacBEEP, was developed with the optical researcher in mind. Optical processing systems for specialized tasks such as cellular automation computation and fractal measurement were constructed. A new family of switchable holograms has enabled several applications for control of laser beams in optical memories. New spatial light modulators and optical logic elements have been demonstrated based on a more manufacturable semiconductor technology. Novel synthetic and polymeric nonlinear materials for optical storage are under development in an integrated memory architecture. SBIR programs enable creative contributions from smaller companies, both product oriented and technology oriented, and support advances that might not otherwise be developed.

  3. All-Optical Regeneration System for Optical Wavelength Division Multiplexed Communication Systems

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to an all-optical regeneration system for regeneration of optical wavelength division multiplexed WDM data signals in an optical WDM communication system. The system comprises a WDM-to-Optical time domain multiplexing OTDM, WDM-to-OTDM, converter, capable of converting....... The system additionally comprises an OTDM-to-WDM converter for converting the output OTDM data signal to an output WDM data signal. An input of the all-optical regenerator unit is in optical communication with an output of the WDM-to-OTDM converter, and an output of the all-optical regenerator unit...... an input WDM data signal comprising multiple wavelength channels into an input OTDM data signal comprising multiple time multiplexed time channels. The system further comprises an all-optical regenerator unit being configured for regenerating the input OTDM data signal into an output OTDM data signal...

  4. Generation of optical vortices in an integrated optical circuit

    Science.gov (United States)

    Tudor, Rebeca; Kusko, Mihai; Kusko, Cristian

    2017-09-01

    In this work, the generation of optical vortices in an optical integrated circuit is numerically demonstrated. The optical vortices with topological charge m = ±1 are obtained by the coherent superposition of the first order modes present in a waveguide with a rectangular cross section, where the phase delay between these two propagating modes is Δφ = ±π/2. The optical integrated circuit consists of an input waveguide continued with a y-splitter. The left and the right arms of the splitter form two coupling regions K1 and K2 with a multimode output waveguide. In each coupling region, the fundamental modes present in the arms of the splitter are selectively coupled into the output waveguide horizontal and vertical first order modes, respectively. We showed by employing the beam propagation method simulations that the fine tuning of the geometrical parameters of the optical circuit makes possible the generation of optical vortices in both transverse electric (TE) and transverse magnetic (TM) modes. Also, we demonstrated that by placing a thermo-optical element on one of the y-splitter arms, it is possible to switch the topological charge of the generated vortex from m = 1 to m = -1.

  5. Integrated optical transceiver with electronically controlled optical beamsteering

    Science.gov (United States)

    Davids, Paul; DeRose, Christopher; Tauke-Pedretti, Anna

    2017-08-22

    A beam-steering optical transceiver is provided. The transceiver includes one or more modules, each comprising an antenna chip and a control chip bonded to the antenna chip. Each antenna chip has a feeder waveguide, a plurality of row waveguides that tap off from the feeder waveguide, and a plurality of metallic nanoantenna elements arranged in a two-dimensional array of rows and columns such that each row overlies one of the row waveguides. Each antenna chip also includes a plurality of independently addressable thermo-optical phase shifters, each configured to produce a thermo-optical phase shift in a respective row. Each antenna chip also has, for each row, a row-wise heating circuit configured to produce a respective thermo-optic phase shift at each nanoantenna element along its row. The control chip includes controllable current sources for the independently addressable thermo-optical phase shifters and the row-wise heating circuits.

  6. Integrated Optical Circuit Engineering For Optical Fiber Gyrocopes

    Science.gov (United States)

    Bristow, Julian P.; We, Albert C.; Keur, M.; Lukas, Greg; Ott, Daniel M...; Sriram, S.

    1988-03-01

    Fiber optic gyroscopes are of interest for low-cost, high performance rotation sensors. Integrated optical implementations of the processing optics offer the hope of mass-production, and associated cost reductions. The development of a suitable integrated optical system has been reported by other authors at a wavelength of 850nm [1]. Despite strong technical advantages at 1.3μm wavelength [2], no results have yet appeared. This wavelength is preferred for telecommunications applications applications, thus significantly reduced fiber costs may be realized. Lithium niobate is relatively immune from the photorefractive effect at this wavelength, whereas it is not at at 850nm [3].

  7. Optical pulse generation using fiber lasers and integrated optics

    International Nuclear Information System (INIS)

    Wilcox, R.B.; Browning, D.F.; Burkhart, S.C.; VanWonterghem, B.W.

    1995-01-01

    We have demonstrated an optical pulse forming system using fiber and integrated optics, and have designed a multiple-output system for a proposed fusion laser facility. Our approach is an advancement over previous designs for fusion lasers, and an unusual application of fiber lasers and integrated optics

  8. Optical computing.

    Science.gov (United States)

    Stroke, G. W.

    1972-01-01

    Applications of the optical computer include an approach for increasing the sharpness of images obtained from the most powerful electron microscopes and fingerprint/credit card identification. The information-handling capability of the various optical computing processes is very great. Modern synthetic-aperture radars scan upward of 100,000 resolvable elements per second. Fields which have assumed major importance on the basis of optical computing principles are optical image deblurring, coherent side-looking synthetic-aperture radar, and correlative pattern recognition. Some examples of the most dramatic image deblurring results are shown.

  9. MEMS optical sensor

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to an all-optical sensor utilizing effective index modulation of a waveguide and detection of a wavelength shift of reflected light and a force sensing system accommodating said optical sensor. One embodiment of the invention relates to a sensor system comprising...... at least one multimode light source, one or more optical sensors comprising a multimode sensor optical waveguide accommodating a distributed Bragg reflector, at least one transmitting optical waveguide for guiding light from said at least one light source to said one or more multimode sensor optical...... waveguides, a detector for measuring light reflected from said Bragg reflector in said one or more multimode sensor optical waveguides, and a data processor adapted for analyzing variations in the Bragg wavelength of at least one higher order mode of the reflected light....

  10. Optical biosensors.

    Science.gov (United States)

    Damborský, Pavel; Švitel, Juraj; Katrlík, Jaroslav

    2016-06-30

    Optical biosensors represent the most common type of biosensor. Here we provide a brief classification, a description of underlying principles of operation and their bioanalytical applications. The main focus is placed on the most widely used optical biosensors which are surface plasmon resonance (SPR)-based biosensors including SPR imaging and localized SPR. In addition, other optical biosensor systems are described, such as evanescent wave fluorescence and bioluminescent optical fibre biosensors, as well as interferometric, ellipsometric and reflectometric interference spectroscopy and surface-enhanced Raman scattering biosensors. The optical biosensors discussed here allow the sensitive and selective detection of a wide range of analytes including viruses, toxins, drugs, antibodies, tumour biomarkers and tumour cells. © 2016 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  11. Optical Pattern Recognition

    Science.gov (United States)

    Yu, Francis T. S.; Jutamulia, Suganda

    2008-10-01

    Contributors; Preface; 1. Pattern recognition with optics Francis T. S. Yu and Don A. Gregory; 2. Hybrid neural networks for nonlinear pattern recognition Taiwei Lu; 3. Wavelets, optics, and pattern recognition Yao Li and Yunglong Sheng; 4. Applications of the fractional Fourier transform to optical pattern recognition David Mendlovic, Zeev Zalesky and Haldum M. Oxaktas; 5. Optical implementation of mathematical morphology Tien-Hsin Chao; 6. Nonlinear optical correlators with improved discrimination capability for object location and recognition Leonid P. Yaroslavsky; 7. Distortion-invariant quadratic filters Gregory Gheen; 8. Composite filter synthesis as applied to pattern recognition Shizhou Yin and Guowen Lu; 9. Iterative procedures in electro-optical pattern recognition Joseph Shamir; 10. Optoelectronic hybrid system for three-dimensional object pattern recognition Guoguang Mu, Mingzhe Lu and Ying Sun; 11. Applications of photrefractive devices in optical pattern recognition Ziangyang Yang; 12. Optical pattern recognition with microlasers Eung-Gi Paek; 13. Optical properties and applications of bacteriorhodopsin Q. Wang Song and Yu-He Zhang; 14. Liquid-crystal spatial light modulators Aris Tanone and Suganda Jutamulia; 15. Representations of fully complex functions on real-time spatial light modulators Robert W. Cohn and Laurence G. Hassbrook; Index.

  12. 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).

  13. Acousto-optic interaction in polyimide coated optical fibers with flexural waves

    OpenAIRE

    ALCUSA-SÁEZ, E. P.; Díez, A.; Rivera-Pérez, E.; Margulis, W.; Norin, L.; Andrés, M. V.

    2017-01-01

    Acousto-optic coupling in polyimide-coated single-mode optical fibers using flexural elastic waves is demonstrated. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. Although the elastic attenuation is significant, we show that acousto-optic coupling can be produced with a reasonably good efficiency. To our knowledge, it is the first experimental demonstration of acousto-optic coupl...

  14. 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.

  15. Piezo-optic and elasto-optic properties of monoclinic triglycine sulfate crystals.

    Science.gov (United States)

    Mytsyk, Bogdan; Demyanyshyn, Natalya; Erba, Alessandro; Shut, Viktor; Mozzharov, Sergey; Kost, Yaroslav; Mys, Oksana; Vlokh, Rostyslav

    2017-12-01

    For the first time, to the best of our knowledge, we have experimentally determined all of the components of the piezo-optic tensor for monoclinic crystals. This has been implemented on a specific example of triglycine sulfate crystals. Based on the results obtained, the complete elasto-optic tensor has been calculated. Acousto-optic figures of merit (AOFMs) have been estimated for the case of acousto-optic interaction occurring in the principal planes of the optical indicatrix ellipsoid and for geometries in which the highest elasto-optic coefficients are involved as effective parameters. It has been found that the highest AOFM value is equal to 6.8×10 -15   s 3 /kg for the case of isotropic acousto-optic interaction with quasi-longitudinal acoustic waves in the principal planes. This AOFM is higher than the corresponding values typical for canonic acousto-optic materials, which are transparent in the deep ultraviolet spectral range.

  16. Optics equations for aero-optical analysis

    Science.gov (United States)

    Sutton, George W.; Pond, John E.

    2011-05-01

    Aero-optical effects occur around moving air vehicles and impact passive imaging or active systems. The air flow around the vehicle is compressed, and often there is a turbulent shear and/or boundary layer both of which cause variations in the index of refraction. Examples of these are reconnaissance aircraft, the Stratospheric Observatory for Infrared Optics (SOFIA), and optically homing hypersonic interceptors. In other applications, a laser beam can be formed within the vehicle, and projected outward and focused on an object. These include the Airborne Laser Laboratory, Airborne Laser and the Airborne Tactical Laser. There are many compressible fluid mechanics computer programs that can predict the air density distribution of the surrounding flow field including density fluctuations in turbulent shear and/or boundary layers. It is necessary for the physical optics to be used to predict the properties of the ensuing image plane intensity distribution, whether passive or active. These include the time-averaged image blur circle and instantaneous realizations. (Ray tracing is a poor approximation that gives erroneous results for small aberrations.)

  17. Automated optical assembly

    Science.gov (United States)

    Bala, John L.

    1995-08-01

    Automation and polymer science represent fundamental new technologies which can be directed toward realizing the goal of establishing a domestic, world-class, commercial optics business. Use of innovative optical designs using precision polymer optics will enable the US to play a vital role in the next generation of commercial optical products. The increased cost savings inherent in the utilization of optical-grade polymers outweighs almost every advantage of using glass for high volume situations. Optical designers must gain experience with combined refractive/diffractive designs and broaden their knowledge base regarding polymer technology beyond a cursory intellectual exercise. Implementation of a fully automated assembly system, combined with utilization of polymer optics, constitutes the type of integrated manufacturing process which will enable the US to successfully compete with the low-cost labor employed in the Far East, as well as to produce an equivalent product.

  18. Optical system design

    CERN Document Server

    Fischer, Robert F

    2008-01-01

    Honed for more than 20 years in an SPIE professional course taught by renowned optical systems designer Robert E. Fischer, Optical System Design, Second Edition brings you the latest cutting-edge design techniques and more than 400 detailed diagrams that clearly illustrate every major procedure in optical design. This thoroughly updated resource helps you work better and faster with computer-aided optical design techniques, diffractive optics, and the latest applications, including digital imaging, telecommunications, and machine vision. No need for complex, unnecessary mathematical derivations-instead, you get hundreds of examples that break the techniques down into understandable steps. For twenty-first century optical design without the mystery, the authoritative Optical Systems Design, Second Edition features: Computer-aided design use explained through sample problems Case studies of third-millennium applications in digital imaging, sensors, lasers, machine vision, and more New chapters on optomechanic...

  19. Intelligent Optical Systems Using Adaptive Optics

    Science.gov (United States)

    Clark, Natalie

    2012-01-01

    Until recently, the phrase adaptive optics generally conjured images of large deformable mirrors being integrated into telescopes to compensate for atmospheric turbulence. However, the development of smaller, cheaper devices has sparked interest for other aerospace and commercial applications. Variable focal length lenses, liquid crystal spatial light modulators, tunable filters, phase compensators, polarization compensation, and deformable mirrors are becoming increasingly useful for other imaging applications including guidance navigation and control (GNC), coronagraphs, foveated imaging, situational awareness, autonomous rendezvous and docking, non-mechanical zoom, phase diversity, and enhanced multi-spectral imaging. The active components presented here allow flexibility in the optical design, increasing performance. In addition, the intelligent optical systems presented offer advantages in size and weight and radiation tolerance.

  20. Applications of Nano-optics.

    Science.gov (United States)

    Zhou, Changhe; Fainman, Yeshaiahu; Sheng, Yunlong

    2011-11-01

    As nanoscale fabrication techniques advance, nano-optics continues to offer enabling solutions to numerous practical applications for information optics. This Applied Optics feature issue focuses on the Application of Nano-optics. © 2011 Optical Society of America

  1. Energy and Power Measurements for Network Coding in the Context of Green Mobile Clouds

    DEFF Research Database (Denmark)

    Paramanathan, Achuthan; Pedersen, Morten Videbæk; Roetter, Daniel Enrique Lucani

    2013-01-01

    results for inter-session network coding in Open-Mesh routers underline that the energy invested in performing network coding pays off by dramatically reducing the total energy for the transmission of data over wireless links. We also show measurements for intra-session network coding in three different......This paper presents an in-depth power and energy measurement campaign for inter- and intra-session network coding enabled communication in mobile clouds. The measurements are carried out on different commercial platforms with focus on routers and mobile phones with different CPU capabilities. Our...

  2. Controlling chaos in Internet congestion control model

    International Nuclear Information System (INIS)

    Chen Liang; Wang Xiaofan; Han Zhengzhi

    2004-01-01

    The TCP end-to-end congestion control plus RED router queue management can be modeled as a discrete-time dynamical system, which may create complex bifurcating and chaotic behavior. Based on the basic features of the TCP-RED model, we propose a time-dependent delayed feedback control algorithm to control chaos in the system by perturbing the accessible RED parameter p max . This method is able to stabilized a router queue occupancy at a level without knowing the exact knowledge of the network. Further, we study the situation of the presence of the UDP traffic

  3. Cisco Networking All-in-One For Dummies

    CERN Document Server

    Tetz, Edward

    2011-01-01

    A helpful guide on all things Cisco Do you wish that the complex topics of routers, switches, and networking could be presented in a simple, understandable presentation? With Cisco Networking All-in-One For Dummies, they are! This expansive reference is packed with all the information you need to learn to use Cisco routers and switches to develop and manage secure Cisco networks. This straightforward-by-fun guide offers expansive coverage of Cisco and breaks down intricate subjects such as networking, virtualization, and database technologies into easily digestible pieces. Drills down complex

  4. Optic disc oedema

    DEFF Research Database (Denmark)

    Nielsen, Marianne Kromann; Hamann, Steffen

    2014-01-01

    Optic disc oedema describes the nonspecific, localized swelling of the optic nerve head regardless of aetiology. Therefore, differentiating among the various aetiologies depends on a thorough history and knowledge of the clinical characteristics of the underlying conditions. Papilloedema strictly...... refers to optic disc oedema as a consequence of elevated intracranial pressure. It is usually a bilateral condition and visual function is preserved until late. Optic disc oedema caused by an anterior optic neuropathy is usually unilateral and accompanied by the loss of visual function....

  5. All-optical NRZ-to-RZ data format conversion with optically injected laser diode or semiconductor optical amplifier

    Science.gov (United States)

    Lin, Gong-Ru; Chang, Yung-Cheng; Yu, Kun-Chieh

    2006-09-01

    By injecting the optical NRZ data into a Fabry-Perot laser diode (FPLD) synchronously modulated at below threshold condition or a semiconductor optical amplifier (SOA) gain-depleted with a backward injected clock stream, the all-optical non-return to zero (NRZ) to return-to-zero (RZ) format conversion of a STM-64 date-stream for synchronous digital hierarchy (SDH) or an OC-192 data stream for synchronous optical network (SONET) in high-speed fiber-optic communication link can be performed. Without the assistance of any complicated RF electronic circuitry, the output RZ data-stream at bit rate of up to 10 Gbit/s is successfully transformed in the optically NRZ injection-locked FPLD, in which the incoming NRZ data induces gain-switching of the FPLD without DC driving current or at below threshold condition. A power penalty of 1.2 dB is measured after NRZ-to-RZ transformation in the FPLD. Alternatively, the all-optical 10Gbits/s NRZ-to-RZ format conversion can also be demonstrated in a semiconductor optical amplifier under a backward dark-optical-comb injection with its duty-cycle 70%, which is obtained by reshaping from the received data clock at 10 GHz. The incoming optical NRZ data-stream is transformed into a pulsed RZ data-stream with its duty-cycle, rms timing jitter, and conversion gain of 15%, 4ps, and 3dB, respectively. In contrast to the FPLD, the SOA based NRZ-to-RZ converter exhibits an enhanced extinction ratio from 7 to 13 dB, and BER of 10 -13 at -18.5 dBm. In particular, the power penalty of the received RZ data-stream has greatly improved by 5 dB as compared to that obtained from FPLD.

  6. Optical metrology for analysis of lobster-eye x-ray optics

    International Nuclear Information System (INIS)

    Irving, Thomas H.K.; Peele, Andrew G.; Nugent, Keith A.

    2003-01-01

    A new method that uses optical microscopy to determine the physical structure of lobster-eye x-ray optics is described. This approach offers the ability to predict x-ray performance without having to take an x-ray measurement. An overlapping series of images of the entrance and exit faces of an optic are obtained and examined by purpose-built software. A 24-parameter description of each channel is obtained from which a quantitative analysis of all the major optic defects, except surface roughness, is performed. Results for a planar lobster-eye optic are used to illustrate this technique and discuss its abilities as well as directions for future enhancements

  7. All-optically integrated photoacoustic and optical coherence tomography: A review

    Directory of Open Access Journals (Sweden)

    Wei Qiao

    2017-07-01

    Full Text Available All-optically integrated photoacoustic (PA and optical coherence tomography (OCT dual-mode imaging technology that could offer comprehensive pathological information for accurate diagnosis in clinic has gradually become a promising imaging technology in the aspect of biomedical imaging during the recent years. This review refers to the technology aspects of all-optical PA detection and system evolution of optically integrated PA and OCT, including Michelson interferometer dual-mode imaging system, Fabry–Perot (FP interferometer dual-mode imaging system and Mach–Zehnder interferometer dual-mode imaging system. It is believed that the optically integrated PA and OCT has great potential applications in biomedical imaging.

  8. Thermal/structural/optical integrated design for optical sensor mounted on unmanned aerial vehicle

    Science.gov (United States)

    Zhang, Gaopeng; Yang, Hongtao; Mei, Chao; Wu, Dengshan; Shi, Kui

    2016-01-01

    With the rapid development of science and technology and the promotion of many local wars in the world, altitude optical sensor mounted on unmanned aerial vehicle is more widely applied in the airborne remote sensing, measurement and detection. In order to obtain high quality image of the aero optical remote sensor, it is important to analysis its thermal-optical performance on the condition of high speed and high altitude. Especially for the key imaging assembly, such as optical window, the temperature variation and temperature gradient can result in defocus and aberrations in optical system, which will lead to the poor quality image. In order to improve the optical performance of a high speed aerial camera optical window, the thermal/structural/optical integrated design method is developed. Firstly, the flight environment of optical window is analyzed. Based on the theory of aerodynamics and heat transfer, the convection heat transfer coefficient is calculated. The temperature distributing of optical window is simulated by the finite element analysis software. The maximum difference in temperature of the inside and outside of optical window is obtained. Then the deformation of optical window under the boundary condition of the maximum difference in temperature is calculated. The optical window surface deformation is fitted in Zernike polynomial as the interface, the calculated Zernike fitting coefficients is brought in and analyzed by CodeV Optical Software. At last, the transfer function diagrams of the optical system on temperature field are comparatively analyzed. By comparing and analyzing the result, it can be obtained that the optical path difference caused by thermal deformation of the optical window is 138.2 nm, which is under PV ≤1 4λ . The above study can be used as an important reference for other optical window designs.

  9. Optic nerve oxygenation

    DEFF Research Database (Denmark)

    Stefánsson, Einar; Pedersen, Daniella Bach; Jensen, Peter Koch

    2005-01-01

    The oxygen tension of the optic nerve is regulated by the intraocular pressure and systemic blood pressure, the resistance in the blood vessels and oxygen consumption of the tissue. The oxygen tension is autoregulated and moderate changes in intraocular pressure or blood pressure do not affect...... the optic nerve oxygen tension. If the intraocular pressure is increased above 40 mmHg or the ocular perfusion pressure decreased below 50 mmHg the autoregulation is overwhelmed and the optic nerve becomes hypoxic. A disturbance in oxidative metabolism in the cytochromes of the optic nerve can be seen...... at similar levels of perfusion pressure. The levels of perfusion pressure that lead to optic nerve hypoxia in the laboratory correspond remarkably well to the levels that increase the risk of glaucomatous optic nerve atrophy in human glaucoma patients. The risk for progressive optic nerve atrophy in human...

  10. Nonlinear optical systems

    CERN Document Server

    Lugiato, Luigi; Brambilla, Massimo

    2015-01-01

    Guiding graduate students and researchers through the complex world of laser physics and nonlinear optics, this book provides an in-depth exploration of the dynamics of lasers and other relevant optical systems, under the umbrella of a unitary spatio-temporal vision. Adopting a balanced approach, the book covers traditional as well as special topics in laser physics, quantum electronics and nonlinear optics, treating them from the viewpoint of nonlinear dynamical systems. These include laser emission, frequency generation, solitons, optically bistable systems, pulsations and chaos and optical pattern formation. It also provides a coherent and up-to-date treatment of the hierarchy of nonlinear optical models and of the rich variety of phenomena they describe, helping readers to understand the limits of validity of each model and the connections among the phenomena. It is ideal for graduate students and researchers in nonlinear optics, quantum electronics, laser physics and photonics.

  11. Fiber-optical accelerometers based on polymer optical fiber Bragg gratings

    DEFF Research Database (Denmark)

    Yuan, Scott Wu; Stefani, Alessio; Bang, Ole

    2010-01-01

    Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer.......Fiber-optical accelerometers based on polymer optical fiber Bragg gratings (FBGs) are reported. We have written 3mm FBGs for 1550nm operation, characterized their temperature and strain response, and tested their performance in a prototype accelerometer....

  12. 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.

  13. Neutron optical potentials

    International Nuclear Information System (INIS)

    Wilmore, D.; Hodgson, P.E.

    1976-01-01

    The purpose of this paper is to provide a guide to the use of optical model computer programs to analyse and calculate neutron data. After a brief discussion of the physical basis of the optical model a survey is given of the most widely used optical model and Hauser-Feshbach computer programs. The range of applicability and reliability of the major optical potentials proposed is assessed by comparison with available experimental data and some observations and suggestions are made for the optimum choice of optical potentials for given purposes of neutron data calculations. (author)

  14. Optical limiting properties of optically active phthalocyanine derivatives

    Science.gov (United States)

    Wang, Peng; Zhang, Shuang; Wu, Peiji; Ye, Cheng; Liu, Hongwei; Xi, Fu

    2001-06-01

    The optical limiting properties of four optically active phthalocyanine derivatives in chloroform solutions and epoxy resin thin plates were measured at 532 nm with 10 ns pulses. The excited state absorption cross-section σex and refractive-index cross-section σr were determined with the Z-scan technique. These chromophores possess larger σex than the ground state absorption cross-section σ0, indicating that they are the potential materials for reverse saturable absorption (RSA). The negative σr values of these chromophores add to the thermal contribution, producing a larger defocusing effect, which may be helpful in further enhancing their optical limiting performance. The optical limiting responses of the thin plate samples are stronger than those of the chloroform solutions.

  15. 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.

  16. Fiber optics in adverse environments

    International Nuclear Information System (INIS)

    Lyous, P.B.

    1982-01-01

    Radiation effects in optical fibers are considered, taking into account recent progress in the investigation of radiation resistant optical fibers, radiation damage in optical fibers, radiation-induced transient absorption in optical fibers, X-ray-induced transient attenuation at low temperatures in polymer clad silica (PCS) fibers, optical fiber composition and radiation hardness, the response of irradiated optical waveguides at low temperatures, and the effect of ionizing radiation on fiber-optic waveguides. Other topics explored are related to environmental effects on components of fiber optic systems, and radiation detection systems using optical fibers. Fiber optic systems in adverse environments are also discussed, giving attention to the survivability of Army fiber optics systems, space application of fiber optics systems, fiber optic wavelength multiplexing for civil aviation applications, a new fiber optic data bus topology, fiber optics for aircraft engine/inlet control, and application of fiber optics in high voltage substations

  17. Optical absorption measurement system

    International Nuclear Information System (INIS)

    Draggoo, V.G.; Morton, R.G.; Sawicki, R.H.; Bissinger, H.D.

    1989-01-01

    This patent describes a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature

  18. Optical computation based on nonlinear total reflectional optical ...

    Indian Academy of Sciences (India)

    Optical computing; beam splitter; optical switch; polarized beams. ... main research direction called quantum information and quantum computation is .... above has several advantages: Firstly, it is easy to be integrated with appropriate.

  19. Emerging Correlation Optics

    DEFF Research Database (Denmark)

    Angelsky, Oleg V.; Gbur, Gregory J.; Polyanskii, Peter

    2012-01-01

    This feature issue of Applied Optics contains a series of selected papers reflecting the state-of-the-art of correlation optics and showing synergetics between the theoretical background and experimental techniques.......This feature issue of Applied Optics contains a series of selected papers reflecting the state-of-the-art of correlation optics and showing synergetics between the theoretical background and experimental techniques....

  20. Fiber Singular Optics

    OpenAIRE

    A. V. Volyar

    2002-01-01

    The present review is devoted to the optical vortex behavior both in free space and optical fibers. The processes of the vortex transformations in perturbed optical fibers are analyzed on the base of the operator of the spin – orbit interaction in order to forecast the possible ways of manufacturing the vortex preserving fibers and their applications in supersensitive optical devices.

  1. Nonlinear Optics and Applications

    Science.gov (United States)

    Abdeldayem, Hossin A. (Editor); Frazier, Donald O. (Editor)

    2007-01-01

    Nonlinear optics is the result of laser beam interaction with materials and started with the advent of lasers in the early 1960s. The field is growing daily and plays a major role in emerging photonic technology. Nonlinear optics play a major role in many of the optical applications such as optical signal processing, optical computers, ultrafast switches, ultra-short pulsed lasers, sensors, laser amplifiers, and many others. This special review volume on Nonlinear Optics and Applications is intended for those who want to be aware of the most recent technology. This book presents a survey of the recent advances of nonlinear optical applications. Emphasis will be on novel devices and materials, switching technology, optical computing, and important experimental results. Recent developments in topics which are of historical interest to researchers, and in the same time of potential use in the fields of all-optical communication and computing technologies, are also included. Additionally, a few new related topics which might provoke discussion are presented. The book includes chapters on nonlinear optics and applications; the nonlinear Schrodinger and associated equations that model spatio-temporal propagation; the supercontinuum light source; wideband ultrashort pulse fiber laser sources; lattice fabrication as well as their linear and nonlinear light guiding properties; the second-order EO effect (Pockels), the third-order (Kerr) and thermo-optical effects in optical waveguides and their applications in optical communication; and, the effect of magnetic field and its role in nonlinear optics, among other chapters.

  2. Cost-Effective Brillouin Optical Time-Domain Analysis Sensor Using a Single Optical Source and Passive Optical Filtering

    Directory of Open Access Journals (Sweden)

    H. Iribas

    2016-01-01

    Full Text Available We present a simplified configuration for distributed Brillouin optical time-domain analysis sensors that aims to reduce the cost of the sensor by reducing the number of components required for the generation of the two optical waves involved in the sensing process. The technique is based on obtaining the pump and probe waves by passive optical filtering of the spectral components generated in a single optical source that is driven by a pulsed RF signal. The optical source is a compact laser with integrated electroabsorption modulator and the optical filters are based on fiber Bragg gratings. Proof-of-concept experiments demonstrate 1 m spatial resolution over a 20 km sensing fiber with a 0.9 MHz precision in the measurement of the Brillouin frequency shift, a performance similar to that of much more complex setups. Furthermore, we discuss the factors limiting the sensor performance, which are basically related to residual spectral components in the filtering process.

  3. Silicon photonic integrated circuits with electrically programmable non-volatile memory functions.

    Science.gov (United States)

    Song, J-F; Lim, A E-J; Luo, X-S; Fang, Q; Li, C; Jia, L X; Tu, X-G; Huang, Y; Zhou, H-F; Liow, T-Y; Lo, G-Q

    2016-09-19

    Conventional silicon photonic integrated circuits do not normally possess memory functions, which require on-chip power in order to maintain circuit states in tuned or field-configured switching routes. In this context, we present an electrically programmable add/drop microring resonator with a wavelength shift of 426 pm between the ON/OFF states. Electrical pulses are used to control the choice of the state. Our experimental results show a wavelength shift of 2.8 pm/ms and a light intensity variation of ~0.12 dB/ms for a fixed wavelength in the OFF state. Theoretically, our device can accommodate up to 65 states of multi-level memory functions. Such memory functions can be integrated into wavelength division mutiplexing (WDM) filters and applied to optical routers and computing architectures fulfilling large data downloading demands.

  4. Phase-preserved optical elevator.

    Science.gov (United States)

    Luo, Yuan; Zhang, Baile; Han, Tiancheng; Chen, Zhi; Duan, Yubo; Chu, Chia-Wei; Barbastathis, George; Qiu, Cheng Wei

    2013-03-25

    The unique superiority of transformation optics devices designed from coordinate transformation is their capability of recovering both ray trajectory and optical path length in light manipulation. However, very few experiments have been done so far to verify this dual-recovery property from viewpoints of both ray trajectory and optical path length simultaneously. The experimental difficulties arise from the fact that most previous optical transformation optics devices only work at the nano-scale; the lack of intercomparison between data from both optical path length and ray trajectory measurement in these experiments obscured the fact that the ray path was subject to a subwavelength lateral shift that was otherwise not easily perceivable and, instead, was pointed out theoretically [B. Zhang et al. Phys. Rev. Lett. 104, 233903, 2010]. Here, we use a simple macroscopic transformation optics device of phase-preserved optical elevator, which is a typical birefringent optical phenomenon that can virtually lift an optical image by a macroscopic distance, to demonstrate decisively the unique optical path length preservation property of transformation optics. The recovery of ray trajectory is first determined with no lateral shift in the reflected ray. The phase preservation is then verified with incoherent white-light interferometry without ambiguity and phase unwrapping.

  5. Quantitative optical trapping and optical manipulation of micro-sized objects

    Directory of Open Access Journals (Sweden)

    Rania Sayed

    2017-10-01

    Full Text Available An optical tweezers technique is used for ultraprecise micromanipulation to measure positions of micrometer scale objects with a precision down to the nanometer scale. It consists of a high performance research microscope with motorized scanning stage and sensitive position detection system. Up to 10 traps can be used quasi-simultaneously. Non photodamage optical trapping of Escherichia coli (E. coli bacteria cells of 2 µm in length, as an example of motile bacteria, has been shown in this paper. Also, efficient optical trapping and rotation of polystyrene latex particles of 3 µm in diameter have been studied, as an optical handle for the pick and place of other tiny objects. A fast galvoscanner is used to produce multiple optical traps for manipulation of micro-sized objects and optical forces of these trapped objects quantified and measured according to explanation of ray optics regime. The diameter of trapped particle is bigger than the wavelength of the trapping laser light. The force constant (k has been determined in real time from the positional time series recorded from the trapped object that is monitored by a CCD camera through a personal computer.

  6. Small scale optics

    CERN Document Server

    Yupapin, Preecha

    2013-01-01

    The behavior of light in small scale optics or nano/micro optical devices has shown promising results, which can be used for basic and applied research, especially in nanoelectronics. Small Scale Optics presents the use of optical nonlinear behaviors for spins, antennae, and whispering gallery modes within micro/nano devices and circuits, which can be used in many applications. This book proposes a new design for a small scale optical device-a microring resonator device. Most chapters are based on the proposed device, which uses a configuration know as a PANDA ring resonator. Analytical and nu

  7. Progress in optics

    CERN Document Server

    Wolf, Emil

    1977-01-01

    In the thirty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. At the time of inception of this series, the first lasers were only just becoming operational, holography was in its infancy, subjects such as fiber optics, integrated optics and optoelectronics did not exist and quantum optics was the domain of only a few physicists. The term photonics had not yet been coined. Today these fields are flourishing and have become areas of specialisation for many science and engineering students and n

  8. Progress in optics

    CERN Document Server

    Wolf, Emil

    2006-01-01

    In the thirty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. At the time of inception of this series, the first lasers were only just becoming operational, holography was in its infancy, subjects such as fiber optics, integrated optics and optoelectronics did not exist and quantum optics was the domain of only a few physicists. The term photonics had not yet been coined. Today these fields are flourishing and have become areas of specialisation for many science and engineering students and n

  9. A modular optical sensor

    Science.gov (United States)

    Conklin, John Albert

    This dissertation presents the design of a modular, fiber-optic sensor and the results obtained from testing the modular sensor. The modular fiber-optic sensor is constructed in such manner that the sensor diaphragm can be replaced with different configurations to detect numerous physical phenomena. Additionally, different fiber-optic detection systems can be attached to the sensor. Initially, the modular sensor was developed to be used by university of students to investigate realistic optical sensors and detection systems to prepare for advance studies of micro-optical mechanical systems (MOMS). The design accomplishes this by doing two things. First, the design significantly lowers the costs associated with studying optical sensors by modularizing the sensor design. Second, the sensor broadens the number of physical phenomena that students can apply optical sensing techniques to in a fiber optics sensor course. The dissertation is divided into seven chapters covering the historical development of fiber-optic sensors, a theoretical overview of fiber-optic sensors, the design, fabrication, and the testing of the modular sensor developed in the course of this work. Chapter 1 discusses, in detail, how this dissertation is organized and states the purpose of the dissertation. Chapter 2 presents an historical overview of the development of optical fibers, optical pressure sensors, and fibers, optical pressure sensors, and optical microphones. Chapter 3 reviews the theory of multi-fiber optic detection systems, optical microphones, and pressure sensors. Chapter 4 presents the design details of the modular, optical sensor. Chapter 5 delves into how the modular sensor is fabricated and how the detection systems are constructed. Chapter 6 presents the data collected from the microphone and pressure sensor configurations of the modular sensor. Finally, Chapter 7 discusses the data collected and draws conclusions about the design based on the data collected. Chapter 7 also

  10. Lagrangian optics

    CERN Document Server

    Lakshminarayanan, Vasudevan; Thyagarajan, K

    2002-01-01

    Ingeometrical optics, light propagation is analyzed in terms of light rays which define the path of propagation of light energy in the limitofthe optical wavelength tending to zero. Many features oflight propagation can be analyzed in terms ofrays,ofcourse, subtle effects near foci, caustics or turning points would need an analysis based on the wave natureoflight. Allofgeometric optics can be derived from Fermat's principle which is an extremum principle. The counterpart in classical mechanics is of course Hamilton's principle. There is a very close analogy between mechanics ofparticles and optics oflight rays. Much insight (and useful results) can be obtained by analyzing these analogies. Asnoted by H. Goldstein in his book Classical Mechanics (Addison Wesley, Cambridge, MA, 1956), classical mechanics is only a geometrical optics approximation to a wave theory! In this book we begin with Fermat's principle and obtain the Lagrangian and Hamiltonian pictures of ray propagation through various media. Given the ...

  11. Comparison of optic area measurement using fundus photography and optical coherence tomography between optic nerve head drusen and control subjects.

    Science.gov (United States)

    Flores-Rodríguez, Patricia; Gili, Pablo; Martín-Ríos, María Dolores; Grifol-Clar, Eulalia

    2013-03-01

    To compare optic disc area measurement between optic nerve head drusen (ONHD) and control subjects using fundus photography, time-domain optical coherence tomography (TD-OCT) and spectral-domain optical coherence tomography (SD-OCT). We also made a comparison between each of the three techniques. We performed our study on 66 eyes (66 patients) with ONHD and 70 healthy control subjects (70 controls) with colour ocular fundus photography at 20º (Zeiss FF 450 IR plus), TD-OCT (Stratus OCT) with the Fast Optic Disc protocol and SD-OCT (Cirrus OCT) with the Optic Disc Cube 200 × 200 protocol for measurement of the optic disc area. The measurements were made by two observers and in each measurement a correction of the image magnification factor was performed. Measurement comparison using the Student's t-test/Mann-Whitney U test, the intraclass correlation coefficient, Pearson/Spearman rank correlation coefficient and the Bland-Altman plot was performed in the statistical analysis. Mean and standard deviation (SD) of the optic disc area in ONHD and in controls was 2.38 (0.54) mm(2) and 2.54 (0.42) mm(2), respectively with fundus photography; 2.01 (0.56) mm(2) and 1.66 (0.37) mm(2), respectively with TD-OCT, and 2.03 (0.49) mm(2) and 1.75 (0.38) mm(2), respectively with SD-OCT. In ONHD and controls, repeatability of optic disc area measurement was excellent with fundus photography and optical coherence tomography (TD-OCT and SD-OCT), but with a low degree of agreement between both techniques. Optic disc area measurement is smaller in ONHD compared to healthy subjects with fundus photography, unlike time-domain and spectral-domain optical coherence tomography in which the reverse is true. Both techniques offer good repeatability, but a low degree of correlation and agreement, which means that optic disc area measurement is not interchangeable or comparable between techniques. Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

  12. Optical CDMA components requirements

    Science.gov (United States)

    Chan, James K.

    1998-08-01

    Optical CDMA is a complementary multiple access technology to WDMA. Optical CDMA potentially provides a large number of virtual optical channels for IXC, LEC and CLEC or supports a large number of high-speed users in LAN. In a network, it provides asynchronous, multi-rate, multi-user communication with network scalability, re-configurability (bandwidth on demand), and network security (provided by inherent CDMA coding). However, optical CDMA technology is less mature in comparison to WDMA. The components requirements are also different from WDMA. We have demonstrated a video transport/switching system over a distance of 40 Km using discrete optical components in our laboratory. We are currently pursuing PIC implementation. In this paper, we will describe the optical CDMA concept/features, the demonstration system, and the requirements of some critical optical components such as broadband optical source, broadband optical amplifier, spectral spreading/de- spreading, and fixed/programmable mask.

  13. Method and apparatus for bistable optical information storage for erasable optical disks

    Science.gov (United States)

    Land, Cecil E.; McKinney, Ira D.

    1990-01-01

    A method and an optical device for bistable storage of optical information, together with reading and erasure of the optical information, using a photoactivated shift in a field dependent phase transition between a metastable or a bias-stabilized ferroelectric (FE) phase and a stable antiferroelectric (AFE) phase in an lead lanthanum zirconate titanate (PLZT). An optical disk contains the PLZT. Writing and erasing of optical information can be accomplished by a light beam normal to the disk. Reading of optical information can be accomplished by a light beam at an incidence angle of 15 to 60 degrees to the normal of the disk.

  14. Quantum optics

    National Research Council Canada - National Science Library

    Agarwal, G. S

    2013-01-01

    .... Focusing on applications of quantum optics, the textbook covers recent developments such as engineering of quantum states, quantum optics on a chip, nano-mechanical mirrors, quantum entanglement...

  15. Design and Analysis of Optimization Algorithms to Minimize Cryptographic Processing in BGP Security Protocols.

    Science.gov (United States)

    Sriram, Vinay K; Montgomery, Doug

    2017-07-01

    The Internet is subject to attacks due to vulnerabilities in its routing protocols. One proposed approach to attain greater security is to cryptographically protect network reachability announcements exchanged between Border Gateway Protocol (BGP) routers. This study proposes and evaluates the performance and efficiency of various optimization algorithms for validation of digitally signed BGP updates. In particular, this investigation focuses on the BGPSEC (BGP with SECurity extensions) protocol, currently under consideration for standardization in the Internet Engineering Task Force. We analyze three basic BGPSEC update processing algorithms: Unoptimized, Cache Common Segments (CCS) optimization, and Best Path Only (BPO) optimization. We further propose and study cache management schemes to be used in conjunction with the CCS and BPO algorithms. The performance metrics used in the analyses are: (1) routing table convergence time after BGPSEC peering reset or router reboot events and (2) peak-second signature verification workload. Both analytical modeling and detailed trace-driven simulation were performed. Results show that the BPO algorithm is 330% to 628% faster than the unoptimized algorithm for routing table convergence in a typical Internet core-facing provider edge router.

  16. Online Expansion Technology for Dynamic Topology Changing ZigBee Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Md. Emdadul Haque

    2014-03-01

    Full Text Available In ZigBee, the router capable devices have restriction to accept a number of devices as children devices. A router capable device can not allow any new device to join as a child device if it reaches to the maximum capacity of children or depth limit. According to ZigBee specification each device has a permanent 64-bit MAC address. If a device joins a ZigBee network, it receives a short 16-bit MAC address from the parent device. If a device can not join a network, it isolates from the network and becomes an orphan node even though address spaces are available in the network. The orphan problem becomes worse when the topology of the network changes dynamically. In this paper we propose an online expansion technology to connect the maximum number of devices specially for dynamic topology changing ZigBee wireless sensor networks. The proposed technology shares available address spaces of the router devices to reduce the number of orphan nodes in the network.

  17. Precision Cleaning and Protection of Coated Optical Components for NIF Small Optics

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, Jim [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-10-19

    The purpose of this procedure shall be to define the precision cleaning of finished, coated, small optical components for NIF at Lawrence Livermore National Laboratories. The term “small optical components” includes coated optics that are set into simple mounts, as well as coated, un-mounted optics.

  18. Characterization of transimpedance amplifier as optical to electrical converter on designing optical instrumentation

    International Nuclear Information System (INIS)

    Hanto, D; Ula, R K

    2017-01-01

    Optical to electrical converter is the main components for designing of the optical instrumentations. In addition, this component is also used as signal conditioning. This component usually consists of a photo detector and amplifier. In this paper, characteristics of commercial amplifiers from Thorlabs PDA50B-EC has been observed. The experiment was conducted by diode laser with power of -5 dBm and wavelength 1310 nm; the optical attenuator to vary optical power from 0 to 60 dB, optical to electrical converter from Thorlabs Amplifier PDA50B-EC; multimode optical fiber to guide the laser; and digital voltmeter to measure the output of converter. The results of the characterization indicate that each channel amplification has a non-linear correlation between optical and electrical parameter; optical conversion measurement range of 20-23 dB to full scale; and different measurement coverage area. If this converter will be used as a part component of optical instrumentation so it should be adjusted suitably with the optical power source. Then, because of the correlation equation is not linear so calculation to determine the interpretation also should be considered in addition to the transfer function of the optical sensor. (paper)

  19. Characterization of transimpedance amplifier as optical to electrical converter on designing optical instrumentation

    Science.gov (United States)

    Hanto, D.; Ula, R. K.

    2017-05-01

    Optical to electrical converter is the main components for designing of the optical instrumentations. In addition, this component is also used as signal conditioning. This component usually consists of a photo detector and amplifier. In this paper, characteristics of commercial amplifiers from Thorlabs PDA50B-EC has been observed. The experiment was conducted by diode laser with power of -5 dBm and wavelength 1310 nm; the optical attenuator to vary optical power from 0 to 60 dB, optical to electrical converter from Thorlabs Amplifier PDA50B-EC; multimode optical fiber to guide the laser; and digital voltmeter to measure the output of converter. The results of the characterization indicate that each channel amplification has a non-linear correlation between optical and electrical parameter; optical conversion measurement range of 20-23 dB to full scale; and different measurement coverage area. If this converter will be used as a part component of optical instrumentation so it should be adjusted suitably with the optical power source. Then, because of the correlation equation is not linear so calculation to determine the interpretation also should be considered in addition to the transfer function of the optical sensor.

  20. Advances in nonlinear optics

    CERN Document Server

    Chen, Xianfeng; Zeng, Heping; Guo, Qi; She, Weilong

    2015-01-01

    This book presents an overview of the state of the art of nonlinear optics from weak light nonlinear optics, ultrafast nonlinear optics to electro-optical theory and applications. Topics range from the fundamental studies of the interaction between matter and radiation to the development of devices, components, and systems of tremendous commercial interest for widespread applications in optical telecommunications, medicine, and biotechnology.

  1. Digital diffractive optics: Have diffractive optics entered mainstream industry yet?

    Science.gov (United States)

    Kress, Bernard; Hejmadi, Vic

    2010-05-01

    When a new technology is integrated into industry commodity products and consumer electronic devices, and sold worldwide in retail stores, it is usually understood that this technology has then entered the realm of mainstream technology and therefore mainstream industry. Such a leap however does not come cheap, as it has a double edge sword effect: first it becomes democratized and thus massively developed by numerous companies for various applications, but also it becomes a commodity, and thus gets under tremendous pressure to cut down its production and integration costs while not sacrificing to performance. We will show, based on numerous examples extracted from recent industry history, that the field of Diffractive Optics is about to undergo such a major transformation. Such a move has many impacts on all facets of digital diffractive optics technology, from the optical design houses to the micro-optics foundries (for both mastering and volume replication), to the final product integrators or contract manufacturers. The main causes of such a transformation are, as they have been for many other technologies in industry, successive technological bubbles which have carried and lifted up diffractive optics technology within the last decades. These various technological bubbles have been triggered either by real industry needs or by virtual investment hype. Both of these causes will be discussed in the paper. The adjective ""digital"" in "digital diffractive optics" does not refer only, as it is done in digital electronics, to the digital functionality of the element (digital signal processing), but rather to the digital way they are designed (by a digital computer) and fabricated (as wafer level optics using digital masking techniques). However, we can still trace a very strong similarity between the emergence of micro-electronics from analog electronics half a century ago, and the emergence of digital optics from conventional optics today.

  2. Optical electronics

    CERN Document Server

    Yariv, Amnon

    1991-01-01

    This classic text introduces engineering students to the first principles of major phenomena and devices of optoelectronics and optical communication technology. Yariv's "first principles" approach employs real-life examples and extensive problems. The text includes separate chapters on quantum well and semiconductor lasers, as well as phase conjugation and its applications. Optical fiber amplification, signal and noise considerations in optical fiber systems, laser arrays and distributed feedback lasers all are covered extensively in major sections within chapters.

  3. Random photonic crystal optical memory

    International Nuclear Information System (INIS)

    Wirth Lima Jr, A; Sombra, A S B

    2012-01-01

    Currently, optical cross-connects working on wavelength division multiplexing systems are based on optical fiber delay lines buffering. We designed and analyzed a novel photonic crystal optical memory, which replaces the fiber delay lines of the current optical cross-connect buffer. Optical buffering systems based on random photonic crystal optical memory have similar behavior to the electronic buffering systems based on electronic RAM memory. In this paper, we show that OXCs working with optical buffering based on random photonic crystal optical memories provides better performance than the current optical cross-connects. (paper)

  4. Tunable micro-optics

    CERN Document Server

    Duppé, Claudia

    2015-01-01

    Presenting state-of-the-art research into the dynamic field of tunable micro-optics, this is the first book to provide a comprehensive survey covering a varied range of topics including novel materials, actuation concepts and new imaging systems in optics. Internationally renowned researchers present a diverse range of chapters on cutting-edge materials, devices and subsystems, including soft matter, artificial muscles, tunable lenses and apertures, photonic crystals, and complete tunable imagers. Special contributions also provide in-depth treatment of micro-optical characterisation, scanners, and the use of natural eye models as inspiration for new concepts in advanced optics. With applications extending from medical diagnosis to fibre telecommunications, Tunable Micro-optics equips readers with a solid understanding of the broader technical context through its interdisciplinary approach to the realisation of new types of optical systems. This is an essential resource for engineers in industry and academia,...

  5. Anterior ischemic optic neuropathy in association with optic nervehead drusen

    Directory of Open Access Journals (Sweden)

    Bharathi Megur

    2014-01-01

    Full Text Available Optic nerve head drusen (ONHD are incidental ophthalmologic finding in the optic nerve. Patients with ONHD are often asymptomatic, but sometimes present with transient visual obscuration′s (TVO, the reported incidence of which is 8.6%. Optic nerve head drusen are of two types: Superficial; visible and deep. The deep-buried drusen mimic papilledema. Because of the varied presentation deep-buried drusen pose a diagnostic challenge to the ophthalmologists. In young patients, they are mistaken for papilledema as it is clinically difficult to detect a buried drusen in the optic nerve head, but are seen on the surface with aging as the retinal nerve fiber layer thins out. They are observed as pale yellow lesions more often located towards the poles. Clinical examination aided with diagnostic tests like computed tomography (CT orbits and ultrasound B scan can help establish the diagnosis. Herein, we report a rare case of optic nerve head drusen in a young lady, who presented with loss of vision and clinical evaluation and investigations suggested ONHD with anterior ischemic optic neuropathy.

  6. Introduction to nonimaging optics

    CERN Document Server

    Chaves, Julio

    2015-01-01

    Introduction to Nonimaging Optics covers the theoretical foundations and design methods of nonimaging optics, as well as key concepts from related fields. This fully updated, revised, and expanded Second Edition: Features a new and intuitive introduction with a basic description of the advantages of nonimaging opticsAdds new chapters on wavefronts for a prescribed output (irradiance or intensity), infinitesimal étendue optics (generalization of the aplanatic optics), and Köhler optics and color mixingIncorporates new material on the simultaneous multiple surface (SMS) design method in 3-D, int

  7. Implementing eco friendly highly reliable upload feature using multi 3G service

    Science.gov (United States)

    Tanutama, Lukas; Wijaya, Rico

    2017-12-01

    The current trend of eco friendly Internet access is preferred. In this research the understanding of eco friendly is minimum power consumption. The devices that are selected have operationally low power consumption and normally have no power consumption as they are hibernating during idle state. To have the reliability a router of a router that has internal load balancing feature will provide the improvement of previous research on multi 3G services for broadband lines. Previous studies emphasized on accessing and downloading information files from Public Cloud residing Web Servers. The demand is not only for speed but high reliability of access as well. High reliability will mean mitigating both direct and indirect high cost due to repeated attempts of uploading and downloading the large files. Nomadic and mobile computer users need viable solution. Following solution for downloading information has been proposed and tested. The solution is promising. The result is now extended to providing reliable access line by means of redundancy and automatic reconfiguration for uploading and downloading large information files to a Web Server in the Cloud. The technique is taking advantage of internal load balancing feature to provision a redundant line acting as a backup line. A router that has the ability to provide load balancing to several WAN lines is chosen. The WAN lines are constructed using multiple 3G lines. The router supports the accessing Internet with more than one 3G access line which increases the reliability and availability of the Internet access as the second line immediately takes over if the first line is disturbed.

  8. Optical Coherence and Quantum Optics

    CERN Document Server

    Mandel, Leonard

    1995-01-01

    This book presents a systematic account of optical coherence theory within the framework of classical optics, as applied to such topics as radiation from sources of different states of coherence, foundations of radiometry, effects of source coherence on the spectra of radiated fields, coherence theory of laser modes, and scattering of partially coherent light by random media. The book starts with a full mathematical introduction to the subject area and each chapter concludes with a set of exercises. The authors are renowned scientists and have made substantial contributions to many of the topi

  9. Optical Filter Assembly for Interplanetary Optical Communications

    Science.gov (United States)

    Chen, Yijiang; Hemmati, Hamid

    2013-01-01

    Ground-based, narrow-band, high throughput optical filters are required for optical links from deep space. We report on the development of a tunable filter assembly that operates at telecommunication window of 1550 nanometers. Low insertion loss of 0.5 decibels and bandwidth of 90 picometers over a 2000 nanometers operational range of detectors has been achieved.

  10. Progress in optics

    CERN Document Server

    Wolf, Emil

    2009-01-01

    In the fourty-seven years that have gone by since the first volume of Progress in Optics was published, optics has become one of the most dynamic fields of science. The volumes in this series which have appeared up to now contain more than 300 review articles by distinguished research workers, which have become permanent records for many important developments.- Backscattering and Anderson localization of light- Advances in oliton manipulation in optical lattices- Fundamental quantum noise in optical amplification- Invisibility cloaks

  11. Elementary wave optics

    CERN Document Server

    Webb, Robert H

    2005-01-01

    This undergraduate textbook presents thorough coverage of the standard topics of classical optics and optical instrument design; it also offers significant details regarding the concepts of modern optics. Its survey of the mathematical tools of optics grants students insights into the physical principles of quantum mechanics.Two principal concepts occur throughout: a treatment of scattering from real scatterers (leading to Huygens' principles, diffraction theory, the index of refraction, and related topics); and the difference between coherent and noncoherent wave phenomena. Examinations of su

  12. Optically resilient 3D micro-optics on the tips of optical fibers

    Science.gov (United States)

    Jonušauskas, Linas

    2017-05-01

    In this paper we present a study aimed at investigating an optical resiliency of polymers that could be applied in 3D femtosecond laser lithography. These include popular in lithography SU8 and OrmoClear as well as hybrid organic-inorganic zirconium containing SZ2080. We show that latter material in its pure (non-photosensitized) form has the best optical resiliency out of all tested materials. Furthermore, its 3D structurability is investigated. Despite threshold-like quality degradation outside fabrication window, we show that this material is suitable for creating complex 3D structures on the tips of optical fibers. Overall it is demonstrated, that unique capability of 3DLL to structure pure materials can lead to very compact functional fiber-based devices that could withstand high (GW/cm2) light intensities.

  13. High-speed optical feeder-link system using adaptive optics

    Science.gov (United States)

    Arimoto, Yoshinori; Hayano, Yutaka; Klaus, Werner

    1997-05-01

    We propose a satellite laser communication system between a ground station and a geostationary satellite, named high- speed optical feeder link system. It is based on the application of (a) high-speed optical devices, which have been developed for ground-based high-speed fiber-optic communications, and (b) the adaptive optics which compensates wavefront distortions due to atmospheric turbulences using a real time feedback control. A link budget study shows that a system with 10-Gbps bit-rate are available assuming the state-of-the-art device performance of the Er-doped fiber amplifier. We further discuss preliminary measurement results of the atmospheric turbulence at the telescope site in Tokyo, and present current study on the design of the key components for the feeder-link laser transceiver.

  14. Progress in optics

    CERN Document Server

    Wolf, Emil

    2015-01-01

    The Progress in Optics series contains more than 300 review articles by distinguished research workers, which have become permanent records for many important developments, helping optical scientists and optical engineers stay abreast of their fields. Comprehensive, in-depth reviewsEdited by the leading authority in the field

  15. Electro-optics laboratory evaluation: Deutsch optical waveguide connectors

    Science.gov (United States)

    1980-01-01

    A description of a test program evaluating the performance of an optical waveguide connector system is presented. Both quality and effectiveness of connections made in an optical fiber, performance of the equipment used and applicability of equipment and components to field conditions are reviewed.

  16. OPTIMASI BANDWITH MENGGUNAKAN TRAFFIC SHAPPING

    Directory of Open Access Journals (Sweden)

    Imam Riadi

    2012-05-01

    Full Text Available Perkembangan layanan komunikasi telah berkembang sangat pesat. Salah satunya adalah pemanfaatan penggunaan bandwith untuk mengakases jaringan Internet. Traffic shapping bandwidth dapat memberikan efesiensi dalam hal pemanfaatan bandwidth pada instansi yang melakukan manajemen dalam lalulintas jaringannya. Metode yang digunakan dalam penelitian ini adalah metode literatur yaitu metode pengumpulan data yang dilakukan dengan mengumpulkan sumber-sumber data yang terkait dan metode eksperimen yaitu melakukan penelitian dengan mengkonfigurasi Mikrotik RouterOS untuk melakukan traffic shapping bandwidth. Hasil penelitian ini adalah router yang dapat melakukan traffic shapping sehingga kualitas koneksi menjadi lebih baik untuk mengakses dan mengambil data dari sebuah website.

  17. Hierarchical micro-mobility management in high-speed multihop access networks

    Institute of Scientific and Technical Information of China (English)

    TANG Bi-hua; MA Xiao-lei; LIU Yuan-an; GAO Jin-chun

    2006-01-01

    This article integrates the hierarchical micro-mobility management and the high-speed multihop access networks (HMAN), to accomplish the smooth handover between different access routers. The proposed soft handover scheme in the high-speed HMAN can solve the micro-mobility management problem in the access network. This article also proposes the hybrid access router (AR) advertisement scheme and AR selection algorithm, which uses the time delay and stable route to the AR as the gateway selection parameters. By simulation, the proposed micro-mobility management scheme can achieve high packet delivery fraction and improve the lifetime of network.

  18. Propuesta de integración de soluciones empresariales VoIP con software libre

    OpenAIRE

    Barba Vera, Ruth Genoveva

    2012-01-01

    Se estudió voip en cisco y elastix para integrarlas y compartir servicios, a través de la troncal sip. Con método experimental, en ambiente de pruebas con tres escenarios, se instaló y configuró Cme 3.3 en router 2811 y elastix 2.2 en pc. Se realizaron llamadas a lo interno de las centrales telefónicas Call Manager Express ó Elastix comprobando la interoperabilidad de las mismas demostrándose que existe una comunicación full dúplex entre tecnologías. Se utilizó equipos cisco: un router 2811,...

  19. Controlling chaos in Internet congestion control model

    Energy Technology Data Exchange (ETDEWEB)

    Chen Liang E-mail: chenmoon110@yahoo.com.cn; Wang Xiaofan; Han Zhengzhi

    2004-07-01

    The TCP end-to-end congestion control plus RED router queue management can be modeled as a discrete-time dynamical system, which may create complex bifurcating and chaotic behavior. Based on the basic features of the TCP-RED model, we propose a time-dependent delayed feedback control algorithm to control chaos in the system by perturbing the accessible RED parameter p{sub max}. This method is able to stabilized a router queue occupancy at a level without knowing the exact knowledge of the network. Further, we study the situation of the presence of the UDP traffic.

  20. Dynamically tunable optical bottles from an optical fiber

    DEFF Research Database (Denmark)

    Chen, Yuhao; Yan, Lu; Rishøj, Lars Søgaard

    2012-01-01

    Optical fibers have long been used to impose spatial coherence to shape free-space optical beams. Recent work has shown that one can use higher order fiber modes to create more exotic beam profiles. We experimentally generate optical bottles from Talbot imaging in the coherent superposition of two...... fiber modes excited with long period gratings, and obtain a 28 μm × 6 μm bottle with controlled contrast up to 10.13 dB. Our geometry allows for phase tuning of one mode with respect to the other, which enables us to dynamically move the bottle in free space....

  1. Optical microparticle manipulation advances and new capabilities offered by diffractive optics

    International Nuclear Information System (INIS)

    Sojfer, V.A.; Kotlyar, V.V.; Khonina, S.N.

    2004-01-01

    The review deals with a promising area in laser optics - optical manipulation. The object under manipulation can be of various nature: from a colloid particle to a molecule, from cell, virus, to a micromechanism part, etc. In the first part of this work a concise review of the articles on optical manipulation of microparticles and atoms published in the last two decades is presented. The second part is devoted t the production of laser beams with self-reproduction properties. Such beams can be most effectively produced using diffractive optical elements (DOEs). The DOE-generated self-reproducing laser beams (stable, axially periodic, rotating, and multiorder) offer new opportunities in optical manipulation of micro- and nano-objects [ru

  2. Optical annealing of CaF2:Mn for cooled optically stimulated luminescence

    International Nuclear Information System (INIS)

    Miller, S.D.; Stahl, K.A.; Endres, G.W.R.; McDonald, J.C.

    1989-01-01

    Optical annealing of the cooled optically stimulated luminescence in CaF 2 :Mn at room temperature has been demonstrated. The laser of choice for optical annealing of CaF 2 : Mn is a 326 nm helium-cadmium ultraviolet laser. A complete cycle of readout and annealing of the CaF 2 :Mn cooled optically stimulated dosemeters can now be accomplished without heating the dosemeters above room temperature. This annealing work represents the next step toward creating a proton-recoil-based fast neutron dosimetry system based on the cooled optically stimulated luminescence technique. (author)

  3. Phase-preserved optical elevator

    OpenAIRE

    Luo, Yuan; Zhang, Baile; Han, Tiancheng; Chen, Zhi; Duan, Yubo; Chu, Chia-Wei; Barbastathis, George; Qiu, Cheng Wei

    2013-01-01

    The unique superiority of transformation optics devices designed from coordinate transformation is their capability of recovering both ray trajectory and optical path length in light manipulation. However, very few experiments have been done so far to verify this dual-recovery property from viewpoints of both ray trajectory and optical path length simultaneously. The experimental difficulties arise from the fact that most previous optical transformation optics devices only work at the nano-sc...

  4. Integrated Optical Circuit Engineering

    Science.gov (United States)

    Sriram, S.

    1985-04-01

    Implementation of single-mode optical fiber systems depends largely on the availability of integrated optical components for such functions as switching, multiplexing, and modulation. The technology of integrated optics is maturing very rapidly, and its growth justifies the optimism that now exists in the optical community.

  5. Accuracy requirements of optical linear algebra processors in adaptive optics imaging systems

    Science.gov (United States)

    Downie, John D.

    1990-01-01

    A ground-based adaptive optics imaging telescope system attempts to improve image quality by detecting and correcting for atmospherically induced wavefront aberrations. The required control computations during each cycle will take a finite amount of time. Longer time delays result in larger values of residual wavefront error variance since the atmosphere continues to change during that time. Thus an optical processor may be well-suited for this task. This paper presents a study of the accuracy requirements in a general optical processor that will make it competitive with, or superior to, a conventional digital computer for the adaptive optics application. An optimization of the adaptive optics correction algorithm with respect to an optical processor's degree of accuracy is also briefly discussed.

  6. Optical holography

    CERN Document Server

    Collier, Robert J; Lin, Lawrence H

    1971-01-01

    Optical Holography deals with the use of optical holography to solve technical problems, with emphasis on the properties of holograms formed with visible light. Topics covered include the Fourier transform, propagation and diffraction, pulsed-laser holography, and optical systems with spherical lenses. A geometric analysis of point-source holograms is also presented, and holograms and hologram spatial filters formed with spatially modulated reference waves are described. This book is comprised of 20 chapters and begins with an introduction to concepts that are basic to understanding hologr

  7. [Clinical feature of chronic compressive optic neuropathy without optic atrophy].

    Science.gov (United States)

    Jiang, Libin; Shi, Jitong; Liu, Wendong; Kang, Jun; Wang, Ningli

    2014-12-01

    To investigate the clinical feature of the chronic compressive optic neuropathy without optic atrophy. Retrospective cases series study. The clinical data of 25 patients (37 eyes) with chronic compressive optic neuropathy without optic atrophy, treated in Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, from October, 2005 to March, 2014, were collected. Those patients had been showing visual symptoms for 6 months or longer, but missed diagnosed or misdiagnosed as other eye diseases due to their normal or slightly changed fundi. The collected data including visual acuities, visual fields, neuroimaging and/or pathologic diagnosis were analyzed. Among the 25 patients, there were 5 males and 20 females, and their ages range from 9 to 74 years [average (47.5 ± 13.4) years]. All patients suffered progressive impaired vision in single eye or both eyes, without exophthalmos or abnormal eye movements. Except one patient had a headache, other patients did not show systemic symptoms. The corrected visual acuities were between HM to 1.0, and their appearances of optic discs and colors of fundi were normal. After neuroimaging and/or pathological examination, it was proven that 14 patients suffered tuberculum sellae meningiomas, 5 patients with hypophysoma, 3 patient with optic nerve sheath meningioma in orbital apex, 1 patient with cavernous hemangioma, 1 patient with vascular malformation in orbital apex and 1 patient with optic nerve glioma. Among the 19 patients whose suffered occupied lesions of saddle area, 14 patients underwent visual field examinations, and only 4 patients showed classic visual field defects caused by optic chiasmal lesions. Occult progressive visual loss was the most important clinical feature of the disease.

  8. Design and experimental verification for optical module of optical vector-matrix multiplier.

    Science.gov (United States)

    Zhu, Weiwei; Zhang, Lei; Lu, Yangyang; Zhou, Ping; Yang, Lin

    2013-06-20

    Optical computing is a new method to implement signal processing functions. The multiplication between a vector and a matrix is an important arithmetic algorithm in the signal processing domain. The optical vector-matrix multiplier (OVMM) is an optoelectronic system to carry out this operation, which consists of an electronic module and an optical module. In this paper, we propose an optical module for OVMM. To eliminate the cross talk and make full use of the optical elements, an elaborately designed structure that involves spherical lenses and cylindrical lenses is utilized in this optical system. The optical design software package ZEMAX is used to optimize the parameters and simulate the whole system. Finally, experimental data is obtained through experiments to evaluate the overall performance of the system. The results of both simulation and experiment indicate that the system constructed can implement the multiplication between a matrix with dimensions of 16 by 16 and a vector with a dimension of 16 successfully.

  9. Design of an optical spatial interferometer with transformation optics

    International Nuclear Information System (INIS)

    Naghibi, Atefeh; Shokooh-Saremi, Mehrdad

    2015-01-01

    In this paper, we apply transformation optics to design an optical spatial interferometer. The transformation equations are described and two-dimensional finite element simulations are presented to numerically confirm the functionality of the device. It is shown that a small change in the refractive index can alter the interference pattern and hence can be detected. The design of the interferometer could expand transformation optics’ applications and make way for introduction of new structures with unique electromagnetic or optical functionalities. (paper)

  10. Performance of magneto-optical glass in optical current transducer application

    International Nuclear Information System (INIS)

    Shen, Yan; Lu, Yunhe; Liu, Zhao; Yu, Xueliang; Zhang, Guoqing; Yu, Wenbin

    2015-01-01

    First, a theoretical analysis was performed on the effect of temperature on the performance of the sensing element of paramagnetic rare earth-doped magneto-optical glass material that can be used in an optical current transducer application. The effect comprises two aspects: the linear birefringence and the Verdet constant. On this basis, rare earth-doped glass temperature characteristics were studied, and the experimental results indicated that the linear birefringence of rare earth-doped glass increased with increasing temperature, while its magneto-optical sensitivity decreased. Comparative experiments performed for various concentrations of rare earth dopant in the glass revealed that changes in the dopant concentration had no significant effect on the performance of magneto-optical glass. At last, a comparison between rare earth-doped magneto-optical and diamagnetic dense flint glass showed that the sensitivity of the former was six times that of the latter, although the temperature stability of the former was poorer. - Highlights: • Theoretical analysis on the effects of temperature on RE glass. • Rare earth doping leads to higher magneto-optical sensitivity. • The sensitivity of the RE glass is six times that of the dense flint glass

  11. Optical aurora detectors: using natural optics to motivate education and outreach

    Science.gov (United States)

    Shaw, Joseph A.; Way, Jesse M.; Pust, Nathan J.; Nugent, Paul W.; Coate, Hans; Balster, Daniel

    2009-06-01

    Natural optical phenomena enjoy a level of interest sufficiently high among a wide array of people to provide ideal education and outreach opportunities. The aurora promotes particularly high interest, perhaps because of its relative rarity in the areas of the world where most people live. A project is being conducted at Montana State University to use common interest and curiosity about auroras to motivate learning and outreach through the design and deployment of optical sensor systems that detect the presence of an auroral display and send cell phone messages to alert interested people. Project participants learn about the physics and optics of the aurora, basic principles of optical system design, radiometric calculations and calibrations, electro-optical detectors, electronics, embedded computer systems, and computer software. The project is moving into a stage where it will provide greatly expanded outreach and education opportunities as optical aurora detector kits are created and disbursed to colleges around our region.

  12. Geometric optics theory and design of astronomical optical systems using Mathematica

    CERN Document Server

    Romano, Antonio

    2016-01-01

    This text, now in its second edition, presents the mathematical background needed to design many optical combinations that are used in astronomical telescopes and cameras. It uses a novel approach to third-order aberration theory based on Fermat’s principle and the use of particular optical paths (called stigmatic paths) instead of rays, allowing for easier derivation of third-order formulae. Each optical combination analyzed is accompanied by a downloadable Mathematica® notebook that automates its third-order design, eliminating the need for lengthy calculations. The essential aspects of an optical system with an axis of rotational symmetry are introduced first, along with a development of Gaussian optics from Fermat’s principal. A simpler approach to third-order monochromatic aberrations based on both Fermat’s principle and stigmatic paths is then described, followed by a new chapter on fifth-order aberrations and their classification. Several specific optical devices are discussed and analyzed, incl...

  13. XIX International Youth School on Coherent Optics and Optical Spectroscopy

    International Nuclear Information System (INIS)

    2016-01-01

    The XIX International Youth School on Coherent Optics and Optical Spectroscopy (COOS2015) was held in Kazan, Russia, from October 5 to October 7 at the Nikolai Lobachevsky Scientific Library of Kazan Federal University. The School follows the global tendency toward comprehensive studies of matter properties and its interaction with electromagnetic fields. Since 1997 more than 100 famous scientists from USA, Germany, Ukraine, Belarussia and Russia had plenary lecture presentations. This is the right place, where over 1000 young scientists had an opportunity to participate in hot discussions regarding the latest scientific news. Many young people have submitted interesting reports on photonics, quantum electronics, laser physics, quantum optics, traditional optical and laser spectroscopy, non-linear optics, material science and nanotechnology. Here we are publishing the full-size papers prepared from the most interesting lectures and reports selected by the Program Committee of the School. (paper)

  14. Design of a multimodal fibers optic system for small animal optical imaging.

    Science.gov (United States)

    Spinelli, Antonello E; Pagliazzi, Marco; Boschi, Federico

    2015-02-01

    Small animals optical imaging systems are widely used in pre-clinical research to image in vivo the bio-distribution of light emitting probes using fluorescence or bioluminescence modalities. In this work we presented a set of simulated results of a novel small animal optical imaging module based on a fibers optics matrix, coupled with a position sensitive detector, devoted to acquire bioluminescence and Cerenkov images. Simulations were performed using GEANT 4 code with the GAMOS architecture using the tissue optics plugin. Results showed that it is possible to image a 30 × 30 mm region of interest using a fiber optics array containing 100 optical fibers without compromising the quality of the reconstruction. The number of fibers necessary to cover an adequate portion of a small animal is thus quite modest. This design allows integrating the module with magnetic resonance (MR) in order to acquire optical and MR images at the same time. A detailed model of the mouse anatomy, obtained by segmentation of 3D MRI images, will improve the quality of optical 3D reconstruction. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  15. Measurement of optical glasses

    International Nuclear Information System (INIS)

    Nicolau-Rebigan, S.

    1978-11-01

    The possibilities of measurement of the optical glasses parameters needed in building optical devices especially in lasers devices are presented. In the first chapter the general features of the main optical glasses as well as the modalities of obtaining them are given. Chapter two defines the optical glass parameters, and the third chapter describes the measuring methods of the optical glass parameters. Finally, the conclusions which point out the utilization of this paper are presented. (author)

  16. Optical tomography of tissues

    International Nuclear Information System (INIS)

    Zimnyakov, D A; Tuchin, Valerii V

    2002-01-01

    Methods of optical tomography of biological tissues are considered, which include pulse-modulation and frequency-modulation tomography, diffusion tomography with the use of cw radiation sources, optical coherent tomography, speckle-correlation tomography of nonstationary media, and optoacoustic tomography. The method for controlling the optical properties of tissues is studied from the point of view of increasing a probing depth in optical coherent tomography. The modern state and prospects of the development of optical tomography are discussed. (review)

  17. Optical imaging and spectroscopy

    CERN Document Server

    Brady, David J

    2009-01-01

    An essential reference for optical sensor system design This is the first text to present an integrated view of the optical and mathematical analysis tools necessary to understand computational optical system design. It presents the foundations of computational optical sensor design with a focus entirely on digital imaging and spectroscopy. It systematically covers: Coded aperture and tomographic imaging Sampling and transformations in optical systems, including wavelets and generalized sampling techniques essential to digital system analysis Geometric, wave, and statis

  18. Optical and electro-optic anisotropy of epitaxial PZT thin films

    Science.gov (United States)

    Zhu, Minmin; Du, Zehui; Jing, Lin; Yoong Tok, Alfred Iing; Tong Teo, Edwin Hang

    2015-07-01

    Strong optical and electro-optic (EO) anisotropy has been investigated in ferroelectric Pb(Zr0.48Ti0.52)O3 thin films epitaxially grown on Nb-SrTiO3 (001), (011), and (111) substrates using magnetron sputtering. The refractive index, electro-optic, and ferroelectric properties of the samples demonstrate the significant dependence on the growth orientation. The linear electro-optic coefficients of the (001), (011), and (111)-oriented PZT thin films were 270.8, 198.8, and 125.7 pm/V, respectively. Such remarkable anisotropic EO behaviors have been explained according to the structure correlation between the orientation dependent distribution, spontaneous polarization, epitaxial strain, and domain pattern.

  19. Optically pumped atoms

    CERN Document Server

    Happer, William; Walker, Thad

    2010-01-01

    Covering the most important knowledge on optical pumping of atoms, this ready reference is backed by numerous examples of modelling computation for optical pumped systems. The authors show for the first time that modern scientific computing software makes it practical to analyze the full, multilevel system of optically pumped atoms. To make the discussion less abstract, the authors have illustrated key points with sections of MATLAB codes. To make most effective use of contemporary mathematical software, it is especially useful to analyze optical pumping situations in the Liouville spa

  20. Serial Diffusion Tensor Imaging of the Optic Radiations after Acute Optic Neuritis

    Directory of Open Access Journals (Sweden)

    Scott C. Kolbe

    2016-01-01

    Full Text Available Previous studies have reported diffusion tensor imaging (DTI changes within the optic radiations of patients after optic neuritis (ON. We aimed to study optic radiation DTI changes over 12 months following acute ON and to study correlations between DTI parameters and damage to the optic nerve and primary visual cortex (V1. We measured DTI parameters [fractional anisotropy (FA, axial diffusivity (AD, radial diffusivity (RD, and mean diffusivity (MD] from the optic radiations of 38 acute ON patients at presentation and 6 and 12 months after acute ON. In addition, we measured retinal nerve fibre layer thickness, visual evoked potential amplitude, optic radiation lesion load, and V1 thickness. At baseline, FA was reduced and RD and MD were increased compared to control. Over 12 months, FA reduced in patients at an average rate of −2.6% per annum (control = −0.51%; p=0.006. Change in FA, RD, and MD correlated with V1 thinning over 12 months (FA: R=0.450, p=0.006; RD: R=-0.428, p=0.009; MD: R=-0.365, p=0.029. In patients with no optic radiation lesions, AD significantly correlated with RNFL thinning at 12 months (R=0.489, p=0.039. In conclusion, DTI can detect optic radiation changes over 12 months following acute ON that correlate with optic nerve and V1 damage.

  1. Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

    Science.gov (United States)

    Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

    2015-01-01

    This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS) and biosensors (FOBS). Fiber optic sensor (FOS) systems use the ability of optical fibers (OF) to guide the light in the spectral range from ultraviolet (UV) (180 nm) up to middle infrared (IR) (10 µm) and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors. PMID:26437407

  2. Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors.

    Science.gov (United States)

    Pospíšilová, Marie; Kuncová, Gabriela; Trögl, Josef

    2015-09-30

    This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS) and biosensors (FOBS). Fiber optic sensor (FOS) systems use the ability of optical fibers (OF) to guide the light in the spectral range from ultraviolet (UV) (180 nm) up to middle infrared (IR) (10 μm) and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors.

  3. 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.

  4. 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.

  5. 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...

  6. Microscale optical cryptography using a subdiffraction-limit optical key

    Science.gov (United States)

    Ogura, Yusuke; Aino, Masahiko; Tanida, Jun

    2018-04-01

    We present microscale optical cryptography using a subdiffraction-limit optical pattern, which is finer than the diffraction-limit size of the decrypting optical system, as a key and a substrate with a reflectance distribution as an encrypted image. Because of the subdiffraction-limit spatial coding, this method enables us to construct a secret image with the diffraction-limit resolution. Simulation and experimental results demonstrate, both qualitatively and quantitatively, that the secret image becomes recognizable when and only when the substrate is illuminated with the designed key pattern.

  7. Fiber Optic Microphone

    Science.gov (United States)

    Cho, Y. C.; George, Thomas; Norvig, Peter (Technical Monitor)

    1999-01-01

    Research into advanced pressure sensors using fiber-optic technology is aimed at developing compact size microphones. Fiber optic sensors are inherently immune to electromagnetic noise, and are very sensitive, light weight, and highly flexible. In FY 98, NASA researchers successfully designed and assembled a prototype fiber-optic microphone. The sensing technique employed was fiber optic Fabry-Perot interferometry. The sensing head is composed of an optical fiber terminated in a miniature ferrule with a thin, silicon-microfabricated diaphragm mounted on it. The optical fiber is a single mode fiber with a core diameter of 8 micron, with the cleaved end positioned 50 micron from the diaphragm surface. The diaphragm is made up of a 0.2 micron thick silicon nitride membrane whose inner surface is metallized with layers of 30 nm titanium, 30 nm platinum, and 0.2 micron gold for efficient reflection. The active sensing area is approximately 1.5 mm in diameter. The measured differential pressure tolerance of this diaphragm is more than 1 bar, yielding a dynamic range of more than 100 dB.

  8. Time domain optical spectrometry with fiber optic waveguides

    International Nuclear Information System (INIS)

    Whitten, W.B.

    1983-01-01

    Spectrometers which use optical fibers to obtain time domain spectral dispersion are reviewed. Pulse transmission through fiber optic waveguides is discussed and the basic requirements for sources and detectors are given. Multiplex spectrometry and time-of-flight spectrometry are then discussed. Resolution, fiber requirements, instrumentation and specific spectrometers are presented

  9. Optical Binding of Nanowires

    Czech Academy of Sciences Publication Activity Database

    Simpson, Stephen Hugh; Zemánek, Pavel; Marago, O.M.; Jones, P.H.; Hanna, S.

    2017-01-01

    Roč. 17, č. 6 (2017), s. 3485-3492 ISSN 1530-6984 R&D Projects: GA ČR GB14-36681G Grant - others:AV ČR(CZ) CNR-16-12 Program:Bilaterální spolupráce Institutional support: RVO:68081731 Keywords : optical binding nanowires * Brownian motion * self-organization * non-equilibrium thermodynamics * non-equilibrium steady state * spin-orbit coupling * emergent phenomena Subject RIV: BH - Optics, Masers, Lasers OBOR OECD: Optics (including laser optics and quantum optics) Impact factor: 12.712, year: 2016

  10. ''Atomic Optics'': Nonimaging Optics on the Nanoscale

    Energy Technology Data Exchange (ETDEWEB)

    Roland Winston Joseph O' Gallagher

    2005-01-15

    This is the final report for a one year close out extension of our basic research program that was established at the University of Chicago more than sixteen years ago to explore and develop the optical sub-discipline that has come to be known as ''nonimaging optics''. This program has been extremely fruitful, having both broadened the range of formalism available for workers in this field and led to the discovery of many new families of optical devices. These devices and techniques have applications wherever the efficient transport and transformation of light distributions are important, in particular in illumination, fiber optics, collection and concentration of sunlight, and the detection of faint light signals in physics and astrophysics. Over the past thirty years, Nonimaging Optics (Welford and Winston, 1989) has brought a fresh approach to the analysis of many problems in classical macro-scale optics. Through the application of phase-space concepts, statistical methods, thermodynamic arguments, etc., many previously established performance limits were able to be broken and many technical surprises with exciting practical applications were discovered. The most recent three-year phase of our long-term continuing program ended in late 2002 and emphasized extending our work in geometrical optics and expanding it to include some interesting questions in physical optics as well as in the new field of statistical optics. This report presents a survey of the basic history and concepts of nonimaging optics and reviews highlights and significant accomplishments over the past fifteen years. This is followed by a more detailed summary of recent research directions and accomplishments during the last three years. This most recent phase was marked by the broadening in scope to include a separate project involving a collaboration with an industrial partner, Science Applications International Corporation (SAIC). This effort was proposed and approved in

  11. Imaging of macrophage dynamics with optical coherence tomography in anterior ischemic optic neuropathy.

    Science.gov (United States)

    Kokona, Despina; Häner, Nathanael U; Ebneter, Andreas; Zinkernagel, Martin S

    2017-01-01

    Anterior ischemic optic neuropathy (AION) is a relatively common cause of visual loss and results from hypoperfusion of the small arteries of the anterior portion of the optic nerve. AION is the leading cause of sudden optic nerve related vision loss with approximately 10 cases per 100'000 in the population over 50 years. To date there is no established treatment for AION and therefore a better understanding of the events occurring at the level of the optic nerve head (ONH) would be important to design future therapeutic strategies. The optical properties of the eye allow imaging of the optic nerve in vivo, which is a part of the CNS, during ischemia. Experimentally laser induced optic neuropathy (eLiON) displays similar anatomical features as anterior ischemic optic neuropathy in humans. After laser induced optic neuropathy we show that hyperreflective dots in optical coherence tomography correspond to mononuclear cells in histology. Using fluorescence-activated flow cytometry (FACS) we found these cells to peak one week after eLiON. These observations were translated to OCT findings in patients with AION, where similar dynamics of hyperreflective dots at the ONH were identified. Our data suggests that activated macrophages can be identified as hyperreflective dots in OCT. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Optical analog transmission device

    International Nuclear Information System (INIS)

    Ikawa, Shinji.

    1994-01-01

    The present invention concerns a device such as electro-optical conversion elements, optoelectric-electric elements and optical transmission channel, not undergoing deleterious effects on the efficiency of conversion and transmission due to temperature, and aging change. That is, a sine wave superposing means superposes, on a detector signal to be transmitted, a sine-wave signal having a predetermined amplitude and at a frequency lower than that of the detector signal. An optoelectric conversion means converts the electric signal as the signal of the sine-wave signal superposing means into an optical signal and outputs the same to an optical transmitting channel. The optoelectric conversion means converts the transmitted signal to an electric signal. A discriminating means discriminates the electric signal into a detector signal and a sine-wave signal. A calculating means calculates an optical transmitting efficiency of the transmitting channel based on the amplitude of the discriminated sine-wave signal. A processing means compensates an amplitude value of the detector signals discriminated by the discriminating means based on the optical transmission efficiency. As a result, an optical analog transmission device can be attained, which conducts optical transmission at a high accuracy without undergoing the defective effects of the optical transmission efficiency. (I.S.)

  13. Fiber-Optic Chemical Sensors and Fiber-Optic Bio-Sensors

    Directory of Open Access Journals (Sweden)

    Marie Pospíšilová

    2015-09-01

    Full Text Available This review summarizes principles and current stage of development of fiber-optic chemical sensors (FOCS and biosensors (FOBS. Fiber optic sensor (FOS systems use the ability of optical fibers (OF to guide the light in the spectral range from ultraviolet (UV (180 nm up to middle infrared (IR (10 μm and modulation of guided light by the parameters of the surrounding environment of the OF core. The introduction of OF in the sensor systems has brought advantages such as measurement in flammable and explosive environments, immunity to electrical noises, miniaturization, geometrical flexibility, measurement of small sample volumes, remote sensing in inaccessible sites or harsh environments and multi-sensing. The review comprises briefly the theory of OF elaborated for sensors, techniques of fabrications and analytical results reached with fiber-optic chemical and biological sensors.

  14. Optical measuring system with an interrogator and a polymer-based single-mode fibre optic sensor system

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to an optical measuring system comprising a polymer-based single-mode fibre-optic sensor system (102), an optical interrogator (101), and an optical arrangement (103) interconnecting the optical interrogator (101) and the polymer-based single-mode fibre-optic sensor...... system (102). The invention further relates to an optical interrogator adapted to be connected to a polymer-based single-mode fibre-optic sensor system via an optical arrangement. The interrogator comprises a broadband light source arrangement (104) and a spectrum analysing arrangement which receives...

  15. Spectral domain optical coherence tomography morphology in optic disc pit associated maculopathy

    Directory of Open Access Journals (Sweden)

    Janusz Michalewski

    2014-01-01

    Full Text Available Purpose: Our purpose was to study the clinical manifestation and course of optic pit maculopathy using Spectral Domain Optical Coherence Tomography (SD- OCT images. Materials and Methods: We used SD-OCT to examine 20 eyes of 19 patients with a macular detachment in combination with an optic. Results: We observed five different fovea appearances in regard to fluid localization. In five eyes, we recorded changes in the fluid distribution with SD-OCT. In 17/20 eyes, we noted a communication between the perineural and subretinal and/or intraretinal space at the margin of the optic disc. Conclusion: 3-dimensional SD-OCT (3D-SDOCT scans revealed a three-fold connection, between subretinal and intraretinal space, perineural space, and the vitreous cavity. Therefore, we suppose that intraretinal or subretinal fluid in optic pit maculopathy may have both a vitreous and cerebrospinal origin. A membrane, covering the optic nerve was noted in 14 cases. Even if it seems intact in some B-scans, it is not complete in others several micrometers apart. Additionally, we observed fluid accumulation below the margin of the optic disc and hyperreflective porous tissue in the optic disc excavation. Those findings do not influence the course of maculopathy.

  16. Optics for engineers

    CERN Document Server

    DiMarzio, Charles A

    2011-01-01

    This book is an excellent resource for teaching any student or scientist who needs to use optical systems. I particularly like the addition of MATLAB scripts and functions. Highly recommended.-Professor James C. Wyant, Dean of College of Optical Sciences, University of ArizonaHis book is clear, concise and highly readable. This is an excellent text.-Professor Changhuei Yang, California Institute of TechnologyAt last, a book on optics that is written with the practising engineer in mind. I have been teaching optics to engineers for many years and have often longed for a text aimed at my student

  17. 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

  18. Optical pulse coupling in a photorefractive crystal, propagation of encoded pulses in an optical fiber, and phase conjugate optical interconnections

    Energy Technology Data Exchange (ETDEWEB)

    Yao, X.S.

    1992-01-01

    In Part I, the author presents a theory to describe the interaction between short optical pulses in a photorefractive crystal. This theory provides an analytical framework for pulse coherence length measurements using a photorefractive crystal. The theory also predicts how a pulse changes its temporal shape due to its coupling with another pulse in a photorefractive crystal. The author describes experiments to demonstrate how photorefractive coupling alters the temporal shape and the frequency spectrum of an optical pulse. The author describes a compact optical field correlator. Using this correlator, the author measured the field cross-correlation function of optical pulses using a photorefractive crystal. The author presents a more sophisticated theory to describe the photorefractive coupling of optical pulses that are too short for the previous theory to be valid. In Part II of this dissertation, the author analyzes how the group-velocity dispersion and the optical nonlinearity of an optical fiber ruin an fiberoptic code-division multiple-access (CDMA) communication system. The author treats the optical fiber's nonlinear response with a novel approach and derives the pulse propagation equation. Through analysis and numerically simulations, the author obtains the maximum and the maximum allowed peak pulse power, as well as the minimum and the maximum allowed pulse width for the communication system to function properly. The author simulates how the relative misalignment between the encoding and the decoding masks affects the system's performance. In Part III the author demonstrates a novel optical interconnection device based on a mutually pumped phase conjugator. This device automatically routes light from selected information-sending channels to selected information-receiving channels, and vice versa. The phase conjugator eliminates the need for critical alignment. It is shown that a large number of optical channels can be interconnected using this

  19. Optical design and testing: introduction.

    Science.gov (United States)

    Liang, Chao-Wen; Koshel, John; Sasian, Jose; Breault, Robert; Wang, Yongtian; Fang, Yi Chin

    2014-10-10

    Optical design and testing has numerous applications in industrial, military, consumer, and medical settings. Assembling a complete imaging or nonimage optical system may require the integration of optics, mechatronics, lighting technology, optimization, ray tracing, aberration analysis, image processing, tolerance compensation, and display rendering. This issue features original research ranging from the optical design of image and nonimage optical stimuli for human perception, optics applications, bio-optics applications, 3D display, solar energy system, opto-mechatronics to novel imaging or nonimage modalities in visible and infrared spectral imaging, modulation transfer function measurement, and innovative interferometry.

  20. [Adaptive optics for ophthalmology].

    Science.gov (United States)

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  1. Photometric device using optical fibers

    International Nuclear Information System (INIS)

    Boisde, Gilbert; Perez, J.-J.

    1981-02-01

    Remote measurements in radioactive environment are now possible with optical fibers. Measurement instruments developed by CEA are constitued of: - an optical probe (5 mm to 1 meter optical path length), - a photometric measurement device, - optical fiber links. 'TELEPHOT' is a photometric device for industrial installations. It is uses interferentiel filters for 2 to 5 simultaneous wave lengths. 'CRUDMETER' measures the muddiness of water. It can be equipped with a high sensitivity cell of 50 cm optical path length tested up to 250 bars. Coupling a double beam spectrophotometer to a remote optical probe, up to 1 meter optical path length, is carried out by means of an optical device using optical fibers links, eventually several hundred meter long. For these equipments special step index large core fibers, 1 to 1.5 mm in diameter, have been developed as well connectors. For industrial control and research these instruments offer new prospect thanks to optical fibers use [fr

  2. Design of a Production Process to Enhance Optical Performance of 3(omega) Optics

    International Nuclear Information System (INIS)

    Prasad, R.R.; Bruere, J.R.; Halpin, J.; Lucero, P.; Mills, S.; Bernacil, M.; Hackel, R.P.

    2003-01-01

    Using the Phoenix pre-production conditioning facility we have shown that raster scanning of 3ω optics using a XeF excimer laser and mitigation of the resultant damage sites with a CO 2 laser can enhance their optical damage resistance. Several large-scale (43 cm x 43 cm) optics have been processed in this facility. A production facility capable of processing several large optics a week has been designed based on our experience in the pre-production facility. The facility will be equipped with UV conditioning lasers--351-nm XeF excimer lasers operating at 100 Hz and 23 ns. The facility will also include a CO 2 laser for damage mitigation, an optics stage for raster scanning large-scale optics, a damage mapping system (DMS) that images large-scale optics and can detect damage sites or precursors as small as ∼ 15 (micro)m, and two microscopes to image damage sites with ∼ 5 (micro)m resolution. The optics will be handled in a class 100 clean room, within the facility that will be maintained at class 1000

  3. Optical properties of marine waters and the development of bio-optical algorithms

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.

    This paper presents the primary optical variables used in the measurement of the optical properties of marine waters. How can in-situ measurements be used in the optical recognition of coastal and open ocean waters. We then look at bio...

  4. Correlator receiver architecture with PnpN optical thyristor operating as optical hard-limiter

    Science.gov (United States)

    Kang, Tae-Gu; Ho Lee, Su; Park, Soonchul

    2011-07-01

    We propose novel correlator receiver architecture with a PnpN optical thyristor operating as optical hard-limiter, and demonstrate a multiple-access interference rejection of the proposed correlator receiver. The proposed correlator receiver is composed of the 1×2 splitter, optical delay line, 2×1 combiner, and fabricated PnpN optical thyristor. The proposed correlator receiver enhances the system performance because it excludes some combinations of multiple-access interference patterns from causing errors as in optical code-division multiple access systems with conventional optical receiver shown in all previous works. It is found that the proposed correlator receiver can fully reject the interference signals generated by decoding processing and multiple access for two simultaneous users.

  5. Gradient-Index Optics

    Science.gov (United States)

    2010-03-31

    nonimaging design capabilities to incorporate 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 12-04-2011 13. SUPPLEMENTARY NOTES The views, opinions...Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Imaging Optics, Nonimaging Optics, Gradient Index Optics, Camera, Concentrator...imaging and nonimaging design capabilities to incorporate manufacturable GRIN lenses can provide imaging lens systems that are compact and

  6. Multiplane optical microscope

    Science.gov (United States)

    Li, Tongcang; Ota, Sadao; Kim, Jeongmin; Wang, Yuan; Zhang, Xiang

    2017-11-21

    This disclosure provides systems, methods, and apparatus related to optical microscopy. In one aspect, an apparatus includes a sample holder, a first objective lens, a plurality of optical components, a second objective lens, and a mirror. The apparatus may directly image a cross-section of a sample oblique to or parallel to the optical axis of the first objective lens, without scanning.

  7. Computational adaptive optics for broadband optical interferometric tomography of biological tissue.

    Science.gov (United States)

    Adie, Steven G; Graf, Benedikt W; Ahmad, Adeel; Carney, P Scott; Boppart, Stephen A

    2012-05-08

    Aberrations in optical microscopy reduce image resolution and contrast, and can limit imaging depth when focusing into biological samples. Static correction of aberrations may be achieved through appropriate lens design, but this approach does not offer the flexibility of simultaneously correcting aberrations for all imaging depths, nor the adaptability to correct for sample-specific aberrations for high-quality tomographic optical imaging. Incorporation of adaptive optics (AO) methods have demonstrated considerable improvement in optical image contrast and resolution in noninterferometric microscopy techniques, as well as in optical coherence tomography. Here we present a method to correct aberrations in a tomogram rather than the beam of a broadband optical interferometry system. Based on Fourier optics principles, we correct aberrations of a virtual pupil using Zernike polynomials. When used in conjunction with the computed imaging method interferometric synthetic aperture microscopy, this computational AO enables object reconstruction (within the single scattering limit) with ideal focal-plane resolution at all depths. Tomographic reconstructions of tissue phantoms containing subresolution titanium-dioxide particles and of ex vivo rat lung tissue demonstrate aberration correction in datasets acquired with a highly astigmatic illumination beam. These results also demonstrate that imaging with an aberrated astigmatic beam provides the advantage of a more uniform depth-dependent signal compared to imaging with a standard gaussian beam. With further work, computational AO could enable the replacement of complicated and expensive optical hardware components with algorithms implemented on a standard desktop computer, making high-resolution 3D interferometric tomography accessible to a wider group of users and nonspecialists.

  8. Silicon Optical Modulator Simulation

    Directory of Open Access Journals (Sweden)

    Soon Thor LIM

    2015-04-01

    Full Text Available We developed a way of predicting and analyzing high speed optical modulator. Our research adopted a bottom-up approach to consider high-speed optical links using an eye diagram. Our method leverages on modular mapping of electrical characteristics to optical characteristics, while attaining the required accuracy necessary for device footprint approaching sub-micron scales where electrical data distribution varies drastically. We calculate for the bias dependent phase shift (2pi/mm and loss (dB/mm for the optical modulator based on the real and imaginary part of complex effective indices. Subsequently, combine effectively both the electrical and optical profiles to construct the optical eye diagram which is the essential gist of signal integrity of such devices.

  9. Nonlinear optics

    CERN Document Server

    Bloembergen, Nicolaas

    1996-01-01

    Nicolaas Bloembergen, recipient of the Nobel Prize for Physics (1981), wrote Nonlinear Optics in 1964, when the field of nonlinear optics was only three years old. The available literature has since grown by at least three orders of magnitude.The vitality of Nonlinear Optics is evident from the still-growing number of scientists and engineers engaged in the study of new nonlinear phenomena and in the development of new nonlinear devices in the field of opto-electronics. This monograph should be helpful in providing a historical introduction and a general background of basic ideas both for expe

  10. Fiber optics: A brief introduction

    International Nuclear Information System (INIS)

    Gruchalla, M.E.

    1989-01-01

    A basic introduction into the principles of fiber optics is presented. A review of both the underlying physical principles and the individual elements of typical fiber-optic systems are presented. The optical phenomenon of total internal reflection is reviewed. The basic construction of the optical fiber is presented. Both step-index and graded-index fiber designs are reviewed. Multimode and single-mode fiber constructions are considered and typical performance parameters given. Typical optical-fiber bandwidth and loss characteristics are compared to various common coaxial cables, waveguides, and air transmission. The constructions of optical-fiber cables are reviewed. Both loose-tube and tightly-buffered designs are considered. Several optical connection approaches are presented. Photographs of several representative optical connectors are included. Light Emitting Diode and Laser Diode emitters for fiber-optic applications are reviewed, and some advantages and shortcomings of each are considered. The phenomenon of modal noise is briefly explained. Both PIN and Avalanche photodetectors are reviewed and their performance parameters compared. Methods of data transmission over optical fiber are introduced. Principles of Wavelength, Frequency, and Time Division Multiplexing are briefly presented. The technology of fiber-optic sensors is briefly reviewed with basic principles introduced. The performance of a fiber-optic strain sensor is included as a practical example. 7 refs., 10 figs

  11. 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

  12. Optical Manipulation System Using a Plurality of Optical Traps

    DEFF Research Database (Denmark)

    2006-01-01

    The present invention relates to an optical manipulation system (10) for generation of a plurality of optical traps for manipulation of micro-objects including nano-objects using electromagnetic radiation forces in a micro-object manipulation volume (14), the system comprising a spatially modulat...

  13. Optically intraconnected computer employing dynamically reconfigurable holographic optical element

    Science.gov (United States)

    Bergman, Larry A. (Inventor)

    1992-01-01

    An optically intraconnected computer and a reconfigurable holographic optical element employed therein. The basic computer comprises a memory for holding a sequence of instructions to be executed; logic for accessing the instructions in sequence; logic for determining for each the instruction the function to be performed and the effective address thereof; a plurality of individual elements on a common support substrate optimized to perform certain logical sequences employed in executing the instructions; and, element selection logic connected to the logic determining the function to be performed for each the instruction for determining the class of each function and for causing the instruction to be executed by those the elements which perform those associated the logical sequences affecting the instruction execution in an optimum manner. In the optically intraconnected version, the element selection logic is adapted for transmitting and switching signals to the elements optically.

  14. UV-cured polymer optics

    Science.gov (United States)

    Piñón, Victor; Santiago, Freddie; Vogelsberg, Ashten; Davenport, Amelia; Cramer, Neil

    2017-10-01

    Although many optical-quality glass materials are available for use in optical systems, the range of polymeric materials is limited. Polymeric materials have some advantages over glass when it comes to large-scale manufacturing and production. In smaller scale systems, they offer a reduction in weight when compared to glass counterparts. This is especially important when designing optical systems meant to be carried by hand. We aimed to expand the availability of polymeric materials by exploring both crown-like and flint-like polymers. In addition, rapid and facile production was also a goal. By using UV-cured thiolene-based polymers, we were able to produce optical materials within seconds. This enabled the rapid screening of a variety of polymers from which we down-selected to produce optical flats and lenses. We will discuss problems with production and mitigation strategies in using UV-cured polymers for optical components. Using UV-cured polymers present a different set of problems than traditional injection-molded polymers, and these issues are discussed in detail. Using these produced optics, we integrated them into a modified direct view optical system, with the end goal being the development of drop-in replacements for glass components. This optical production strategy shows promise for use in lab-scale systems, where low-cost methods and flexibility are of paramount importance.

  15. Fiber optic hydrophone

    Science.gov (United States)

    Kuzmenko, Paul J.; Davis, Donald T.

    1994-01-01

    A miniature fiber optic hydrophone based on the principles of a Fabry-Perot interferometer. The hydrophone, in one embodiment, includes a body having a shaped flexible bladder at one end which defines a volume containing air or suitable gas, and including a membrane disposed adjacent a vent. An optic fiber extends into the body with one end terminating in spaced relation to the membrane. Acoustic waves in the water that impinge on the bladder cause the pressure of the volume therein to vary causing the membrane to deflect and modulate the reflectivity of the Fabry-Perot cavity formed by the membrane surface and the cleaved end of the optical fiber disposed adjacent to the membrane. When the light is transmitted down the optical fiber, the reflected signal is amplitude modulated by the incident acoustic wave. Another embodiment utilizes a fluid filled volume within which the fiber optic extends.

  16. Reflective Optics for Microdiffraction

    International Nuclear Information System (INIS)

    Ice, G.E.

    2007-01-01

    Nondispersive optics are essential for emerging microdiffraction and nanobeam research. Here we describe extensions to traditional Kirkpatrick Baez optics required to develop nondispersive microdiffraction and nanoprobe optics with 1-10 nm spatial resolution

  17. Assessing tether anchor labeling and usability in pickup trucks.

    Science.gov (United States)

    Klinich, Kathleen D; Manary, Miriam A; Malik, Laura A; Flannagan, Carol A; Jermakian, Jessica S

    2018-04-03

    The objective of this study was to investigate vehicle factors associated with child restraint tether use and misuse in pickup trucks and evaluate 4 labeling interventions designed to educate consumers on proper tether use. Volunteer testing was performed with 24 subjects and 4 different pickup trucks. Each subject performed 8 child restraint installations among the 4 pickups using 2 forward-facing restraints: a Britax Marathon G4.1 and an Evenflo Triumph. Vehicles were selected to represent 4 different implementations of tether anchors among pickups: plastic loop routers (Chevrolet Silverado), webbing routers (Ram), back wall anchors (Nissan Frontier), and webbing routers plus metal anchors (Toyota Tundra). Interventions included a diagram label, Quick Response (QR) Code linked to video instruction, coordinating text label, and contrasting text tag. Subjects used the child restraint tether in 93% of trials. However, tether use was completely correct in only 9% of trials. An installation was considered functional if the subject attached the tether to a tether anchor and had a tight installation (ignoring routing and head restraint position); 28% of subjects achieved a functional installation. The most common installation error was attaching the tether hook to the anchor/router directly behind the child restraint (near the top of the seatback) rather than placing the tether through the router and attaching it to the anchor in the adjacent seating position. The Nissan Frontier, with the anchor located on the back wall of the cab, had the highest rate of correct installations but also had the highest rate of attaching the tether to components other than the tether anchor (seat adjustor, child restraint storage hook, around head restraint). None of the labeling interventions had a significant effect on correct installation; not a single subject scanned the QR Code to access the video instruction. Subjects with the most successful installations spent extensive time

  18. Optical programmable metamaterials

    Science.gov (United States)

    Gong, Cheng; Zhang, Nan; Dai, Zijie; Liu, Weiwei

    2018-02-01

    We suggest and demonstrate the concept of optical programmable metamaterials which can configure the device's electromagnetic parameters by the programmable optical stimuli. In such metamaterials, the optical stimuli produced by a FPGA controlled light emitting diode array can switch or combine the resonance modes which are coupled in. As an example, an optical programmable metamaterial terahertz absorber is proposed. Each cell of the absorber integrates four meta-rings (asymmetric 1/4 rings) with photo-resistors connecting the critical gaps. The principle and design of the metamaterials are illustrated and the simulation results demonstrate the functionalities for programming the metamaterial absorber to change its bandwidth and resonance frequency.

  19. Optical geometry

    International Nuclear Information System (INIS)

    Robinson, I.; Trautman, A.

    1988-01-01

    The geometry of classical physics is Lorentzian; but weaker geometries are often more appropriate: null geodesics and electromagnetic fields, for example, are well known to be objects of conformal geometry. To deal with a single null congruence, or with the radiative electromagnetic fields associated with it, even less is needed: flag geometry for the first, optical geometry, with which this paper is chiefly concerned, for the second. The authors establish a natural one-to-one correspondence between optical geometries, considered locally, and three-dimensional Cauchy-Riemann structures. A number of Lorentzian geometries are shown to be equivalent from the optical point of view. For example the Goedel universe, the Taub-NUT metric and Hauser's twisting null solution have an optical geometry isomorphic to the one underlying the Robinson congruence in Minkowski space. The authors present general results on the problem of lifting a CR structure to a Lorentz manifold and, in particular, to Minkowski space; and exhibit the relevance of the deviation form to this problem

  20. All-optical virtual private network and ONUs communication in optical OFDM-based PON system.

    Science.gov (United States)

    Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun

    2011-11-21

    We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible. © 2011 Optical Society of America

  1. Blind Data Attack on BGP Routers

    Science.gov (United States)

    2017-03-01

    Second Reader Dr. Cynthia Irvine Chair, Cyber Academic Group iii THIS PAGE INTENTIONALLY LEFT BLANK iv ABSTRACT Transport Communication Protocol (TCP...Postgraduate School. The experience of higher learning at this institution was incredible, and I would whole-heartedly recommend it to any of my peers and...data attack packets to the victim device. Scapy is a Python library that is used to craft and send packets [28]. BGP is supported in Python through

  2. All-optical pulse data generation in a semiconductor optical amplifier gain controlled by a reshaped optical clock injection

    Science.gov (United States)

    Lin, Gong-Ru; Chang, Yung-Cheng; Yu, Kun-Chieh

    2006-05-01

    Wavelength-maintained all-optical pulse data pattern transformation based on a modified cross-gain-modulation architecture in a strongly gain-depleted semiconductor optical amplifier (SOA) is investigated. Under a backward dark-optical-comb injection with 70% duty-cycle reshaping from the received data clock at 10GHz, the incoming optical data stream is transformed into a pulse data stream with duty cycle, rms timing jitter, and conversion gain of 15%, 4ps, and 3dB, respectively. The high-pass filtering effect of the gain-saturated SOA greatly improves the extinction ratio of data stream by 8dB and reduces its bit error rate to 10-12 at -18dBm.

  3. Fractal vector optical fields.

    Science.gov (United States)

    Pan, Yue; Gao, Xu-Zhen; Cai, Meng-Qiang; Zhang, Guan-Lin; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

    2016-07-15

    We introduce the concept of a fractal, which provides an alternative approach for flexibly engineering the optical fields and their focal fields. We propose, design, and create a new family of optical fields-fractal vector optical fields, which build a bridge between the fractal and vector optical fields. The fractal vector optical fields have polarization states exhibiting fractal geometry, and may also involve the phase and/or amplitude simultaneously. The results reveal that the focal fields exhibit self-similarity, and the hierarchy of the fractal has the "weeding" role. The fractal can be used to engineer the focal field.

  4. 50 years of nonlinear optics

    International Nuclear Information System (INIS)

    Shen Yuanrang

    2011-01-01

    This article presents a brief introduction to the birth and early investigations of nonlinear optics, such as second harmonic generation,sum and difference frequency generation, stimulated Raman scattering,and self-action of light etc. Several important research achievements and applications of nonlinear optics are presented as well, including nonlinear optical spectroscopy, phase conjugation and adaptive optics, coherent nonlinear optics, and high-order harmonic generation. In the end, current and future research topics in nonlinear optics are summarized. (authors)

  5. Accuracies Of Optical Processors For Adaptive Optics

    Science.gov (United States)

    Downie, John D.; Goodman, Joseph W.

    1992-01-01

    Paper presents analysis of accuracies and requirements concerning accuracies of optical linear-algebra processors (OLAP's) in adaptive-optics imaging systems. Much faster than digital electronic processor and eliminate some residual distortion. Question whether errors introduced by analog processing of OLAP overcome advantage of greater speed. Paper addresses issue by presenting estimate of accuracy required in general OLAP that yields smaller average residual aberration of wave front than digital electronic processor computing at given speed.

  6. Optical Computers and Space Technology

    Science.gov (United States)

    Abdeldayem, Hossin A.; Frazier, Donald O.; Penn, Benjamin; Paley, Mark S.; Witherow, William K.; Banks, Curtis; Hicks, Rosilen; Shields, Angela

    1995-01-01

    The rapidly increasing demand for greater speed and efficiency on the information superhighway requires significant improvements over conventional electronic logic circuits. Optical interconnections and optical integrated circuits are strong candidates to provide the way out of the extreme limitations imposed on the growth of speed and complexity of nowadays computations by the conventional electronic logic circuits. The new optical technology has increased the demand for high quality optical materials. NASA's recent involvement in processing optical materials in space has demonstrated that a new and unique class of high quality optical materials are processible in a microgravity environment. Microgravity processing can induce improved orders in these materials and could have a significant impact on the development of optical computers. We will discuss NASA's role in processing these materials and report on some of the associated nonlinear optical properties which are quite useful for optical computers technology.

  7. Phase-Modulated Optical Communication Systems

    CERN Document Server

    Ho, Keang-Po

    2005-01-01

    Fiber-optic communication systems have revolutionized our telecommunication infrastructures – currently, almost all telephone land-line, cellular, and internet communications must travel via some form of optical fibers. In these transmission systems, neither the phase nor frequency of the optical signal carries information – only the intensity of the signal is used. To transmit more information in a single optical carrier, the phase of the optical carrier must be explored. As a result, there is renewed interest in phase-modulated optical communications, mainly in direct-detection DPSK signals for long-haul optical communication systems. When optical amplifiers are used to maintain certain signal level among the fiber link, the system is limited by amplifier noises and fiber nonlinearities. Phase-Modulated Optical Communication Systems surveys this newly popular area, covering the following topics: The transmitter and receiver for phase-modulated coherent lightwave systems Method for performance analysis o...

  8. The optical system of the proposed Chinese 12-m optical/infrared telescope

    Science.gov (United States)

    Su, Ding-qiang; Liang, Ming; Yuan, Xiangyan; Bai, Hua; Cui, Xiangqun

    2017-08-01

    The lack of a large-aperture optical/infrared telescope has seriously affected the development of astronomy in China. In 2016, the authors published their concept study and suggestions for a 12-m telescope optical system. This article presents the authors' further research and some new results. Considering that this telescope should be a general-purpose telescope for a wide range of scientific goals and could be used for frontier scientific research in the future, the authors studied and designed a variety of 12-m telescope optical systems for comparison and final decision-making. In general, we still adopt our previous configuration, but the Nasmyth and prime-focus corrector systems have been greatly improved. In this article, the adaptive optics is given special attention. Ground-layer adaptive optics (GLAO) is adopted. It has a 14-arcmin field of view. The secondary mirror is used as the adaptive optical deformable mirror. Obviously, not all the optical systems in this telescope configuration will be used or constructed at the same stage. Some will be for the future and some are meant for research rather than for construction.

  9. Optic Disc and Optic Cup Segmentation Methodologies for Glaucoma Image Detection: A Survey

    Directory of Open Access Journals (Sweden)

    Ahmed Almazroa

    2015-01-01

    Full Text Available Glaucoma is the second leading cause of loss of vision in the world. Examining the head of optic nerve (cup-to-disc ratio is very important for diagnosing glaucoma and for patient monitoring after diagnosis. Images of optic disc and optic cup are acquired by fundus camera as well as Optical Coherence Tomography. The optic disc and optic cup segmentation techniques are used to isolate the relevant parts of the retinal image and to calculate the cup-to-disc ratio. The main objective of this paper is to review segmentation methodologies and techniques for the disc and cup boundaries which are utilized to calculate the disc and cup geometrical parameters automatically and accurately to help the professionals in the glaucoma to have a wide view and more details about the optic nerve head structure using retinal fundus images. We provide a brief description of each technique, highlighting its classification and performance metrics. The current and future research directions are summarized and discussed.

  10. Optic Disc and Optic Cup Segmentation Methodologies for Glaucoma Image Detection: A Survey

    Science.gov (United States)

    Almazroa, Ahmed; Burman, Ritambhar; Raahemifar, Kaamran; Lakshminarayanan, Vasudevan

    2015-01-01

    Glaucoma is the second leading cause of loss of vision in the world. Examining the head of optic nerve (cup-to-disc ratio) is very important for diagnosing glaucoma and for patient monitoring after diagnosis. Images of optic disc and optic cup are acquired by fundus camera as well as Optical Coherence Tomography. The optic disc and optic cup segmentation techniques are used to isolate the relevant parts of the retinal image and to calculate the cup-to-disc ratio. The main objective of this paper is to review segmentation methodologies and techniques for the disc and cup boundaries which are utilized to calculate the disc and cup geometrical parameters automatically and accurately to help the professionals in the glaucoma to have a wide view and more details about the optic nerve head structure using retinal fundus images. We provide a brief description of each technique, highlighting its classification and performance metrics. The current and future research directions are summarized and discussed. PMID:26688751

  11. A Framework for Scalable TSV Assignment and Selection in Three-Dimensional Networks-on-Chips

    Directory of Open Access Journals (Sweden)

    Amir Charif

    2017-01-01

    Full Text Available 3D integration can greatly benefit future many-cores by enabling low-latency three-dimensional Network-on-Chip (3D-NoC topologies. However, due to high cost, low yield, and frequent failures of Through-Silicon Via (TSV, 3D-NoCs are most likely to include only a few vertical connections, resulting in incomplete topologies that pose new challenges in terms of deadlock-free routing and TSV assignment. The routers of such networks require a way to locate the nodes that have vertical connections, commonly known as elevators, and select one of them in order to be able to reach other layers when necessary. In this paper, several alternative TSV selection strategies requiring a constant amount of configurable bits per router are introduced. Each proposed solution consists of a configuration algorithm, which provides each router with the necessary information to locate the elevators, and a routing algorithm, which uses this information at runtime to route packets to an elevator. Our algorithms are compared by simulation to highlight the advantages and disadvantages of each solution under various scenarios, and hardware synthesis results demonstrate the scalability of the proposed approach and its suitability for cost-oriented designs.

  12. Scenarios for control and data flows in multiprotocol over ATM

    Science.gov (United States)

    Kujoory, Ali

    1997-10-01

    The multiprotocol over ATM (MPOA), specified by the ATM Forum, provides an architecture for transfer of Internetwork layer packets (Layer 3 datagram such as IP, IPX) over ATM subnets or across the emulated LANs. MPOA provides shortcuts that bypass routers to avoid router bottlenecks. It is a grand union of some of the existing standards such as LANE by the ATM Forum, NHRP by the IETF, and the Q.2931 by ITU. The intent of this paper is to clarify the data flows between pairs of source and destination hosts in an MPOA system. It includes scenarios for both the intra- and inter-subnet flows between different pairs of MPOA end-systems. The intrasubnet flows simply use LANE for address resolution or data transfer. The inter-subnet flows may use a default path for short-lived flows or a shortcut for long-lived flows. The default path uses the LANE and router capabilities. The shortcut path uses LANE plus NHRP for ATM address resoluton. An ATM virtual circuit is established before the data transfer. This allows efficient transfer of internetwork layer packets over ATM for real-time applications.

  13. Principles of Eliminating Access Control Lists within a Domain

    Directory of Open Access Journals (Sweden)

    Vic Grout

    2012-04-01

    Full Text Available The infrastructure of large networks is broken down into areas that have a common security policy called a domain. Security within a domain is commonly implemented at all nodes. However this can have a negative effect on performance since it introduces a delay associated with packet filtering. When Access Control Lists (ACLs are used within a router for this purpose then a significant overhead is introduced associated with this process. It is likely that identical checks are made at multiple points within a domain prior to a packet reaching its destination. Therefore by eliminating ACLs within a domain by modifying the ingress/egress points with equivalent functionality an improvement in the overall performance can be obtained. This paper considers the effect of the delays when using router operating systems offering different levels of functionality. It considers factors which contribute to the delay particularly due to ACLs and by using theoretical principles modified by practical calculation a model is created. Additionally this paper provides an example of an optimized solution which reduces the delay through network routers by distributing the security rules to the ingress/egress points of the domain without affecting the security policy.

  14. Supporting BPMN choreography with system integration artefacts for enterprise process collaboration

    Science.gov (United States)

    Nie, Hongchao; Lu, Xudong; Duan, Huilong

    2014-07-01

    Business Process Model and Notation (BPMN) choreography modelling depicts externally visible message exchanges between collaborating processes of enterprise information systems. Implementation of choreography relies on designing system integration solutions to realise message exchanges between independently developed systems. Enterprise integration patterns (EIPs) are widely accepted artefacts to design integration solutions. If the choreography model represents coordination requirements between processes with behaviour mismatches, the integration designer needs to analyse the routing requirements and address these requirements by manually designing EIP message routers. As collaboration scales and complexity increases, manual design becomes inefficient. Thus, the research problem of this paper is to explore a method to automatically identify routing requirements from BPMN choreography model and to accordingly design routing in the integration solution. To achieve this goal, recurring behaviour mismatch scenarios are analysed as patterns, and corresponding solutions are proposed as EIP routers. Using this method, a choreography model can be analysed by computer to identify occurrences of mismatch patterns, leading to corresponding router selection. A case study demonstrates that the proposed method enables computer-assisted integration design to implement choreography. A further experiment reveals that the method is effective to improve the design quality and reduce time cost.

  15. Optical Computing

    Indian Academy of Sciences (India)

    Other advantages of optics include low manufacturing costs, immunity to ... It is now possible to control atoms by trapping single photons in small, .... cement, and optical spectrum analyzers. ... risk of noise is further reduced, as light is immune to electro- ..... mode of operation including management of large multimedia.

  16. Intelligent Optics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Intelligent Optics Laboratory supports sophisticated investigations on adaptive and nonlinear optics; advancedimaging and image processing; ground-to-ground and...

  17. 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

  18. 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

  19. Radiative properties of optical board embedded with optical black holes

    International Nuclear Information System (INIS)

    Qiu, J.; Liu, L.H.; Hsu, P.-F.

    2011-01-01

    Unique radiative properties, such as wavelength-selective transmission or absorption, have been intensively studied. Historically, geometries for wavelength-selective of light absorption were developed based on metallic periodical structures, which were only applied in the case of TM wave incidence due to the excitation of surface plasmons. In this paper, we develop an alternative approach to selective wavelength of light absorption (both TE and TM waves), based on an optical board periodical embedded with optical black holes. Numerical work was carried out to study such structure's radiative properties within the wavelength range of 1-100 μm. The electromagnetic wave transmission through such a structure is predicted by solving Maxwell's equations using the finite-difference time-domain (FDTD) method. Spectral absorptance varies with the period of optical black holes. When the incidence wavelength is much larger than the inner core radius, most of the light energy will be transmitted through the inner core. Otherwise, the energy will be mainly absorbed. Numerical results of the radiative properties of the optical board with different incidence wavelengths are also obtained. The effect of the oblique incidence wave is investigated. This study helps us gain a better understanding of the radiative properties of an optical board embedded with optical black holes and develop an alternative approach to selective light absorption.

  20. Using spectral-domain optical coherence tomography to detect optic neuropathy in patients with craniosynostosis.

    Science.gov (United States)

    Dagi, Linda R; Tiedemann, Laura M; Heidary, Gena; Robson, Caroline D; Hall, Amber M; Zurakowski, David

    2014-12-01

    Detecting and monitoring optic neuropathy in patients with craniosynostosis is a clinical challenge due to limited cooperation, and subjective measures of visual function. The purpose of this study was to appraise the correlation of peripapillary retinal nerve fiber layer (RNFL) thickness measured by spectral-domain ocular coherence tomography (SD-OCT) with indication of optic neuropathy based on fundus examination. The medical records of all patients with craniosynostosis presenting for ophthalmic evaluation during 2013 were retrospectively reviewed. The following data were abstracted from the record: diagnosis, historical evidence of elevated intracranial pressure, current ophthalmic evaluation and visual field results, and current peripapillary RNFL thickness. A total of 54 patients were included (mean age, 10.6 years [range, 2.4-33.8 years]). Thirteen (24%) had evidence of optic neuropathy based on current fundus examination. Of these, 10 (77%) demonstrated either peripapillary RNFL elevation and papilledema or depression with optic atrophy. Sensitivity for detecting optic atrophy was 88%; for papilledema, 60%; and for either form of optic neuropathy, 77%. Specificity was 94%, 90%, and 83%, respectively. Kappa agreement was substantial for optic atrophy (κ = 0.73) and moderate for papilledema (κ = 0.39) and for either form of optic neuropathy (κ = 0.54). Logistic regression indicated that peripapillary RNFL thickness was predictive of optic neuropathy (P optic neuropathy than visual field testing (likelihood ratio = 10.02; P = 0.002). Sensitivity and specificity of logMAR visual acuity in detecting optic neuropathy were 15% and 95%, respectively. Peripapillary RNFL thickness measured by SD-OCT provides adjunctive evidence for identifying optic neuropathy in patients with craniosynostosis and appears more sensitive at detecting optic atrophy than papilledema. Copyright © 2014 American Association for Pediatric Ophthalmology and Strabismus. Published by

  1. Ultra-high accuracy optical testing: creating diffraction-limitedshort-wavelength optical systems

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman,Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli,Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

    2005-08-03

    Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-{angstrom} and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date.

  2. Coding for optical channels

    CERN Document Server

    Djordjevic, Ivan; Vasic, Bane

    2010-01-01

    This unique book provides a coherent and comprehensive introduction to the fundamentals of optical communications, signal processing and coding for optical channels. It is the first to integrate the fundamentals of coding theory and optical communication.

  3. Modeling of semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Bischoff, Svend; Berg, Tommy Winther

    We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed.......We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed....

  4. Improved Optical Fiber Chemical Sensors

    Science.gov (United States)

    Egalon, Claudio O.; Rogowski, Robert S.

    1994-01-01

    Calculations, based on exact theory of optical fiber, have shown how to increase optical efficiency sensitivity of active-core, step-index-profile optical-fiber fluorosensor. Calculations result of efforts to improve efficiency of optical-fiber chemical sensor of previous concept described in "Making Optical-Fiber Chemical Sensors More Sensitive" (LAR-14525). Optical fiber chemical detector of enhanced sensitivity made in several configurations. Portion of fluorescence or chemiluminescence generated in core, and launched directly into bound electromagnetic modes that propagate along core to photodetector.

  5. Optical design of an athermalised dual field of view step zoom optical system in MWIR

    Science.gov (United States)

    Kucukcelebi, Doruk

    2017-08-01

    In this paper, the optical design of an athermalised dual field of view step zoom optical system in MWIR (3.7μm - 4.8μm) is described. The dual field of view infrared optical system is designed based on the principle of passive athermalization method not only to achieve athermal optical system but also to keep the high image quality within the working temperature between -40°C and +60°C. The infrared optical system used in this study had a 320 pixel x 256 pixel resolution, 20μm pixel pitch size cooled MWIR focal plane array detector. In this study, the step zoom mechanism, which has the axial motion due to consisting of a lens group, is considered to simplify mechanical structure. The optical design was based on moving a single lens along the optical axis for changing the optical system's field of view not only to reduce the number of moving parts but also to athermalize for the optical system. The optical design began with an optimization process using paraxial optics when first-order optics parameters are determined. During the optimization process, in order to reduce aberrations, such as coma, astigmatism, spherical and chromatic aberrations, aspherical surfaces were used. As a result, athermalised dual field of view step zoom optical design is proposed and the performance of the design using proposed method was verified by providing the focus shifts, spot diagrams and MTF analyzes' plots.

  6. Optical Characterization of Doped Thermoplastic and Thermosetting Polymer-Optical-Fibers

    Directory of Open Access Journals (Sweden)

    Igor Ayesta

    2017-03-01

    Full Text Available The emission properties of a graded-index thermoplastic polymer optical fiber and a step-index thermosetting one, both doped with rhodamine 6G, have been studied. The work includes a detailed analysis of the amplified spontaneous emission together with a study of the optical gains and losses of the fibers. The photostability of the emission of both types of fibers has also been investigated. Comparisons between the results of both doped polymer optical fibers are presented and discussed.

  7. Quantum optics for experimentalists

    CERN Document Server

    Ou, Zhe-Yu Jeff

    2017-01-01

    This book on quantum optics is from the point of view of an experimentalist. It approaches the theory of quantum optics with the language of optical modes of classical wave theory, with which experimentalists are most familiar.

  8. Optically Anomalous Crystals

    CERN Document Server

    Shtukenberg, Alexander; Kahr, Bart

    2007-01-01

    Optical anomalies in crystals are puzzles that collectively constituted the greatest unsolved problems in crystallography in the 19th Century. The most common anomaly is a discrepancy between a crystal’s symmetry as determined by its shape or by X-ray analysis, and that determined by monitoring the polarization state of traversing light. These discrepancies were perceived as a great impediment to the development of the sciences of crystals on the basis of Curie’s Symmetry Principle, the grand organizing idea in the physical sciences to emerge in the latter half of the 19th Century. Optically Anomalous Crystals begins with an historical introduction covering the contributions of Brewster, Biot, Mallard, Brauns, Tamman, and many other distinguished crystallographers. From this follows a tutorial in crystal optics. Further chapters discuss the two main mechanisms of optical dissymmetry: 1. the piezo-optic effect, and 2. the kinetic ordering of atoms. The text then tackles complex, inhomogeneous crystals, and...

  9. Quantum optics

    Energy Technology Data Exchange (ETDEWEB)

    Drummond, P D [University of Queensland, St. Lucia, QLD (Australia).Physics Department

    1999-07-01

    Full text: Quantum optics in Australia has been an active research field for some years. I shall focus on recent developments in quantum and atom optics. Generally, the field as a whole is becoming more and more diverse, as technological developments drive experiments into new areas, and theorists either attempt to explain the new features, or else develop models for even more exotic ideas. The recent developments include quantum solitons, quantum computing, Bose-Einstein condensation, atom lasers, quantum cryptography, and novel tests of quantum mechanics. The talk will briefly cover current progress and outstanding problems in each of these areas. Copyright (1999) Australian Optical Society.

  10. Development of optical sciences in Poland

    Science.gov (United States)

    Romaniuk, Ryszard S.

    2013-10-01

    Research and technical communities for optics, photonics and optoelectronics is grouped in this country in several organizations and institutions. These are: Photonics Society of Poland (PSP), Polish Committee of Optoelectronics of SEP, Photonics Section of KEiT PAN, Laser Club at WAT, and Optics Section of PTF. Each of these communities keeps slightly different specificity. PSP publishes a quarterly journal Photonics Letters of Poland, stimulates international cooperation, and organizes conferences during Industrial Fairs on Innovativeness. PKOpto SEP organizes didactic diploma competitions in optoelectronics. KEiT PAN takes patronage over national conferences in laser technology, optical fiber technology and communications, and photonics applications. SO-PTF has recently taken a decision to organize a cyclic event "Polish Optical Conference". The third edition of this conference PKO'2013 was held in Sandomierz on 30.06-04.07.2013. The conference scientific and technical topics include: quantum and nonlinear optics, photon physics, optic and technology of lasers and other sources of coherent radiation, optoelectronics, optical integrated circuits, optical fibers, medical optics, instrumental optics, optical spectroscopy, optical metrology, new optical materials, applications of optics, teaching in optics. This paper reviews chosen works presented during the III Polish Optical Conference (PKO'2013), representing the research efforts at different national institutions.

  11. Fiber optic strain measurements using an optically-active polymer

    Science.gov (United States)

    Buckley, Leonard J.; Neumeister, Gary C.

    1992-03-01

    A study encompassing the use of an optically-active polymer as the strain-sensing medium in an organic matrix composite was performed. Several compounds were synthesized for use as the inner cladding material for silica fiber-optic cores. These materials include a diacetylene containing polyamide. It is possible to dynamically modify the optical properties of these materials through changes in applied strain or temperature. By doing so the characteristic absorption in the visible is reversibly shifted to a higher energy state. The polymer-coated fiber-optic cores were initially studied in epoxy resin. Additionally, one of the polyamide/diacetylene polymers was studied in a spin-fiber form consisting of 15 micron filaments assembled in multifilament tows. The most promising configuration and materials were then investigated further by embedding in graphite/epoxy composite laminates. In each case the shift in the visible absorption peak was monitored as a function of applied mechanical strain.

  12. Optical Axis Identification Technique for Free Space Optics Transmission

    Directory of Open Access Journals (Sweden)

    Yuki Tashiro

    2017-07-01

    Full Text Available This paper describes optical axis adjustment technique for an active free space optics transmission system. This system precisely controls the direction of a collimated thin laser beam using a motor driven laser emitting mechanism and positioning photodiodes. Before beginning laser beam feedback control, it is required to guide the laser beam within the range of the positioning photodiodes for initial laser beam alignment. This paper proposes an arrival position presumption method of laser beam traveling along the long distance from transmitter. A positioning sensor containing several photodiodes measures laser luminescence distribution, and analytically calculates the optical axis of laser beam according to the modified Gaussian beam optics based on four or five distributed local intensity of laser luminescence. Experiments are conducted to evaluate the accuracy of the presumption, and results reveal that the method is effective in leading the laser beam onto a distant receiver.

  13. Optical metamaterials with quasicrystalline symmetry: symmetry-induced optical isotropy

    International Nuclear Information System (INIS)

    Kruk, S.S.; Decker, M.; Helgert, Ch.; Neshev, D.N.; Kivshar, Y.S.; Staude, I.; Powell, D.A.; Pertsch, Th.; Menzel, Ch.; Helgert, Ch.; Etrich, Ch.; Rockstuhl, C.; Menzel, Ch.

    2013-01-01

    Taking advantage of symmetry considerations, we have analyzed the potential of various metamaterials to affect the polarization state of light upon oblique illumination. We have shown that depending on the angle of illumination, metamaterials are able to support specific polarization states. The presented methodology that using ellipticity and circular dichroism, provides an unambiguous language for discussing the impact of the inherent symmetry of the metamaterial lattices on their far-field response. Our findings allow the quantification analysis of the impact of inter-element coupling and lattice symmetry on the optical properties of metamaterials, and to separate this contribution from the response associated with a single meta-atom. In addition, we have studied the concept of optical quasicrystalline metamaterials, revealing that the absence of translational symmetry (periodicity) of quasicrystalline metamaterials causes an isotropic optical response, while the long-range positional order preserves the resonance properties. Our findings constitute an important step towards the design of optically isotropic metamaterials and metasurfaces. (authors)

  14. Remote nano-optical beam focusing lens by illusion optics

    Science.gov (United States)

    Margousi, David; Shoorian, Hamed Reza

    2014-08-01

    In this paper, as a new application of illusion optics, a nano-optical plasmonic focusing lens structure is proposed to manipulate the light remotely by employing illusion optics theory. Plasmonic nano-optic lenses that enable super-focusing beyond the diffraction limit have been proposed as an alternative to the conventional dielectric-based refractive lenses. In the presence of an illusion device, the electromagnetic plane-waves can penetrate into a metal layer and a clear focus appears. When the illusion device is removed, waves are blocked to transmit through the metal wall. In comparison with conventional methods, our proposed method avoids any physical changes or damages in the original structure. The proposed structure can be realized by isotropic layered materials, using effective medium theory. The special feature of the proposed structure and the device concepts introduced in this work gives it an opportunity to be used as a flexible element in ultrahigh nano-scale integrated circuits for miniaturization and tuning purposes.

  15. OPTIMASI BANDWITH MENGGUNAKAN TRAFFIC SHAPPING

    Directory of Open Access Journals (Sweden)

    Imam Riadi

    2010-01-01

    Full Text Available Perkembangan layanan komunikasi telah berkembang sangat pesat. Salah satunya adalah pemanfaatan penggunaan bandwith untuk mengakases jaringan Internet. Traffic shapping bandwidth dapat memberikan efesiensi dalam hal pemanfaatan bandwidth pada instansi yang melakukan manajemen dalam lalulintas jaringannya. Metode yang digunakan dalam penelitian ini adalah metode literatur yaitu metode pengumpulan data yang dilakukan dengan mengumpulkan sumber- sumber data yang terkait dan metode eksperimen yaitu melakukan penelitian dengan mengkonfigurasi Mikrotik RouterOS untuk melakukan traffic shapping bandwidth. Hasil penelitian ini adalah router yang dapat melakukan traffic shapping sehingga kualitas koneksi menjadi lebih baik untuk mengakses dan mengambil data dari sebuah website. Kata kunci : Optimasi, Bandwith, Traffic Shapping, MikroTik. 

  16. OPTICAL FIBRES AND FIBREOPTIC SENSORS: Polarisation reflectometry of anisotropic optical fibres

    Science.gov (United States)

    Konstantinov, Yurii A.; Kryukov, Igor'I.; Pervadchuk, Vladimir P.; Toroshin, Andrei Yu

    2009-11-01

    Anisotropic, polarisation-maintaining fibres have been studied using a reflectometer and integrated optic polariser. Linearly polarised pulses were launched into the fibre under test at different angles between their plane of polarisation and the main optical axis of the fibre. A special procedure for the correlation analysis of these reflectograms is developed to enhance the reliability of the information about the longitudinal optical uniformity ofanisotropic fibres.

  17. Advanced optical instruments technology

    Science.gov (United States)

    Shao, Mike; Chrisp, Michael; Cheng, Li-Jen; Eng, Sverre; Glavich, Thomas; Goad, Larry; Jones, Bill; Kaarat, Philip; Nein, Max; Robinson, William

    1992-08-01

    The science objectives for proposed NASA missions for the next decades push the state of the art in sensitivity and spatial resolution over a wide range of wavelengths, including the x-ray to the submillimeter. While some of the proposed missions are larger and more sensitive versions of familiar concepts, such as the next generation space telescope, others use concepts, common on the Earth, but new to space, such as optical interferometry, in order to provide spatial resolutions impossible with other concepts. However, despite their architecture, the performance of all of the proposed missions depends critically on the back-end instruments that process the collected energy to produce scientifically interesting outputs. The Advanced Optical Instruments Technology panel was chartered with defining technology development plans that would best improve optical instrument performance for future astrophysics missions. At this workshop the optical instrument was defined as the set of optical components that reimage the light from the telescope onto the detectors to provide information about the spatial, spectral, and polarization properties of the light. This definition was used to distinguish the optical instrument technology issues from those associated with the telescope, which were covered by a separate panel. The panel identified several areas for optical component technology development: diffraction gratings; tunable filters; interferometric beam combiners; optical materials; and fiber optics. The panel also determined that stray light suppression instruments, such as coronagraphs and nulling interferometers, were in need of general development to support future astrophysics needs.

  18. Dynamic optical arbitrary waveform shaping based on cascaded optical modulators of single FBG.

    Science.gov (United States)

    Chen, Jingyuan; Li, Peili

    2015-08-10

    A dynamic optical arbitrary waveform generation (O-AWG) with amplitude and phase independently controlled in optical modulators of single fiber Bragg Grating (FBG) has been proposed. This novel scheme consists of several optical modulators. In the optical modulator (O-MOD), a uniform FBG is used to filter spectral component of the input signal. The amplitude is controlled by fiber stretcher (FS) in Mach-Zehnder interference (MZI) structure through interference of two MZI arms. The phase is manipulated via the second FS in the optical modulator. This scheme is investigated by simulation. Consequently, optical pulse trains with different waveforms as well as pulse trains with nonuniform pulse intensity, pulse spacing and pulse width within each period are obtained through FSs adjustment to alter the phase shifts of signal in each O-MOD.

  19. 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...

  20. Improving fiber-optic laser beam delivery by incorporating GRADIUM optics

    International Nuclear Information System (INIS)

    Hunter, B.V.; Leong, K.H.

    1997-01-01

    The performance of a fiber-optic laser beam delivery system strongly depends on the fiber and the optics used to image the fiber face on the workpiece. We have compared off-the-shelf homogenous (BK7) and GRADIUM (axial-gradient) singlets to determine what improvement the GRADIUM offers in practice to the typical laser user. The realized benefit for this application, although significant, is much smaller than would be realized by a conventional imaging application. The figure of merit for laser-based materials processing is the 86% energy-enclosure radius, which is not directly supported by commerical ray-tracing software. Therefore empirical rules of thumb are presented to understand when GRADIUM (or any other well-corrected optics) will yield meaningful improvement to the beam delivery system. copyright 1997 Optical Society of America