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Sample records for beamlet optical switch

  1. Design and performance of the beamlet optical switch

    Energy Technology Data Exchange (ETDEWEB)

    Rhodes, M.A.; Woods, B.W.; DeYoreo, J.J. [and others

    1996-06-01

    High-energy lasers for Inertial Confinement Fusion (ICF) experiments are typically designed with large apertures (>30 cm) to keep the fluence below the damage threshold of the various optical components. Until recently, no optical switch technology could be scaled to the aperture size, aperture shape (square), and switching speed required for the next generation of ICF drivers. This step is critical: The Beamlet multipass amplifier cavity uses a full-aperture optical switch to trap the laser pulse within the cavity and to divert the pulse out of the cavity when it reaches the required energy. By rotating the polarization of the beam, a Pockels cell in the switch controls whether the beam is transmitted through, or reflected from, the polarizer. In this article the authors describe an optical switch technology that does scale to the required aperture size and shape for Beamlet and the porposed National Ignition Facility (NIF) laser, and can employ a thin crystal. This switch consists of a thin-film polarizer and a plasma-electrode Pockels cell (PEPC), the latter originally invented at Lawrence Livermore National Laboratory (LLNL) in the 1980s and under further development since 1991. After discussing the PEPC concept, they present the design and optical performance of a 32 x 32 cm{sup 2} prototype PEPC, including discussions of the crystals, the PEPC assembly, the vacuum and gas system, and the high-voltage pulsers. Then they describe the performance of the 37 x 37 cm{sup 2} PEPC construced specifically for the Beamlet laser. Finally, they discuss important technology issues that arose during PEPC development: cathode sputtering, cathode heating, nonuniformities in the switching profile, switch-pulse leakage current, and an estimate of the plasma density and temperature produced during PEPC operation.

  2. Large-aperture, high-damage-threshold optics for beamlet

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.H.; Atherton, L.J.; DeYoreo, J.J. [and others

    1996-06-01

    Beamlet serves as a test bed for the proposed National Ignition Facility (NIF) laser design and components. Therefore, its optics are similar in size and quality to those proposed for the NIF. In general, the optics in the main laser cavity and transport section of Beamlet are larger and have higher damage thresholds than the optics manufactured for any of the previous laser systems. In addition, the quality of the Beamlet optical materials is higher, leading to better wavefront quality, higher optical transmission, and lower-intensity modulation of the output laser beam than, for example, that typically achieved on Nova. In this article, the authors discuss the properties and characteristics of the large-aperture optics used on Beamlet.

  3. Performance modeling of Beamlet

    Energy Technology Data Exchange (ETDEWEB)

    Auerbach, J.M.; Lawson, J.K.; Rotter, M.D.; Sacks, R.A.; Van Wonterghem, B.W.; Williams, W.H.

    1995-06-27

    Detailed modeling of beam propagation in Beamlet has been made to predict system performance. New software allows extensive use of optical component characteristics. This inclusion of real optical component characteristics has resulted in close agreement between calculated and measured beam distributions.

  4. 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.

  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...... are often considered as a part of the optical cross-connect, where also optical space switching is performed. Therefore, space switching based on both optical gates and interferometric switches is investigated. Moreover, an experiment including both space switching and wavelength conversion is carried out...

  6. Beamlet focal plane diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Caird, J.A.; Nielsen, N.D.; Patton, H.G.; Seppala, L.G.; Thompson, C.E.; Wegner, P.J.

    1996-12-01

    This paper describes the major optical and mechanical design features of the Beamlet Focal Plane Diagnostic system as well as measurements of the system performance, and typical data obtained to date. We also discuss the NIF requirements on the focal spot that we are interested in measuring, and some of our plans for future work using this system.

  7. Optical packet switched networks

    DEFF Research Database (Denmark)

    Hansen, Peter Bukhave

    1999-01-01

    Optical packet switched networks are investigated with emphasis on the performance of the packet switch blocks. Initially, the network context of the optical packet switched network is described showing that a packet network will provide transparency, flexibility and bridge the granularity gap...... between the electrical switched layer and the WDM transport layer. Analytical models are implemented to determine the signal quality ghrough the switch blocks in terms of power penalty and to assess the traffic performance of different switch block architectures. Further, a computer simulation model...... is used to investigate the influence on the traffic performance of asynchronous operation of the switch blocks. The signal quality investigation illustrates some of the component requirements in respect to gain saturation in SOA gates and crosstalk in order to obtain high cascadability of the switch...

  8. Optical packet switching

    Science.gov (United States)

    Shekel, Eyal; Ruschin, Shlomo; Majer, Daniel; Levy, Jeff; Matmon, Guy; Koenigsberg, Lisa; Vecht, Jacob; Geron, Amir; Harlavan, Rotem; Shfaram, Harel; Arbel, Arnon; McDermott, Tom; Brewer, Tony

    2005-02-01

    We report here a scalable, multichassis, 6.3 terabit core router, which utilizes our proprietary optical switch. The router is commercially available and deployed in several customer sites. Our solution combines optical switching with electronic routing. An internal optical packet switching network interconnects the router"s electronic line cards, where routing and buffering functions take place electronically. The system architecture and performance will be described. The optical switch is based on Optical Phased Array (OPA) technology. It is a 64 x 64, fully non-blocking, optical crossbar switch, capable of switching in a fraction of a nanosecond. The basic principles of operation will be explained. Loss and crosstalk results will be presented, as well as the results of BER measurements of a 160 Gbps transmission through one channel. Basic principles of operation and measured results will be presented for the burst-mode-receivers, arbitration algorithm and synchronization. Finally, we will present some of our current research work on a next-generation optical switch. The technological issues we have solved in our internal optical packet network can have broad applicability to any global optical packet network.

  9. Optical switching device

    NARCIS (Netherlands)

    Broeder, F.J.A. den; Hanzen, R.M.N.; Duine, P.A.; Jungblut, R.M.; Draijer, C.; Roozeboom, F.; Sluis, P. van der

    2000-01-01

    A description is given of an optical switching device (1) comprising a transparent substrate (3), a switching film (5) of a hydride compound of a trivalent transition or rare earth metal having a thickness of 300 nm, and a palladium capping layer (7) having a thickness of 30 nm. The capping layer is

  10. Optical Packet Switching Demostrator

    DEFF Research Database (Denmark)

    Mortensen, Brian Bach; Berger, Michael Stübert

    2002-01-01

    In the IST project DAVID (data and voice integration over DWDM) work is carried out defining possible architectures of future optical packet switched networks. The feasibility of the architecture is to be verified in a demonstration set-up. This article describes the demonstrator set-up and the m......In the IST project DAVID (data and voice integration over DWDM) work is carried out defining possible architectures of future optical packet switched networks. The feasibility of the architecture is to be verified in a demonstration set-up. This article describes the demonstrator set...

  11. Micron-focused ion beamlets

    Science.gov (United States)

    Chowdhury, Abhishek; Bhattacharjee, Sudeep

    2010-05-01

    A multiple beam electrode system (MBES) is used to provide focused ion beamlets of elements from a compact microwave plasma. In this study, a honeycomb patterned plasma electrode with micron size apertures for extracting ion beamlets is investigated. The performance of the MBES is evaluated with the help of two widely adopted and commercially available beam simulation tools, AXCEL-INP and SIMION, where the input parameters are obtained from our experiments. A simple theoretical model based upon electrostatic ray optics is employed to compare the results of the simulations. It is found that the results for the beam focal length agree reasonably well. Different geometries are used to optimize the beam spot size and a beam spot ˜5-10 μm is obtained. The multiple ion beamlets will be used to produce microfunctional surfaces on soft matter like polymers. Additionally, the experimental set-up and plans are presented in the light of above applications.

  12. Beamlet laser diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Burkhart, S.C.; Behrendt, W.C.; Smith, I.

    1996-06-01

    Beamlet is instrumented extensively to monitor the performance of the overall laser system and many of its subsystems. Beam diagnostics, installed in key locations, are used to fully characterize the beam during its propagation through the multipass cavity and the laser`s output section. This article describes the diagnostics stations located on Beamlet and discusses the design, calibration, and performance of the Beamlet calorimeters. The authors used Nova`s diagnostics packages to develop the Beamlet design to determine beam energy, spatial profile, temporal profile, and other beam parameters. Technologic improvements within the last several years in controls, charge-coupled device (CCD) cameras, and fast oscilloscopes have allowed the authors to obtain more accurate measurements on the Beamlet laser system. They briefly cover some of these techniques, including a description of their LabVIEW based data acquisition system.

  13. Beamlet pulsed-power system

    Energy Technology Data Exchange (ETDEWEB)

    Larson, D.

    1996-06-01

    The 13-MJ Beamlet pulsed-power system provides power to the 512 flash lamps in the cavity and booster amplifiers. Since the flash lamps pump all of the apertures in the 2 x 2 amplifier array, the capacitor bank provides roughly four times the energy required to pump the single active beam line. During the 40 s prior to the shot, the capacitors are charged by constant-current power supplies. Ignitron switches transfer the capacitor energy to the flash lamps via coaxial cables. A preionization system triggers the flash lamps and delivers roughly 1 % of the capacitor energy 200 {mu}s prior to the main discharge. This is the first time flash-lamp preionization has been used in a large facility. Preionization improves the amplifier efficiency by roughly 5% and increases the lifetime of the flash lamps. LabVIEW control panels provide an operator interface with the modular controls and diagnostics. To improve the reliability of the system, high-energy-density, self-healing, metallized dielectric capacitors are used. High-frequency, voltage-regulated switching power supplies are integrated into each module on Beamlet, allowing greater independence among the modules and improved charge voltage accuracy, flexibility, and repeatability.

  14. Key Technologies for Optical Packet Switching

    Institute of Scientific and Technical Information of China (English)

    Akira; Okada

    2003-01-01

    The paper describes our recent progress on key technologies and components for realizing optical packet switching, including an out-of-band optical label switching technique, an optical packet synchronizer and a burst-mode optical receiver.

  15. Key Technologies for Optical Packet Switching

    Institute of Scientific and Technical Information of China (English)

    Akira Okada

    2003-01-01

    The paper describes our recent progress on key technologies and components for realizing optical packet switching,including an out-of-band optical label switching technique, an optical packet synchronizer and a burst-mode optical receiver.

  16. Low power all optical switches

    Institute of Scientific and Technical Information of China (English)

    Alireza Bananej; LI Chun-fei 李淳飞

    2004-01-01

    In this paper, we propose a new design of all fiber optical switches by using a high finesse ring resonator (RR) side coupled Mach-Zehnder interferometer. We will show that by compensating the total loss in the RR the switching power can be decreased greatly and by loss, compensating the bistability effect in RR can be cancelled and the switching performance can be improved. In addition, we will show that by using Erbium doped fiber for fabricating the RR we can obtain switching power threshold in mW range.

  17. Modeling beam propagation and frequency conversion for the beamlet laser

    Energy Technology Data Exchange (ETDEWEB)

    Auerbach, J.M.

    1996-06-01

    The development of the Beamlet laser has involved extensive and detailed modeling of laser performance and beam propagation to: (1) predict the performance limits of the laser, (2) select system configurations with higher performance, (3) analyze experiments and provide guidance for subsequent laser shots, and (4) design optical components and establish component manufacturing specifications. In contrast to modeling efforts of previous laser systems such as Nova, those for Beamlet include as much measured optical characterization data as possible. This article concentrates on modeling of beam propagation in the Beamlet laser system, including the frequency converter, and compares modeling predictions with experimental results for several Beamlet shots. It briefly describes the workstation-based propagation and frequency conversion codes used to accomplish modeling of the Beamlet.

  18. Design and performance of the beamlet amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Erlandson, A.C.; Rotter, M.D.; Frank, M.D.; McCracken, R.W.

    1996-06-01

    In future laser systems, such as the National Ignition Facility (NIF), multi-segment amplifiers (MSAs) will be used to amplify the laser beam to the required levels. As a prototype of such a laser architecture, the authors have designed, built, and tested flash-lamp-pumped, Nd:Glass, Brewster-angle slab MSAs for the Beamlet project. In this article, they review the fundamentals of Nd:Glass amplifiers, describe the MSA geometry, discuss parameters that are important in amplifier design, and present our results on the characterization of the Beamlet MSAs. In particular, gain and beam steering measurements show that the Beamlet amplifiers meet all optical performance specifications and perform close to model predictions.

  19. 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.

  20. A Demonstration of Automatically Switched Optical Network

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    We build an automatically switched optical network (ASON) testbed with four optical cross-connect nodes. Many fundamental ASON features are demonstrated, which is implemented by control protocols based on generalized multi-protocol label switching (GMPLS) framework.

  1. Multi-beamlet investigation of the deflection compensation methods of SPIDER beamlets

    Energy Technology Data Exchange (ETDEWEB)

    Baltador, C., E-mail: carlo.baltador@igi.cnr.it; Veltri, P.; Agostinetti, P.; Chitarin, G.; Serianni, G. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete S.p.A), Corso Stati Uniti, 4, 35127 Padova (Italy)

    2016-02-15

    SPIDER (Source for Production of Ions of Deuterium Extracted from a Rf plasma) is an ion source test bed designed to extract and accelerate a negative ion current up to 40 A and 100 kV whose first beam is expected by the end of 2016. Two main effects perturb beamlet optics during the acceleration stage: space charge repulsion and the deflection induced by the permanent magnets (called co-extracted electron suppression magnets) embedded in the EG. The purpose of this work is to evaluate and compare benefits, collateral effects, and limitations of electrical and magnetic compensation methods for beamlet deflection. The study of these methods has been carried out by means of numerical modeling tools: multi-beamlet simulations have been performed for the first time.

  2. Multi-beamlet investigation of the deflection compensation methods of SPIDER beamlets

    Science.gov (United States)

    Baltador, C.; Veltri, P.; Agostinetti, P.; Chitarin, G.; Serianni, G.

    2016-02-01

    SPIDER (Source for Production of Ions of Deuterium Extracted from a Rf plasma) is an ion source test bed designed to extract and accelerate a negative ion current up to 40 A and 100 kV whose first beam is expected by the end of 2016. Two main effects perturb beamlet optics during the acceleration stage: space charge repulsion and the deflection induced by the permanent magnets (called co-extracted electron suppression magnets) embedded in the EG. The purpose of this work is to evaluate and compare benefits, collateral effects, and limitations of electrical and magnetic compensation methods for beamlet deflection. The study of these methods has been carried out by means of numerical modeling tools: multi-beamlet simulations have been performed for the first time.

  3. Ultrafast photonic crystal optical switching

    Institute of Scientific and Technical Information of China (English)

    GONG Qi-huang; HU Xiao-yong

    2006-01-01

    Photonic crystal,a novel and artificial photonic material with periodic dielectric distribution,possesses photonic bandgap and can control the propagation states of photons.Photonic crystal has been considered to be a promising candidate for the future integrated photonic devices.The properties and the fabrication method of photonic crystal are expounded.The progresses of the study of ultrafast photonic crystal optical switching are discussed in detail.

  4. Image edge detection based on beamlet transform

    Institute of Scientific and Technical Information of China (English)

    Li Jing; Huang Peikang; Wang Xiaohu; Pan Xudong

    2009-01-01

    Combining beamlet transform with steerable filters, a new edge detection method based on line gra-dient is proposed. Compared with operators based on point local properties, the edge-detection results with this method achieve higher SNR and position accuracy, and are quite helpful for image registration, object identification, etc. Some edge-detection experiments on optical and SAR images that demonstrate the significant improvement over classical edge operators are also presented. Moreover, the template matching result based on edge information of optical reference image and SAR image also proves the validity of this method.

  5. Optical packet switching without packet alignment

    DEFF Research Database (Denmark)

    Hansen, Peter Bukhave; Danielsen, Søren Lykke; Stubkjær, Kristian

    1998-01-01

    Operation without packet alignment of an all-optical packet switch is proposed and predicted feasible through a detailed traffic analysis. Packet alignment units are eliminated resulting in a simple switch architecture while optimal traffic performance is maintained through the flexibility provided...

  6. Nonlinear interface optical switch structure for dual mode switching revisited

    Science.gov (United States)

    Bussjager, Rebecca J.; Osman, Joseph M.; Chaiken, Joseph

    1998-07-01

    There is a need for devices which will allow integration of photonic/optical computing subsystems into electronic computing architectures. This presentation reviews the nonlinear interface optical switch (NIOS) concept and then describes a new effect, the erasable optical memory (EOM) effect. We evaluate an extension of the NIOS device to allow simultaneous optical/electronic, i.e. dual mode, switching of light utilizing the EOM effect. Specific devices involve the fabrication of thin film tungsten (VI) oxide (WO3) and tungsten (V) oxide (W2O5) on the hypotenuse of glass (BK-7), fused silica (SiO2) and zinc selenide (ZnSe) right angle prisms. Chemical reactions and temporal response tests were performed and are discussed.

  7. Isolation of Integrated Optical Acousto-Optic Switch

    Institute of Scientific and Technical Information of China (English)

    XIAO Li-Feng; LIU Ying; WANG Wei-Peng; GENG Fan

    2006-01-01

    @@ Isolation of a new structured acousto-optic switch based on an integrated optical polarization-independent quasicollinear acousto-optic tunable filter is studied in detail. The factors that influence the isolation of the optical switch are analysed, the expressions of the isolation are educed, and the isolation of the device is measured in experiment. It is found that the isolation mainly depends on the TE/TM mode intensity ratio, the mode-splitter extinction rate, and the conversion efficiency.

  8. United assembly algorithm for optical burst switching

    Institute of Scientific and Technical Information of China (English)

    Jinhui Yu(于金辉); Yijun Yang(杨教军); Yuehua Chen(陈月华); Ge Fan(范戈)

    2003-01-01

    Optical burst switching (OBS) is a promising optical switching technology. The burst assembly algorithm controls burst assembly, which significantly impacts performance of OBS network. This paper provides a new assembly algorithm, united assembly algorithm, which has more practicability than conventional algorithms. In addition, some factors impacting selections of parameters of this algorithm are discussed and the performance of this algorithm is studied by computer simulation.

  9. Hybrid Optical Switching for Data Center Networks

    Directory of Open Access Journals (Sweden)

    Matteo Fiorani

    2014-01-01

    Full Text Available Current data centers networks rely on electronic switching and point-to-point interconnects. When considering future data center requirements, these solutions will raise issues in terms of flexibility, scalability, performance, and energy consumption. For this reason several optical switched interconnects, which make use of optical switches and wavelength division multiplexing (WDM, have been recently proposed. However, the solutions proposed so far suffer from low flexibility and are not able to provide service differentiation. In this paper we introduce a novel data center network based on hybrid optical switching (HOS. HOS combines optical circuit, burst, and packet switching on the same network. In this way different data center applications can be mapped to the optical transport mechanism that best suits their traffic characteristics. Furthermore, the proposed HOS network achieves high transmission efficiency and reduced energy consumption by using two parallel optical switches. We consider the architectures of both a traditional data center network and the proposed HOS network and present a combined analytical and simulation approach for their performance and energy consumption evaluation. We demonstrate that the proposed HOS data center network achieves high performance and flexibility while considerably reducing the energy consumption of current solutions.

  10. Micro electro mechanical system optical switching

    Science.gov (United States)

    Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J

    2013-12-17

    The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

  11. Vertically Integrated Thermo-Optic Waveguide Switch Using Optical Polymers

    Institute of Scientific and Technical Information of China (English)

    Ki-Hong; Kim; Sang-Yung; Shin; Doo-Sun; Choi

    2003-01-01

    We propose and fabricate a vertically integrated thermo-optic waveguide switch. It controls the optical path between two vertically stacked waveguides using the thermo-optic effect of optical polymer. The measured crosstalk is less than -10 dB.

  12. Vertically Integrated Thermo-Optic Waveguide Switch Using Optical Polymers

    Institute of Scientific and Technical Information of China (English)

    Ki-Hong Kim; Sang-Yung Shin; Doo-Sun Choi

    2003-01-01

    We propose and fabricate a vertically integrated thermo-optic waveguide switch. It controls the optical path between two vertically stacked waveguides using the thermo-optic effect of optical polymer. The measured crosstalk is less than-10 dB.

  13. 160-Gb/s Silicon All-Optical Packet Switch for Buffer-less Optical Burst Switching

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Pu, Minhao;

    2015-01-01

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

  14. Amalgamation of interacting light beamlets in Kerr-type media

    DEFF Research Database (Denmark)

    Christiansen, Peter Leth; Rasmussen, Kim; Berge, L;

    1997-01-01

    The interaction of optical filaments in bulk self-focusing media is investigated theoretically and numerically. The nature of this interaction is shown to vary with the incident individual powers and relative phases of the beamlets. By means of virial arguments supported by numerical results it i...

  15. All-optical switching in optically induced nonlinear waveguide couplers

    Energy Technology Data Exchange (ETDEWEB)

    Diebel, Falko, E-mail: falko.diebel@uni-muenster.de; Boguslawski, Martin; Rose, Patrick; Denz, Cornelia [Institut für Angewandte Physik and Center for Nonlinear Science (CeNoS), Westfälische Wilhelms-Universität Münster, 48149 Münster (Germany); Leykam, Daniel; Desyatnikov, Anton S. [Nonlinear Physics Centre, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)

    2014-06-30

    We experimentally demonstrate all-optical vortex switching in nonlinear coupled waveguide arrays optically induced in photorefractive media. Our technique is based on multiplexing of nondiffracting Bessel beams to induce various types of waveguide configurations. Using double- and quadruple-well potentials, we demonstrate precise control over the coupling strength between waveguides, the linear and nonlinear dynamics and symmetry-breaking bifurcations of guided light, and a power-controlled optical vortex switch.

  16. Optical Packet Switching Scheme Using Multi-optical-code Labels

    Institute of Scientific and Technical Information of China (English)

    LI Shu-wen; ZHANG Qi; YU Chong-xiu; XIN Xiang-jun; XIONG Fei

    2009-01-01

    Proposed is a novel optical code(OC) label switching scheme in which an optical label is constructed by multiple parallel optical codes. The performances of splitting loss and BER are simulated and analyzed. Simulation results show that the proposed label can be correctly recognized to perform packet switching. Compared with reported schemes using one OC as a label, the splitting loss in our proposal is lowered.

  17. 160-Gb/s Silicon All-Optical Packet Switch for Buffer-less Optical Burst Switching

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Pu, Minhao

    2015-01-01

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

  18. Evaluation of laser diode based optical switches for optical processors

    Science.gov (United States)

    Swanson, Paul D.; Parker, Michael A.; Libby, Stuart I.

    1993-07-01

    Three optical switching elements have been designed, fabricated, and tested for use in an integrated, optical signal processor. The first, an optical NOR logic gate, uses gain quenching as a means of allowing one (or more) light beam(s) to control the output light. This technique, along with the use of a two pad bistable output laser, is used in demonstrating the feasibility of the second device, an all optical RS flip flop. The third device consists of a broad area orthogonal model switching laser, whose corollary outputs correspond to the sign of the voltage difference between its two high impedance electrical inputs. This device also has possible memory applications if bistable mode switching within the broad area laser can be achieved.

  19. Node design in optical packet switched networks

    DEFF Research Database (Denmark)

    Nord, Martin

    2006-01-01

    The thesis discusses motivation, realisation and performance of the Optical Packet Switching (OPS) network paradigm. The work includes proposals for designs and methods to efficiently use both the wavelength- and time domain for contention resolution in asynchronous operation. The project has also...... adapting network performance to the different acceptable packet loss rate levels of supported applications, while improving overall bandwidth efficiency. The project has evaluated QoS differentiation methods and proposed schemes with improved efficiency, which also include jitter sensitivity as a Qo...... proposed parallel designs to overcome scalability constraints and to support migration scenarios. Furthermore, it has proposed and demonstrated optical input processing schemes for hybrids networks to simultaneously support OPS and Optical Circuit Switching. Quality of Service (QoS) differentiation enables...

  20. Design and Simulation of Routing-switching Protocol Based on Optical Switch Array

    Institute of Scientific and Technical Information of China (English)

    HE Wei; MAO You-ju; LIU Jiang

    2004-01-01

    An optical routing- switching technology based on optical switch array is proposed. The characteristics of the blocking and nonblocking networks are analyzed and compared, odd- even sorting network is used to realize optical routing- switching, relative routing- switching protocol is designed.Simulation test under load shows that it can reduce a blocking effectively and enhance an efficiency of switching. Further, it can transfer the processing and switching within parallel computer from electric domain to optical domain. It can make parallel computer coordinating computing and processing at much more higher speed, storing and transmitting even more efficiently.

  1. Two Novel Structures of Optical Packet Switching Nodes

    Institute of Scientific and Technical Information of China (English)

    YIN Hongxi; XU Anshi; WU Deming

    2001-01-01

    All-optical packet switching networkis currently one of the research hotspots of all-opticalcommunication networks and optical packet switchingnodes are the key technique of optical packet switch-ing network. In this paper, two novel structures ofoptical packet switching nodes are put forward, and the switching capacity of the node and the packet con-tention resolution are analyzed. These two switchingarchitectures can realize wavelength routing switchingfunction and broadcast-and-select switching functionrespectively. They are simple but efficient for realizingoptical packet switching network.

  2. Research of high speed optical switch based on compound semiconductor

    Institute of Scientific and Technical Information of China (English)

    WANG MingHua; QI Wei; YU Hui; JIANG XiaoQing; YANG JianYi

    2009-01-01

    High-speed optical switch and its array are the crucial components of all-optical switching system. This paper presents the analytical model of a total-internal-reflection (TIR) optical switch. By employing the carrier injection effect in GaAs and the GaAs/AlGaAs double heterojunction structure, the X-junction TIR switch and the Mach-Zehnder interference (MZI) switch are demonstrated at 1.55 IJm. The measured results show that the extinction ratio of both switches exceeds 20 dB. The switching speed reaches the scale of 10 ns.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  4. All-optical devices for ultrafast packet switching

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  5. Nanofiber-based all-optical switches

    CERN Document Server

    Kien, Fam Le

    2016-01-01

    We study all-optical switches operating on a single four-level atom with the $N$-type transition configuration in a two-mode nanofiber cavity with a significant length (on the order of $20$ mm) and a moderate finesse (on the order of 300) under the electromagnetically induced transparency (EIT) conditions. In our model, the gate and probe fields are the quantum nanofiber-cavity fields excited by weak classical light pulses, and the parameters of the $D_2$ line of atomic cesium are used. We examine two different switching schemes. The first scheme is based on the effect of the presence of a photon in the gate mode on the EIT of the probe mode. The second scheme is based on the use of EIT to store a photon of the gate mode in the population of an appropriate atomic level, which leads to the reduction of the transmission of the field in the probe mode. We investigate the dependencies of the switching contrast on various parameters, such as the cavity length, the mirror reflectivity, and the detunings and powers ...

  6. Beamlet pulse-generation and wavefront-control system

    Energy Technology Data Exchange (ETDEWEB)

    Van Wonterghem, B.M.; Salmon, J.T.; Wilcox, R.W.

    1996-06-01

    The Beamlet pulse-generation system (or {open_quotes}front end{close_quotes}) refers to the laser hardware that generates the spatially and temporally shaped pulse that is injected into the main laser cavity. All large ICF lasers have pulse-generation systems that typically consist of a narrow-band oscillator, elector-optic modulators for temporal and bandwidth shaping, and one or more preamplifiers. Temporal shaping is used to provide the desired laser output pulse shape and also to compensate for gain saturation effects in the large-aperture amplifiers. Bandwidth is applied to fulfill specific target irradiation requirements and to avoid stimulated Brillouin scattering (SBS) in large-aperture laser components. Usually the sharp edge of the beam`s spatial intensity profile is apodized before injection in the main amplifier beam line. This prevents large-amplitude ripples on the intensity profile. Here the authors briefly review the front-end design and discuss improvements to the oscillator and modulator systems. Their main focus, however, is to describe Beamlet`s novel beam-shaping and wavefront-control systems that have recently been fully activated and tested.

  7. Analysis of a digital microstrip optical switch: a novel method

    Science.gov (United States)

    Al-Ruwaihi, Khalid M.; Hindy, Moataza A.

    1997-02-01

    A time domain analysis of an optically controlled digital microstrip switch for microwave integrated circuits on Si substrates is studied. A new model for high-frequency pulse propagation on a microstrip optical switch for different optical parameters is presented. A frequency-dependent macromodel for a microstrip line with a gap is implemented in Spice 3, taking into consideration high-frequency pulse dispersion, conductor and dielectric losses, metallization thickness, gap length, and different optical parameters such as optical energy, surface recombination velocities, and diffusion of generated carriers. In addition, the developed model has been used to optimize the switching frequency, gap length, level of optical power, and suitable substrate material parameters.

  8. Analysis of a digital microstrip optical switch: a novel method.

    Science.gov (United States)

    Al-Ruwaihi, K M; Hindy, M A

    1997-02-20

    A time domain analysis of an optically controlled digital microstrip switch for microwave integrated circuits on Si substrates is studied. A new model for high-frequency pulse propagation on a microstrip optical switch for different optical parameters is presented. A frequency-dependent macromodel for a microstrip line with a gap is implemented in Spice 3, taking into consideration high-frequency pulse dispersion, conductor and dielectric losses, metallization thickness, gap length, and different optical parameters such as optical energy, surface recombination velocities, and diffusion of generated carriers. In addition, the developed model has been used to optimize the switching frequency, gap length, level of optical power, and suitable substrate material parameters.

  9. Performance analysis of a scalable optical packet switching architecture

    Science.gov (United States)

    Wu, Ho-Ting; Tuan, Chia-Wei

    2010-10-01

    We carry out the analysis of a scalable switching architecture for all-optical packet switching networks. The underlying switch is based on a 2×2 two-stage multibuffer switched delay-line-based optical switching node. By incorporating an additional bypass line and employing a novel switch control strategy, the optical packet switching node can effectively resolve packet contentions, thus reducing the packet deflection probability substantially. In this work, we develop an exact queueing model from a discrete time Markov chain (DTMC) to evaluate the system performance under bursty, nonbursty, symmetric, and asymmetric traffic conditions. The accurate deflection probability and mean packet delay are obtained from this analytical model. Furthermore, we derive an approximate analysis to calculate the lower bound of deflection probability without the heavy computational complexities incurred by the exact analytical model. Simulation results are performed to confirm the validity of our analytic models.

  10. Variable time-period optical switching: a novel OBS implementation

    Institute of Scientific and Technical Information of China (English)

    Jinsong Zhang(张劲松); Mingcui Cao(曹明翠); Fengguang Luo(罗风光); Tao Chen(陈涛)

    2003-01-01

    In this paper, we proposed a novel optical switching method based on optical burst switching (OBS), we call it variable time-period optical switching (VTPOS). It can both support circuit services and other immerged packet services. It has better usability of bandwidth, shorter offset and latency time than others of unidirectional transport signaling mechanisms for OBS. It supports deflection switching for improve blocking performance without the need of schedule buffer. It introduces a time pointer and phase indicator that made synchronous more precisely and requires less guard time, it also classifies the different services classes with a relative QoS model.

  11. Design of multimode interference optical switches with area modulation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Based on the self-imaging effect, multimode interference (MMI) optical switches with area modulation were proposed. The field transfer matrix was introduced to analyze the MMI switches. As an example, the phase modulation parameters of a 3 × 3 MMI switch for different switching cases were obtained by solving the field transfer equation. And the finite-difference beam propagation method (FD-BPM) was used to confirm the analytical results.

  12. 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

  13. Novel polarization diversity without switch duplication of a Si-wire PILOSS optical switch.

    Science.gov (United States)

    Tanizawa, Ken; Suzuki, Keijiro; Ikeda, Kazuhiro; Namiki, Shu; Kawashima, Hitoshi

    2016-04-04

    We demonstrate the compact polarization diversity based on the bidirectional full-port use of a path-independent-insertion-loss (PILOSS) optical switch. A polarization-diversity 4 × 4 strictly non-blocking optical switch is developed using a single thermooptic PILOSS Si-wire switch and fiber-based polarization beam splitters (PBSs) and combiners (PBCs). We measure characteristics of the switch and confirm that the proposed configuration demonstrates the performance in the insertion loss, polarization-dependent loss (PDL), and differential group delay (DGD) comparable with that of a conventional polarization-diversity 4 × 4 PILOSS switch using double switch elements. On the other hand, higher crosstalk is observed. The crosstalk increase is associated with the backward crosstalk at a waveguide intersection based on a directional coupler. The effect of the backward crosstalk on the total crosstalk is estimated, and future prospects are discussed.

  14. DESIGN OF AN ARRAYED WAVEGUIDE GRATINGS BASED OPTICAL PACKET SWITCH

    Directory of Open Access Journals (Sweden)

    VAIBHAV SHUKLA

    2016-12-01

    Full Text Available Optical packet switching is considered as the future of data transfer technologyin combination with middle-aged electronics. The biggest challenge encountered in optical packet switching is the lack of optical buffers for storing the contending packets. Therefore, for the contention resolution of packets, a temporary storage in terms of fiber delay lines is used. This task is accomplished by an optical packet switch. In this paper, a design modification in the AWGR (Arrayed Waveguide Grating Router is presented for improving the switch performance. The power budget analysis of the switch is also presented to estimate the sufficient power level of the switch. The obtained results clearly reveal that the architecture presented in this paper can be operated in micro-watts in comparison to the earlier optical switch which operates in milli watts regime. Finally, simulation results are presented to obtain packet loss probability and average delay. Even at the higher load of 0.6, the switch presented in this paper provides a very low loss probability (10^6 and delay remain within 2 slots.

  15. Techniques for labeling of optical signals in bust switched networks

    DEFF Research Database (Denmark)

    Tafur Monroy, Idelfonso; Koonen, A. M. J.; Zhang, Jianfeng

    2003-01-01

    multiplexed (WDM) networks due to its single forwarding algorithm, thus yielding low latency, and it enables scaling to terabit rates. Moreover, LOBS is compatible with the general multiprotocol label switching (GMPLS) framework for a unified control plane. We present a review on techniques for labeling......We present a review of significant issues related to labeled optical burst switched (LOBS) networks and technologies enabling future optical internet networks. Labeled optical burst switching provides a quick and efficient forwarding mechanism of IP packets/bursts over wavelength division...

  16. An optical fan for light beams for high-precision optical measurements and optical switching

    CERN Document Server

    Zhou, Zhi-Yuan; Ding, Dong-Sheng; Jiang, Yun-Kun; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen; Guo, Guang-Can

    2014-01-01

    The polarization and orbital angular momentum properties of light are of great importance in optical science and technology in the fields of high precision optical measurements and high capacity and high speed optical communications. Here we show, a totally new method, based on a combination of these two properties and using the thermal dispersion and electro-optical effect of birefringent crystals, the construction of a simple and robust scheme to rotate a light beam like a fan. Using a computer-based digital image processing technique, we determine the temperature and the thermal dispersion difference of the crystal with high resolution. We also use the rotation phenomenon to realize thermo-optic and electro-optic switches. The basic operating principles for measurement and switching processes are presented in detail. The methods developed here will have wide practical applicability in various fields, including remote sensing, materials science and optical communication networks.

  17. Performance improvement for optical packet switch with shared buffers

    Institute of Scientific and Technical Information of China (English)

    Junjie Yang; Qingji Zeng; Jie Li; Tong Ye; Guolong Zhu

    2005-01-01

    @@ In this paper, an inner wavelength method is proposed to enlarge buffering capacity of shared fiber delay line buffers. In addition, an optical packet switch called extended shared buffer type optical packet switch(extended SB-OPS) is proposed to realize the inner wavelength method. In order to further improve performance of extended SB-OPS, a greedy algorithm based on inner wavelength method is introduced.The performance of extended SB-OPS is evaluated by simulation experiments.

  18. Potential roles of optical interconnections within broadband switching modules

    Science.gov (United States)

    Lalk, Gail R.; Habiby, Sarry F.; Hartman, Davis H.; Krchnavek, Robert R.; Wilson, Donald K.; Young, Kenneth C., Jr.

    1991-04-01

    An investigation of potential physical design bottlenecks in future broadband telecommunication switches has led to the identification of several areas where optical interconnections may play a role in the practical realization of required system performance. In the model used the speed and interconnection densities as well as requirements for ease-of-access and efficient power utilization challenge conventional partitioning and packaging strategies. Potential areas where optical interconnections may relieve some of the physical design bottlenecks include fiber management at the customer interface to the switch routing and distribution of high-density interconnections within the fabric of the switch and backplane interconnections to increase system throughput.

  19. All-optical high performance graphene-photonic crystal switch

    Science.gov (United States)

    Hoseini, Mehrdad; Malekmohammad, Mohammad

    2017-01-01

    The all-optical switch is realized based on nonlinear transmission changes in Fano resonance of 2D photonic crystals (PhC) which enhances the light intensity on the graphene in PhC; and in this study, the graphene layer is used as the nonlinear material. The refractive index change of graphene layer leads to a shift in the Fano resonance frequency due to the input light intensity through the Kerr nonlinear effect. Through finite-difference time-domain simulation, it is found that the high performance of all-optical switching can be achieved by the designed structure with a threshold pump intensity as low as MW/cm2. This structure is featured by optical bistability. The obtained results are applicable in micro optical integrated circuits for modulators, switches and logic elements for optical computation.

  20. Titanium Oxide Intelligent "Optical Switch" Surface

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Bio-mimic\tsuper-hydrophobic\tand super-hydrophilic switches were highly concerned because of their extensive application perspectives in gene transfers,non-loss liquid transportation,micro fluid,gene chips,and slow released drug.

  1. Advanced Optical Burst Switched Network Concepts

    Science.gov (United States)

    Nejabati, Reza; Aracil, Javier; Castoldi, Piero; de Leenheer, Marc; Simeonidou, Dimitra; Valcarenghi, Luca; Zervas, Georgios; Wu, Jian

    In recent years, as the bandwidth and the speed of networks have increased significantly, a new generation of network-based applications using the concept of distributed computing and collaborative services is emerging (e.g., Grid computing applications). The use of the available fiber and DWDM infrastructure for these applications is a logical choice offering huge amounts of cheap bandwidth and ensuring global reach of computing resources [230]. Currently, there is a great deal of interest in deploying optical circuit (wavelength) switched network infrastructure for distributed computing applications that require long-lived wavelength paths and address the specific needs of a small number of well-known users. Typical users are particle physicists who, due to their international collaborations and experiments, generate enormous amounts of data (Petabytes per year). These users require a network infrastructures that can support processing and analysis of large datasets through globally distributed computing resources [230]. However, providing wavelength granularity bandwidth services is not an efficient and scalable solution for applications and services that address a wider base of user communities with different traffic profiles and connectivity requirements. Examples of such applications may be: scientific collaboration in smaller scale (e.g., bioinformatics, environmental research), distributed virtual laboratories (e.g., remote instrumentation), e-health, national security and defense, personalized learning environments and digital libraries, evolving broadband user services (i.e., high resolution home video editing, real-time rendering, high definition interactive TV). As a specific example, in e-health services and in particular mammography applications due to the size and quantity of images produced by remote mammography, stringent network requirements are necessary. Initial calculations have shown that for 100 patients to be screened remotely, the network

  2. Ultrafast optical switching in three-dimensional photonic crystals

    NARCIS (Netherlands)

    Mazurenko, D.A.

    2004-01-01

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

  3. Crossbar Switches For Optical Data-Communication Networks

    Science.gov (United States)

    Monacos, Steve P.

    1994-01-01

    Optoelectronic and electro-optical crossbar switches called "permutation engines" (PE's) developed to route packets of data through fiber-optic communication networks. Basic network concept described in "High-Speed Optical Wide-Area Data-Communication Network" (NPO-18983). Nonblocking operation achieved by decentralized switching and control scheme. Each packet routed up or down in each column of this 5-input/5-output permutation engine. Routing algorithm ensures each packet arrives at its designated output port without blocking any other packet that does not contend for same output port.

  4. Optical computation based on nonlinear total reflectional optical switch at the interface

    Indian Academy of Sciences (India)

    Jianqi Zhang; Huan Xu

    2009-03-01

    A new scheme of binary half adder and full adder is proposed. It realizes a kind of all-optical computation which is based on the polarization coding technique and the nonlinear total reflectional optical switches.

  5. Experimental demonstration of tunable multiple optical orthogonal codes sequences-based optical label for optical packets switching

    Science.gov (United States)

    Zhang, Chongfu; Qiu, Kun; Zhou, Heng; Ling, Yun; Wang, Yawei; Xu, Bo

    2010-03-01

    In this paper, the tunable multiple optical orthogonal codes sequences (MOOCS)-based optical label for optical packet switching (OPS) (MOOCS-OPS) is experimentally demonstrated for the first time. The tunable MOOCS-based optical label is performed by using fiber Bragg grating (FBG)-based optical en/decoders group and optical switches configured by using Field Programmable Gate Array (FPGA), and the optical label is erased by using Semiconductor Optical Amplifier (SOA). Some waveforms of the MOOCS-based optical label, optical packet including the MOOCS-based optical label and the payloads are obtained, the switching control mechanism and the switching matrix are discussed, the bit error rate (BER) performance of this system is also studied. These experimental results show that the tunable MOOCS-OPS scheme is effective.

  6. Optical Switching in Silicon Nanowaveguide Ring Resonators Based on Kerr Effect and TPA Effect

    Institute of Scientific and Technical Information of China (English)

    LI Chun-Fei; DOU Na

    2009-01-01

    We analyze theoretically the 1 × 2 low-power all-optical switching in silicon nanowaveguide ring resonators (RR) based on the Kerr effect and two-photon absorption (TPA), and give a comparison between both the all-optical switches. The calculation shows that the switching power of the TPA-RR switch is 3 orders smaller than that of the Kerr-RR switch. The switching time for both the switches is about 100ps.

  7. Magneto-optical switch with amorphous silicon waveguides on magneto-optical garnet

    Science.gov (United States)

    Ishida, Eiichi; Miura, Kengo; Shoji, Yuya; Mizumoto, Tetsuya; Nishiyama, Nobuhiko; Arai, Shigehisa

    2016-08-01

    We fabricated a magneto-optical (MO) switch with a hydrogenated amorphous silicon waveguide on an MO garnet. The switch is composed of a 2 × 2 Mach-Zehnder interferometer (MZI). The switch state is controlled by an MO phase shift through a magnetic field generated by a current flowing in an electrode located on the MZI. The switching operation was successfully demonstrated with an extinction ratio of 11.7 dB at a wavelength of 1550 nm.

  8. All-Optical Switches in Optical Time-Division Multiplexing Technology: Theory,Experience and Application

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Optical time division multiplexing (OTDM) is one of thepromisinig ways for the future high-speed optical fiber communication networks. All-optical switch is, being one of the core technologies of OTDM systems and networks, crucial to realize the various signal processes including time-division demultiplexing, packet switching, all-optical regenerating and so on. This thesis mainly studies various all-optical switch technologies and their utilization in the fields of all-optical signal processings in the OTDM systems and networks. The main jobs are listed as follows.(1) A novel all-optical ultrafast demultiplexing scheme using the soliton self-trapping effect in birefringent fiber is proposed.(2) The demultiplexing performance of the Nonlinear Optical Loop Mirror(NOLM) is thoroughly analyzed and its optimization is further discussed.(3) The performance analysis and the configuration optimization of the all-optical switches based on the Semiconductor Optical Amplifier(SOA) are systematically presented. The speed limitation of the all-optical SOA switches induced by the fast gain depletion of SOA is discussed. Besides, a novel SOA switch is proposed, which adopts the asymmetric Mach-Zehnder Interferometer configuration.(4) The 8×2\\^5 Gb/s OTDM experimental transmission system along 105 km standard fiber is realized using the NOLM demultiplexer.(5) The NOLM switch is used to realize the all-optical 3R regeneration of 2\\^5 Gb/s Return-to-Zero signal.(6) The feasibility and limitation of the all-optical SOA packet switch is discussed. And a developed MZI configuration of SOA packet switch is further shown to improve the packet switching performance. Finally, an all-optical packet dropping node suitable in the networks with ring or bus configuration and an all-optical packet switching node in the ShuffleNet networks are proposed to show the feasibility of all-optical packet switching through combining the all-optical switches and the reasonable logic decisions.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    of a four wavelength-division-multiplexed channel system operating on a WiMax frequency band and employing an orthogonal-frequency-division-multiplexing modulation at 625 Mbits/s per channel, transmission of the data over 20 km of optical fiber, and active switching in a 1 × 16 active optical switch...

  10. High-performance quantitative robust switching control for optical telescopes

    Science.gov (United States)

    Lounsbury, William P.; Garcia-Sanz, Mario

    2014-07-01

    This paper introduces an innovative robust and nonlinear control design methodology for high-performance servosystems in optical telescopes. The dynamics of optical telescopes typically vary according to azimuth and altitude angles, temperature, friction, speed and acceleration, leading to nonlinearities and plant parameter uncertainty. The methodology proposed in this paper combines robust Quantitative Feedback Theory (QFT) techniques with nonlinear switching strategies that achieve simultaneously the best characteristics of a set of very active (fast) robust QFT controllers and very stable (slow) robust QFT controllers. A general dynamic model and a variety of specifications from several different commercially available amateur Newtonian telescopes are used for the controller design as well as the simulation and validation. It is also proven that the nonlinear/switching controller is stable for any switching strategy and switching velocity, according to described frequency conditions based on common quadratic Lyapunov functions (CQLF) and the circle criterion.

  11. Stochastic Pulse Switching in a Degenerate Resonant Optical Medium

    CERN Document Server

    Atkins, Ethan P; Kovacic, Gregor; Gabitov, Ildar R

    2012-01-01

    Using the idealized integrable Maxwell-Bloch model, we describe random optical-pulse polarization switching along an active optical medium in the Lambda-configuration with disordered occupation numbers of its lower energy sub-level pair. The description combines complete integrability and stochastic dynamics. For the single-soliton pulse, we derive the statistics of the electric-field polarization ellipse at a given point along the medium in closed form. If the average initial population difference of the two lower sub-levels vanishes, we show that the pulse polarization will switch intermittently between the two circular polarizations as it travels along the medium. If this difference does not vanish, the pulse will eventually forever remain in the circular polarization determined by which sub-level is more occupied on average. We also derive the exact expressions for the statistics of the polarization-switching dynamics, such as the probability distribution of the distance between two consecutive switches a...

  12. Advances in Anisotropic Materials for Optical Switching

    Science.gov (United States)

    2010-09-16

    overcome this cha llcnge we have developed a fundamentally new concept of optica ll y switchable clements based 011 dim’active wave plates (OWs). DWs...doped liquid crysta ls," J. Phys. D.: Appl. Phys., 25, 492-499 ( 1992). 17. T . Ikeda, O. Tsutsumi , " Optica l switching and image storage by

  13. Optically initiated silicon carbide high voltage switch

    Science.gov (United States)

    Caporaso, George J.; Sampayan, Stephen E.; Sullivan, James S.; Sanders; David M.

    2011-02-22

    An improved photoconductive switch having a SiC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.

  14. Architectures of electro-optical packet switched networks

    DEFF Research Database (Denmark)

    Berger, Michael Stubert

    2004-01-01

    , a benchmarking study has been carried out to compare power consumption of electrical and optical packet switches. The basic principles for Traffic Engineering and Quality of Service provisioning are discussed, and a simple scheme for Traffic Engineering in a best effort TCP/IP based nework is proposed. Also......, Constraint Based Routing is examined, and the effect from taking the link load into account is evaluated. It is believed that electrical packet switching will satisfy demands in the coming years, and this work covers several aspects hereof. A new load balancing scheme for multipath packet switches...

  15. Research on performance of multicasting in optical packet switched networks

    Institute of Scientific and Technical Information of China (English)

    Xin Liu; Yuefeng Ji; Lin Bai; Hongxiang Wang; Yongmei Sun

    2009-01-01

    @@ Different multicasting schemes in optical packet switched networks are discussed, including the parallel mode, serial mode, and hybrid mode multicasting schemes.Simulated modeling technique is applied to compare the network-level performance of the three multicasting schemes.A conclusion can be drawn from the results that since the hybrid-mode multicasting scheme can increase the multicast success ratio and reduce the packet retransmission times compared with the other two schemes, it is the best choice for delivering multicasting sessions in the optical packet switched networks.

  16. 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...... optical networks. The factors governing the modulation bandwidth of SOAs are determined, and schemes for reducing detrimental patterning effects are discussed. Three types of SOA-based switches are investigated numerically: so-called standardmode and differential-mode switches, and the filtering assisted...... switch. Differential -mode switches are shown to eliminate one contribution to the patterning effects, referred to as the linear patterning. This enables operation at bitrates far beyond the limit set by the carrier lifetime, but ultimately a saturation-induced patterning effect, nonlinear patterning...

  17. Flexible-rate optical packet generation/detection and label swapping for optical label switching networks

    Science.gov (United States)

    Wu, Zhongying; Li, Juhao; Tian, Yu; Ge, Dawei; Zhu, Paikun; Chen, Yuanxiang; Chen, Zhangyuan; He, Yongqi

    2017-03-01

    In recent years, optical label switching (OLS) gains lots of attentions due to its intrinsic advantages to implement protocol, bit-rate, granularity and data format transparency packet switching. In this paper, we propose a novel scheme to realize flexible-rate optical packet switching for OLS networks. At the transmitter node, flexible-rate packet is generated by parallel modulating different combinations of optical carriers generated from the optical multi-carrier generator (OMCG), among which the low-speed optical label occupies one carrier. At the switching node, label is extracted and re-generated in label processing unit (LPU). The payloads are switched based on routing information and new label is added after switching. At the receiver node, another OMCG serves as local oscillators (LOs) for optical payloads coherent detection. The proposed scheme offers good flexibility for dynamic optical packet switching by adjusting the payload bandwidth and could also effectively reduce the number of lasers, modulators and receivers for packet generation/detection. We present proof-of-concept demonstrations of flexible-rate packet generation/detection and label swapping in 12.5 GHz grid. The influence of crosstalk for cascaded label swapping is also investigated.

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

    DEFF Research Database (Denmark)

    Fjelde, Tina

    2002-01-01

    Gbit/s demultiplexing and 2x10 to 20 Gbit/s multiplexing. Lastly, the IWC’s capabilities as an optical logic gate for enabling more complex signal processing are demonstrated and four applications hereof are discussed. Logic OR and AND are verified in full at 10 Gbit/s using PRBS sequences coupled......This thesis focuses on functionalities that are important for the realisation of future all-optical packet switched networks, and which may be implemented using the interferometric wavelength converter. The European IST research project DAVID, with the aim of demonstrating the feasibility of a Tbit....../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...

  19. EIT-based MZ-MMI all-optical switch

    Science.gov (United States)

    Bahrami, A.; Rostami, A.; Nazari, F.; Abbasian, K.

    2010-11-01

    We propose a new control structure for all-optical switching in multimode inference (MMI)-based Mach-Zehnder interferometer (MZI) devices. This structure is composed of an MZI doped by three-level nanocrystals for the realization of electromagnetically induced transparency (EIT) in the lower arm. We use two different intensities of control field for two states of the proposed switch. Using a control field in both of the two switching states is necessary, where the EIT region is transparent. By changing the intensity of the control field, the refractive index of the doped region changes, which makes the phase difference between the two arms of the MZI. Hence, the switching operation takes place. Simulation results show that the extinction ratio of the device is -32dB in the worst case.

  20. 100GHz Integrated All-Optical Switch Enabled by ALD

    CERN Document Server

    Moille, Gregory; Morgenroth, Laurence; Lehoucq, Gaëlle; Neuilly, François; Hu, Bowen; Decoster, Didier; de Rossi, Alfredo

    2015-01-01

    The carrier lifetime of a photonic crystal all-optical switch is optimized by controlling the surface of GaAs by Atomic Layer Deposition. We demonstrate an all optical modulation capability up to 100GHz at Telecom wavelengths, with a contrast as high as 7dB. Wavelength conversion has also been demonstrated at a repetition rate of 2.5GHz with average pump power of about 0.5mW

  1. Q-switched Nd:YAG optical vortex lasers.

    Science.gov (United States)

    Kim, D J; Kim, J W; Clarkson, W A

    2013-12-02

    Q-switched operation of a high-quality Nd:YAG optical vortex laser with the first order Laguerre-Gaussian mode and well-determined helical wavefronts using a fiber-based pump beam conditioning scheme is reported. A simple two-mirror resonator incorporating an acousto-optic Q-switch was employed, along with an etalon and a Brewster plate to enforce the particular helicity of the output. The laser yielded Q-switched pulses with ~250 μJ pulse energy and ~33 ns pulse duration (FWHM) at a 0.1 kHz repetition rate for 5.1 W of absorbed pump power. The handedness of the helical wavefronts was preserved regardless of the repetition rates. The prospects of further power scaling and improved laser performance are discussed.

  2. Optical mode switch based on multimode interference couplers

    Science.gov (United States)

    Xiao, Huifu; Deng, Lin; Zhao, Guolin; Liu, Zilong; Meng, Yinghao; Guo, Xiaonan; Liu, Guipeng; Liu, Su; Ding, Jianfeng; Tian, Yonghui

    2017-02-01

    In this paper, we propose an optical mode switch based on two cascaded multimode interference (MMI) couplers. After a fundamental mode divided into two equal-power fundamental modes in the first MMI coupler, the thermo-optic effect is employed to modulate the phase of the two fundamental modes before directed to the next MMI for the purpose of mode switching. By adjusting the electric signals applied to the modulation arms, the proposed device can implement mode switching in three states: (a) one first-order and two fundamental modes simultaneously output, (b) one first-order mode output, and (c) two fundamental modes output. As a result, the simulated excess losses are -0.29 dB, -0.10 dB, and -0.63 dB, respectively.

  3. A congestion alleviated scheme in optical burst switching network

    Institute of Scientific and Technical Information of China (English)

    Gang Wang; Hongxiang Wang; Yuefeng Ji

    2008-01-01

    An optical burst switching (OBS) network platform is established with a ring topology of three nodes. A congestion alleviated scheme using advanced token protocol and wavelength tunable receivers is demonstrated to optimize the network platform. Experimental results testify that this scheme can resist collision at the level of 0.1% congestion rate.

  4. Simulation of Optical Packet—Switched Metropolitan Area Network

    Institute of Scientific and Technical Information of China (English)

    朱炳春; 贾潞华; 等

    2002-01-01

    This paper introduces architectures of two types optical packet-switched metropolitan area networks and their media access control protocols.We have designed ralated network simulation systems.With these simulation systems,the characteristics and performanceof the two MANs can be achieved.

  5. Resource allocation in circuit-switched all-optical networks

    Science.gov (United States)

    Marquis, Douglas; Barry, Richard A.; Finn, Steven G.; Parikh, Salil A.; Swanson, Eric A.; Thomas, Robert E.

    1996-03-01

    We describe an all-optical network testbed deployed in the Boston area, and research surrounding the allocation of optical resources -- frequencies and time slots -- within the network. The network was developed by a consortium of AT&T Bell Laboratories, Digital Equipment Corporation, and Massachusetts Institute of Technology under a grant from ARPA. The network is organized as a hierarchy consisting of local, metropolitan, and wide area nodes tea support optical broadcast and routing modes. Frequencies are shared and reused to enhance network scalability. Electronic access is provided through optical terminals that support multiple services having data rates between 10 Mbps/user and 10 Gbps/user. Of particular interest for this work is the 'B-service,' which simultaneously hops frequency and time slots on each optical terminal to allow frequency sharing within the AON. B-service provides 1.244 Gbps per optical terminal, with bandwidth for individual connections divided in increments as small as 10 Mbps. We have created interfaces between the AON and commercially available electronic circuit-switched and packet-switched networks. The packet switches provide FDDI (datacomm), T3 (telecomm), and ATM/SONET switching at backplane rates of over 3 Gbps. We show results on network applications that dynamically allocate optical bandwidth between electronic packet-switches based on the offered load presented by users. Bandwidth allocation granularity is proportional to B-Service slots (10-1244 Mbps), and switching times are on the order of one second. We have also studied the effects of wavelength changers upon the network capacity and blocking probabilities in wide area all-optical networks. Wavelength changers allow a change in the carrier frequency (within the network) without disturbing the data modulation. The study includes both a theoretical model of blocking probabilities based on network design parameters, and a computer simulation of blocking in networks with and

  6. Optical switching by stimulated thermal Rayleigh scattering

    Science.gov (United States)

    Peterson, Lauren M.

    1986-06-01

    Preliminary experiments were conducted whose ultimate goal is to develop all-optical control functions useful in an all-optical or optical-electronic hybrid digital computer or for optical interconnects. Stimulated thermal Rayleigh scattering (STRS) based upon generator experiments was pursued for scattering angles of 90 deg and 180 deg (backscattering). A pulsed nitrogen laser pumped dye laser served as the radiation source and the interaction medium was a liquid to which an absorbing dye was added. STRS amplifier experiments were successful and gain was observed and studied parametrically using eosine dye in ethanol. The gain was found to increase (although the gain coefficient decreased) with increasing pump power and the gain was found to be a maximum at an absorption coefficient of about 2.6 per cm. The generator experiments did not lead to stimulated scattering due to the limited output power of the laser and its multi-longitudinal spectral mode content. These studies will be continued along with analytical modeling in order to characterize the interaction and to enable the optimization of the scattering process.

  7. Integrated optical buffers for packet-switched networks

    Science.gov (United States)

    Burmeister, Emily Frances

    Routers form the backbone of the Internet, directing data to the right locations with huge throughput capacity of terabits/second) and very few errors (1 error allowed in 1012 bits). However, as the Internet continues to grow rapidly, so must the capacity of electronic routers, thereby also growing in footprint and power consumption. The energy bill alone has developers looking for an alternate solution. Today's routers can only operate with electrical signals although Internet data is transmitted optically. This requires the data to be converted from the optical domain to the electrical domain and back again. Optical routers have the potential of saving in power by omitting these conversions, but have been held back in part by the lack of a practical optical memory device. This work presents the first integrated optical buffer for next generation optical packet-switched networks. Buffering is required in a router to move packets of data in order to avoid collisions between packets heading to the same destination at the same time. The device presented here uses an InP-based two-by-two switch with a silica waveguide delay to form a recirculating buffer. Packet storage was shown with 98% packet recovery for 5 circulations. Autonomous contention resolution was demonstrated with two buffered channels to show that the technology is a realistic solution for creating multiple element buffers on multiple router ports. This thesis proposes and demonstrates the first integrated optical random access memory, thereby making a great stride toward high capacity optical routers.

  8. A high average power electro-optic switch using KTP

    Energy Technology Data Exchange (ETDEWEB)

    Ebbers, C.A.; Cook, W.M.; Velsko, S.P.

    1994-04-01

    High damage threshold, high thermal conductivity, and small thermo-optic coefficients make KTiOPO{sub 4} (KTP) an attractive material for use in a high average power Q-switch. However, electro-chromic damage and refractive index homogeneity have prevented the utilization of KTP in such a device in the past. This work shows that electro-chromic damage is effectively suppressed using capacitive coupling, and a KTP crystal can be Q-switched for 1.5 {times} 10{sup 9} shots without any detectable electro-chromic damage. In addition, KTP with the high uniformity and large aperture size needed for a KTP electro-optic Q-switch can be obtained from flux crystals grown at constant temperature. A thermally compensated, dual crystal KTP Q-switch, which successfully produced 50 mJ pulses with a pulse width of 8 ns (FWHM), has been constructed. In addition, in off-line testing the Q-switch showed less than 7% depolarization at an average power loading of 3.2 kW/cm{sup 2}.

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

    DEFF Research Database (Denmark)

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

    2003-01-01

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

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    with only 0.9-dB power penalty to achieve BER of 1E-9. Using the proposed labeling scheme, optical packet switching of 640 Gb/s data packets is experimentally demonstrated in which two data packets are labeled by making none and one spectral hole using a notch filter and are switched using a LiNbO$_3...

  12. Casimir switch: steering optical transparency with vacuum forces

    CERN Document Server

    Liu, X -f; Jing, H

    2016-01-01

    The Casimir force, originating from vacuum zero-point energy, is one of the most intriguing purely quantum effects. It has attracted renewed interests in current field of nanomechanics, due to the rapid size decrease of on-chip devices. Here we study the optomechanically-induced transparency (OMIT) with a tunable Casimir force. We find that the optical output rate can be significantly altered by the vacuum force, even terminated and then restored, indicating a highly-controlled optical switch. Our result addresses the possibility of designing exotic optical nano-devices by harnessing the power of vacuum.

  13. Simulation of the Physical Performance of Optical Packet Switching Nodes

    Institute of Scientific and Technical Information of China (English)

    王春华; 李力; 等

    2002-01-01

    A graphical and visual simulation system for the study of optical packet switching(OPS)nodes is accomplished.With the simulation system,the effect on physical performance-bit error rate(BER)due to a variety of factors such as the crosstalk parameters of OPS nodes,number of cascaded OPS nodes,length of optical output buffer,traffic load and fluctuation of amplitude of optical signals are evaluated.Reliability of the simulation system is proved by the analytical results obtained in all the above cases.

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

    Science.gov (United States)

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

    2013-12-01

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

  15. Recent Advances in Optically Controlled Bulk Semiconductor Switches

    Science.gov (United States)

    1985-06-01

    REO!NT AIJifl,NCES IN (FTICALIX ~1Ra.LW IILK SHttiaHlOCIOR swrrams L. Bovino , T. Burke, R. Youmans, M. Weiner, J. Carter U.S. Ar~ Electronics...fabrication of all of our optically activated switches. B.e.fer.enc.es. 1. L. Bovino , R. Youmans, T. Burke, M.Weiner, "Modulator Circuits Using Q...tically Activated Switches", Record of 16th Power Modulator SYJll>o- siurn, pp 235-239, June 1984. 2. M. Weiner, T. Burke, R. Youmans, L. Bovino , J

  16. Ultrafast polarization optical switch constructed from one-dimensional photonic crystal and its performance analysis

    Institute of Scientific and Technical Information of China (English)

    WANG Tao; LI Qing; GAO DingShan

    2009-01-01

    All-optical switch with the ultrafast optical switching rate is a key device in the next generation optical network. In this article, we propose a polarization switch with ps switching time, which is constructed from one-dimensional resonant photonic crystal (1D RPC). The model of switch operating at 1.5 μm is established based on the optical stark effect (OSE). We calculate the performance indices of the switch and the influences of errors of periods and refractive index on the performance characteristics.

  17. Microscopic model for all optical switching in ferromagnets

    Science.gov (United States)

    Cornelissen, T. D.; Córdoba, R.; Koopmans, B.

    2016-04-01

    The microscopic mechanism behind the all optical switching (AOS) in ferromagnets has triggered intense scientific debate. Here, the microscopic three-temperature model is utilized to describe AOS in a perpendicularly magnetized ferromagnetic Co/Pt system. We demonstrate that AOS in such a ferromagnet can be explained with the Inverse Faraday Effect (IFE). The influence of the strength and lifetime of the IFE induced field pulse on the switching process are investigated. We found that because of strong spin-orbit coupling, the minimal lifetime of the IFE needed to obtain switching is of the order of 0.1 ps, which is shorter than previously assumed. Moreover, spatial images of the domain pattern after AOS in Co/Pt, as well as their dependence on applying an opposite magnetic field, are qualitatively reproduced.

  18. Design and analysis of optical burst-switched networks

    Science.gov (United States)

    Xiong, Yijun; Vandenhoute, Marc; Cankaya, Hakki C.

    1999-08-01

    Optical burst switching (OBS) is a promising solution for building terabit optical routers and realizing IP over D- WDM. In this paper, we describe the basic concept of OBS and a general architecture of optical routers. The key design issues related to the OBS are discussed, notably, burstification, offset-time management and channel scheduling. A simple channel scheduling algorithm called LAUC (Latest Available Unscheduled Channel) algorithm is presented, which is also called Horizon algorithm in the literature. The performance of optical routers under random and self-similar traffic is thoroughly studied via computer simulations. Our study indicates that the distribution of burst length is not exponential any more. For the FDL (fiber delay line) optical buffer, the burst loss ratio is quite sensitive to the traffic characteristic of bursts when using the LAUC algorithm.

  19. Double-Teeth-Shaped Plasmonic Waveguide Electro-Optical Switches

    Institute of Scientific and Technical Information of China (English)

    ZHU Jia-Hu; HUANG Xu-Guang; MEI Xian

    2011-01-01

    @@ An electro-optical switch based on a plasmonic T-shaped waveguide structure with a double-teeth-shaped waveguide filled with 4-dimet4ylamino-N-methyl-4stilbazolium tosylate is proposed and numerically investigated.TheFinite-difference time domain simulation results reveal that the structure can operate as a circuit switch by controlling the external voltages V1 and/or V2.The proposed structure can also operate as a variable optical attenuator, which can continuously attenuate the power of a light beam from 6dB to 30dB by an external electrical field.The structure is of small size of a few hundred nanometers.Our results may open a possibility to construct nanoscale high-density photonic integration circuits.

  20. All-Optical Switching in Photonic Crystal Cavities

    DEFF Research Database (Denmark)

    Heuck, Mikkel

    All-Optical switching in photonic crystal waveguide-cavity structures is studied predominantly theoretically and numerically, but also from an experimental point of view. We have calculated the first order perturbations to the resonance frequency and decay rate of cavity modes, using a mathematical...... separated. This device was fabricated and characterized by colleagues within the group, and it was shown to perform very well in terms of cross-talk between the signal and pump. Theoretical investigations as well as practical design proposals have resulted from a study of waveguide-cavity structures...... exhibiting Fano resonances. These devices were predicted to be superior to structures with the more well-known Lorentzian line shape in terms of energy consumption and switching contrast. Finally, the mathematical framework of optimal control theory was employed as a general setting, in which the optical...

  1. High-Resolution Mammography Detector Employing Optical Switching Readout

    Science.gov (United States)

    Irisawa, Kaku; Kaneko, Yasuhisa; Yamane, Katsutoshi; Sendai, Tomonari; Hosoi, Yuichi

    Conceiving a new detector structure, FUJIFILM Corporation has successfully put its invention of an X-ray detector employing "Optical Switching" into practical use. Since Optical Switching Technology allows an electrode structure to be easily designed, both high resolution of pixel pitch and low electrical noise readout have been achieved, which have consequently realized the world's smallest pixel size of 50×50 μm2 from a Direct-conversion FPD system as well as high DQE. The digital mammography system equipped with this detector enables to acquire high definition images while maintaining granularity. Its outstanding feature is to be able to acquire high-precision images of microcalcifications which is an important index in breast examination.

  2. Silicon Modulators, Switches and Sub-systems for Optical Interconnect

    Science.gov (United States)

    Li, Qi

    Silicon photonics is emerging as a promising platform for manufacturing and integrating photonic devices for light generation, modulation, switching and detection. The compatibility with existing CMOS microelectronic foundries and high index contrast in silicon could enable low cost and high performance photonic systems, which find many applications in optical communication, data center networking and photonic network-on-chip. This thesis first develops and demonstrates several experimental work on high speed silicon modulators and switches with record performance and novel functionality. A 8x40 Gb/s transmitter based on silicon microrings is first presented. Then an end-to-end link using microrings for Binary Phase Shift Keying (BPSK) modulation and demodulation is shown, and its performance with conventional BPSK modulation/ demodulation techniques is compared. Next, a silicon traveling-wave Mach- Zehnder modulator is demonstrated at data rate up to 56 Gb/s for OOK modulation and 48 Gb/s for BPSK modulation, showing its capability at high speed communication systems. Then a single silicon microring is shown with 2x2 full crossbar switching functionality, enabling optical interconnects with ultra small footprint. Then several other experiments in the silicon platform are presented, including a fully integrated in-band Optical Signal to Noise Ratio (OSNR) monitor, characterization of optical power upper bound in a silicon microring modulator, and wavelength conversion in a dispersion-engineered waveguide. The last part of this thesis is on network-level application of photonics, specically a broadcast-and-select network based on star coupler is introduced, and its scalability performance is studied. Finally a novel switch architecture for data center networks is discussed, and its benefits as a disaggregated network are presented.

  3. Electro-optical switching by liquid-crystal controlled metasurfaces

    CERN Document Server

    Decker, Manuel; Minovich, Alexander; Staude, Isabelle; Miroshnichenko, Andrey E; Chigrin, Dmitry; Neshev, Dragomir N; Jagadish, Chennupati; Kivshar, Yuri S

    2013-01-01

    We study the optical response of a metamaterial surface created by a lattice of split-ring resonators covered with a nematic liquid crystal and demonstrate millisecond timescale switching between electric and magnetic resonances of the metasurface. This is achieved due to a high sensitivity of liquid-crystal molecular reorientation to the symmetry of the metasurface as well as to the presence of a bias electric field. Our experiments are complemented by numerical simulations of the liquid-crystal reorientation.

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

    Institute of Scientific and Technical Information of China (English)

    Wu Bao-Jun; Cui Fu-Cheng

    2012-01-01

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

  5. Novel coherent optical OFDM-based transponder for optical slot switched networks

    DEFF Research Database (Denmark)

    Mestre, Miquel A.; Estaran, Jose M.; Jenneve, Philippe

    2016-01-01

    We report a novel coherent optical OFDM transponder approach capable of recovering microsecond-scale data-burst while adapting to tight filtering constraints present in optical slot switched intradatacenter networks. Filtering effects in such large node-count environments are reviewed. The CO...

  6. Separation and insertion of optical bit-serial label in optical packet switching

    Institute of Scientific and Technical Information of China (English)

    Yun Ling; Kun Qiu; Mian Zheng

    2006-01-01

    @@ The bipolar phase-shift-keying (BPSK) optical orthogonal codes (OOCs) are inserted into the optical packet format of bit-serial label. The ultra-fast separation of the label and payload is performed through the auto-correlation pulses indicating the time position at which the optical switch changes the state.The insertion of the new label can also be realized by detecting the auto-correlation pulse at the line rate. Especially, the scheme can be adapted to the asynchronous separation and insertion and realize the variable-length packet switching. The results of simulation verify the feasibility of the scheme.

  7. All-optical switching and nonlinear optical properties of HBT in ethanol solution

    Institute of Scientific and Technical Information of China (English)

    Zheng Jia-Jin; Zhang Gui-Lan; Guo Yang-Xue; Li Xiang-Ping; Chen Wen-Ju

    2007-01-01

    This paper demonstrates an all-optical switching model system comprising a single pulsed pump beam at 355 nm and a CW He-Ne signal beam at 632.8 nm with 2-(2'-hydroxyphenyl)benzothiazole (HBT) in ethanol solution. The origins of the optical switching effect were discussed. By the study of nonlinear optical properties for HBT in ethanol solvent, this paper verified that the excited-state intramolecular proton transfer (ESIPT) effect of HBT and the thermal effect of solvent worked on quite different time scales and together induced the change of the refractive index of HBT solution, leading to the signal beam deflection. The results indicated that the HBT molecule could be an excellent candidate for high-speed and high-sensitive optical switching devices.

  8. A novel all-optical label processing based on multiple optical orthogonal codes sequences for optical packet switching networks

    Science.gov (United States)

    Zhang, Chongfu; Qiu, Kun; Xu, Bo; Ling, Yun

    2008-05-01

    This paper proposes an all-optical label processing scheme that uses the multiple optical orthogonal codes sequences (MOOCS)-based optical label for optical packet switching (OPS) (MOOCS-OPS) networks. In this scheme, each MOOCS is a permutation or combination of the multiple optical orthogonal codes (MOOC) selected from the multiple-groups optical orthogonal codes (MGOOC). Following a comparison of different optical label processing (OLP) schemes, the principles of MOOCS-OPS network are given and analyzed. Firstly, theoretical analyses are used to prove that MOOCS is able to greatly enlarge the number of available optical labels when compared to the previous single optical orthogonal code (SOOC) for OPS (SOOC-OPS) network. Then, the key units of the MOOCS-based optical label packets, including optical packet generation, optical label erasing, optical label extraction and optical label rewriting etc., are given and studied. These results are used to verify that the proposed MOOCS-OPS scheme is feasible.

  9. A novel optical burst switching architecture for high speed networks

    Institute of Scientific and Technical Information of China (English)

    Amit Kumar Garg; R. S. Kaler

    2008-01-01

    A novel optical burst switching (OBS) high speed network architecture has been proposed. To verify its feasibility and evaluate its performance, just-enough-time (JET) signaling has been considered as a high performance protocol. In the proposed architecture, to avoid burst losses, firstly, a short-priorconfirrnation-packet (SPCP) is sent over the control channel that simulates the events that the actual packet will experience. Once SPCP detects a drop at any of the intermediate nodes, the actual packet is not sent but the process repeats. In order to increase network utilization, cost effectiveness and to overcome some limitations of conventional OBS, inherent codes (e.g., orthogonal optical codes (OOC)),which are codified only in intensity, has been used. Through simulations, it shows that a decrease in burst loss probability, cost effectiveness and a gain in processing time are obtained when optical label processing is used as compared with electronic processing.

  10. 160 Gbit/s optical packet switching using a silicon chip

    DEFF Research Database (Denmark)

    Hu, Hao; Ji, Hua; Galili, Michael;

    2012-01-01

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

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

    Data.gov (United States)

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

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

    Science.gov (United States)

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

    2011-07-05

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

  13. Diarylethene-modified nucleotides for switching optical properties in DNA

    Directory of Open Access Journals (Sweden)

    Sebastian Barrois

    2012-06-01

    Full Text Available Diarylethenes were attached to the 5-position of 2’-deoxyuridine in order to yield three different photochromic nucleosides. All nucleosides were characterized with respect to their absorption and photochromic properties. Based on these results, the most promising photochromic DNA base modification was incorporated into representative oligonucleotides by using automated phosphoramidite chemistry. The switching of optical properties in DNA can be achieved selectively at 310 nm (forward and 450 nm (backward; both wavelengths are outside the normal nucleic acid absorption range. Moreover, this nucleoside was proven to be photochemically stable and allows switching back and forth several times. These results open the way for the use of diarylethenes as photochromic compounds in DNA-based architectures.

  14. Reconfigurable nonblocking 4-port silicon thermo-optic optical router based on Mach-Zehnder optical switches.

    Science.gov (United States)

    Yang, Lin; Xia, Yuhao; Zhang, Fanfan; Chen, Qiaoshan; Ding, Jianfeng; Zhou, Ping; Zhang, Lei

    2015-04-01

    We demonstrate a reconfigurable nonblocking 4-port silicon thermo-optic optical router based on Mach-Zehnder optical switches. For all optical links in its 9 routing states, the optical signal-to-noise ratios are larger than 15 dB in the wavelength range from 1525 to 1565 nm. Each optical link of the optical router can manipulate 50 wavelength-division-multiplexing channels with the data rate of 32 Gbps for each channel in the same wavelength range. Its average energy efficiency is about 16.3 fJ/bit, and its response time is about 19 μs.

  15. All-optical switching of magnetoresistive devices using telecom-band femtosecond laser

    Science.gov (United States)

    He, Li; Chen, Jun-Yang; Wang, Jian-Ping; Li, Mo

    2015-09-01

    Ultrafast all-optical switching of the magnetization of various magnetic systems is an intriguing phenomenon that can have tremendous impact on information storage and processing. Here, we demonstrate all-optical switching of GdFeCo alloy films using a telecom-band femtosecond fiber laser. We further fabricate Hall cross devices and electrically readout all-optical switching by measuring anomalous Hall voltage changes. The use of a telecom laser and the demonstrated all-optical switching of magnetoresistive devices represent the first step toward integration of opto-magnetic devices with mainstream photonic devices to enable novel optical and spintronic functionalities.

  16. Optimization of all-optical EDFA-based Sagnac-interferometer switch.

    Science.gov (United States)

    Wang, Fei; Li, Chunfei

    2007-10-17

    We perform optimization of all-optical EDFA-based Sagnac - interferometer switch through an analytical model and numerical simulations by solving nonlinear Schrödinger equations. The effects of the performance of EDFA on the bit rate and the switching power are investigated for all-optical switch based on self-phase or cross-phase modulation. The simulated results show that ultra-low switching power (EDFA.

  17. Micro Electro Mechanical Systems (MEMS) Micro-Switches for Use in DC, RF, and Optical Applications

    Science.gov (United States)

    Suzuki, Kenichiro

    2002-06-01

    Micromachined micro-switches have stimulated the development of the core infrastructure technology for the next generation communication systems because of their superior performance. They are fabricated by similar silicon micromachined processes, but the switch structure and its characteristics depend on each application. Micro electro mechanical systems (MEMS) technology has been applied to micro relays, RF switches, and optical switches; as a result, optical and mechanical performance has been improved.

  18. Performance analysis of multiple optical orthogonal codes sequences-based optical labels for optical packet switching networks

    Science.gov (United States)

    Zhang, Chongfu; Ma, Chunli; Wang, Zhengsuan; Qiu, Kun

    2011-09-01

    Multiple optical orthogonal codes sequences (MOOCS)-based optical labels for optical packet switching (MOOCS-OPS) were proposed and studied in our previous works. In order to evaluate the performances of the MOOCS-OPS networks resulting from interference of the MOOCS-based optical labels, we utilize a new study method that applies the independent case of multiple optical orthogonal codes to derive the probability function of the MOOCS-OPS networks for the first time. Additionally, the optical label processing time, the utilization efficiency, and the packet loss rate in the MOOCS-OPS networks are also considered. We discuss the performance and efficiency characteristics with a variety of parameters, and compare some characteristics of the system employed by a single optical orthogonal code or MOOCS-based optical labels. The performances of the system are also calculated, and our results verify that the method and the networks are effective. Moreover, it is found that performances of the MOOCS-OPS networks would, negatively, be worsened, compared with the single optical orthogonal code-based optical label for optical packet switching; however, the MOOCS-OPS networks can greatly enlarge the scalability of the optical packet switching networks.

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

    Science.gov (United States)

    Song, Jang-Kun

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

  20. Picosecond all-optical switching in hydrogenated amorphous silicon microring resonators

    CERN Document Server

    Pelc, Jason S; Vo, Sonny; Santori, Charles; Fattal, David A; Beausoleil, Raymond G

    2014-01-01

    We utilize cross-phase modulation to observe all-optical switching in microring resonators fabricated with hydrogenated amorphous silicon (a-Si:H). Using 2.7-ps pulses from a mode-locked fiber laser in the telecom C-band, we observe optical switching of a cw telecom-band probe with full-width at half-maximum switching times of 14.8 ps, using approximately 720 fJ of energy deposited in the microring. In comparison with telecom-band optical switching in crystalline silicon microrings, a-Si:H exhibits substantially higher switching speeds due to reduced impact of free-carrier processes.

  1. Optical switch phenomenon in a self-defocusing medium

    Institute of Scientific and Technical Information of China (English)

    Huagang Li; Zhihua Luo

    2009-01-01

    A spatial optical switch phenomenon caused by the induced focusing of a weak probe beam occurring in self-defocusing nonlinear media is discussed theoretically.A weak beam is induced to focus when it copropagates with an intense pump beam under the conditions that the probe and pump beams peak at different positions and propagate in different directions.Due to the effect of cross-phase modulation,the weak beam can not only be focused but also be deflected.The phenomenon is discussed by numerically solving the coupled amplitude equations.

  2. Study of Crosstalk propoerty in an Optical Packet Switching Node

    Institute of Scientific and Technical Information of China (English)

    王春华; 李力; 等

    2002-01-01

    The effect of queuing delay of output buffer on the crosstalk property in optical packel switching nodes in investigated.The relationship between crosstalk and buffer length is obtained.From the calculation and simulation results,it is concluded that the corsstalk power penalty predominantly depends on the buffer length,the longer the buffer,the greater the penalty,as well as the random range of the penalty.While comparing with the effect of queuing delay,the effect of random routing path delay takes very little proportion in the total power penalty.

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

    Science.gov (United States)

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

    2008-09-29

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

  4. Experimental demonstration of optical switching and routing via four-wave mixing spatial shift.

    Science.gov (United States)

    Nie, Zhiqiang; Zheng, Huaibin; Zhang, Yanpeng; Zhao, Yan; Zuo, Cuicui; Li, Changbiao; Chang, Hong; Xiao, Min

    2010-01-18

    We demonstrate the shift characteristics of four-wave mixing (FWM) beam spots which are controlled by the strong laser fields via the large cross-Kerr nonlinearity. The shift distances and directions are determined by the nonlinear dispersions. Based on such spatial displacements of the FWM beams, as well as the probe beam, we experimentally demonstrate spatial optical switching for one beam or multiple optical beams, which can be used for all-optical switching, switching arrays and routers.

  5. A single-stage optical load-balanced switch for data centers.

    Science.gov (United States)

    Huang, Qirui; Yeo, Yong-Kee; Zhou, Luying

    2012-10-22

    Load balancing is an attractive technique to achieve maximum throughput and optimal resource utilization in large-scale switching systems. However current electronic load-balanced switches suffer from severe problems in implementation cost, power consumption and scaling. To overcome these problems, in this paper we propose a single-stage optical load-balanced switch architecture based on an arrayed waveguide grating router (AWGR) in conjunction with fast tunable lasers. By reuse of the fast tunable lasers, the switch achieves both functions of load balancing and switching through the AWGR. With this architecture, proof-of-concept experiments have been conducted to investigate the feasibility of the optical load-balanced switch and to examine its physical performance. Compared to three-stage load-balanced switches, the reported switch needs only half of optical devices such as tunable lasers and AWGRs, which can provide a cost-effective solution for future data centers.

  6. Optically implemented broadband blueshift switch in the terahertz regime.

    Science.gov (United States)

    Shen, Nian-Hai; Massaouti, Maria; Gokkavas, Mutlu; Manceau, Jean-Michel; Ozbay, Ekmel; Kafesaki, Maria; Koschny, Thomas; Tzortzakis, Stelios; Soukoulis, Costas M

    2011-01-21

    We experimentally demonstrate, for the first time, an optically implemented blueshift tunable metamaterial in the terahertz (THz) regime. The design implies two potential resonance states, and the photoconductive semiconductor (silicon) settled in the critical region plays the role of intermediary for switching the resonator from mode 1 to mode 2. The observed tuning range of the fabricated device is as high as 26% (from 0.76 THz to 0.96 THz) through optical control to silicon. The realization of broadband blueshift tunable metamaterial offers opportunities for achieving switchable metamaterials with simultaneous redshift and blueshift tunability and cascade tunable devices. Our experimental approach is compatible with semiconductor technologies and can be used for other applications in the THz regime.

  7. Optically controlled multiple switching operations of DNA biopolymer devices

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-21

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

  8. Properties of Controllable Soliton Switching in Optical Lattices with Longitudinal Exponential-Asymptotic Modulation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jun; XUE Chun-Hua; QI Yi-Hong; LOU Sen-Yue

    2008-01-01

    The properties of controllable soliton switching in Kerr-type optical lattices with different modulation are investigated theoretically and simulated numerically. The results show that the optical lattices can be available for all-optical soliton switching through utilization for length-scale competition effects. And through longitudinal exponential-asymptotic modulation for the linear refractive index, the properties of soliton switching in the optical lattices can be improved. The number of output channels of soliton switching can be controlled by the parameters such as incident angle, asymptotic rate of longitudinal modulation, guiding parameter and form factor.

  9. Technology of optical switch in all optical communication%全光通信中的光开关技术

    Institute of Scientific and Technical Information of China (English)

    李红春; 赵巧霞; 陶晓燕; 王豆豆

    2011-01-01

    Optical switch is the kernel device of all optical switchingCurrently the study on optical switch has become the focus of all optical communication. This paper summarized the principle of optical switch, analyzed the application of optical switch. The traditional mechanical, micro electro-mechanical system (MEMS) and thermo-optic switch were further divided, and their characteristics were pointed out. Then an evaluation system was put forward for optical switch assessment, by comparing the qualitative and quantitative of the four common optical switches,the advatnges and inadequacics of different types of optical switches were pointed out. Finauy,according to the trend of all optical communication, the large-scale array, high speed, transparent and low loss optical switch is the key development of direction.%光开关是实现全光交换的核心器件,光开关的研究已成为全光通信领域研究的焦点.本文首先对光开关的原理进行归纳,总结光开关的应用范围.对传统机械式光开关、微电子机械式光开关、热光开关进行了进一步地划分,分析了它们的结构形式和性能特点.设计了光开关性能评价指标体系,对常见的4种光开关进行了定性与定量对比,指出不同类型光开关的优点和不足之处.最后依据全光通信网的发展趋势,指出大容童、高速、透明、低损耗是光开关的重点发展方向.

  10. Design, installation, commissioning and operation of a beamlet monitor in the negative ion beam test stand at NIFS

    Energy Technology Data Exchange (ETDEWEB)

    Antoni, V.; Agostinetti, P.; Brombin, M.; Cervaro, V.; Delogu, R.; Fasolo, D.; Franchin, L.; Ghiraldelli, R.; Molon, F.; Pasqualotto, R.; Serianni, G., E-mail: gianluigi.serianni@igi.cnr.it; Tollin, M.; Veltri, P. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA) (Italy); De Muri, M. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA) (Italy); INFN-LNL, v.le dell' Università 2, I-35020, Legnaro (PD) Italy (Italy); Ikeda, K.; Kisaki, M.; Nakano, H.; Takeiri, Y.; Tsumori, K. [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Muraro, A. [Istituto di Fisica del Plasma (IFP-CNR) – Via Cozzi 53, 20125, Milano (Italy)

    2015-04-08

    In the framework of the accompanying activity for the development of the two neutral beam injectors for the ITER fusion experiment, an instrumented beam calorimeter is being designed at Consorzio RFX, to be used in the SPIDER test facility (particle energy 100keV; beam current 50A), with the aim of testing beam characteristics and to verify the source proper operation. The main components of the instrumented calorimeter are one-directional carbon-fibre-carbon composite tiles. Some prototype tiles have been used as a small-scale version of the entire calorimeter in the test stand of the neutral beam injectors of the LHD experiment, with the aim of characterising the beam features in various operating conditions. The extraction system of the NIFS test stand source was modified, by applying a mask to the first gridded electrode, in order to isolate only a subset of the beamlets, arranged in two 3×5 matrices, resembling the beamlet groups of the ITER beam sources. The present contribution gives a description of the design of the diagnostic system, including the numerical simulations of the expected thermal pattern. Moreover the dedicated thermocouple measurement system is presented. The beamlet monitor was successfully used for a full experimental campaign, during which the main parameters of the source, mainly the arc power and the grid voltages, were varied. This contribution describes the methods of fitting and data analysis applied to the infrared images of the camera to recover the beamlet optics characteristics, in order to quantify the response of the system to different operational conditions. Some results concerning the beamlet features are presented as a function of the source parameters.

  11. Design, installation, commissioning and operation of a beamlet monitor in the negative ion beam test stand at NIFS

    Science.gov (United States)

    Antoni, V.; Agostinetti, P.; Brombin, M.; Cervaro, V.; Delogu, R.; De Muri, M.; Fasolo, D.; Franchin, L.; Ghiraldelli, R.; Ikeda, K.; Kisaki, M.; Molon, F.; Muraro, A.; Nakano, H.; Pasqualotto, R.; Serianni, G.; Takeiri, Y.; Tollin, M.; Tsumori, K.; Veltri, P.

    2015-04-01

    In the framework of the accompanying activity for the development of the two neutral beam injectors for the ITER fusion experiment, an instrumented beam calorimeter is being designed at Consorzio RFX, to be used in the SPIDER test facility (particle energy 100keV; beam current 50A), with the aim of testing beam characteristics and to verify the source proper operation. The main components of the instrumented calorimeter are one-directional carbon-fibre-carbon composite tiles. Some prototype tiles have been used as a small-scale version of the entire calorimeter in the test stand of the neutral beam injectors of the LHD experiment, with the aim of characterising the beam features in various operating conditions. The extraction system of the NIFS test stand source was modified, by applying a mask to the first gridded electrode, in order to isolate only a subset of the beamlets, arranged in two 3×5 matrices, resembling the beamlet groups of the ITER beam sources. The present contribution gives a description of the design of the diagnostic system, including the numerical simulations of the expected thermal pattern. Moreover the dedicated thermocouple measurement system is presented. The beamlet monitor was successfully used for a full experimental campaign, during which the main parameters of the source, mainly the arc power and the grid voltages, were varied. This contribution describes the methods of fitting and data analysis applied to the infrared images of the camera to recover the beamlet optics characteristics, in order to quantify the response of the system to different operational conditions. Some results concerning the beamlet features are presented as a function of the source parameters.

  12. Ultrafast Nyquist OTDM demultiplexing using optical Nyquist pulse sampling in an all-optical nonlinear switch.

    Science.gov (United States)

    Hirooka, Toshihiko; Seya, Daiki; Harako, Koudai; Suzuki, Daiki; Nakazawa, Masataka

    2015-08-10

    We propose the ultrahigh-speed demultiplexing of Nyquist OTDM signals using an optical Nyquist pulse as both a signal and a sampling pulse in an all-optical nonlinear switch. The narrow spectral width of the Nyquist pulses means that the spectral overlap between data and control pulses is greatly reduced, and the control pulse itself can be made more tolerant to dispersion and nonlinear distortions inside the nonlinear switch. We apply the Nyquist control pulse to the 640 to 40 Gbaud demultiplexing of DPSK and DQPSK signals using a nonlinear optical loop mirror (NOLM), and demonstrate a large performance improvement compared with conventional Gaussian control pulses. We also show that the optimum spectral profile of the Nyquist control pulse depends on the walk-off property of the NOLM.

  13. Research progresses of SOI optical waveguide devices and integrated optical switch matrix

    Institute of Scientific and Technical Information of China (English)

    YU Jinzhong; CHEN Shaowu; XIA Jinsong; WANG Zhangtao; FAN Zhongchao; LI Yanping; LIU Jingwei; YANG Di; CHEN Yuanyuan

    2005-01-01

    SOI (silicon-on-insulator) is a new material with a lot of important perform- ances such as large index difference, low transmission loss. Fabrication processes for SOI based optoelectronic devices are compatible with conventional IC processes. Having the potential of OEIC monolithic integration, SOI based optoelectronic devices have shown many good characteristics and become more and more attractive recently. In this paper, the recent progresses of SOI waveguide devices in our research group are presented. By highly effective numerical simulation, the single mode conditions for SOI rib waveguides with rectangular and trapezoidal cross-section were accurately investigated. Using both chemical anisotropic wet etching and plasma dry etching techniques, SOI single mode rib waveguide, MMI coupler, VOA (variable optical attenuator), 2×2 thermal-optical switch were successfully designed and fabricated. Based on these, 4×4 and 8×8 SOI optical waveguide integrated switch matrixes are demonstrated for the first time.

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  15. Optimization of Waveguide Structure for Tunable Optical Switch in Si/SiGe System

    Institute of Scientific and Technical Information of China (English)

    Seongjae Boo; Won-Taek Han

    2003-01-01

    A new electro-optical device using Si/SiGe-system with two parallel ridge waveguides is proposed for optical switching and the optimization of the structure for a single mode operation is investigated.

  16. MEMS Torsion-Mirror Actuators for Optical Switching or Attenuating Applications

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Novel MEMS torsion-mirror actuators with monolithically integrated fiber self-holding structures are fabricated, and investigated experimentally and theoretically. Their electromechanical and optical characteristics are acceptable for optical switching or attenuating applications.

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

    DEFF Research Database (Denmark)

    Nord, Martin

    2005-01-01

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

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

    Data.gov (United States)

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

  19. Preparation, thermo-optic property and simulation of optical switch based on azo benzothiazole polymer

    Science.gov (United States)

    Cao, Zhijuan; Qiu, Fengxian; Wang, Qing; Cao, Guorong; Guan, Yijun; Zhuang, Lin; Xu, Xiaolong; Wang, Jie; Chen, Qian; Yang, Dongya

    2013-04-01

    An azo chromophore molecule 4-[(benzothiazole-2-yl)diazenyl]phenyl-1,3-diamine (BTPD) was prepared with 2-amino benzothiazole and m-phenylenediamine by diazo-coupling reaction. Then, the chromophore molecule BTPD was polymerized with NJ-210 and isophorone diisocyanate (IPDI) to obtain novel azo benzothiazole polymer (BTPU). The structures of BTPD and BTPU were characterized using the Fourier transform infrared, UV-visible spectroscopy, DSC and TGA. The physical properties of the obtained BTPU were investigated. The refractive index ( n) of BTPU was demonstrated at different temperature and wavelength (532, 650 and 850 nm) using attenuated total reflection technique. The transmission loss and dispersion characteristic of BTPU film were investigated using the CCD digital imaging devices and Sellmeyer equation. A Y-branch and 2 × 2 Mach-Zehnder interferometer (MZI) polymeric thermo-optic switches based on the thermo-optic effect of prepared BTPU were proposed and the performance of switches was simulated. The results indicated that the power consumption of the Y-branch thermo-optic switch could be only 0.6 mW. The Y-branch and MZI switching rising and falling times obtained were 8.0 and 1.8 ms.

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

  1. SOI-Based 16×16 Thermo-Optic Waveguide Switch Matrix

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuan-Yuan; LI Yan-Ping; SUN Fei; YANG Di; CHEN Shao-Wu; YU Jin-Zhong

    2006-01-01

    @@ A 16 × 16 thermo-optic waveguide switch matrix has been designed and fabricated on silicon-on-insulator wafer.For reducing device length, blocking switch matrix configuration is chosen. The building block of the matrix is a 2 × 2 switch cell with a Mach-Zehnder interferometer configuration, where a multi-mode interferometer serves as splitter/combiners. Spot size converters and isolating grooves are integrated on the same chip to reduce loss and power consumption. Average power consumption of the switch cell is 220mW. The switching time of a switch cell is less than 3 μs.

  2. Coherent all-optical switching in a bistable waveguide-cavity-waveguide system

    DEFF Research Database (Denmark)

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

    2011-01-01

    All optical switching based on non-linear material effects is a promising technique for use in future optical communication systems. Promising advances in the field has been achieved using optical microcavities in photonic crystals to increase the optical field strength and hence reduce...... the required power of the input field [1]. In this work we consider an alternative method of switching, in which the input power is kept constant and only the phase of the input field is varied....

  3. High bandwidth all-optical 3×3 switch based on multimode interference structures

    Science.gov (United States)

    Le, Duy-Tien; Truong, Cao-Dung; Le, Trung-Thanh

    2017-03-01

    A high bandwidth all-optical 3×3 switch based on general interference multimode interference (GI-MMI) structure is proposed in this study. Two 3×3 multimode interference couplers are cascaded to realize an all-optical switch operating at both wavelengths of 1550 nm and 1310 nm. Two nonlinear directional couplers at two outer-arms of the structure are used as all-optical phase shifters to achieve all switching states and to control the switching states. Analytical expressions for switching operation using the transfer matrix method are presented. The beam propagation method (BPM) is used to design and optimize the whole structure. The optimal design of the all-optical phase shifters and 3×3 MMI couplers are carried out to reduce the switching power and loss.

  4. Proposal for all-optical controllable switch using dipole induced transparency (DIT)

    Science.gov (United States)

    Eftekhari, K.; Abbasian, K.; Rostami, A.

    2010-05-01

    We propose a novel all-optical controllable switch using photonic crystal cavity. For doing this work, the dipole induced transparency phenomenon realized through interaction of light with multilevel nanocrystals is used. Multilevel nanocrystals are doped to photonic crystal rods. Using the proposed structure and applying the control field, the absorbing medium converts to transparent one and switching operation is obtained. Analytical relation for evaluation of the proposed device considering quantum optical effects is presented and studied by investigation of effects of parameters on switching characteristics. We show that high quality all-optical switching operation can be obtained.

  5. Cascaded transformerless DC-DC voltage amplifier with optically isolated switching devices

    Science.gov (United States)

    Sridharan, Govind (Inventor)

    1993-01-01

    A very high voltage amplifier is provided in which plural cascaded banks of capacitors are switched by optically isolated control switches so as to be charged in parallel from the preceding stage or capacitor bank and to discharge in series to the succeeding stage or capacitor bank in alternating control cycles. The optically isolated control switches are controlled by a logic controller whose power supply is virtually immune to interference from the very high voltage output of the amplifier by the optical isolation provided by the switches, so that a very high voltage amplification ratio may be attained using many capacitor banks in cascade.

  6. A Novel Model of Resolving Contention in Optical Burst Switched Networks

    Institute of Scientific and Technical Information of China (English)

    Huang Anpeng(黄安鹏); Xie Linzhen; Li Jingcong; Li Zhengbin; Xu Anshi

    2004-01-01

    A Novel segmentation and feedback model (SFM) applied to resolve collision has been proposed. The SFM is featured with Burst Segmentation and Prioritized Feedback (BSPF) that are used to provide quality of service (QoS) and realize high throughput and faster switching in the optical burst switched networks. Simulation and performance analyses show that the SFM effectively avoid collision in optical burst switching (OBS). Long delay time of deflection routing and immature technology of wavelength converter and optical buffer are not employed in the SFM. The SFM not only realizes quick switching but also allows preemption for higher priority bursts.

  7. Universal method for constructing N-port non-blocking optical router based on 2 × 2 optical switch for photonic networks-on-chip.

    Science.gov (United States)

    Chen, Qiaoshan; Zhang, Fanfan; Ji, Ruiqiang; Zhang, Lei; Yang, Lin

    2014-05-19

    We propose a universal method for constructing N-port non-blocking optical router for photonic networks-on-chip, in which all microring (MR) optical switches or Mach-Zehnder (M-Z) optical switches behave as 2 × 2 optical switches. The optical router constructed by the proposed method has minimum optical switches, in which the number of the optical switches is reduced about 50% compared to the reported optical routers based on MR optical switches and more than 30% compared to the reported optical routers based on M-Z optical switches, and therefore is more compact in footprint and more power-efficient. We also present a strict mathematical proof of the non-blocking routing of the proposed N-port optical router.

  8. Performance analysis of optical multicast in a new switching structure

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The emergence of new services demands multicast function in optical network.Because of the high cost and complex architecture of multicast capable (MC) node, splitter-sharing switch structure is introduced in which the light splitters are shared by all input signals.To accommodate to this situation, by extending resource ReSerVation protocol-traffic engineering (RSVP-TE) and open shortest path first-traffic engineering (OSPF-TE), a new optical multicast mechanism is provided and the signaling flow and its finite state machine model are given.At the same time, a multicast routing algorithm in splitter-sharing optical network and a changing link weight policy to balance network traffic are proposed.Simulations in NSFNET show no matter with or without wavelength converters, when the number of splitters is 25% of that demanded by traditional MC nodes, the multicast performance has been close to the ideal circumstance.Wavelength converters and changing link weight help much in improving the traffic performance when the number of splitters is adequate.

  9. Magnetostrictive Micro Mirrors for an Optical Switch Matrix

    Directory of Open Access Journals (Sweden)

    Myeong-Woo Cho

    2007-10-01

    Full Text Available We have developed a wireless-controlled compact optical switch by siliconmicromachining techniques with DC magnetron sputtering. For the optical switchingoperation, micro mirror is designed as cantilever shape size of 5mm×800μm×50μm.TbDyFe film is sputter-deposited on the upper side of the mirror with the condition as: Argas pressure below 1.2×10-9 torr, DC input power of 180W and heating temperature of up to250°C for the wireless control of each component. Mirrors are actuated by externallyapplied magnetic fields for the micro application. Applied beam path can be changedaccording to the direction and the magnitude of applied magnetic field. Reflectivity changes,M-H curves and X-ray diffractions of sputtered mirrors are measured to determine magneto-optical, magneto-elastic properties with variation in sputtered film thickness. The deflectedangle-magnetic field characteristics of the fabricated mirror are measured.

  10. Research of Asymmetric Y-Branching Total Internal Reflection All-Optical Switch

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Y-branching TIR all-optical switch have been fabricated. When the switching optical intensity is 149.9W/mm2, the extinction ratio is 18dB. A theoretical model was also proposed which provided a good fit to the experimental data.

  11. Compact Hybrid Subsystem of 16 Channel Optical Demultiplexer, 2x2 Switches, Optical Power Monitors and Control Circuit

    Institute of Scientific and Technical Information of China (English)

    Kenichiro Takahashi; Toshihiko Kishimoto; Shintaro Mouri; Youichi Hata; Hideaki Yusa; Mitsuaki Tamura; Kazuhito Saito; Hisao Maki

    2003-01-01

    A compact hybrid subsystem of 16channel optical demultiplexer, 2x2 switches, optical power monitors and control circuit board is developed. The subsystem is able to add or drop arbitrary optical channels and monitor the optical power level by software commands. The size of the subsystem is 170x200x30(mm).

  12. A Novel All-Optical Switch in a Double-Loop Sagnac Ring Coupled with a Nonlinear Ring Resonator

    Institute of Scientific and Technical Information of China (English)

    LI Jun-Qing; LI Li; ZHAO Jia-Qun; LI Chun-Fei

    2004-01-01

    @@ We propose a novel configuration of all-optical switch based on a double-loop Sagnac ring coupled with a nonlinear ring resonator. In the case of self-phase modulation, the reducing switching threshold power down to mW is predicted, which is the improvement of earlier works on all-optical switches. The switch optimization is analysed.A way to increase the response speed of all-optical switches is suggested.

  13. Laser Trimming for Adjustment of Grating Offset in Phase-Shifted Fiber Grating Coupler for All-Optical Switching Application

    Institute of Scientific and Technical Information of China (English)

    Hirohisa; Yokota; Yutaka; Sasaki

    2003-01-01

    We theoretically investigated laser trimming to adjust grating offset in phase-shifted fiber grating coupler (FGC) for all-optical switching application. It was clarified that the trimming made the extinction ratio higher in all-optical FGC switch.

  14. Thermo-optically tunable switching in an electro-microtube ring resonator

    Science.gov (United States)

    Zeng, Jing; Zhu, Tao; Deng, Ming

    2015-07-01

    We propose a tunable optical switching based on thermo-optic nonlinear effect in an electro-microtube ring resonator (EMRR) made by a capillary embedded with a heating wire. The significant modes shift in the EMRR for nonlinear switching are attributed to a huge joule heat generated by the heating wire, leading to the resonant wavelength shifts over 0.9nm when using 250mA current. In our viewpoints, with such a significant performance, the EMRR may be practically applied to switching, optical filter, sensing and optical network process.

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

    Science.gov (United States)

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

    2016-01-01

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

  16. A vertically-coupled liquid-crystal long-range plasmonic optical switch

    CERN Document Server

    Zografopoulos, Dimitrios C

    2012-01-01

    An optical switch based on liquid-crystal tunable long-range metal stripe waveguides is proposed and theoretically investigated. A nematic liquid crystal layer placed between a vertical configuration consisting of two gold stripes is shown to allow for the extensive electro-optic tuning of the coupler's waveguiding characteristics. Rigorous liquid-crystal switching studies are coupled with the investigation of the optical properties of the proposed plasmonic structure, taking into account different excitation conditions and the impact of LC-scattering losses. A directional coupler optical switch is demonstrated, which combines low power consumption, low cross-talk, short coupling lengths, along with sufficiently reduced insertion losses.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    In this paper, we report on an experimental validation of dynamic distribution of wireless-over-fiber by employing optical switching using semiconductor optical amplifiers; the rest of the network was designed according to the channel distribution over the optical spectra required by the optical...

  18. All optical contention detection and resolution for asynchronous variable length optical packets switching

    Science.gov (United States)

    Farhat, Rim; Farhat, Amel; Menif, Mourad

    2016-04-01

    We proposed a novel 2×2 all optical packet switching router architecture supporting asynchronous, labelled and variablelength packet. A proof of concept through Matlab Simulink simulation is validated. Then we discussed the three possible scenarios to demonstrate the contention resolution technique based on deflection routing. We have showing that the contending packet is detected and forwarded according FIFO (First In First Out) strategy to another output.

  19. All-optical encryption based on interleaved waveband switching modulation for optical network security.

    Science.gov (United States)

    Fok, Mable P; Prucnal, Paul R

    2009-05-01

    All-optical encryption for optical code-division multiple-access systems with interleaved waveband-switching modulation is experimentally demonstrated. The scheme explores dual-pump four-wave mixing in a 35 cm highly nonlinear bismuth oxide fiber to achieve XOR operation of the plaintext and the encryption key. Bit 0 and bit 1 of the encrypted data are represented by two different wavebands. Unlike on-off keying encryption methods, the encrypted data in this approach has the same intensity for both bit 0 and bit 1. Thus no plaintext or ciphertext signatures are observed.

  20. Patterning Effects in Ultrafast All-Optical Photonic Crystal Nanocavity Switches

    DEFF Research Database (Denmark)

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

    2011-01-01

    All-optical switches are expected to play a key role in increasing the bandwidth of future communication networks by replacing slower electronic components for certain signal processing tasks. Previous work has demonstrated the possibility of switching a single pulse [1,2]. However, a more...... realistic investigation of the switching performance requires longer random pulse sequences, since detrimental effects may accumulate over time scales longer than one pulse duration. This has been investigated for switches based on semiconductor optical amplifiers [3], but in this work the focus...

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

    Science.gov (United States)

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

    2007-11-01

    We present the results of a transmission experiment, over 110 km of field installed fiber, for an all-optical 160 Gb/s packet switching system. The system uses in-band optical labels which are processed entirely in the optical domain using a narrow-band all-optical filter. The label decision information is stored by an optical flip-flop, which output controls a high-speed wavelength converter based on ultra-fast cross-phase modulation in a single semiconductor optical amplifier. The packet switched node is located in between two different fiber sections, each having a length of 54.3-km. The field installed fibers are located around the city of Eindhoven in the Netherlands. The results show how the all-optical switch can effectively route the packets based on the optical information and that such packets may be transmitted across the fiber with an acceptable penalty level.

  2. Continuous wave terahertz spectroscopy system with stably tunable beat source using optical switch

    Science.gov (United States)

    Eom, Joo Beom; Kim, Chihoon; Ahn, Jaesung

    2017-01-01

    A tunable beat source has been made using an optical switch module. A stably-tunable beat source for continuous wave terahertz spectroscopy system was implemented by simply connecting 16 coaxial distributed feedback laser diodes to an optical switch. The terahertz frequency was rapidly changed without frequency drifts by changing the optical path. The continuous wave terahertz frequency was tuned from 0.05 to 0.8 THz in steps of 50 GHz or 0.4 nm. We measured continuous wave terahertz waveforms emitted from the photomixers using the switched optical beat source. We also calculated the terahertz frequency peaks by taking fast Fourier transforms of the measured terahertz waveforms. By equipping the implemented tunable beat source with an optical switch, a continuous wave terahertz spectroscopy system was constructed and used to demonstrate the feasibility of continuous wave terahertz spectroscopy for nondestructive tests using the spectra of two type of Si wafers with different resistivity.

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    In this paper we analyze the impact of WDM-enhanced optical circuit switching on the power consumption of multiple Data Center Network (DCN) architectures. Traditional three-tier Tree, Fat-Tree and a ring-based structure are evaluated and optical switching is selectively introduced on different l...... an optically switched core benefits most the ring-based network. For the latter, the core ring nodes need fewer long-reach transponders at the trunk interfaces and benefit from more efficient traffic grooming in the access part....

  4. Improved optical packet switching structure with recirculation buffer and feedback tunable wavelength converter

    Institute of Scientific and Technical Information of China (English)

    Cheng Wu; Shilin Xiao

    2009-01-01

    The performance of an optical switching network is mainly determined by its core node structure.An improved optical packet switching(OPS)node structure based on recirculation optical fiber delay line(FDL)and feedback tunable wavelength converter(TWC),and a specific scheduling algorithm for the node structure are presented.This switching structure supports both point-to-point and point-to-multi-points broadcasting transmission with superior capacity expansion performance.Its superiority in packet loss probability is proved by simulation.

  5. New Remote Gas Sensor Using Rapid Electro-Optical Path Switching

    Science.gov (United States)

    Sachse, G. W.; Lebel, P. J.; Wallio, H. A.; Vay, S. A.; Wang, L. G.

    1994-01-01

    Innovative gas filter correlation radiometer (GFCR) features nonmechanical switching of internal optical paths. Incoming radiation switched electro-optically, by means of polarization, between two optical paths, one of which contains correlation gas cell while other does not. Advantages include switching speed, 2 to 3 orders of magnitude faster than mechanical techniques, and high reliability. Applications include regional studies of atmospheric chemistry from either manned or unmanned aircraft as well as satellite studies of global distributions, sources and sink mechanisms for key species involved in chemistry of troposphere. Commercial applications: ability to survey many miles of natural gas pipelines rapidly from aircraft, pinpointing gas leaks by measuring methane at 2.3 micrometers.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

    We propose and demonstrate a new structure of a Data Vortex switch node for all-optical routing of wavelength-division-multiplexing (WDM) 10-Gb/s optical packets. The proposed node consists of two Mach-Zehnder interferometers with integrated semiconductor optical amplifier: an optical AND gate...... and a high-speed optical switch. In the experiment, WDM 10-Gb/s data packets are successfully routed with 1-dB power penalty at a bit-error rate of 10(-9)....

  7. Optical switches based on CdS single nanowire

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Yi [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Hu, Chenguo, E-mail: hucg@cqu.edu.cn [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); Zheng, Chunhua; Zhang, Hulin [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); Yang, Rusen [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245 (United States); Tian, Yongshu [Chongqing Communication College, Chongqing 400035 (China)

    2010-10-15

    CdS nanowires have been synthesized by a composite-hydroxide-mediated approach. The characterization of the nanowire with X-ray diffraction, scanning electron microscopy, and transmission electron microscopy indicated a single-crystalline hexagonal structure growing along [21-bar 1-bar 0] direction with length up to 100 {mu}m. The UV-visible reflection spectrum demonstrated a band gap of 2.36 eV. A strong light emission centered at 543 nm was observed under different excitation wavelengths of 300, 320, 360 and 400 nm, which was further confirmed by a bright fluorescent imaging of a single CdS nanowire. The photocurrent response based on a single CdS nanowire showed distinct optical switch under the intermittent illumination of white light. The rise and decay time were less than 1.0 and 0.2 s, respectively, indicating high crystallization with fewer trap centers in the CdS nanowires. It is possible that the undesirable trapping effects on grain-boundaries for photoconductors could be avoided thanks to the single-crystalline nature of the CdS nanowires.

  8. Optimizing Fiber Topologies for WDM Optical Networks Based on Multi-Granularity Optical Switching Technology

    Institute of Scientific and Technical Information of China (English)

    LI Junjie; ZHOU Bingkun; ZHANG Hanyi; LI Yanhe

    2006-01-01

    For the quality of service (QoS) and fairness considerations, the hop counts of various lightpaths in a wavelength division multiplexing (WDM) optical network should be short and compact. The development of multi-granularity optical switching technology has made it possible to construct various fiber topologies over a fixed physical topology. This paper describes a fiber topology design (FTD) problem, which minimizes the maximum number of required fibers in the physical links for a maximum lightpath hop count in the fiber topology. After the formular description for the FTD problem, a method was given to obtain the lower bound on the maximum number of required fibers. For large or moderate scale networks, three heuristic algorithms are given to efficiently solve the FTD problem. This study gives a new way to optimize the resource configuration performance in WDM optical networks at the topology level and proves its effectiveness via both analyses and numerical experiments.

  9. Investigation of patterning effects in ultrafast SOA-based optical switches

    DEFF Research Database (Denmark)

    Xu, Jing; Zhang, Xinliang; Mørk, Jesper

    2010-01-01

    Ultrafast optical switching employing semiconductor optical amplifier (SOA) based optical switches has been demonstrated at bitrates up to 640 Gbit/s. However, patterning effects caused by relatively slow recovery processes in semiconductor structures remain as an important deteriorating factor...... that limits the ultimate speed at which SOA-based switches can be operated. In this paper, we investigate the patterning effects of SOA-based switches using a systematic approach. A simple condition for the lower bound limit of the bit pattern length that should be adopted in the performance evaluations...... of the switches is derived. It is shown that the minimum bit pattern length scales linearly with the bitrate and the recovery time of the SOA. To overcome the excessive computation time needed for numerical analysis at long pseudorandom binary sequence (PRBS) lengths, an effective method, i.e., periodic method...

  10. Recurrent state-switching of a two-state quantum dot laser by optical feedback

    Science.gov (United States)

    Virte, Martin; Breuer, Stefan; Sciamanna, Marc; Panajotov, Krassimir

    2016-04-01

    In this contribution, we experimentally report recurrent switching between ground and excited state emission in a quantum dot laser controlled by optical feedback. We demonstrate that changing the phase of the optical feedback can efficiently induce switching between the two emission processes of the laser. Experimentally, by using an external mirror placed on a piezo-actuator, we were able to achieve incomplete switching between ground and excited state emission, i.e. without complete extinction of the modes. The switching takes place for variations of the external cavity length at the wavelength scale, i.e. around 1.2 um. Theoretically, we successfully link this switching behaviour with the evolution of the modal gain difference between the two modes induced by the variations of the optical feedback phase.

  11. An Easily Operating Polymer 1×4 Optical Waveguide Switch Matrix Based on Vertical Couplers

    Institute of Scientific and Technical Information of China (English)

    Kaixin Chen; Pak L Chu; Hau Ping Chan; Kin S. Chiang

    2007-01-01

    A three-dimensional (3D) polymer thermo-optic (TO) 1×4 waveguide switch matrix based on vertical couplers is demonstrated. It consists of four basic 3D switch units and because of its 3D structure, its construction is compact, only 9mm in length; moreover, the control logic of the entire switch is very simple, the light signal can be easily switched to any output port by operating only a single switch unit. The finished devices exhibit a switching extinction ratio greater than 21 dB for all of four output ports and the crosstalk between two adjacent output ports is lower than n for all switching units is about 50 mW.

  12. Electronic Transport Properties of a Naphthopyran-Based Optical Molecular Switch:an ab initio Study

    Institute of Scientific and Technical Information of China (English)

    XIA Cai-Juan; LIU De-Sheng; ZHANG Ying-Tang

    2011-01-01

    The electronic transport properties of a. Naphthopyran-based molecular optical switch are investigated by using the nonequilibrium Green's Function formalism combined with first-principles density functional theory. The molecule that comprises the switch can convert between its open and closed forms upon photoexcitation. Theoretical results show that the current through the open form is significantly larger than that through the closed form, which is different from other optical switches based on ring-opening reactions of the molecular bridge. The maximum on-off ratio (about 90) can be obtained at 1.4 V. The physical origin of the switching behavior is interpreted based on the spatial distributions of molecular orbitals and the HOMO-LUMO gap. Our result shows that the naphthopyran-based molecule is a good candidate for optical molecular switches and will be useful in the near future.%@@ ronic transport properties of a naphthopyran-based molecular optical switch are investigated by using the nonequilibrium Green's function formalism combined with first-principles density functional theory.The molecule that comprises the switch can convert between its open and closed forms upon photoexcitation.Theoretical results show that the current through the open form is significantly larger than that through the closed form,which is different from other optical switches based on ring-opening reactions of the molecular bridge.The maximum on-off ratio(about 90)can be obtained at 1.4 V.The physical origin of the switching behavior is interpreted based on the spatial distributions of molecular orbitals and the HOMO-LUMO gap.Our result shows that the naphthopyran-based molecule is a good candidate for optical molecular switches and will be useful in the near future.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    . In addition, we propose a novel synchronization algorithm that enables automatic synchronization of software defined networking controlled all-optical TDM switching nodes connected in a ring network. Besides providing synchronization, the algorithm also can facilitate dynamic slot size change and failure...... multiplexing transmission and switching of data bursts when using the proposed algorithm to provide synchronization....

  14. All-Optical Switching Using Fabry-Perot Laser Diodes(Invited paper)

    Institute of Scientific and Technical Information of China (English)

    P. K. A. Wai; L. Y. Chan; H. Y. Tam

    2003-01-01

    In this paper, we investigate all-optical packet switching using a multi-wavelength mutual injection-locked Fabry-Perot laser diode. We observe error-free packet-switching of a 10 Gb/s signal with an extinction ratio of 16.9.

  15. All-Optical Switching Using Fabry-Perot Laser Diodes (Invited paper)

    Institute of Scientific and Technical Information of China (English)

    P.; K.; A.; Wai; L.; Y.; Chan; H.; Y.; Tam

    2003-01-01

    In this paper, we investigate all-optical packet switching using a multi-wavelength mutual injection-locked Fabry-Perot laser diode. We observe error-free packet-switching of a 10 Gb/s signal with an extinction ratio of 16.9.

  16. 640 Gbit/s Optical Packet Switching using a Novel In-Band Optical Notch-Filter Labeling Scheme

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  17. Mode-selective optical packet switching in mode-division multiplexing networks.

    Science.gov (United States)

    Diamantopoulos, N P; Hayashi, M; Yoshida, Y; Maruta, A; Maruyama, R; Kuwaki, N; Takenaga, K; Uemura, H; Matsuo, S; Kitayama, K

    2015-09-07

    A novel mode-selective optical packet switching, based on mode-multiplexers/demultiplexers and multi-port optical micro-electro-mechanical systems (MEMS) switches, has been proposed and experimentally demonstrated. The experimental demonstration was performed using the LP(01), LP(11a) and LP(11b) modes of a 30-km long mode-division multiplexed few-mode fiber link, utilizing 40 Gb/s, 16-QAM signals.

  18. System description and initial performance results for beamlet

    Energy Technology Data Exchange (ETDEWEB)

    Van Wonterghem, B.M.; Murray, J.R.; Campbell, J.H. [and others

    1996-06-01

    The Department of Energy has proposed to design and construct a National Ignition Facility (NIF) for Inertial Confinement Fusion (ICF) research. This facility will contain a frequency-tripled, Nd:Glass laser system capable of irradiating fusion targets at an energy and power of 1.8 MJ and 500 TW. The laser output pulse contains most of the energy, where the low-intensity leading foot is 15-20 ns long and the final high-intensity pulse is 3-4 ns long. The laser will have 192 independent {open_quotes}beamlets,{close_quotes} each having a final square clear aperture of 40 x 40 cm{sup 2} and an output beam area slightly smaller than the clear aperture. A Conceptual Design Report (CDR), prepared in May 1994, discusses the laser and facility design in detail. The authors have constructed and are now testing a scientific prototype of a single beamlet of the proposed NIF laser. The purpose of these tests is to show that the novel features proposed for the NIF laser design will perform as projected and that the laser is ready for final engineering design. The final dimensions and component arrangements for NIF will differ somewhat from the scientific prototype, but the differences are sufficiently small that tests on the prototype can be used to demonstrate performance essentially equivalent to a NIF beamlet.

  19. Electrostatic steering and beamlet aiming in large neutral beam injectors

    Science.gov (United States)

    Veltri, P.; Cavenago, M.; Chitarin, G.; Marcuzzi, D.; Sartori, E.; Serianni, G.; Sonato, P.

    2015-04-01

    Neutral beam injection is the main method for plasma heating in magnetic confinement fusion devices. In high energy injector (E>100 keV/amu), neutrals are obtained with reasonable efficiency by conversion of negative ions (H- or D-) via electron detachment reactions. In the case of ITER injectors, which shall operate at 1 MeV, a total ion current of ˜ 40 A is required to satisfy the heating power demand. Gridded electrodes are therefore used in the accelerator, so that 1280 negative ion beamlets are accelerated together. A carefully designed aiming system is required to control the beamlet trajectories, and to deliver their power on a focal point located several meters away from the beam source. In nowadays injectors, the aiming is typically obtained by aperture offset technique or by grid shaping. This paper discuss an alternative concept of beamlets aiming, based on an electrostatic "steerer" to be placed at the end of the accelerator. A feasibility study of this component is also presented, and its main advantages and drawbacks with respect to other methods are discussed.

  20. Electrostatic steering and beamlet aiming in large neutral beam injectors

    Energy Technology Data Exchange (ETDEWEB)

    Veltri, P., E-mail: pierluigi.veltri@igi.cnr.it; Chitarin, G.; Marcuzzi, D.; Sartori, E.; Serianni, G.; Sonato, P. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4 - 35127 Padova (Italy); Cavenago, M. [INFN-LNL, viale dell' Università n. 2, 35020 Legnaro (Italy)

    2015-04-08

    Neutral beam injection is the main method for plasma heating in magnetic confinement fusion devices. In high energy injector (E>100 keV/amu), neutrals are obtained with reasonable efficiency by conversion of negative ions (H- or D-) via electron detachment reactions. In the case of ITER injectors, which shall operate at 1 MeV, a total ion current of ∼ 40 A is required to satisfy the heating power demand. Gridded electrodes are therefore used in the accelerator, so that 1280 negative ion beamlets are accelerated together. A carefully designed aiming system is required to control the beamlet trajectories, and to deliver their power on a focal point located several meters away from the beam source. In nowadays injectors, the aiming is typically obtained by aperture offset technique or by grid shaping. This paper discuss an alternative concept of beamlets aiming, based on an electrostatic ”steerer” to be placed at the end of the accelerator. A feasibility study of this component is also presented, and its main advantages and drawbacks with respect to other methods are discussed.

  1. 1×N rotary vertical micromirror for optical switching applications

    Science.gov (United States)

    Tu, Ching-Chen; Fanchiang, Kuohao; Liu, Cheng-Hsien

    2005-01-01

    We report a 1xN rotary optical switching mirror actuated by an electrostatic comb-driver for the optical networking. A variety of MEMS optical switching mirrors have been recently proposed. Some of these devices utilize surface micromachined films as reflection micromirrors and result in optical degradation. Some of these devices fabricated by bulk micromachining highly rely on delicate assembly for the micromirrors to the top of the actuators. In this paper, we focus on developing a rotary optical switching micromirror with no need of delicate assembly. The rotary actuator and the switching micromirror are both fabricated by deep RIE in our design. We use the Spin-On-Glass (SOG), which is used as the intermediated layer in the low temperature boning, to fabricate a rotary MEMS optical switching mirror with self-assembly. We successfully assemble the micromirror on top of the rotor stage of the rotary actuator. Experimental results show that our rotary vertical micromirror rotates about 1.5° under 150 volts. The first vibration mode of this rotary switching MEMS mirror is a rotary mode and appears around 3.4 kHz, which is measured via a Polytec laser doppler vibrometer.

  2. Single-photon all-optical switching using coupled microring resonators

    Indian Academy of Sciences (India)

    Wenge Yang; Amitabh Joshi; Min Xiao

    2007-08-01

    We study the nonlinear phase response of a microring resonator coupled to a bus waveguide and the use of this nonlinear phase shift to store information in the microring resonator and enhance the switching characteristics of a Mach–Zehnder interferometer (MZI). By introducing coupling between adjacent microring resonators, the switching characteristics of the MZI can be exponentially enhanced as a function of the number of microring resonators, when compared to the linear enhancement for uncoupled resonators. With only a few moderate-finesse microring resonators, the switching power can be reduced to attowatt level, allowing for photonic switching devices that operate at single-photon level in ordinary optical waveguides.

  3. A 4 × 4 Strictly Nonblocking Silicon-on-Insulator Thermo-Optic Switch Matrix

    Institute of Scientific and Technical Information of China (English)

    YANG Di; LI Yan-Ping; CHEN Shao-Wu; YU Jin-Zhong

    2005-01-01

    @@ A 4 × 4 strictly nonblocking thermo-optic switch matrix implemented with a 2 × 2 Mach-Zehnder switch unit was fabricated in silicon-on-insulator wafer. Insertion losses of the shortest and the longest path in the device are about 14.8dB and 19.2dB, respectively. The device presents a very low loss dependent on wavelength. For one switch unit, the power consumption needed for operation is measured to be 0.270 W-0.288 W and the switching time is about 13 ± 1μs.

  4. Fabrication of Thermo-Optic Switch in Silicon-on-Insulator

    Institute of Scientific and Technical Information of China (English)

    王章涛; 夏金松; 樊中朝; 陈少武; 余金中

    2003-01-01

    Silicon-on-insulator technology has been used to fabricate 2 × 2 thermo-optic switches. The switch shows crosstalk of-23.4 dB and extinction ratio of 18.1 dB in the bar-state. The switching speed is less than 30 μs and the power consumption is about 420mW. The measured excess loss is 1.8 dB. These merits make the switch more attractive for applications in wavelength division multiplexing.

  5. Efficient high repetition rate electro-optic Q-switched laser with an optically active langasite crystal

    Science.gov (United States)

    Ma, Shihui; Yu, Haohai; Zhang, Huaijin; Han, Xuekun; Lu, Qingming; Ma, Changqin; Boughton, Robert I.; Wang, Jiyang

    2016-07-01

    With an optically active langasite (LGS) crystal as the electro-optic Q-switch, we demonstrate an efficient Q-switched laser with a repetition rate of 200 kHz. Based on the theoretical analysis of the interaction between optical activity and electro-optic property, the optical activity of the crystal has no influence on the birefringence during Q-switching if the quarter wave plate used was rotated to align with the polarization direction. With a Nd:LuVO4 crystal possessing a large emission cross-section and a short fluorescence lifetime as the gain medium, a stable LGS Q-switched laser was designed with average output power of 4.39 W, corresponding to a slope efficiency of 29.4% and with a minimum pulse width of 5.1 ns. This work represents the highest repetition rate achieved so far in a LGS Q-switched laser and it can provide a practical Q-switched laser with a tunable high repetition rates for many applications, such as materials processing, laser ranging, medicine, military applications, biomacromolecule materials, remote sensing, etc.

  6. Cavity electromagnetically induced transparency and all-optical switching using ion Coulomb crystals

    DEFF Research Database (Denmark)

    Albert, Magnus; Dantan, Aurelien Romain; Drewsen, Michael

    2011-01-01

    nonlinear interactions, such as those based on electromagnetic induced transparency (EIT)2, 3, 4, 5, 6, 9, 10, 11, 12. Here, we demonstrate for the first time EIT as well as all-optical EIT-based light switching using ion Coulomb crystals situated in an optical cavity. Changes from essentially full...... transmission to full absorption of a single photon probe field are achieved within unprecedentedly narrow EIT windows of a few tens of kilohertz. By applying a weak switching field, this allows us to demonstrate nearly perfect switching of the transmission of the probe field. The results represent important...

  7. Compact all-optical switches based on photon-induced suppression of mode interference

    Institute of Scientific and Technical Information of China (English)

    Longzhi Li; Yi Tang; Jianyi Yang; Minghua Wang; Xiaoqing Jiang

    2006-01-01

    @@ An optically activated optical switch based on suppression of mode interference (SMI) is presented. The imaging properties of multi-mode interference (MMI) section in the switch with Y-branch can be modified by a controlling light injection. The switch was simulated by finite difference beam propagation method(FD-BPM) and fabricated on GaAIAs/GaAs epitaxial materials. At the wavelength of 1.31 μm, the primary experiment showed an extinction ratio of about 8 dB with controlling light power density of 73.5W/mm2.

  8. Ultrafast coherent dynamics of a photonic crystal all-optical switch

    CERN Document Server

    Colman, Pierre; Yu, Yi; Mørk, Jesper

    2016-01-01

    We present pump-probe measurements of an all-optical photonic crystal switch based on a nanocavity, resolving fast coherent temporal dynamics. The measurements demonstrate the importance of coherent effects typically neglected when considering nanocavity dynamics. In particular, we report the observation of an idler pulse. The measurements are in good agreement with a theoretical model that allows us to ascribe the observation to oscillations of the free carrier population in the nanocavity. The effect opens perspectives for the realization of new all-optical photonic crystal switches with unprecedented switching contrast.

  9. Synthesis, physical properties and simulation of thermo-optic switch based on azo benzothiazole heterocyclic polymer

    Science.gov (United States)

    Qiu, Fengxian; Chen, Caihong; Zhou, Qiaolan; Cao, Zhijuan; Cao, Guorong; Guan, Yijun; Yang, Dongya

    2014-05-01

    A chromophore molecule 4-[(benzothiazole-2-yl)diazenyl]phenyl-1,3-diamine (BTPD) was prepared with 2-amino benzothiazole and m-phenylenediamine by diazo-coupling reaction. Then, the BTPD was polymerized with polyether polyol (NJ-220) and isophorone diisocyanate (IPDI) to obtain novel azo benzothiazole polyurethane-urea (BTPUU). The chemical structures of BTPD and BTPUU were characterized by FT-IR and UV-visible spectroscopy. The thermal and mechanical properties of BTPUU film were investigated. The refractive index and transmission loss of BTPUU film were measured at different temperatures and different laser wavelengths (532 nm, 650 nm and 850 nm) by an attenuated total reflection (ATR) technique and CCD digital imaging devices. The thermo-optic coefficients of BTPUU are -4.7086 × 10-4 °C-1 (532 nm), -6.5257 × 10-4 °C-1 (650 nm) and -5.1029 × 10-4 °C-1 (850 nm), respectively. A Y-branch switch and Mach-Zehnder interferometer (MZI) thermo-optic switches based on thermo-optic effect were proposed and the performances of the switches were simulated, respectively. The results show that the power consumption of the Y-branch thermo-optic switch is only 3.28 mW. The response times of Y-branch and MZI switches are 8.0 ms and 2.0 ms, respectively. The results indicate that the prepared BTPUU has high potential for the applications of the Y-branch digital optical switch (DOS), MZI thermo-optic switch, directional coupler (DC) switch and optical modulators.

  10. Energy-bandwidth trade-off in all-optical photonic crystal microcavity switches

    DEFF Research Database (Denmark)

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

    2011-01-01

    The performance of all-optical switches is a compromise between the achievable bandwidth of the switched signal and the energy requirement of the switching operation. In this work we consider a system consisting of a photonic crystal cavity coupled to two input and two output waveguides....... As a specific example of a switching application, we investigate the demultiplexing of an optical time division multiplexed signal. To quantify the energy-bandwidth trade-off, we introduce a figure of merit for the detection of the demultiplexed signal. In such investigations it is crucial to consider...... patterning effects, which occur on time scales that are longer than the bit period. Our analysis is based on a coupled mode theory, which allows for an extensive investigation of the influence of the system parameters on the switching dynamics. The analysis is shown to provide new insights into the ultrafast...

  11. Optimization of silicon-on-insulator based optical switch using tapered waveguides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optimiz ed 2×2 switches based on silicon-on-insulator (SOI) were demonstrated. In the design, single mode rib waveguides and multimode interferences (MMIs) are connected by tapered waveguides to reduce the mode coupling loss between the two types of waveguides. The average insertion loss of the switches is about -16.9 dB and the excess loss of one is measured of -1.3 dB. The worst crosstalk is larger than 25 dB. Experimental results indicate that some of the main characteristics of optical switches are improved in the modified design, which is according with theoretic analysis. The novel design can be used to improve the characteristics of optical switch matrixes based on 2×2 switch units.

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

  13. Analysis of S-SEED's characteristics in optical switch

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This article introduces the basic structure of a symmetric self-electrooptic effect device (S-SEED), and applies the Kirchoff's current law and a purely equivalent capacitive model, to analyze S-SEED's switch characteristics. Linear approximation and N-segment approximation are utilized to obtain S-SEED's voltage-time (V-T) and characteristics. Theoretical analysis is verified by simulations, and the results demonstrate that the precision of S-SEED's switch time can satisfy the requirement in applications with linear approximation. Moreover, the simulations compare S-SEED's switch characteristics with different input powers and input contrast ratios, which reveal that increasing input contrast ratio is an effective way to improve S-SEED's switch characteristics.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  15. Inertial Confinement Fusion quarterly report, October--December 1994. Volume 5, No. 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The ICF quarterly report is published by the Inertial Confinement Fusion Program at the Lawrence Livermore National Laboratory. Topics included in this issue include: system description and initial performance results for beamlet, design and performance of the beamlet amplifiers and optical switch, beamlet pulse-generation and wavefront-control system, large-aperture, high- damage-threshold optics for beamlet, beamlet pulsed power system, beamlet laser diagnostics, and beam propagation and frequency conversion modeling for the beamlet laser.

  16. Nonlinear optical switching and optical limiting in colloidal CdSe quantum dots investigated by nanosecond Z-scan measurement

    Science.gov (United States)

    Valligatla, Sreeramulu; Haldar, Krishna Kanta; Patra, Amitava; Desai, Narayana Rao

    2016-10-01

    The semiconductor nanocrystals are found to be promising class of third order nonlinear optical materials because of quantum confinement effects. Here, we highlight the nonlinear optical switching and optical limiting of cadmium selenide (CdSe) quantum dots (QDs) using nanosecond Z-scan measurement. The intensity dependent nonlinear absorption and nonlinear refraction of CdSe QDs were investigated by applying the Z-scan technique with 532 nm, nanosecond laser pulses. At lower intensities, the nonlinear process is dominated by saturable absorption (SA) and it is changed to reverse saturable absorption (RSA) at higher intensities. The SA behaviour is attributed to the ground state bleaching and the RSA is ascribed to free carrier absorption (FCA) of CdSe QDs. The nonlinear optical switching behaviour and reverse saturable absorption makes CdSe QDs are good candidate for all-optical device and optical limiting applications.

  17. Efficient all-optical switch using a Λ atom in a cavity QED system

    DEFF Research Database (Denmark)

    Nielsen, Anne E. B.; Kerckhoff, Joseph

    2011-01-01

    We propose an all-optical switch constructed from a two-mode optical resonator containing a strongly coupled, three-state system. The coupling allows a weak, continuous wave laser drive to incoherently control the transmission of a much stronger, continuous wave signal laser into (and through) th...

  18. Optical Waveguide Switches Employing Total-Internal-Reflection (TIR) Effect (Invited Paper)

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this paper, our recent research work on the total-internal-reflection optical switch is presented. The thermo-optic effect of polymeric materials and the photon-induced carrier effect of GaAlAs/GaAs are used in our devices.

  19. An all-optical matrix multiplication scheme with non-linear material based switching system

    Institute of Scientific and Technical Information of China (English)

    Archan Kumar Das; Sourangshu Mukhopadhyay

    2005-01-01

    Optics is a potential candidate in information, data, and image processing. In all-optical data and information processing, optics has been used as information carrying signal because of its inherent advantages of parallelism. Several optical methods are proposed in support of the above processing. In many algebraic,arithmetic, and image processing schemes fundamental logic and memory operations are conducted exploring all-optical devices. In this communication we report an all-optical matrix multiplication operation with non-linear material based switching circuit.

  20. Nonlinear all-optical switch based on a white-light cavity

    Science.gov (United States)

    Li, Na; Xu, Jingping; Song, Ge; Zhu, Chengjie; Xie, Shuangyuan; Yang, Yaping; Zubairy, M. Suhail; Zhu, Shi-Yao

    2016-04-01

    It is well known that there is a bottleneck for nonlinear all-optical switching, namely, the switching power and the switching time cannot be lowered simultaneously. A lower switching power requires a resonator with a high quality (Q ) factor, but leads to a longer switching time. We propose to overcome this bottleneck by replacing the nonlinear cavity in such an all-optical switch by a white-light cavity. This can be done by doping three-level atoms in the ring resonator and applying incoherent pump and coherent driving fields on it. The white-light cavity possesses broadband resonance in a linear region. Therefore, for the incident pulse, a broad range of frequency components can take part in the nonlinear process, and so it requires lower power to achieve switching compared to the conventional ring resonator. On the other hand, the refractive index of a white-light cavity has negative dispersion, leading to a fast group velocity. This results in a shorter time to build up the resonant response, yielding a short switching time.

  1. Dynamics of all-optically switched micropillar resonances

    CERN Document Server

    Thyrrestrup, Henri; Ctistis, Georgios; Claudon, Julien; Vos, Willem L

    2014-01-01

    Here we do frequency and time resolved switching of a single GaAs/AlGa micropillar cavity with a pillar diameter of 6 mu using a ultrafast pump-probe setup. The switching is achieved by two-photon excitation of free carriers by an femtosecond pump pulse. We observe a simultaneously frequency shift of the first two transverse micropillar modes and obtain high resolution frequency traces of the two resonances in time. A difference in the the maximum switching magnitude of 12% point is caused by spatial inhomogeneous excitation of carriers in the pillar. The relaxation dynamic of the two resonances show a strongly non-exponential decay. We interpret the non-exponential dynamics in term of a second order decay model for the spontaneous recombination of electron and hole for the free carriers and a slow free carrier trapping time of ~300 ps.

  2. A New All-Optical Switching Node Including Virtual Memory and Synchronizer

    Directory of Open Access Journals (Sweden)

    Selma Batti

    2010-02-01

    Full Text Available This paper presents an architecture for an all optical switching node. The architecture is suitable for optical packet and optical burst switching and provides appropriate contention resolution schemes and QoS guarantees. A concept, called virtual memory, is developed to allow controllable and reasonable periods for delaying optical traffics. Related to its implementation, several engineering issues are discussed, including the use of loopbased optical delay lines, fiber Bragg gratings, and limited number of signal amplifications. In particular, two implementations using optical flip-flop and laser neuron network based control units are analyzed. This paper also discusses the implementation and performance of an alloptical synchronizer that is able to synchronize arriving data units to be aligned on the clock signal associated with the beginning time of slots, in the node, with an acceptable error.

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

    CERN Document Server

    Bányai, L

    1989-01-01

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

  4. Ultrafast all-optical switching using signal flow graph for PANDA resonator.

    Science.gov (United States)

    Bahadoran, Mahdi; Ali, Jalil; Yupapin, Preecha P

    2013-04-20

    In this paper, the bifurcation behavior of light in the PANDA ring resonator is investigated using the signal flow graph (SFG) method, where the optical transfer function for the through and drop ports of the PANDA Vernier system are derived. The optical nonlinear phenomena, such as bistability, Ikeda instability, and dynamics of light in the silicon-on-insulator (SOI) PANDA ring resonator with four couplers are studied. The transmission curves for bistability and instability as a function of the resonant mode numbers and coupling coefficients for the coupler are derived by the SFG method and simulated. The proposed system has an advantage as no optical pumping component is required. Simulated results show that closed-loop bistable switching can be generated and achieved by varying mode resonant numbers in the SOI-PANDA Vernier resonator, where a smooth and closed-loop bistable switching with low relative output/input power can be obtained and realized. The minimum through-port switching time of 1.1 ps for resonant mode numbers of 5;4;4 and minimum drop port switching time of 1.96 ps for resonant mode numbers of 9;7;7 of the PANDA Vernier resonator are achieved, which makes the PANDA Vernier resonator an operative component for optical applications, such as optical signal processing and a fast switching key in photonics integrated circuits.

  5. Optimized design and fabrication of nanosecond response electro optic switch based on ultraviolet-curable polymers

    Institute of Scientific and Technical Information of China (English)

    赵旭亮; 岳远斌; 刘通; 孙健; 王希斌; 孙小强; 陈长鸣; 张大明

    2015-01-01

    A nanosecond response waveguide electro-optic (EO) switch based on ultraviolet (UV) sensitive polymers of Norland optical adhesive (NOA73) and Dispersed Red 1 (DR1) doped SU-8 (DR1/SU-8) is designed and fabricated. The absorption properties, refractive indexes, and surface morphologies of NOA73 film are characterized. The single-mode transmission condition is computed by the effective index method, and the percentage of optical field distributed in EO layer is optimized to be 93.78%. By means of spin-coating, thermal evaporation, photolithography, and inductively coupled plasma etching, a Mach–Zehnder inverted-rib waveguide EO switch with micro-strip line electrode is fabricated on a silicon substrate. Scanning electron microscope characterization proves the physic-chemical compatibility between NOA73 cladding and DR1/SU-8 core material. The optical transmission loss of the fabricated switch is measured to be 2.5 dB/cm. The rise time and fall time of switching are 3.199 ns and 2.559 ns, respectively. These results indicate that the inverted-rib wave-guide based on UV-curable polymers can effectively reduce the optical transmission loss and improve the time response performance of an EO switch.

  6. RETRACTED — Preparation of helical biphenyl polyurethane and its low power consumption thermo-optic switch

    Science.gov (United States)

    Wang, Qing; Qiu, Fengxian; Yang, Dongya; Cao, Guorong; Guan, Yijun; Shen, Qiang; Zhuang, Lin; Cao, Zhijuan; Ye, Feiyan

    2013-04-01

    Azo chromophore molecule (NDPD) and helical biphenyl polyurethane (HBPU) were prepared. The chemical structures of NDPD and HBPU were characterized by FTIR and UV-vis spectroscopy. The measurements of refractive index, thermo-optic coefficient (dn/dT), transmission loss, refractive index dispersions and Sellmeyer coefficients of HBPU were measured using ATR technique, CCD digital imaging devices and Sellmeyer equation. The results showed that HBPU would be useful for the design of high performance digital optical switch. The prepared HBPU was utilized as core material to propose a Y-branch thermo-optic switch, which was based on thermo-optic effect of HBPU at the infrared communication wavelength of 1.55 μm. With branching angle of 0.143° and the finite difference beam propagation method (FD-BPM), the polymeric thermo-optic switch was simulated. The simulation results indicated that the device has a low switching power of 1.68 mW and a switching response time of 7.0 ms.

  7. A scalable silicon photonic chip-scale optical switch for high performance computing systems.

    Science.gov (United States)

    Yu, Runxiang; Cheung, Stanley; Li, Yuliang; Okamoto, Katsunari; Proietti, Roberto; Yin, Yawei; Yoo, S J B

    2013-12-30

    This paper discusses the architecture and provides performance studies of a silicon photonic chip-scale optical switch for scalable interconnect network in high performance computing systems. The proposed switch exploits optical wavelength parallelism and wavelength routing characteristics of an Arrayed Waveguide Grating Router (AWGR) to allow contention resolution in the wavelength domain. Simulation results from a cycle-accurate network simulator indicate that, even with only two transmitter/receiver pairs per node, the switch exhibits lower end-to-end latency and higher throughput at high (>90%) input loads compared with electronic switches. On the device integration level, we propose to integrate all the components (ring modulators, photodetectors and AWGR) on a CMOS-compatible silicon photonic platform to ensure a compact, energy efficient and cost-effective device. We successfully demonstrate proof-of-concept routing functions on an 8 × 8 prototype fabricated using foundry services provided by OpSIS-IME.

  8. Comments on: Optical computation based on nonlinear total reflectional optical switch at the interface

    Indian Academy of Sciences (India)

    Y A Zaghloul

    2015-12-01

    As we read the paper by Jianqi Zhang and Huan Xu, Pramana – J. Phys. 72, 547 (2009), two issues became clear, that warranted writing this comment. First, the switch, which is the main building block of the devices, and which is used to route the signal, does not work as explained in Section 4.1. Accordingly, the optical router does not work as explained, either. In addition, the half adder does not work as explained and a completely different Truth Table is obtained. The full adder is left to the reader as an exercise. Secondly, the previously published work, which is closely related to the work reported, was not referenced or discussed. In the following paragraphs we discuss each issue in some detail to give the authors the opportunity to better explain their work and clear such issues.

  9. A novel graphene oxide-polyimide as optical waveguide material: Synthesis and thermo-optic switch properties

    Science.gov (United States)

    Cao, Tianlin; Zhao, Fanyu; Da, Zulin; Qiu, Fengxian; Yang, Dongya; Guan, Yijun; Cao, Guorong; Zhao, Zerun; Li, Jiaxin; Guo, Xiaotong

    2016-10-01

    In this work, a novel graphene oxide-polyimide (GOPI) as optical waveguide material was prepared. The structure, mechanical, thermal property and morphology of the GOPI was characterized by using fourier transform infrared, UV-visible spectroscopy, near-infrared spectrum, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscope and transmission electron microscopy. The thermo-optic coefficients (dn/dT) are -9.16 × 10-4 (532 nm), -7.56 × 10-4 (650 nm) and -4.82 × 10-4 (850 nm) °C-1, respectively. Based on the thermo-optic effect of prepared GOPI as waveguide material, a Y-branch with branching angle of 0.143° and Mach-Zehnder thermo-optic switches were designed. Using finite difference beam propagation method (FD-BPM) method, the simulation results such as power consumptions and response times of two different thermo-optic switches were obtained.

  10. Experimental Demonstration of Optical Switching of Tbit/s Data Packets for High Capacity Short-Range Networks

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros; Kamchevska, Valerija; Hu, Hao;

    2015-01-01

    Record-high 1.28-Tbit/s optical data packets are experimentally switched in the optical domain using a LiNbO3 switch. An in-band notch-filter labeling scheme scalable to 65,536 labels is employed and a 3-km transmission distance is demonstrated.......Record-high 1.28-Tbit/s optical data packets are experimentally switched in the optical domain using a LiNbO3 switch. An in-band notch-filter labeling scheme scalable to 65,536 labels is employed and a 3-km transmission distance is demonstrated....

  11. Design of buffer structure at core nodes in optical burst switching

    Institute of Scientific and Technical Information of China (English)

    LI Lei; ZHANG Min-gde; SUN Xiao-han

    2006-01-01

    Reasonable and effective buffer structures are proposed in core routers /nodes of optical burst switching.Based on the model of burst traffics and their contentions,the basic qualifications for the design of buffer structures are concluded.With these qualifications,buffer and switch integrated structures are proposed;and by conclusion and expansion,the classification rules of buffer structures are also proposed from different angles.The schemes to integrate structures are analyzed and simulated.

  12. Optimum design of a polymer electro-optic microring resonator switch

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Novel transfer functions are presented for a polymer electro-optic microring resonator switches. The resonating process of the light in the microring is simulated using the formulas. Then the optimization of the structural parameters is performed,and the characteristics are analyzed, such as the resonance time, output spectrum, operation voltage, insertion loss and crosstalk were analyzed. The simulation results show that the designed device exhibits favorable switching functions.

  13. Optical switching of cross intensity correlation in cavity electromagnetically induced transparency

    Science.gov (United States)

    Rao, Shi; Hu, Xiangming; Xu, Jun; Li, Lingchao

    2017-03-01

    We present optical switching of cross intensity correlation in the context of cavity electromagnetically induced transparency configuration. For symmetrical parameters, the cross intensity correlation switches from negative to positive as the atom–pump detunings change symmetrically from one case to the other. In terms of the dressed atomic states and the Bogoliubov modes we analyze the atom–photon interaction mechanism for the switching behavior, and present a numerical verification. As a by-product, we show noise squeezing of the sum or difference intensity in a limited region of parameters.

  14. Performance Trade-Offs for Wavelength Striping Optical Switching Using a Novel Star Architecture

    Directory of Open Access Journals (Sweden)

    Enrique Rodriguez-Colina

    2016-01-01

    Full Text Available This work describes various performance trade-offs that arise from the use of a technique for optical switching under various network topologies. Such switching operation can be summarized as follows: (a user data are divided into fixed-length fragments, (b each fragment is assigned to a different wavelength, and (c all wavelengths are simultaneously switched to the egress links. This concept of dividing user data into several wavelengths to be simultaneously switched is called wavelength striping and its purpose is to reduce latency and increase throughput for short distance interconnects. We depart from previous work where a building block implementing this basic switching function has been built around semiconductor optical amplifiers (SOAs. In this paper, we investigate diverse trade-offs that arise from the use of this switching approach in different network topologies. One of the main issues addressed in this paper is the relation between cascadability and bit error rate (BER. In this case, our results indicate that a switch fabric can cascade up to five stages without exceeding a BER of 10−9 and without incurring in power budget problems. We also show that the performance degradation, introduced by cascading SOAs, can be compensated with a star interconnect architecture that is introduced. Other issues addressed in this paper are the effect of scalability on cost and the effect of latency on TCP performance and reliability.

  15. A Simple Performance Analysis of a Core Node in an Optical Burst Switched Network

    CERN Document Server

    Morsy, Mohamed H S; Shalaby, Hossam M H

    2008-01-01

    A simple mathematical model that considers the performance of an intermediate node having wavelength conversion capability in an OBS network is presented in this paper. The model assumes that the node has variable wavelength conversion capability which means that the node may have no, partial or full conversion capability. Two performance measures are derived from the model; namely, the steady state throughput and the average burst loss probability assuming Poisson traffic arrivals. In addition, a simulation work is performed in order to validate the results of our proposed model. Optimum values for the wavelength conversion capability in the node, which lead to minimum burst loss probability, are reached for different traffic conditions. Keywords: Optical Burst Switching (OBS), Optical Circuit Switching (OCS), Optical Packet Switching (OPS), Just-In-Time (JIT), Just-Enough-Time (JET).

  16. Ultrafast, broadband, and configurable midinfrared all-optical switching in nonlinear graphene plasmonic waveguides

    Directory of Open Access Journals (Sweden)

    Kelvin J. A. Ooi

    2016-07-01

    Full Text Available Graphene plasmonics provides a unique and excellent platform for nonlinear all-optical switching, owing to its high nonlinear conductivity and tight optical confinement. In this paper, we show that impressive switching performance on graphene plasmonic waveguides could be obtained for both phase and extinction modulations at sub-MW/cm2 optical pump intensities. Additionally, we find that the large surface-induced nonlinearity enhancement that comes from the tight confinement effect can potentially drive the propagating plasmon pump power down to the pW range. The graphene plasmonic waveguides have highly configurable Fermi-levels through electrostatic-gating, allowing for versatility in device design and a broadband optical response. The high capabilities of nonlinear graphene plasmonics would eventually pave the way for the adoption of the graphene plasmonics platform in future all-optical nanocircuitry.

  17. Sub-picosecond optical switching with a negative index metamaterial

    Energy Technology Data Exchange (ETDEWEB)

    Dani, Keshav M [Los Alamos National Laboratory; Upadhya, Prashant C [Los Alamos National Laboratory; Zahyum, Ku [CHTM-UNM

    2009-01-01

    Development of all-optical signal processing, eliminating the performance and cost penalties of optical-electrical-optical conversion, is important for continu,ing advances in Terabits/sec (Tb/s) communications.' Optical nonlinearities are generally weak, traditionally requiring long-path, large-area devicesl,2 or very high-Q, narrow-band resonator structures.3 Optical metamaterials offer unique capabilities for optical-optical interactions. Here we report 600 femtosecond (fs) all-optical modulation using a fIShnet (2D-perforated metallamorphous-Si (a-Si)/metal film stack) negative-index meta material with a structurally tunable broad-band response near 1.2 {micro}m. Over 20% modulation (experimentally limited) is achieved in a path length of only 116 nm by photo-excitation of carriers in the a-Si layer. This has the potential for Tb/s aU-optical communication and will lead to other novel, compact, tunable sub-picosecond (ps) photonic devices.

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

    DEFF Research Database (Denmark)

    Colman, Pierre; Heuck, Mikkel; Yu, Yi;

    2014-01-01

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

  19. Fast and efficient silicon thermo-optic switching based on reverse breakdown of pn junction.

    Science.gov (United States)

    Li, Xianyao; Xu, Hao; Xiao, Xi; Li, Zhiyong; Yu, Yude; Yu, Jinzhong

    2014-02-15

    We propose and demonstrate a fast and efficient silicon thermo-optic switch based on reverse breakdown of the pn junction. Benefiting from the direct heating of silicon waveguide by embedding the pn junction into the waveguide center, fast switching with on/off time of 330 and 450 ns and efficient thermal tuning of 0.12  nm/mW for a 20 μm radius microring resonator are achieved, indicating a high figure of merit of only 8.8  mW·μs. The results here show great potential for application in the future optical interconnects.

  20. Harnessing the polariton drag effect to design an electrically controlled optical switch.

    Science.gov (United States)

    Berman, Oleg L; Kezerashvili, Roman Ya; Kolmakov, German V

    2014-10-28

    We propose a design of a Y-shaped electrically controlled optical switch based on the studies of propagation of an exciton-polariton condensate in a patterned optical microcavity with an embedded quantum well. The polaritons are driven by a time-independent force due to the microcavity wedge shape and by a time-dependent drag force owing to the interaction of excitons in a quantum well and the electric current running in a neighboring quantum well. It is demonstrated that by applying the drag force one can direct more than 90% of the polariton flow toward the desired branch of the switch with no hysteresis. By considering the transient dynamics of the polariton condensate, we estimate the response speed of the switch as 9.1 GHz. We also propose a design of the polariton switch in a flat microcavity based on the geometrically identical Y-shaped quantum wells where the polariton flow is only induced by the drag force. The latter setup enables one to design a multiway switch that can act as an electrically controlled optical transistor with on and off functions. Finally, we performed the simulations for a microcavity with an embedded gapped graphene layer and demonstrated that in this case the response speed of the switch can be increased up to 14 GHz for the same switch size. The simulations also show that the energy gap in the quasiparticle spectrum in graphene can be utilized as an additional parameter that controls the propagation of the signals in the switch.

  1. Switching between optical bistability and multistability in plasmonic multilayer nanoparticles

    Science.gov (United States)

    Daneshfar, Nader; Naseri, Tayebeh

    2017-01-01

    We study the nonlinear optical response of multilayer metallic nanoparticles driven by an electromagnetic wave, which can show large field enhancement, hence significantly enhancing optical processes. In addition to optical bistability (OB), we find that optical multistability (OM), which plays a more important role in some applications than OB, is achievable and can be obtained in a multilayer plasmonic nanoparticle. Our results demonstrate that owing to strong localized fields created in the core and each layer of multilayer nanoshells, which occurs in the particles at frequencies close to the surface plasmon resonance, multilayer nanoparticles are promising systems with unique optical characteristics to control the light by light at the nanometer scale. It is demonstrated that OB can be converted to OM via adjusting the wavelength of the applied field and the size of the nanoshell, and the system can manifest optical hysteresis. It is found that the optical bistable or multistable threshold and the shape of hysteresis loops are strongly dependent on the thickness of shells, the incident wavelength, the permittivity of the surrounding medium, and the composition of the core and the inner/outer layers. We also give a discussion on the impact of the exciton-plasmon interaction and the intrinsic size effect on the nonlinear optical response of multilayer spherical nanoparticles.

  2. On the Highly Stable Performance of Loss-Free Optical Burst Switching Networks

    Directory of Open Access Journals (Sweden)

    Milos Kozak

    2016-01-01

    Full Text Available Increase of bandwidth demand in data networks, driven by the continuous growth of the Internet and the increase of bandwidth greedy applications, raise the issue of how to support all the bandwidth requirements in the near future. Three optical switching paradigms have been defined and are being investigated: Optical Circuit Switching (OCS; Optical Packet Switching (OPS; and Optical Burst Switching (OBS. Among these paradigms, OBS is seen as the most appropriate solution today. However, OBS suffers from high burst loss as a result of contention in the bufferless mode of operation. This issue was investigated by Coutelen et al., 2009 who proposed the loss-free CAROBS framework whereby signal convertors of the optical signal to the electrical domain ensure electrical buffering. Convertors increase the network price which must be minimized to reduce the installation and operating costs of the CAROBS framework. An analysis capturing convertor requirements, with respect to the number of merging flows and CAROBS node offered load, was carried out. We demonstrated the convertor location significance, which led to an additional investigation of the shared wavelength convertors scenario. Shared wavelength convertors significantly decrease the number of required convertors and show great promise for CAROBS. Based on this study we can design a CAROBS network to contain a combination of simple and complex nodes that include none or some convertors respectively, a vital feature of network throughput efficiency and cost.

  3. Design of a Multicast Optical Packet Switch Based on Fiber Bragg Grating Technology for Future Networks

    Science.gov (United States)

    Cheng, Yuh-Jiuh; Yeh, Tzuoh-Chyau; Cheng, Shyr-Yuan

    2011-09-01

    In this paper, a non-blocking multicast optical packet switch based on fiber Bragg grating technology with optical output buffers is proposed. Only the header of optical packets is converted to electronic signals to control the fiber Bragg grating array of input ports and the packet payloads should be transparently destined to their output ports so that the proposed switch can reduce electronic interfaces as well as the bit rate. The modulation and the format of packet payloads may be non-standard where packet payloads could also include different wavelengths for increasing the volume of traffic. The advantage is obvious: the proposed switch could transport various types of traffic. An easily implemented architecture which can provide multicast services is also presented. An optical output buffer is designed to queue the packets if more than one incoming packet should reach to the same destination output port or including any waiting packets in optical output buffer that will be sent to the output port at a time slot. For preserving service-packet sequencing and fairness of routing sequence, a priority scheme and a round-robin algorithm are adopted at the optical output buffer. The fiber Bragg grating arrays for both input ports and output ports are designed for routing incoming packets using optical code division multiple access technology.

  4. All-optical switching in a symmetric three-waveguide coupler with phase-mismatched absorptive central waveguide.

    Science.gov (United States)

    Chen, Yijing; Ho, Seng-Tiong; Krishnamurthy, Vivek

    2013-12-20

    All-optical switching operation based on manipulation of absorption in a three-waveguide directional coupler is theoretically investigated. The proposed structure consists of one absorptive central waveguide and two identical passive side waveguides. Optically induced absorption change in the central waveguide effectively controls the coupling of light between the two side waveguides, leading to optical switching action. The proposed architecture alleviates the fabrication challenges and waveguide index matching conditions that limit previous demonstrations of similar switching schemes based on a two-waveguide directional coupler. The proposed device accommodates large modal index difference between absorptive and passive waveguides without compromising the switching extinction ratio.

  5. Evaluation of QoS differentiation mechanisms in asynchronous bufferless optical packet-switched networks

    DEFF Research Database (Denmark)

    Overby, H.; Stol, N.; Nord, Martin

    2006-01-01

    Existing quality of service differentiation schemes for today's IP over point-to-point optical WDM networks take advantage of electronic RAM to implement traffic management algorithms in order to isolate the service classes. Since practical optical RAM is not available, these techniques...... are not suitable for a future all-optical network. Hence, new schemes are needed to support QoS differentiation in optical packet-switched (OPS) networks. In this article we first present an overview of existing QoS differentiation mechanisms suitable for asynchronous bufferless OPS. We then compare...

  6. Electrical characterization of all-optical helicity-dependent switching in ferromagnetic Hall crosses

    Science.gov (United States)

    El Hadri, M. S.; Pirro, P.; Lambert, C.-H.; Bergeard, N.; Petit-Watelot, S.; Hehn, M.; Malinowski, G.; Montaigne, F.; Quessab, Y.; Medapalli, R.; Fullerton, E. E.; Mangin, S.

    2016-02-01

    We present an experimental study of all-optical helicity-dependent switching (AO-HDS) of ferromagnetic Pt/Co/Pt heterostructures with perpendicular magnetic anisotropy. The sample is patterned into a Hall cross and the AO-HDS is measured via the anomalous Hall effect. This all-electrical probing of the magnetization during AO-HDS enables a statistical quantification of the switching ratio for different laser parameters, such as the threshold power to achieve AO-HDS and the exposure time needed to reach complete switching at a given laser power. We find that the AO-HDS is a cumulative process, a certain number of optical pulses is needed to obtain a full and reproducible helicity-dependent switching. The deterministic switching of the ferromagnetic Pt/Co/Pt Hall cross provides a full "opto-spintronic device," where the remanent magnetization can be all-optically and reproducibly written and erased without the need of an external magnetic field.

  7. ASE suppression of XeCl excimer laser MOPA system using UV electro-optical switch

    Science.gov (United States)

    Hu, Yun; Zhao, Xue-qing; Xue, Quan-xi; Wang, Da-hui; Zheng, Guo-xin; Hua, Heng-qi; Zhang, Yongsheng; Zhu, Yong-xiang; Xiao, Wei-wei; Wang, Li

    2013-05-01

    In high power eximer laser system, amplified spontaneous emission (ASE) decreases the signal contrast ratio severely, leads to waveform broadening and distortion, and impacts on accurate physical experiments. In this article, based on principle of short pulse generation by electro-optical (E-O) switch, a method for ASE suppression of laser amplifiers chain was established. A series of studies on UV electro-optical switches were carried out, and electro-optical (E-O) switches with high extinction ratio were developed. In the waveform clipping experiments of the first pre-amplifier, the extinction ratio of the single and cascaded dual E-O switch reaches 103 and 104 order of magnitude, the laser pulse signal contrast ratio was promoted to 105 and 106 level, respectively. In the experiments of single channel MOPA (Master Oscillator Power Amplifier system), the cascaded dual E-O switch was adopted to suppress ASE of the whole system, and a fine narrow pulse was obtained on the target surface, which gives out one effective solution to the problem of waveform amplification of the high power eximer laser system.

  8. Transparent ceramic photo-optical semiconductor high power switches

    Science.gov (United States)

    Werne, Roger W.; Sullivan, James S.; Landingham, Richard L.

    2016-01-19

    A photoconductive semiconductor switch according to one embodiment includes a structure of sintered nanoparticles of a high band gap material exhibiting a lower electrical resistance when excited by light relative to an electrical resistance thereof when not exposed to the light. A method according to one embodiment includes creating a mixture comprising particles, at least one dopant, and at least one solvent; adding the mixture to a mold; forming a green structure in the mold; and sintering the green structure to form a transparent ceramic. Additional system, methods and products are also presented.

  9. Experimental study on an all-optical switching based on MF-NOLM

    Institute of Scientific and Technical Information of China (English)

    SONG Xue-peng; REN Xiao-min; ZHANG Xia; YANG Guang-qiang; HUANG Yong-qing

    2006-01-01

    In this paper,the experiment on an all-optical switching is reported based on a microstructure fiber(MF)-nonlinear optical loop mirror(NOLM).In the experiment,a 25-meter-long MF(γ=36W-1km-1@1 550 nm) is used as a nonlinear medium of the nonlinear optical loop mirror and the input signal is generated by a 10 GHz tunable picosecond laser source,with a full-width at half-maximum (FWHM) of 2 ps and centered at 1 550 nm.With the increase of input power,a π nonlinear phase shift is obtained by a 40/60 coupler in the experiment,but the same result can not be found by a 48/52 coupler.Additionally,the switching devices can also be used as an all-optical regeneration.

  10. All-optical switching in a continuously operated and strongly coupled atom-cavity system

    CERN Document Server

    Dutta, Sourav

    2016-01-01

    We experimentally demonstrate collective strong coupling, optical bi-stability (OB) and all-optical switching in a system consisting of ultracold 85Rb atoms, trapped in a dark magneto-optical trap (DMOT), coupled to an optical Fabry-Perot cavity. The strong coupling is established by measuring the vacuum Rabi splitting (VRS) of a weak on-axis probe beam. The dependence of VRS on the probe beam power is measured and bi-stability in the cavity transmission is observed. We demonstrate control over the transmission of the probe beam through the atom-cavity system using a free-space off-axis control beam and show that the cavity transmission can be switched on and off in micro-second timescales using micro-Watt control powers. The utility of the system as a tool for sensitive, in-situ and rapid measurements is envisaged.

  11. A nonlinear plasmonic resonator for three-state all-optical switching

    KAUST Repository

    Amin, Muhammad

    2014-01-01

    A nonlinear plasmonic resonator design is proposed for three-state all-optical switching at frequencies including near infrared and lower red parts of the spectrum. The tri-stable response required for three-state operation is obtained by enhancing nonlinearities of a Kerr medium through multiple (higher order) plasmons excited on resonator\\'s metallic surfaces. Indeed, simulations demonstrate that exploitation of multiple plasmons equips the proposed resonator with a multi-band tri-stable response, which cannot be obtained using existing nonlinear plasmonic devices that make use of single mode Lorentzian resonances. Multi-band three-state optical switching that can be realized using the proposed resonator has potential applications in optical communications and computing. © 2014 Optical Society of America.

  12. Photocurrent switching method based on photoisomerization of diarylethene layer for nondestructive readout of photochromic optical memory.

    Science.gov (United States)

    Tsujioka, Tsuyoshi; Onishi, Itaru; Natsume, Daisuke

    2010-07-10

    We report on photocurrent switching based on photoisomerization for the nondestructive readout of photochromic optical memory. The photoisomerization of a diarylethene (DAE) memory layer switched the photocurrent generated in a light-absorbing phthalocyanine layer upon irradiation of a laser light. This switching is based on the ionization potential change of the DAE molecules. Switching characteristics of the photocurrent were investigated for the laser light with a wavelength of 410 nm, 630 nm, or 780 nm. Excellent on-off ratios of the photocurrent were achieved by irradiation at 630 nm and 780 nm. When the pulsed laser light with a wavelength of 780 nm was repeatedly irradiated to the colored and uncolored memory devices, no change of the photocurrent signal levels was observed, even after 8 x 10(5) cycles, indicating a successful demonstration of the nondestructive readout.

  13. A Bidirectional “Y” Type OXC Structure Using the Least Optical Switches

    Institute of Scientific and Technical Information of China (English)

    TAO Zhenning; WU Deming; XU Anshi

    2000-01-01

    In this paper, a bidirectional Y type optical cross-connect structure is introduced. It minimizes the number of 2 × 2 optical switches by utilizing the route characteristic of a bidirectional Y type OTN node. The method to satisfy this route request by our OXC is demonstrated. The wavelength utilizing efficiency between our structure and the nonblocking bidirectional Y type OTN node has also compared. The blocking, complexity, loss, loss uniformity and cross-talk characteristics are also demonstrated.

  14. Modeling and performance analysis of IP access interface in optical transmission networks with packet switching

    OpenAIRE

    Lackovic, Marko; Bungarzeanu, Cristian

    2006-01-01

    The article analyzes the influence of the Internet Protocol (IP) access interface on the packet loss probability and delay times in the optical packet switched network. The network and node model have been proposed, and the structure of the IP access interface, including assembler and holder, have been included in the analysis. It has been shown that the increase of the maximum optical packet sizes, as well as use of the holding feature as contention resolution mechanism, decrease the packet ...

  15. AN EFFECTIVE MODEL TO EVALUATE BLOCKING PROBABILITY OF TIME-SLOTTED OPTICAL BURST SWITCHED NETWORKS

    Institute of Scientific and Technical Information of China (English)

    Yang Zongkai; Ou Liang; Tan Xiansi

    2006-01-01

    Time-slotted optical burst switched network is a potential technique to support IP over Wavelength Division Multiplexing (WDM) by introduce Time Division Multiplexing (TDM) channel to Optical Burst Switching (OBS) technology. This paper presents a framework to evaluate blocking performance of time-slotted OBS networks with multi-fiber wavelength channels. The proposed model is efficient for not only single class traffic such as individual circuit switch traffics or best-effort traffics but also mixed multi-class traffics.The effectiveness of the proposed model is validated by simulation results. The study shows that blocking performance of multi-fiber TS-OBS network is acceptable for future Internet services.

  16. Minimizing the Switch and Link Conflicts in an Optical Multi-stage Interconnection Network

    Directory of Open Access Journals (Sweden)

    Ved Prakash Bhardwaj

    2011-07-01

    Full Text Available Multistage Interconnection Networks (MINs are very popular in switching and communication applications. A MIN connects N inputs to N outputs and is referred as an N andamp;times; N MIN; having size N. Optical Multistage Interconnection Network (OMIN represents an important class of Interconnection networks. Crosstalk is the basic problem of OMIN. Switch Conflict and Link Conflict are the two main reason of crosstalk. In this paper, we are considering both problems. A number of techniques like Optical window, Improved Window, Heuristic, Genetic, and Zero have been proposed earlier in this research domain. In this paper, we have proposed two algorithms called Address Selection Algorithm and Route Selection Algorithm (RSA. RSA is based on Improved Window Method. We have applied the proposed algorithms on existing Omega network, having shuffleexchange connection pattern. The main functionality of ASA and RSA is to minimize the number of switch and link conflicts in the network and to provide conflict free routes.

  17. Optical switching of electric charge transfer pathways in porphyrin: a light-controlled nanoscale current router.

    Science.gov (United States)

    Thanopulos, Ioannis; Paspalakis, Emmanuel; Yannopapas, Vassilios

    2008-11-05

    We introduce a novel molecular junction based on a thiol-functionalized porphyrin derivative with two almost energetically degenerate equilibrium configurations. We show that each equilibrium structure defines a pathway of maximal electric charge transfer through the molecular junction and that these two conduction pathways are spatially orthogonal. We further demonstrate computationally how to switch between the two equilibrium structures of the compound by coherent light. The optical switching mechanism is presented in the relevant configuration subspace of the compound, and the corresponding potential and electric dipole surfaces are obtained by ab initio methods. The laser-induced isomerization takes place in two steps in tandem, while each step is induced by a two-photon process. The effect of metallic electrodes on the electromagnetic irradiation driving the optical switching is also investigated. Our study demonstrates the potential for using thiol-functionalized porphyrin derivatives for the development of a light-controlled nanoscale current router.

  18. Minimizing the Switch and Link Conflicts in an Optical Multi-stage Interconnection Network

    CERN Document Server

    Bhardwaj, Ved Prakash; Tyagi, Vipin

    2012-01-01

    Multistage Interconnection Networks (MINs) are very popular in switching and communication applications. A MIN connects N inputs to N outputs and is referred as an N \\times N MIN; having size N. Optical Multistage Interconnection Network (OMIN) represents an important class of Interconnection networks. Crosstalk is the basic problem of OMIN. Switch Conflict and Link Conflict are the two main reason of crosstalk. In this paper, we are considering both problems. A number of techniques like Optical window, Improved Window, Heuristic, Genetic, and Zero have been proposed earlier in this research domain. In this paper, we have proposed two algorithms called Address Selection Algorithm and Route Selection Algorithm (RSA). RSA is based on Improved Window Method. We have applied the proposed algorithms on existing Omega network, having shuffle-exchange connection pattern. The main functionality of ASA and RSA is to minimize the number of switch and link conflicts in the network and to provide conflict free routes.

  19. Reversible, electrical and optical switching on silver 3-phenyl-1-ureidonitrile complex thin films

    Institute of Scientific and Technical Information of China (English)

    张昊旭; 时东霞; 宋延林; 刘虹雯; 侯士敏; 薛增泉; 高鸿钧

    2002-01-01

    We report on the reversible, electrical and optical switching on silver 3-phenyl-l-ureidonitrile complex thin films.The films can switch from a high impedance state to a low impedance state with an applied electric field at the thresholdof 3.5 × 107V/m. Furthermore, the films can be switched back to the original state by treating the samples at about80℃. The optical recording is fulfilled using a semiconductor laser with a wavelength of 780nm. Erasure can beaccomplished by bulk heating or by the laser working with the power beneath the threshold. No loss of the organic wasfound in the experiments. This material may have a potential application in ultrahigh data density storage.

  20. Preparation, optical properties and 1 Multiplication-Sign 2 polymeric thermo-optic switch of polyurethane-urea

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Fengxian, E-mail: fxqiuchem@163.com [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Cao, Zhijuan [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Cao, Guorong; Guan, Yijun; Shen, Qiang [Department of Physics, Jiangsu University, Zhenjiang 212013 (China); Wang, Qing; Yang, Dongya [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China)

    2012-08-15

    A polyurethane-urea (PUU) containing azo chromophore, polyether polyol (NJ-220) and isophorone diisocyanate (IPDI) was prepared. The structure, thermal property and mechanical properties of obtained PUU were characterized and measured by the UV-visible spectroscopy, Fourier transform infrared, Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The refractive index (n) of PUU was determined at different temperature and wavelength (532 nm, 650 nm and 850 nm) using attenuated total reflection (ATR) technique, and the thermo-optic coefficients (dn/dT) were -5.3643 Multiplication-Sign 10{sup -4} Degree-Sign C{sup -1}, -5.2500 Multiplication-Sign 10{sup -4} Degree-Sign C{sup -1} and -4.6071 Multiplication-Sign 10{sup -4} Degree-Sign C{sup -1}, respectively. Using the Charge Coupled Device (CCD) digital imaging devices, transmission loss of PUU was measured and the value was 0.659 dB cm{sup -1}. A 1 Multiplication-Sign 2 polymeric thermo-optic switch based on the thermo-optic effect of PUU film was proposed. With branching angle of 0.143 Degree-Sign and the finite difference beam propagation method (FD-BPM), the polymeric thermo-optic switch was simulated. The result showed that the power consumption of the thermo-optic switch could be only 0.72 mW, and the response time of the switch was about 3.0 ms. The obtained PUU has a significant improvement in reducing the power consumption and response time compared with those of the normal polymeric thermo-optic switches. -- Highlights: Black-Right-Pointing-Pointer Preparation and structural characterization of a novel azo polyurethane-urea (PUU). Black-Right-Pointing-Pointer The mechanical performance and thermal property of PUU film. Black-Right-Pointing-Pointer The thermo-optic property, transmission loss and dispersion property of PUU. Black-Right-Pointing-Pointer Proposed a new 1 Multiplication-Sign 2 polymeric thermo-optic switch.

  1. First application of quantum annealing to IMRT beamlet intensity optimization

    Science.gov (United States)

    Nazareth, Daryl P.; Spaans, Jason D.

    2015-05-01

    Optimization methods are critical to radiation therapy. A new technology, quantum annealing (QA), employs novel hardware and software techniques to address various discrete optimization problems in many fields. We report on the first application of quantum annealing to the process of beamlet intensity optimization for IMRT. We apply recently-developed hardware which natively exploits quantum mechanical effects for improved optimization. The new algorithm, called QA, is most similar to simulated annealing, but relies on natural processes to directly minimize a system’s free energy. A simple quantum system is slowly evolved into a classical system representing the objective function. If the evolution is sufficiently slow, there are probabilistic guarantees that a global minimum will be located. To apply QA to IMRT-type optimization, two prostate cases were considered. A reduced number of beamlets were employed, due to the current QA hardware limitations. The beamlet dose matrices were computed using CERR and an objective function was defined based on typical clinical constraints, including dose-volume objectives, which result in a complex non-convex search space. The objective function was discretized and the QA method was compared to two standard optimization methods, simulated annealing and Tabu search, run on a conventional computing cluster. Based on several runs, the average final objective function value achieved by the QA was 16.9 for the first patient, compared with 10.0 for Tabu and 6.7 for the simulated annealing (SA) method. For the second patient, the values were 70.7 for the QA, 120.0 for Tabu and 22.9 for the SA. The QA algorithm required 27-38% of the time required by the other two methods. In this first application of hardware-enabled QA to IMRT optimization, its performance is comparable to Tabu search, but less effective than the SA in terms of final objective function values. However, its speed was 3-4 times faster than the other two methods

  2. An optical and theoretical investigation of the ultrafast dynamics of a bisthienylethene-based photochromic switch

    NARCIS (Netherlands)

    Hania, P.R.; Telesca, R.; Lucas, L.N.; Pugzlys, A; van Esch, J. H; Feringa, B.L.; Snijders, J.G.; Duppen, K.

    2002-01-01

    The switching behavior of 1,2-bis(5-phenyl-2-methylthien-3-yl)cyclopentene is studied by means of polarization selective nonlinear optical spectroscopy and time-dependent density functional theory. The combined information from the observed population and orientational dynamics together with the res

  3. Design and Fabrication of Micromechanical Optical Switches Based on the Low Applied Voltage

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A micromechanical optical switch driven by electrostatic was fabricated with (100) silicon and tilted 2.5° (111) silicon. The pull-in voltage is 13.2V, the insertion loss is less than 1.4dB, the crosstalk is less than -50 dB.

  4. Femtosecond all-optical switching in AlGaAs waveguides using a time division interferometer

    Science.gov (United States)

    Lagasse, M. J.; Anderson, K. K.; Haus, H. A.; Fujimoto, J. G.

    1989-05-01

    All-optical switching of femtosecond pulses in AlGaAs waveguides is investigated using a novel time division interferometric technique which eliminates thermal imbalances. In addition to an instantaneous refractive index nonlinearity, free-carrier generation via two-photon absorption produces a response of several hundred picoseconds.

  5. Ultrafast coherent dynamics of a photonic crystal all-optical switch

    DEFF Research Database (Denmark)

    Colman, Pierre; Hansen, Per Lunnemann; Yu, Yi

    2016-01-01

    We present pump-probe measurements of an all-optical photonic crystal switch based on a nanocavity, resolving fast coherent temporal dynamics. The measurements demonstrate the importance of coherent effects typically neglected when considering nanocavity dynamics. In particular, we report...

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

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  7. Compensations of beamlet deflections for 1 MeV accelerator of ITER NBI

    Science.gov (United States)

    Kashiwagi, Mieko; Taniguchi, Masaki; Umeda, Naotaka; Dairaku, Masayuki; Tobari, Hiroyuki; Yamanaka, Haruhiko; Watanabe, Kazuhiro; Inoue, Takashi; de Esch, H. P. L.; Grisham, Larry R.; Boilson, Deirdre; Hemsworth, Ronald S.; Tanaka, Masanobu

    2013-02-01

    Compensation methods of beamlet deflections have been studied in a three dimensional (3D) beam analysis using OPERA-3d code for 1 MeV accelerator of the ITER neutral beam injector (NBI). The beamlet deflection is caused by i) magnetic field generated by permanent magnets embedded in the extraction grid (EXG) for electron suppression and ii) space charge repulsion between the beamlets and beam groups. Moreover, the beamlet deflection is caused due to electric field distortion formed by a grid support structure. In order to compensate the beamlet deflections due to i) and ii), an aperture offset of 0.6 mm was applied in the electron suppression grid (ESG) and a metal bar with 3 mm in thickness, so-called a kerb, was attached around the aperture area at the back side of the ESG, respectively. Detailed configuration of the compensation methods was also considered so as to suppress the beam spread due to the electric field distortion and to lower electric field concentrations at the edge of the kerb. For the beamlets near the grid support structure, the beamlet deflection due to the space charge repulsion could be negated due to the electric field distortion formed by the grid support structure.

  8. Packetisation in Optical Packet Switch Fabrics using adaptive timeout values

    DEFF Research Database (Denmark)

    Mortensen, Brian Bach

    2006-01-01

    to the inter arrival rate at the individual VOQs. The remaining thresholds applies to the optical slot level inter arrival rate at the input and output line cards. If any measurements are beyond a given threshold, the higher timeout value is used. The proposed method can be used to make a trade-off between...... either because the timer reaches a specific timeout value, or because the optical packet is completely filled with segments. Only two distinct values of the timeout value are used. Which of the two timeout values to use, is selected by 3 different control thresholds. The first threshold level applies...

  9. Design and Performance Evaluation of Optical Ethernet Switching Architecture with Liquid Crystal on Silicon-Based Beam-Steering Technology

    Science.gov (United States)

    Cheng, Yuh-Jiuh; Chou, H.-H.; Shiau, Yhi; Cheng, Shu-Ying

    2016-07-01

    A non-blocking optical Ethernet switching architecture with liquid crystal on a silicon-based beam-steering switch and optical output buffer strategies are proposed. For preserving service packet sequencing and fairness of routing sequence, priority and round-robin algorithms are adopted at the optical output buffer in this research. Four methods were used to implement tunable fiber delay modules for the optical output buffers to handle Ethernet packets with variable bit-rates. The results reported are based on the simulations performed to evaluate the proposed switching architecture with traffic analysis under a traffic model captured from a real-core network.

  10. Testing a new multipass laser architecture on beamlet

    Energy Technology Data Exchange (ETDEWEB)

    Vann, C.S.; Laniesse, F.; Patton, H.G. [and others

    1996-06-01

    The authors completed proof-of-principle tests on Beamlet for a new multipass laser architecture that is the baseline design for the French Megajoule laser and a backup concept for the U.S. National Ignition Facility (NIF) laser. These proposed laser facilities for Inertial Confinement Fusion (ICF) research are described in their respective Conceptual Design Reports. The lasers are designed to deliver 1.8 MJ and 500 TW of 0.35-{mu}m light onto a fusion target using 240 independent beams for the Megajoule laser and 192 beams for the NIF laser. Both lasers use flash-lamp pumped glass amplifiers and have approximately 38-cm square output beams. However, there are significant differences in their architecture. This article describes those differences, and their significance.

  11. Optical Switching Impact on TCP Throughput Limited by TCP Buffers

    NARCIS (Netherlands)

    Moura, Giovane C.M.; Fioreze, Tiago; Boer, de Pieter-Tjerk; Pras, Aiko; Nunzi, G.; Scoglio, C.; Li, X.

    2009-01-01

    In this paper, we observe the performance of TCP throughput when self-management is employed to automatically move flows from the IP level to established connections at the optical level. This move can result in many packets arriving out of order at the receiver and even being discarded, since some

  12. Optical gating of perylene bisimide fluorescence using dithienylcyclopentene photochromic switches

    Energy Technology Data Exchange (ETDEWEB)

    Pärs, Martti; Köhler, Jürgen, E-mail: juergen.koehler@uni-bayreuth.de [Experimental Physics IV, University of Bayreuth, 95440 Bayreuth (Germany); Gräf, Katja; Bauer, Peter; Thelakkat, Mukundan [Applied Functional Polymers, University of Bayreuth, 95440 Bayreuth (Germany)

    2013-11-25

    The emission of millions of fluorescence photons from a chromophore is controlled by the absorption of a few tens of photons in a photochromic molecule. The parameters that determine the efficiency of this process are investigated, providing insights for the development of an all-optical gate.

  13. Five-port silicon optical router based on Mach—Zehnder optical switches for photonic networks-on-chip

    Science.gov (United States)

    Yunchou, Zhao; Hao, Jia; Jianfeng, Ding; Lei, Zhang; Xin, Fu; Lin, Yang

    2016-11-01

    With the continuous development of integrated circuits, the performance of the processor has been improved steadily. To integrate more cores in one processor is an effective way to improve the performance of the processor, while it is impossible to further improve the property of the processor by only increasing the clock frequency. For a processor with integrated multiple cores, its performance is determined not only by the number of cores, but also by communication efficiency between them. With more processor cores integrated on a chip, larger bandwidths are required to establish the communication among them. The traditional electrical interconnect has gradually become a bottleneck for improving the performance of multiple-core processors due to its limited bandwidth, high power consumption, and long latency. The optical interconnect is considered as a potential way to solve this issue. The optical router is the key device for realizing the optical interconnect. Its basic function is to achieve the data routing and switching between the local node and the multi-node. In this paper we present a five-port optical router for Mesh photonics network-on-chip. A five-port optical router composed of eight thermally tuned silicon Mach—Zehnder optical switches is demonstrated. The experimental spectral responses indicate that the optical signal-to-noise ratios of the optical router are over 13 dB in the wavelength range of 1525-1565 nm for all of its 20 optical links. Each optical link can manipulate 50 wavelength channels with the channel spacing of 100 GHz and the data rate of 32 Gbps for each wavelength channel in the same wavelength range. The lowest energy efficiency of the optical router is 43.4 fJ/bit. Project supported by the National High Technology Research and Development Program of China (Nos. 2015AA010103, 2015AA010901) and the National Natural Science Foundation of China (Nos. 61575187, 61235001, 61505198, 61377067).

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  15. Modelling a nonlinear optical switching in a standard photonic crystal fiber infiltrated with carbon disulfide

    Science.gov (United States)

    Munera, Natalia; Acuna Herrera, Rodrigo

    2016-06-01

    In this letter, a numerical analysis is developed for the propagation of ultrafast optical pulses through a standard photonic crystal fiber (PCF) consisting of two infiltrated holes using carbon disulfide (CS2). This material is a good choice since it has highly nonlinear properties, what makes it a good candidate for optical switching and broadband source at low power compared to traditional nonlinear fiber coupler. Based on supermodes theory, a set of generalized nonlinear equations is presented in order to study the propagation characteristics. It is shown in this letter that it is possible to get optical switching behavior at low power and how the dispersion, as well as, the two infiltrated holes separation influence this effect. Finally, we see that supercontinuum generation can be induced equally in both infiltrated holes despite no initial excitation at one hole.

  16. Passively Q -Switched 1.57- m Intracavity Optical Parametric Oscillator

    Science.gov (United States)

    Yashkir, Yuri; van Driel, Henry M.

    1999-04-01

    We demonstrate an eye-safe KTP-based optical parametric oscillator (OPO) driven intracavity by a diode-pumped 1064-nm Nd:YAG laser, passively Q -switched by a Cr 4 :YAG crystal. The characteristics of this system, which operates at 1570 nm with a repetition rate as high as 50 Hz, are studied as a function of Cr 4 :YAG optical density. Under optimum conditions the OPO generates 1.5-mJ, 3.4 0.1-ns pulses in a single transverse mode. For a Cr 4 :YAG Q -switch element with an optical density of 0.5 the conversion efficiency of the intracavity energy is 45% with the ratio of OPO to Nd:YAG peak-pulse intensity exceeding unity. These and other OPO characteristics compare favorably with a simple rate equation model of the OPO dynamics.

  17. Passively Q-switched 1.57-microm intracavity optical parametric oscillator.

    Science.gov (United States)

    Yashkir, Y; van Driel, H M

    1999-04-20

    We demonstrate an eye-safe KTP-based optical parametric oscillator (OPO) driven intracavity by a diode-pumped 1064-nm Nd:YAG laser, passively Q-switched by a Cr4+:YAG crystal. The characteristics of this system, which operates at 1570 nm with a repetition rate as high as 50 Hz, are studied as a function of Cr4+:YAG optical density. Under optimum conditions the OPO generates 1.5-mJ, 3.4 +/- 0.1-ns pulses in a single transverse mode. For a Cr4+:YAG Q-switch element with an optical density of 0.5 the conversion efficiency of the intracavity energy is approximately 45% with the ratio of OPO to Nd:YAG peak-pulse intensity exceeding unity. These and other OPO characteristics compare favorably with a simple rate equation model of the OPO dynamics.

  18. Performance evaluation of 10GBASE optical transceivers for Cisco 10-gigabit Ethernet switching architecture

    Science.gov (United States)

    Zhang, Xiaojing; Cain, Jeff C.

    2002-09-01

    This paper presents the process and methodology employed to perform evaluation and analyses for the optical interface that delivers and receives 10Gb/s Ethernet traffic on Cisco's industrial leading switching architecture. Especially, we examined in detail the optical properties for commercially available 10GBASE-LR transceiver modules, with respect to IEEE 802.3ae specifications. The sampled results under room temperature are listed for comparison. Eye diagrams were recorded as a function of transmission distance, as well as temperature variation. System stability issues are also studied following a brief introduction to Cisco standard ODVT (Optical Design Verification Test) procedure.

  19. Optical switching and detection of 640 Gbits/s optical time-division multiplexed data packets transmitted over 50 km of fiber

    DEFF Research Database (Denmark)

    Gomez-Agis, F.; Hu, Hao; Luo, J.

    2011-01-01

    We demonstrate 1 × 4 optical-packet switching with error-free transmission of 640 Gbits/s single-wavelength optical time-division multiplexed data packets including clock distribution and short pulse generation for optical time demultiplexing based on a cavityless pulse source. © 2011 Optical...

  20. Performance evaluation for an optical hybrid switch with circuit queued reservations

    Science.gov (United States)

    Wong, Eric W. M.; Zukerman, Moshe

    2005-11-01

    We provide here a new loss model for an optical hybrid switch that can function as an optical burst switch or optical circuit switch or both simultaneously. We introduce the feature of circuit queued reservation. That is, if a circuit request arrives and cannot find a free wavelength, and if there are not too many requests queued for reservations, it may join a queue and wait until such wavelength becomes available. We first present an analysis based on a 3-dimension state-space Markov chain that provides exact results for the blocking probabilities of bursts and circuits. We also provide results for the proportion of circuits that are delayed and the mean delay of the circuits that are delay. Because it is difficult to exactly compute the blocking probability in realistic scenarios with a large number of wavelengths, we derive computationally scalable and accurate approximations which are based on reducing the 3-dimension state space into a single dimension. These scalable approximations that can produce performance results in a fraction of a second can readily enable switch dimensioning.

  1. Performance evaluation of an optical hybrid switch with circuit queued reservations and circuit priority preemption

    Science.gov (United States)

    Wong, Eric W. M.; Zukerman, Moshe

    2006-11-01

    We provide here a new loss model for an optical hybrid switch that can function as an optical burst switch and/or optical circuit switch. Our model is general as it considers an implementation whereby some of the circuits have preemptive priority over bursts and others are allowed to queue their reservations. We first present an analysis based on a 3-dimension state-space Markov chain that provides exact results for the blocking probabilities of bursts and circuits, the proportion of circuits that are delayed and the mean delay of the circuits that are delayed. Because it is difficult to exactly compute the blocking probability in realistic scenarios with a large number of wavelengths, we derive computationally a scalable and accurate approximations based on reducing the 3-dimension state space into a single dimension. These scalable approximations that can produce performance results in a fraction of a second can readily enable switch dimensioning. Extensive numerical results are presented to demonstrate the accuracy and the use of the new approximations.

  2. Data Transparent and Polarization Insensitive All-Optical Switch based on Fibers with Enhanced Nonlinearity

    Directory of Open Access Journals (Sweden)

    M. Komanec

    2014-09-01

    Full Text Available We have developed a data transparent optical packet switch prototype employing wavelength conversion based on four-wave mixing. The switch is composed of an electro-optical control unit and an all-optical switching segment. To achieve higher switching efficiencies, Ge-doped silica suspended-core and chalcogenide arsenicselenide single-mode fibers were experimentally evaluated and compared to conventional highly-nonlinear fiber. Improved connectorization technology has been developed for Ge-doped suspended-core fiber, where we achieved connection losses of 0.9 dB. For the arsenic-selenide fiber we present a novel solid joint technology, with connection losses of only 0.25 dB, which is the lowest value presented up-to-date. Conversion efficiency of -13.7 dB was obtained for the highly-nonlinear fiber, which is in perfect correlation with previously published results and thus verifies the functionality of the prototype. Conversion efficiency of -16.1 dB was obtained with arsenic-selenide fiber length reduced to five meters within simulations, based on measurement results with a 26 m long component. Employment of such a short arsenic-selenide fiber segment allows significant broadening of the wavelength conversion spectral range due to possible neglection of dispersion.

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

    DEFF Research Database (Denmark)

    Franzl, Gerald; Hayat, Faisal; Holynski, Tomasz

    2011-01-01

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

  4. Syudy of Token Generation for Burst Traffic Shaping in Optical Burst Switching Networks

    Institute of Scientific and Technical Information of China (English)

    Tang Wan; So Won-ho; Lu Ji-guang; Kim Young-chon

    2004-01-01

    Traffic shaping is one of important control operation to guarantee the Quality of Service (QoS) in optical burst switching (OBS) networks. The efficiency of traffic shaping is mainly determined by token generation method. In this paper, token generation methods of traffic shaping are evaluated by using three kinds of probability distribution, and are analyzed in terms of burst blocking probability, throughput and correlation by simulation. The simulation results show that the token generation methods decrease the burst correlation of Label Switched Paths (LSPs), and solve traffic congestion as well. The different burst arrival processes have small impact on the blocking probability for OBS networks.

  5. Optical Switching in VO2 films by below-gap excitation

    Energy Technology Data Exchange (ETDEWEB)

    Dipartimento di Fisica, Universita?di Brescia, Italy; Universite du Quebec, INRS energie et materiaux, Varennes, Quebec; Department of Physics. Clarendon Laboratory, University of Oxford, UK; Department of Physics, University of Tokyo; Institute of Physics, University of Tsukuba, Ibaraki, Japan; Cavalleri, Andrea; Rini, Matteo; Giannetti, Claudio; Fourmaux, Sylvain; Wall, Simon; Hao, Zhao; Parmigiani, Fulvio; Fujimori, Atsushi; Onoda, Masashige; Kieffer, Jean-Claude; Schoenlein, Robert W.; Cavalleri, Andrea

    2008-03-14

    We study the photo-induced insulator-metal transition in VO2, correlating threshold and dynamic evolution with excitation wavelength. In high-quality single crystal samples, we find that switching can only be induced with photon energies above the 670-meV gap. This contrasts with the case of polycrystalline films, where formation of the metallic state can also be triggered with photon energies as low as 180 meV, well below the bandgap. Perfection of this process may be conducive to novel schemes for optical switches, limiters and detectors, operating at room temperature in the mid-IR.

  6. Information Model for Connection Management in Automatic Switched Optical Network

    Institute of Scientific and Technical Information of China (English)

    Xu Yunbin(徐云斌); Song Hongsheng; Gui Xuan; Zhang Jie; Gu Wanyi

    2004-01-01

    The three types of connections (Permanent Connection, Soft Permanent Connection and Switched Connection) provided by ASON can adapt the requirement of different network services. Management and maintenance of these three connections are the most important aspect of ASON management. The information models proposed in this paper are used for the purpose of ASON connection management. Firstly a new information model is proposed to meet the requirement for the control plane introduced by ASON. In this model, a new class ControlNE is given, and the relationship between the ControlNE and the transport NE (network element) is also defined. Then this paper proposes information models for the three types of connections for the first time, and analyzes the relationship between the three kinds of connections and the basic network transport entities. Finally, the paper defines some CORBA interfaces for the management of the three connections. In these interfaces, some operations such as create or release a connection are defined, and some other operations can manage the performance of the three kinds of connections, which is necessary for a distributed management system.

  7. Reduction of nonlinear patterning effects in SOA-based All-optical Switches using Optical filtering

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Mørk, Jesper; Skaguchi, J.

    2005-01-01

    We explain theoretically, and demonstrate and quantify experimentally, how appropriate filtering can reduce the dominant nonlinear patterning effect, which limits the performance of differential-mode SOA-based switches.......We explain theoretically, and demonstrate and quantify experimentally, how appropriate filtering can reduce the dominant nonlinear patterning effect, which limits the performance of differential-mode SOA-based switches....

  8. Operators Manual and Technical Reference for the Z-Beamlet Phase Modulation Failsafe System: Version 1.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Darrell J.

    2014-09-01

    The need for pulse energies exceeding 4 kJ and pulse lengths [?] 2 ns in Sandia's Z-Beamlet laser (ZBL) requires that the single-frequency spectrum of its fiber-laser master oscillator be converted to a phase modulated spectrum with a modulation in dex [?] 5. Because accidental injection of single-frequency light into ZBL could result i n damage to optical materials from transverse stimulated Brillouin scattering, the presence of phase modulated (PM) light must be monitored by a reliable failsafe system that can stop a las er shot within of a few 10's of ns following a failure of the PM system. This requirement is met by combining optical heterodyne detection with high-speed electronics to indicate the pres ence or absence of phase modulated light. The transition time for the failsafe signal resultin g from a sudden failure using this technique is approximately 35 ns. This is sufficiently short to safely stop a single-frequency laser pulse from leaving ZBL's regenerative amplifier with a n approximately 35 ns margin of safety. This manual and technical reference contains detai led instructions for daily use of the PM failsafe system and provides enough additional informat ion for its maintenance and repair.

  9. 1×4 Optical packet switching of variable length 640 Gbit/s data packets using in-band optical notch-filter labeling

    DEFF Research Database (Denmark)

    Medhin, Ashenafi Kiros; Kamchevska, Valerija; Galili, Michael;

    2014-01-01

    We experimentally perform 1×4 optical packet switching of variable length 640 Gbit/s OTDM data packets using in-band notch-filter labeling with only 2.7-dB penalty. Up to 8 notches are employed to demonstrate scalability of the labeling scheme to 1×256 switching operation.......We experimentally perform 1×4 optical packet switching of variable length 640 Gbit/s OTDM data packets using in-band notch-filter labeling with only 2.7-dB penalty. Up to 8 notches are employed to demonstrate scalability of the labeling scheme to 1×256 switching operation....

  10. Performance optimization of optical switches in ferroelectric liquid crystals and polymers operating at 1550 nm

    Science.gov (United States)

    Asquini, Rita; Gizzi, Claudio; Beccherelli, Romeo; d'Alessandro, Antonio

    2004-01-01

    A multilayer structure realizing an optical switch with ferroelectric liquid crystal, polymeric buffers and waveguides has been analyzed at the wavelength of 1550 nm, focusing on fabrication and design tolerances. The used liquid crystal FELIX-M4851-025 from Clariant is aligned by Nylon6 and embedded between two polymeric waveguides. ITO is deposited on quartz substrates to apply voltage to the cell and polymeric buffers are employed to reduce ITO absorption losses. The polymers consisted of poly(pentafluorostyrene-co-glycidyl methacrylate). Light is switched between the optical waveguides by reorienting the liquid crystal. Optimization in terms of optical losses and extinction ratios was carried out by varying layer thicknesses, refractive indices of waveguides and buffers, and the angle α between the normal to the smectic layers and the propagation direction. An optimized device with α = 51°, refractive indices of 1.475 and 1.462, thicknesses of 3 and 6 μm for waveguides and buffer, respectively and 4.4 μm for the liquid crystal layer, exhibits an extinction ratio of 59.6 dB with losses as low as 0.8 dB for a length of only 174 μm. A device design using single mode channel waveguides for optical switching matrices has been also carried out.

  11. High-contrast fluorescence imaging in fixed and living cells using optimized optical switches.

    Directory of Open Access Journals (Sweden)

    Liangxing Wu

    Full Text Available We present the design, synthesis and characterization of new functionalized fluorescent optical switches for rapid, all-visible light-mediated manipulation of fluorescence signals from labelled structures within living cells, and as probes for high-contrast optical lock-in detection (OLID imaging microscopy. A triazole-substituted BIPS (TzBIPS is identified from a rational synthetic design strategy that undergoes robust, rapid and reversible, visible light-driven transitions between a colorless spiro- (SP and a far-red absorbing merocyanine (MC state within living cells. The excited MC-state of TzBIPS may also decay to the MC-ground state emitting near infra-red fluorescence, which is used as a sensitive and quantitative read-out of the state of the optical switch in living cells. The SP to MC transition for a membrane-targeted TzBIPS probe (C₁₂-TzBIPS is triggered at 405 nm at an energy level compatible with studies in living cells, while the action spectrum of the reverse transition (MC to SP has a maximum at 650 nm. The SP to MC transition is complete within the 790 ns pixel dwell time of the confocal microscope, while a single cycle of optical switching between the SP and MC states in a region of interest is complete within 8 ms (125 Hz within living cells, the fastest rate attained for any optical switch probe in a biological sample. This property can be exploited for real-time correction of background signals in living cells. A reactive form of TzBIPS is linked to secondary antibodies and used, in conjunction with an enhanced scope-based analysis of the modulated MC-fluorescence in immuno-stained cells, for high-contrast immunofluorescence microscopic analysis of the actin cytoskeleton.

  12. VO(2) based waveguide-mode plasmonic nano-gratings for optical switching.

    Science.gov (United States)

    Sharma, Yashna; Tiruveedhula, Veeranjaneya A; Muth, John F; Dhawan, Anuj

    2015-03-09

    In this paper, we present one dimensional plasmonic narrow groove nano-gratings, covered with a thin film of VO(2) (Vanadium Dioxide), as novel optical switches. These narrow groove gratings couple the incident optical radiation to plasmonic waveguide modes leading to high electromagnetic fields in the gaps between the nano-gratings. Since VO(2) changes from its semiconductor to its metallic phase on heating, on exposure to infra-red light, or on application of voltage, the optical properties of the underlying plasmonic grating also get altered during this phase transition, thereby resulting in significant switchability of the reflectance spectra. Moreover, as the phase transition in VO(2) can occur at femto-second time-scales, the VO(2)-coated plasmonic optical switch described in this paper can potentially be employed for ultrafast optical switching. We aim at maximizing this switchability, i.e., maximizing the differential reflectance (DR) between the two states (metallic and semiconductor) of this VO(2) coated nano-grating. Rigorous Coupled Wave Analysis (RCWA) reveals that the switching wavelengths - i.e., the wavelengths at which the values of the differential reflectance between VO(2) (S) and VO(2) (M) phases are maximum - can be tuned over a large spectral regime by varying the nano-grating parameters such as groove width, depth of the narrow groove, grating width, and thickness of the VO(2) layer. A comparison of the proposed ideal nano-gratings with various types of non-ideal nano-gratings - i.e., nano-gratings with non-parallel sidewalls - has also been carried out. It is found that significant switchability is also present for these non-ideal gratings that are easy to fabricate. Thus, we propose highly switchable and wide-spectra VO(2) based narrow groove nano-gratings that do not have a complex structure and can be easily fabricated.

  13. Effect of switching time on timer-based burst assembly and its effect on voice-over-Internet protocol quality of service over optical burst switching networks

    Science.gov (United States)

    Tachibana, Takuji; Kurita, Kaori; Kasahara, Shoji

    2006-07-01

    It is well known that performance, such as burst loss probability and transmission delay, for optical burst switching (OBS) networks greatly depends on the switching time of the OBS switch. We analyze the switching-time effect on the burst loss probability using a continuous-time Markov chain. In our analysis, the transmission time of a burst is characterized with both the burst size and the switching time, and the burst loss probability, burst throughput, and data throughput are explicitly derived using the Geo,M/M/c/c queueing model. Numerical examples show that our analysis is quite useful for investigating the effect of the switching time on the timer-based burst assembly. We also consider voice-over-Internet Protocol (VoIP) service as a delay-sensitive application, and we investigate the switching time on the VoIP service. From our performance analysis, we derive an appropriate switching time and a burst processing time of the VoIP service in terms of the transmission distance.

  14. Multicast contention resolution based on time-frequency joint scheduling in elastic optical switching networks

    Science.gov (United States)

    Liu, Huanlin; Li, Yuan; Peng, Han; Huang, Jun; Kong, Deqian

    2017-01-01

    Resolving the optical multicast contention in optical switch node is an effective approach to improve the performance of elastic optical multicast switch. An optical node architecture integrating with output shared all-optical Orthogonal Frequency Division Multiplexing (OFDM) network coding technology and shared feedback fiber delay lines (FDLs) buffer is designed. And a time-frequency joint scheduling strategy (TFJSS) is proposed. In TFJSS, the maximal weighted independent set algorithm is used to select the output packets with no overlapping spectrum among the contending multicast packets. The remaining contention packets are compressed by OFDM network coding with all-optical XOR operation. Hence, the contention is avoided in spectrum domain by encoding the contending unicast/multicast packets and changing the carrier frequency of encoded packets. If the network coding cannot successfully resolve the contending packets, the shared feedback FDLs are called to address the contention in time domain. Compared with the existing node architecture and scheduling algorithm, the simulation results show that the proposed architecture and the TFJSS can reduce the packet loss probability with low delay largely.

  15. Total internal reflection optical switch using the reverse breakdown of a pn junction in silicon.

    Science.gov (United States)

    Kim, Jong-Hun; Park, Hyo-Hoon

    2015-11-01

    We demonstrate a new type of silicon total-internal-reflection optical switch with a simple pn junction functioning both as a reflector and a heater. The reflector is placed between asymmetrically y-branched multimode waveguides with an inclination angle corresponding to half of the branch angle. When the reflector is at rest, incident light is reflected in accordance to the refractive index difference due to the plasma dispersion effect of the pre-doped carriers. Switching to the transmission state is attained under a reverse breakdown of the pn junction by the thermo-optic effect which smears the refractive index difference. From this switching scheme, we confirmed the switching operation with a shallow total-internal-reflection region of 1 μm width. At a 6° branch angle, an extinction ratio of 12 dB and an insertion loss of -4.2  dB are achieved along with a thermal heating power of 151.5 mW.

  16. Symmetric two dimensional photonic crystal coupled waveguide with point defect for optical switch application

    CERN Document Server

    Hardhienata, Hendradi

    2012-01-01

    Two dimensional (2D) photonic crystals are well known for its ability to manipulate the propagation of electromagnetic wave inside the crystal. 1D and 2D photonic crystals are relatively easier to fabricate than 3D because the former work in the microwave and far infrared regions whereas the later work in the visible region and requires smaller lattice constants. In this paper, simulation for a modified 2D PC with two symmetric waveguide channels where a defect is located inside one of the channel is performed. The simulation results show that optical switching is possible by modifying the refractive index of the defect. If more than one structure is applied this feature can potentially be applied to produce a cascade optical switch.

  17. All-optical ultrafast switching of Si woodpile photonic band gap crystals

    CERN Document Server

    Euser, T G; Fleming, J G; Gralak, B; Polman, Albert; Vos, W L; Euser, Tijmen G.; Molenaar, Adriaan J.; Gralak, Boris; Polman, Albert; Vos, Willem L.

    2006-01-01

    We present ultrafast all-optical switching measurements of Si woodpile photonic band gap crystals at telecom frequencies. The crystals are homogeneously excited by a two-photon process. We probe the switching by measuring reflectivity over broad frequency ranges as a function of time. At short delay times, we observe that the photonic gap becomes narrower than in the unswitched case. After 1 ps, the complete gap has shifted to higher frequencies. This intricate behavior is the result of competing refractive index changes due to the electronic Kerr effect and to optically excited free carriers. The frequency shift of the band gap as a function of pump intensity agrees well with Fourier modal method calculations with no freely adjustable parameters.

  18. Investigation on TCP/IP Congestion Control in Optical Burst Switched (OBS Network

    Directory of Open Access Journals (Sweden)

    Ms. Payal Daryani

    2012-03-01

    Full Text Available Transport Control Protocol (TCP is the dominant protocol in modern communication networks, in which the issues of reliability, flow, and congestion control must be handled efficiently. In this review paper an analytical switching is used to exploit the huge bandwidth of optical fibers for future high speed internet backbone. It carries multiple packets, in their turn. Different aggregation schemes have been considered and evaluated.TCP performance greatly depends on the TCP congestion window behavior that is related to loss events occurring in the optical burst switched network, there is a special term called traffic shaping by which we control over the network according to the network load .that means we increase or decrease the send rate according to the network demand.

  19. Passive all-optical polarization switch, binary logic gates, and digital processor.

    Science.gov (United States)

    Zaghloul, Y A; Zaghloul, A R M; Adibi, A

    2011-10-10

    We introduce the passive all-optical polarization switch, which modulates light with light. That switch is used to construct all the binary logic gates of two or more inputs. We discuss the design concepts and the operation of the AND, OR, NAND, and NOR gates as examples. The rest of the 16 logic gates are similarly designed. Cascading of such gates is straightforward as we show and discuss. Cascading in itself does not require a power source, but feedback at this stage of development does. The design and operation of an SR Latch is presented as one of the popular basic sequential devices used for memory cells. That completes the essential components of an all-optical polarization digital processor. The speed of such devices is well above 10 GHz for bulk implementations and is much higher for chip-size implementations. In addition, the presented devices do have the four essential characteristics previously thought unique to the microelectronic ones.

  20. High-Q silica zipper cavity for optical radiation pressure driven MOMS switch

    CERN Document Server

    Tetsumoto, Tomohiro

    2014-01-01

    We design a silica zipper cavity that has high optical and mechanical Q (quality factor) values and demonstrate numerically the feasibility of a radiation pressure driven micro opto-mechanical system (MOMS) directional switch. The silica zipper cavity has an optical Q of 6.0x10^4 and an effective mode volume Vmode of 0.66{\\lambda}^3 when the gap between two cavities is 34 nm. We found that this Q/V_mode value is five times higher than can be obtained with a single nanocavity design. The mechanical Q (Q_m) is determined by thermo-elastic damping and is 2.0x10^6 in a vacuum at room temperature. The opto-mechanical coupling rate g_OM is as high as 100 GHz/nm, which allows us to move the directional cavity-waveguide system and switch 1550-nm light with 770-nm light by controlling the radiation pressure.

  1. Optical Orthogonal Code Construction Using Rejected Delays Reuse for Increasing SubWavelength-Switching Capacity

    Science.gov (United States)

    Khattab, Tamer M. S.; Alnuweiri, Hussein M.

    2006-09-01

    Using a mathematical proof, the authors establish that in element-by-element greedy algorithms based on extended set representation of optical orthogonal codes (OOCs), smaller delay elements rejected during a construction step can be accepted in later steps. They design a novel algorithm that exploits this property and call it the rejected delays reuse (RDR) greedy algorithm. They show that employing the RDR method leads to code lengths that are shorter than those achieved for OOCs constructed using the classical greedy algorithm for the same code weight and the same number of simultaneous codes constraints. They then define a quantitative measure (factor) for OOCs efficiency based on its ability to expand subwavelength-switching capacity. They call this factor the expansion efficiency factor. They use this factor to show that reducing the code length, for the same code constraints, enhances the capacity of subwavelength optical code switched networks.

  2. Analysis on optical bistability parameters in photonic switching devices

    Science.gov (United States)

    Sarafraz, Hossein; Sayeh, Mohammad R.

    2016-06-01

    An investigation has been done on the parameters of a hysteretic bistable optical Schmitt trigger device. From a design point of view, it is important to know the regions where this bistability occurs and is fully functional with respect to its subsystem parameters. Otherwise experimentally reaching such behavior will be very time-consuming and frustrating, especially with multiple devices employed in a single photonic circuit. A photonic Schmitt trigger consisting of two feedbacked inverting amplifiers, each characterized by -m (slope), A (y-intercept), and B (constant base) parameters is considered. This system is investigated dynamically with a varying input to find its stable and unstable states both mathematically and with simulation. In addition to a complete mathematical analysis of the system, we also describe how m, A, and B can be properly chosen in order to satisfy certain system conditions that result in bistability. More restrictions are also imposed to these absolute conditions by the system conditions as will be discussed. Finally, all results are verified in a more realistic photonic simulation.

  3. A new prediction method at the edge of optical burst switching network

    Institute of Scientific and Technical Information of China (English)

    Zhicheng Sui; Qingji Zeng; Shilin Xiao

    2005-01-01

    To achieve lower assembly delay at optical burst switching edge node, this paper proposes an approach called current weight length prediction (CWLP) to improve existing estimate mechanism in burst assembly.is introduced to make a dynamic tradeoff between the current and past traffic under different offset time.Simulation results show that CWLP can achieve a significant improvement in terms of traffic estimation in various offset time and offered load.

  4. A sub-femtojoule electrical spin-switch based on optically trapped polariton condensates

    Science.gov (United States)

    Dreismann, Alexander; Ohadi, Hamid; Del Valle-Inclan Redondo, Yago; Balili, Ryan; Rubo, Yuri G.; Tsintzos, Simeon I.; Deligeorgis, George; Hatzopoulos, Zacharias; Savvidis, Pavlos G.; Baumberg, Jeremy J.

    2016-10-01

    Practical challenges to extrapolating Moore’s law favour alternatives to electrons as information carriers. Two promising candidates are spin-based and all-optical architectures, the former offering lower energy consumption, the latter superior signal transfer down to the level of chip-interconnects. Polaritons--spinor quasi-particles composed of semiconductor excitons and microcavity photons--directly couple exciton spins and photon polarizations, combining the advantages of both approaches. However, their implementation for spintronics has been hindered because polariton spins can be manipulated only optically or by strong magnetic fields. Here we use an external electric field to directly control the spin of a polariton condensate, bias-tuning the emission polarization. The nonlinear spin dynamics offers an alternative route to switching, allowing us to realize an electrical spin-switch exhibiting ultralow switching energies below 0.5 fJ. Our results lay the foundation for development of devices based on the electro-optical control of coherent spin ensembles on a chip.

  5. Synthesis and characterization of azo-containing organometallic thin films for all optical switching applications

    Science.gov (United States)

    Gatri, R.; Fillaut, J.-L.; Mysliwiec, J.; Szukalski, A.; Bartkiewicz, S.; El-Ouazzani, H.; Guezguez, I.; Khammar, F.; Sahraoui, B.

    2012-05-01

    Novel photoresponsive materials based on azo-containing bifunctional ruthenium-acetylides have been synthesized. All optical switching based on the Optical Kerr Effect in the organometallic thin films based on ruthenium(II) acetylides containing an azobenzene moiety as a photochromic unit in the main pi-conjugated system dispersed in a poly(methyl methacrylate) matrix has been observed. The excitation beam was delivered from a picosecond laser at wavelength 532 nm while dynamics of induced sample birefringence was probed by a non-absorbed linearly polarized beam of cw He-Ne laser (632.8 nm). The influence of ruthenium part on dynamics of molecular motions has been shown.

  6. All-optical switching in an open V-type atomic system

    Science.gov (United States)

    Jafarzadeh, H.

    2017-02-01

    In this paper, the optical bistability (OB) and absorption properties of a weak probe field in an open V-type three-level atomic system have been investigated. We found that the OB threshold could be reduced via spontaneously generated coherence (SGC), coherent and incoherent pump fields, atomic injection, and exit rates. We also found that the threshold intensity of OB in an open system was less than that in the closed system. The all-optical switching due to the OB has also been discussed.

  7. 25-Gbit/s burst-mode optical receiver using high-speed avalanche photodiode for 100-Gbit/s optical packet switching.

    Science.gov (United States)

    Nada, Masahiro; Nakamura, Makoto; Matsuzaki, Hideaki

    2014-01-13

    25-Gbit/s error-free operation of an optical receiver is successfully demonstrated against burst-mode optical input signals without preambles. The receiver, with a high-sensitivity avalanche photodiode and burst-mode transimpedance amplifier, exhibits sufficient receiver sensitivity and an extremely quick response suitable for burst-mode operation in 100-Gbit/s optical packet switching.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  9. High-performance and power-efficient 2${\\times}$2 optical switch on Silicon-on-Insulator

    CERN Document Server

    Han, Zheng; Checoury, Xavier; Bourderionnet, Jérôme; Boucaud, Philippe; De Rossi, Alfredo; Combrié, Sylvain

    2015-01-01

    A compact (15{\\mu}m${\\times}${\\mu}m) and highly-optimized 2${\\times}$2 optical switch is demonstrated on a CMOS-compatible photonic crystal technology. On-chip insertion loss are below 1dB, static and dynamic contrast are 40dB and >20dB respectively. Owing to efficient thermo-optic design, the power consumption is below 3 mW while the switching time is 1 {\\mu}s.

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

    Calabretta, Nicola; Miao, Wang; Dorren, Harm

    2016-03-01

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

  12. Reversible optical switching of antiferromagnetism in TbMnO3

    Science.gov (United States)

    Manz, Sebastian; Matsubara, Masakazu; Lottermoser, Thomas; Büchi, Jonathan; Iyama, Ayato; Kimura, Tsuyoshi; Meier, Dennis; Fiebig, Manfred

    2016-10-01

    Lasers can be used to control the magnetization of a ferromagnet via optically driven thermal and electronic excitation. Transfer of this concept to antiferromagnets is appealing because of the increasing technological interest in antiferromagnetism. Controlling spin structures in antiferromagnets is challenging, however, because of their zero magnetization. In a proof-of-principle experiment we demonstrate that optical control of antiferromagnetic domains is nevertheless possible. We reverse the antiferromagnetic order parameter in multiferroic TbMnO3 repeatedly, using light pulses of two different colours. Switching depends on a unique relation between the wavelength of the light, its optical absorption and the electric polarization field induced by the antiferromagnetic order of TbMnO3. We then demonstrate sequential laser-controlled writing and erasure of antiferromagnetic domains. The universality of reversible optical antiferromagnetic switching is derived by Monte Carlo simulations. Opto-magnetism is thus complemented by an important degree of freedom, namely local control of antiferromagnetism by means of light.

  13. Probing the electrical switching of a memristive optical antenna by STEM EELS

    Science.gov (United States)

    Schoen, David T.; Holsteen, Aaron L.; Brongersma, Mark L.

    2016-07-01

    The scaling of active photonic devices to deep-submicron length scales has been hampered by the fundamental diffraction limit and the absence of materials with sufficiently strong electro-optic effects. Plasmonics is providing new opportunities to circumvent this challenge. Here we provide evidence for a solid-state electro-optical switching mechanism that can operate in the visible spectral range with an active volume of less than (5 nm)3 or ~10-6 λ3, comparable to the size of the smallest electronic components. The switching mechanism relies on electrochemically displacing metal atoms inside the nanometre-scale gap to electrically connect two crossed metallic wires forming a cross-point junction. These junctions afford extreme light concentration and display singular optical behaviour upon formation of a conductive channel. The active tuning of plasmonic antennas attached to such junctions is analysed using a combination of electrical and optical measurements as well as electron energy loss spectroscopy in a scanning transmission electron microscope.

  14. Demonstration of all-optical MDM/WDM switching for short-reach networks.

    Science.gov (United States)

    Wu, Zhongying; Li, Juhao; Ge, Dawei; Ren, Fang; Zhu, Paikun; Mo, Qi; Li, Zhengbin; Chen, Zhangyuan; He, Yongqi

    2016-09-19

    Mode division multiplexing (MDM) has been widely investigated in optical transmission systems and networks to improve network capacity. However, the MDM receiver is always expensive and complex because coherent detection and multiplex-input-and-multiplex-output (MIMO) digital signal processing (DSP) are required to demultiplex each spatial mode. In this paper, we investigate the application of MDM in short-reach scenarios such as datacenter networking. Two-dimensional MDM and wavelength division multiplexing node structure based on low modal-crosstalk few-mode fiber (FMF) and components is proposed, in which signal in each mode or wavelength can be independently switched. We experimentally demonstrate independent adding, dropping and switching functionalities with two linearly polarized modes and four wavelength channels over a total 11.8-km 2-mode low modal-crosstalk FMFs. The structure is simple without coherent detection or MIMO DSP. Only slight penalties of receiver sensitivity are observed for all switching operations. The influence of modal-crosstalk accumulation for cascaded switching nodes is also investigated.

  15. Simulation of the switching performance of an optically triggered pseudo-spark thyratron

    Science.gov (United States)

    Pak, Hoyoung; Kushner, Mark J.

    1989-09-01

    The optically triggered pseudo-spark, also known as the back-lit thyratron, is a low-pressure plasma switch having an unheated metallic cathode, which has performance specifications competitive with conventional hot cathode thyratrons. In this paper a computer simulation of the BLT is presented. The simulation consists of a 2 1/2 -dimensional time-dependent continuum model for electron and ion transport using the local field approximation. The model includes an external circuit, and the user may specify the type of gas, pressure, geometry, and electrode materials. Predictions for the anode delay time are compared to experiment as a function of pressure (p), cathode-anode spacing (d), and trigger fluence. We find that switch closure depends critically on the formation of a virtual anode in front of the cathode hole by generation of positive space charge, and that the anode delay time decreases with increasing p, trigger fluence d, and cathode hole diameter. We also find switch performance is not well characterized by the pd product as in other plasma switches. Rather, we find these quantities depend separately on p and d in a manner which is a function of the geometry of the cathode.

  16. Optical node for fast packet-switching networks in the KEOPS project: structure and performance aspects

    Science.gov (United States)

    Chiaroni, Dominique; Lavigne, Bruno; Tran, Tri; Hamon, Laure; Jourdan, Amaury

    1998-10-01

    The future telecommunication network will have to face the dramatic increase of subscribers as well as the increase of the user bandwidth through new services. All-optical packet switching techniques can become a strategic objective to offer on an unique technology a service-transparent network. In this paper, we will describe in detail the structure of an optical packet switching node developed in the framework of the ACTS 043 KEOPS project. An analysis of the key functions will be reported to fulfill system requirements including cascadability. In particular the input synchronization, the Broadcast-and-select switching matrix and the output regenerative interface will be described and physical performance will be assessed through theoretical analysis: quality of the signal, packet jitter and packet power fluctuation. The electronic circuitry for the control of the components of each sub-block will be described. Finally, experimental validations of a 160 Gbit/s throughput node will be reported. In order to complete the analysis, the logical performance in a Bernoulli-type traffic will be regarded. In particular an optimized buffer including a recirculation loop will be studied. Logical performance exhibiting a packet loss rate lower than 10-9 for a 0.8 load and mean packet delay as low as 3 packet slots will be illustrated, thereby demonstrating full compatibility with ATM constraints. Finally, new perspectives in terms of throughput potential through cascading will be drawn.

  17. Electrically controlled optical-mode switch for fundamental mode and first order mode

    Science.gov (United States)

    Imansyah, Ryan; Tanaka, Tatsushi; Himbele, Luke; Jiang, Haisong; Hamamoto, Kiichi

    2016-08-01

    We have proposed an optical mode switch, the principle of which is based on the partial phase shift of injected light; therefore, one important issue is to clarify the proper design criteria for the mode combiner section. We focused on the bending radius of the S-bend waveguide issue that is connected to the multi mode waveguide in the Y-junction section that acts as mode combiner. Long radius leads to undesired mode coupling before the Y-junction section, whereas a short radius causes radiation loss. Thus, we simulated this mode combiner by the beam-propagation method to obtain the proper radius. In addition, we used a trench pin structure to simplify the fabrication process into a single-step dry-etching process. As a result, we successfully fabricated an optical-mode switch with the bending radius R = 610 µm. It showed the successful electrical mode switching and the achieved mode crosstalk was approximately -10 dB for 1550 nm wavelength with the injection current of 60 mA (5.7 V).

  18. All-optical scanhead for ultrasound and photoacoustic imaging-Imaging mode switching by dichroic filtering.

    Science.gov (United States)

    Hsieh, Bao-Yu; Chen, Sung-Liang; Ling, Tao; Guo, L Jay; Li, Pai-Chi

    2014-03-01

    Ultrasound (US) and photoacoustic (PA) multimodality imaging has the advantage of combining good acoustic resolution with high optical contrast. The use of an all-optical scanhead for both imaging modalities can simplify integration of the two systems and miniaturize the imaging scanhead. Herein we propose and demonstrate an all-optical US/PA scanhead using a thin plate for optoacoustic generation in US imaging, a polymer microring resonator for acoustic detection, and a dichroic filter to switch between the two imaging modes by changing the laser wavelength. A synthetic-aperture focusing technique is used to improve the resolution and contrast. Phantom images demonstrate the feasibility of this design, and show that axial and lateral resolutions of 125 μm and 2.52°, respectively, are possible.

  19. N-port strictly non-blocking optical router based on Mach-Zehnder optical switch for photonic networks-on-chip

    Science.gov (United States)

    Geng, Minming; Tang, Zhenhua; Chang, Kan; Huang, Xufang; Zheng, Jiali

    2017-01-01

    A universal method for constructing an N-port strictly non-blocking optical router based on 2×2 Mach-Zehnder optical switch for photonic networks-on-chip is proposed. By analyzing the routing table of the N-port optical router, the relationship between the optical links of port m→port n and port m→port n-1 is indicated, as well as the relationships between the block matrices of the N-port optical router. The strictly non-blocking property of the N-port optical router is proved by the contradiction method. The scale of the N-port optical router can be increased with the improvement of the performance of the Mach-Zehnder optical switch.

  20. Correlations between switching of conductivity and optical radiation observed in thin graphite-like films

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, S.G. [Institute for Nuclear Research of Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, 117312 Moscow (Russian Federation)], E-mail: lebedev@inr.ru; Yants, V.E. [Institute for Nuclear Research of Russian Academy of Sciences, 60th October Anniversary Prospect, 7a, 117312 Moscow (Russian Federation); Lebedev, A.S. [Lomonosov Moscow State University, Faculty of Computational Mathematics and Cybernetics GSP-2, Vorobievy Gory, 119992 Moscow (Russian Federation)

    2008-06-01

    The satisfactory explanation of anomalous electromagnetics in thin graphite-like carbon films till now is absent. The most comprehensible explanation may be the high-temperature superconductivity (HTSC). The pulse widths of spasmodic switching of electrical conductivity measured in this work in the graphite-like nanostructured carbon films, produced by methods of the carbon arc (CA) and chemical vapor deposition (CVD), are 1 and 2 ns correspondingly. Such fast switching completely excludes the thermal mechanism of the process. According to HTSC logic, in the time vicinity close to jump of electroresistance, it is necessary to expect the generation of optical radiation in the infrared (IR) range. This work presents the first results on registration of IR radiation caused by the sharp change of conductivity in thin graphite-like carbon films.

  1. A compact plasmonic MOS-based 2x2 electro-optic switch

    CERN Document Server

    Ye, Chenran; Soref, Richard A; Sorger, Volker J

    2015-01-01

    We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS) mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, Indium-Tin-Oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 dB (7) dB for the CROSS (BAR) state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with Siliconon- Insulator platforms to for low-cost manufacturing.

  2. Strictly non-blocking 4×4 silicon electro-optic switch matrix

    Science.gov (United States)

    Zhou, Pei-Ji; Xing, Jie-Jiang; Li, Xian-Yao; Li, Zhi-Yong; Yu, Jin-Zhong; Yu, Yu-De

    2015-12-01

    The first path-independent insertion-loss (PILOSS) strictly non-blocking 4×4 silicon electro-optic switch matrix is reported. The footprint of this switch matrix is only 4.6 mm×1.0 mm. Using single-arm modulation, the crosstalk measured in this test is -13 dB˜ -27 dB. And a maximum crosstalk deterioration of 6dB caused by two-path interference is also found. Project supported by the National Basic Research Program of China (Grant No. 2011CB301701), the National High Technology Research and Development Program of China (Grant Nos. 2013AA014402, 2012AA012202, and 2015AA016904), and the National Natural Science Foundation of China (Grant Nos. 61275065 and 61107048).

  3. Resonators induced transparency and optical switching assisted by optofluidic pump system

    Science.gov (United States)

    Chen, Fang; Sun, Li-Hui

    2016-12-01

    A tunable plasmonic induced transparency (PIT)-based light switching is proposed and investigated. The proposed structure consists of a bus waveguide, two nanoresonators and an optofluidic pump system for actively tuning the system’s transmission. By using the finite difference time domain method, it is found that the interferences between the dark and bright mode resonators can be controlled by manipulating the fluid filled in the resonator, leading to an actively tunable plasmonic switch, the transmittance can be flexibly tuned from near unity to zero. The structure in our paper has the following advantages, such as ultracompact size and easy fabrication. Our study will provide a possibility for designing the ultrafast devices in highly integrated optical circuits.

  4. Double layers liquid-crystal microlens arrays used in optical switches

    Science.gov (United States)

    Wang, Cheng; Fan, Di; Zhang, Bo; Tong, Qing; Luo, Jun; Lei, Yu; Zhang, Xinyu; Xie, Changsheng

    2015-12-01

    Based on our previous works in liquid-crystal microlens arrays (LCMAs), a new kind of optical switches using the 24×24 fiber arrays coupled with the LCMAs, which have a key dual-mode function of the switches about on and off state and work in visible and infrared range, is proposed and fabricated in this paper. Different with other common LCMAs, this new kind of dual-mode LCMAs includes two layers of control electrodes deposited directly over the surface of the top glass substrate in LC microcavity fabricated. The first layer is the patterned electrode, which is designed into basic circular holes with suitable diameter, and the second is the planar electrode. Both layered electrodes are effectively separated by a thin SiO2 film with a typical thickness of about several micrometers, and then the dual-mode microlenses are driven by applied electrical signals with different root mean square (rms) voltage.

  5. A compact plasmonic MOS-based 2×2 electro-optic switch

    Science.gov (United States)

    Ye, Chenran; Liu, Ke; Soref, Richard A.; Sorger, Volker J.

    2015-01-01

    We report on a three-waveguide electro-optic switch for compact photonic integrated circuits and data routing applications. The device features a plasmonic metal-oxide-semiconductor (MOS) mode for enhanced light-matter-interactions. The switching mechanism originates from a capacitor-like design where the refractive index of the active medium, indium-tin-oxide, is altered via shifting the plasma frequency due to carrier accumulation inside the waveguide-based MOS structure. This light manipulation mechanism controls the transmission direction of transverse magnetic polarized light into either a CROSS or BAR waveguide port. The extinction ratio of 18 (7) dB for the CROSS (BAR) state, respectively, is achieved via a gating voltage bias. The ultrafast broadband fJ/bit device allows for seamless integration with silicon-on-insulator platforms for low-cost manufacturing.

  6. Problem of Channel Utilization and Merging Flows in Buffered Optical Burst Switching Networks

    Directory of Open Access Journals (Sweden)

    Milos Kozak

    2013-01-01

    Full Text Available In the paper authors verify two problems of methods of operational research in optical burst switching. The first problem is at edge node, related to the medium access delay. The second problem is at an intermediate node related to buffering delay. A correction coefficient K of transmission speed is obtained from the first analysis. It is used in to provide a full-featured link of nominal data rate. Simulations of the second problem reveal interesting results. It is not viable to prepare routing and wavelength assignment based on end-to-end delay, i.e. link's length or number of hops, as commonly used in other frameworks (OCS, Ethernet, IP, etc. nowadays. Other parameters such as buffering probability must be taken into consideration as well. Based on the buffering probability an estimation of the number of optical/electrical converters can be made. This paper concentrates important traffic constraints of buffered optical burst switching. It allows authors to prepare optimization algorithms for regenerators placement in CAROBS networks using methods of operational research.

  7. Reversible optical switching of highly confined phonon-polaritons with an ultrathin phase-change material

    Science.gov (United States)

    Li, Peining; Yang, Xiaosheng; Maß, Tobias W. W.; Hanss, Julian; Lewin, Martin; Michel, Ann-Katrin U.; Wuttig, Matthias; Taubner, Thomas

    2016-08-01

    Surface phonon-polaritons (SPhPs), collective excitations of photons coupled with phonons in polar crystals, enable strong light-matter interaction and numerous infrared nanophotonic applications. However, as the lattice vibrations are determined by the crystal structure, the dynamical control of SPhPs remains challenging. Here, we realize the all-optical, non-volatile, and reversible switching of SPhPs by controlling the structural phase of a phase-change material (PCM) employed as a switchable dielectric environment. We experimentally demonstrate optical switching of an ultrathin PCM film (down to 7 nm, detect ultra-confined SPhPs (polariton wavevector kp > 70k0, k0 = 2π/λ) in quartz. Our proof of concept allows the preparation of all-dielectric, rewritable SPhP resonators without the need for complex fabrication methods. With optimized materials and parallelized optical addressing we foresee application potential for switchable infrared nanophotonic elements, for example, imaging elements such as superlenses and hyperlenses, as well as reconfigurable metasurfaces and sensors.

  8. A Theoretical Study on an Optical Switch Using Interfered Evanescent Light

    CERN Document Server

    Kitsunezaki, Naofumi; Kitsunezaki, Akio

    2009-01-01

    In an optical configuration consisting of a flat plate of vacuum between upper and lower spaces of uniform dielectric regions of n>1, we have calculated two output light intensities for two input lights from the Maxwell's equations as functions of the incision angle, a light intensity ratio, a phase difference of the two input lights, and a thickness of the vacuum layer, where the two input lights come from upper and lower dielectric regions with the same incision angles, and one of the output light goes into upper dielectric and the other goes into lower dielectric. We have found that, when evanescent lights exist at the upper and lower boundary and interfere each other, there is one set of incision angles and phase differences for any combination of an input light ratio and a thickness of the vacuum layer where one of output lights becomes zero. This finding will possibly lead to an innovative optical switch with which an optical output light can be switched on and off with a control light with an intensity...

  9. Improved silica-PLC Mach-Zehnder interferometer type optical switches with error dependence compensation of directional coupler

    Science.gov (United States)

    Wang, Jun; Yi, Jia; Guo, Lijun; Liu, Peng; Hall, Trevor J.; Sun, DeGui

    2017-03-01

    For the most popular structure of planer lightwave circuit (PLC) 2×2 thermo-optic switches, Mach-Zehnder interferometer (MZI), a full range of splitting ratio errors of directional coupler (DC) are investigated. All the parameters determining the splitting ratio are the dimensions and the refractive indices of the waveguide core and cladding layers. In this work, the coherent relationships between the waveguide size and the refractive indices are analyzed and then the error compensation between the width and the refractive index of waveguide core, and the controllable effect of over clad layer refractive index error upon the MZI-type optical switch are all discovered with numerical calculation and BPM simulations. Then, an MZI-type 2×2 thermo-optic switch having a higher error tolerance is established with the efficient optimizations of all the 3 dB-DC parameters. As a result, for the symmetric MZI switch, an insertion loss of 1.5 dB and optical extinction ratio of over 20 dB are realized for the average tolerance of±5.0%. An asymmetric arm optical phase and unequal arm lengths is also employed to improve the uniformities of insertion loss. The agreements between the designs and the experiments are recognized, leading to a wide adoption of practical silica-PLC optical switch products.

  10. Optical Switching and Detection of 640 Gb/s OTDM Data Packets Transmitted over 50 km of fibre

    DEFF Research Database (Denmark)

    Gomez-Agis, Fausto; Hu, Hao; Luo, Jun;

    2011-01-01

    We demonstrate 1X4 optical-packet switching with error-free transmission of 640 Gb/s single-wavelength OTDM data-packets including instantaneous clock extraction and short pulse generation for optical time-demultiplexing based on a cavity-less pulse source....

  11. Surface plasmon polariton assisted optical switching in noble bimetallic nanoparticle system

    Energy Technology Data Exchange (ETDEWEB)

    Dhara, Sandip, E-mail: dhara@igcar.gov.in, E-mail: chenkh@pub.iams.sinica.edu.tw [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Lu, C.-Y.; Tu, W.-S. [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Magudapathy, P. [Materials Physics Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Huang, Y.-F.; Chen, K.-H., E-mail: dhara@igcar.gov.in, E-mail: chenkh@pub.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan (China); Center for Condensed Matter Science, National Taiwan University, Taipei 106, Taiwan (China)

    2015-01-12

    Photoresponse of bimetallic Au-Ag nanoparticle embedded soda glass (Au-Ag@SG) substrate is reported for surface plasmon assisted optical switching using 808 nm excitation. Au-Ag@SG system is made by an ion beam technique where Ag{sup +} is introduced first in the soda glass matrix by ion exchange technique. Subsequently, 400 keV Au{sup +} is implanted in the sample for different fluences, which is followed by an ion beam annealing process using 1 MeV Si{sup +} at a fixed fluence of 2 × 10{sup 16} ions·cm{sup −2}. Characteristic surface plasmon resonance (SPR) peaks around 400 and 550 nm provided evidence for the presence of Au and Ag nanoparticles. An optical switching in the Au-Ag@SG system with 808 nm, which is away from the characteristic SPR peaks of Ag and Au nanoparticles, suggests the possible role of two photon absorption (TPA) owing to the presence of interacting electric dipole in these systems. The role of surface plasmon polariton is emphasized for the propagation of electronic carrier belonging to the conduction electron of Au-Ag system in understanding the observed photoresponse. Unique excitation dependent photoresponse measurements confirm the possible role of TPA process. A competitive interband and intraband transitions in the bimetallic system of Au and Ag, which may be primarily responsible for the observation, are validated qualitatively using finite difference time domain calculations where inter-particle separation of Au and Ag plays an important role. Thus, a smart way of optical switching can be envisaged in noble bimetallic nanocluster system where long wavelength with higher skin depth can be used for communication purpose.

  12. ZnO nanowire-based all-optical switch with Reset-Set flip-flop function

    Science.gov (United States)

    Mu, L. X.; Shi, W. S.; Zhang, T. P.; Zhang, H. Y.; Wang, Y.; She, G. W.; Gao, Y. H.; Wang, P. F.; Chang, J. C.; Lee, S. T.

    2011-04-01

    An all-optical switch with Reset-Set (RS) flip-flop function has been developed by attaching a derivative of spiropyran on the surface of zinc oxide (ZnO) Nanowire. Using UV/visible irradiation and the fluorescence of spiropyran-modified ZnO nanowire as inputs—set/reset and output, RS flip-flop function can be performed on a single ZnO nanowire or a nanowire array. The configuration of the current all-optical switch represents a potential for developing small-sized all-optical devices, which could be further exploited at higher level of integration.

  13. Sun-tracking optical element realized using thermally activated transparency-switching material.

    Science.gov (United States)

    Apostoleris, Harry; Stefancich, Marco; Lilliu, Samuele; Chiesa, Matteo

    2015-07-27

    We present a proof of concept demonstration of a novel optical element: a light-responsive aperture that can track a moving light beam. The element is created using a thermally-activated transparency-switching material composed of paraffin wax and polydimethylsiloxane (PDMS). Illumination of the material with a focused beam causes the formation of a localized transparency at the focal spot location, due to local heating caused by absorption of a portion of the incident light. An application is proposed in a new design for a self-tracking solar collector.

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

    Directory of Open Access Journals (Sweden)

    Yuhua Chen

    2008-01-01

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

  15. Field-effect active plasmonics for ultracompact electro-optic switching

    OpenAIRE

    Müstecaplıoğlu, Özgür E.; Çetin, Arif E.; Yanık, Ahmet A.; Mertiri, Alket; Erramilli, Shyamsunder; Altuğ, Hatice

    2012-01-01

    Field-effect active plasmonics for ultracompact electro-optic switching Arif E. Çetin, Ahmet A. Yanik, Alket Mertiri, Shyamsunder Erramilli, Özgür E. Müstecaplolu, and Hatice Altug Citation: Applied Physics Letters 101, 121113 (2012); doi: 10.1063/1.4754139 View online: http://dx.doi.org/10.1063/1.4754139 View Table of Contents: http://scitation.aip.org/content/aip/journal/apl/101/12?ver=pdfcov Published by the AIP Publishing Articles you may be interested in A proposal f...

  16. A novel scheme based on minimum delay at the edges for optical burst switching networks

    Institute of Scientific and Technical Information of China (English)

    Jinhui Yu(于金辉); Yijun Yang(杨毅军); Yuehua Chen(陈月华); Ge Fan(范戈)

    2003-01-01

    This paper proposes a novel scheme based on minimum delay at the edges (MDE) for optical burst switching(OBS) networks. This scheme is designed to overcome the long delay at the edge nodes of OBS networks.The MDE scheme features simultaneous burst assembly, channel scheduling, and pre-transmission of controlpacket. It also features estimated setup and explicit release (ESXR) signaling protocol. The MDE schemecan minimize the delay at the edge nodes for data packets, and improve the end-to-end latency performancefor OBS networks. In addition, comparing with the conventional scheme, the performances of the MDEscheme are analyzed in this paper.

  17. Femtosecond studies of nonlinear optical switching in GaAs waveguides using time-domain interferometry

    Science.gov (United States)

    Anderson, Kristin K.; LaGasse, Michael J.; Haus, Hermann A.; Fujimoto, James G.

    1990-05-01

    We describe the application of a new femtosecond measurement technique, time division interferometry, for investigating the transient nonlinear index in waveguides. This technique performs an interferometric measurement using a time division multiplexed reference pulse and achieves high sensitivity with increased immunity to acoustic and thermal parasitics. Using a tunable femtosecond laser source, direct measurements of the wavelength dependent nonresonant nonlinear index have been performed in A1GaAs waveguides. In addition, conventional pump and probe absorption measurements permit the investigation of carrier dynamics, band filling, and two photon absorption effects. Two photon absorption is found to be a potentially serious limiting effect for obtaining all optical switching.

  18. A Novel De-noising Model Based on Independent Component Analysis and Beamlet Transform

    Directory of Open Access Journals (Sweden)

    Guangming Zhang

    2012-06-01

    Full Text Available Vehicle video key frame processing as an important part of intelligent transportation systems plays a significant role. Traditional vehicle video key frame extraction often has lots of noises, it can’t meet the requirements of the recognition and tracking. In this paper, a novel method which is combined independent component analysis with beamlet transform is proposed. Firstly, a random matrix was produce to separate the key frame into a separated image for estimate. Then beamlet transform was applied to optimize the coefficients. At last, the coefficients were selected for image reconstruction by inverse of the beamlet transform. By contrast, this approach could remove more noises and reserve more details, and the efficiency of our approach is better than other traditional de-noising approaches.

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

    Science.gov (United States)

    Jannson, Tomasz; Kostrzewski, Andrew

    1994-09-01

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

  20. Performance Evaluation of the Loop Buffer Switch Under Prioritized Traffic and Optical Regeneration

    Directory of Open Access Journals (Sweden)

    Devesh Pratap Singh

    2012-12-01

    Full Text Available In this paper, an all-optical regenerator based, photonic packet switch architecture, which consists of the fiber loop for the storage of the contending packets, is considered. In the loop buffer, the available buffer space may not be fully utilized due to the limited re-circulation count of the data placed on buffer. This limit can be counteracted by placing a pool of regenerators inside the buffer. As optical regenerators are costly devices, hence they should be placed optimally in the buffer. The simulations results are presented by consider Prioritized and non – prioritized traffic. It is shown in the results that regeneration of data is essential if prioritized traffic has to be considered.

  1. Magneto-optical switching of Bloch surface waves in magnetophotonic crystals

    Science.gov (United States)

    Romodina, M. N.; Soboleva, I. V.; Fedyanin, A. A.

    2016-10-01

    Bloch-surface-wave (BSW) excitation controlled by Faraday rotation in one-dimensional magnetophotonic crystals is presented. Dispersion curves of the Bloch surface wave and waveguide modes of magnetophotonic crystals consisting of silicon dioxide and bismuth-substituted yttrium-iron-garnet (Bi:YIG) quarter-wavelength-thick layers are calculated using Berreman's 4×4 transfer matrix method. Enhanced Faraday rotation observed in the magnetophotonic crystals in the spectral vicinity of the BSW resonance enables the magneto-optical switching of BSWs. The excitation of the BSWs at the magnetophotonic crystal surface for p-polarized incident light is induced by magneto-optical activity in the Bi:YIG layers.

  2. Femtosecond investigations of optical switching and χ(3) in GaAs waveguides

    Science.gov (United States)

    LaGasse, Michael J.; Anderson, Kristin K.; Wang, Christine A.; Haus, Hermann A.; Fujimoto, James G.

    1990-08-01

    We describe a new technique for performing femtosecond transient measurements of nonlinear index and absorption in waveguide devices. Using a time division interferometry technique in conjunction with a tunable femtosecond laser source we have performed the first measurement of the wavelength dependent nonresonant nonlinear index in A1GaAs. Contributions to nonlinear index arise from both virtual as well as real population mediated processes depending on the wavelength detuning from resonance. Complementary pump-probe measurements of transient absorption provide information on excited state population as well as two-photon induced absorption processes. These measurements provide imformation on the mechanism and dynamics of fundamental nonlinear optical processes below the band edge in semiconductors and are relevant to possible all optical switching applications in waveguide devices.

  3. On the size-dependent magnetism and all-optical magnetization switching of transition-metal silicide nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Glushkov, G. I.; Tuchin, A. V.; Popov, S. V.; Bityutskaya, L. A., E-mail: me144@phys.vsu.ru [Voronezh State University (Russian Federation)

    2015-12-15

    Theoretical investigations of the electronic structure, synthesis, and all-optical magnetization switching of transition-metal silicide nanostructures are reported. The magnetic moment of the nanostructures is studied as a function of the silicide cluster size and configuration. The experimentally demonstrated magnetization switching of nanostructured nickel silicide by circularly polarized light makes it possible to create high-speed storage devices with high density data recording.

  4. Thermo-optic control of dielectric-loaded plasmonic Mach-Zehnder interferometers and directional coupler switches

    DEFF Research Database (Denmark)

    Gosciniak, J.; Markey, L.; Dereux, A.

    2012-01-01

    We report detailed experimental studies of compact fiber-coupled dielectric-loaded plasmonic waveguide components-Mach-Zehnder interferometers (MZIs) and directional couplers (DCs)-whose operation at telecom wavelengths is controlled via the thermo-optic effect by electrically heating the gold st......, and wavelength dependent low power (similar to 0.92 mW) rerouting is achieved with DC switches. Furthermore, simulations were performed to confirm the switching characteristics of the components....

  5. Universal dynamics and deterministic switching of dissipative Kerr solitons in optical microresonators

    Science.gov (United States)

    Guo, H.; Karpov, M.; Lucas, E.; Kordts, A.; Pfeiffer, M. H. P.; Brasch, V.; Lihachev, G.; Lobanov, V. E.; Gorodetsky, M. L.; Kippenberg, T. J.

    2017-01-01

    Temporal dissipative Kerr solitons in optical microresonators enable the generation of ultrashort pulses and low-noise frequency combs at microwave repetition rates. They have been demonstrated in a growing number of microresonator platforms, enabling chip-scale frequency combs, optical synthesis of low-noise microwaves and multichannel coherent communications. In all these applications, accessing and maintaining a single-soliton state is a key requirement--one that remains an outstanding challenge. Here, we study the dynamics of multiple-soliton states and report the discovery of a simple mechanism that deterministically switches the soliton state by reducing the number of solitons one by one. We demonstrate this control in Si3N4 and MgF2 resonators and, moreover, we observe a secondary peak to emerge in the response of the system to a pump modulation, an effect uniquely associated with the soliton regime. Exploiting this feature, we map the multi-stability diagram of a microresonator experimentally. Our measurements show the physical mechanism of the soliton switching and provide insight into soliton dynamics in microresonators. The technique provides a method to sequentially reduce, monitor and stabilize an arbitrary state with solitons, in particular allowing for feedback stabilization of single-soliton states, which is necessary for practical applications.

  6. Analysis of electro-optic switches with series-coupled multiple microring resonators

    Institute of Scientific and Technical Information of China (English)

    YAN Xin; MA Chun-sheng; ZHENG Chuan-tao; WANG Xian-yin; ZHANG Da-ming

    2009-01-01

    In terms of the coupled mode theory, microring resonance and electro-optic modulation princeple, a reasonable project is proposed for designing an electro-optic switch with the series-coupled multiple microring resonators. The simulation and optimization are performed at the resonant wavelength of 1550 nm. The results are as follows: the core size of the microring is 1.6 μm×1.6 μm, the confined layer between the core and the electrode is 1.6 μm, the thickness of the electrode is 0.15 μm, the radius ofthe microring is 15.2 μm, the coupling gap between the microring and the channel is 0.14 μm, and the one between the microring and the microring is 0.6 μm, microring number M is 4, the switching voltage is 4 V, the insertion loss is 5.4 dB, and the crosstalk is -20 dB. The output spectrum is much flatter and much steeper than that of the single microring.

  7. High-temperature optically activated GaAs power switching for aircraft digital electronic control

    Science.gov (United States)

    Berak, J. M.; Grantham, D. H.; Swindal, J. L.; Black, J. F.; Allen, L. B.

    1983-01-01

    Gallium arsenide high-temperature devices were fabricated and assembled into an optically activated pulse-width-modulated power control for a torque motor typical of the kinds used in jet engine actuators. A bipolar heterojunction phototransistor with gallium aluminum arsenide emitter/window, a gallium arsenide junction field-effect power transistor and a gallium arsenide transient protection diode were designed and fabricated. A high-temperature fiber optic/phototransistor coupling scheme was implemented. The devices assembled into the demonstrator were successfully tested at 250 C, proving the feasibility of actuator-located switching of control power using optical signals transmitted by fibers. Assessments of the efficiency and technical merits were made for extension of this high-temperature technology to local conversion of optical power to electrical power and its control at levels useful for driving actuators. Optical power sources included in the comparisons were an infrared light-emitting diode, an injection laser diode, tungsten-halogen lamps and arc lamps. Optical-to-electrical power conversion was limited to photovoltaics located at the actuator. Impedance matching of the photovoltaic array to the load was considered over the full temperature range, -55 C to 260 C. Loss of photovoltaic efficiency at higher temperatures was taken into account. Serious losses in efficiency are: (1) in the optical source and the cooling which they may require in the assumed 125 C ambient, (2) in the decreased conversion efficiency of the gallium arsenide photovoltaic at 260 C, and (3) in impedance matching. Practical systems require improvements in these areas.

  8. A 2×2 SOI mach-zehnder thermo-optical switch based on strongly guided paired multimode interference couplers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A silicon-on-insulator 2×2 Mach-Zehnder thermo-optical switch is developed based on strongly guided paired multimode interference couplers. The multimode-interference couplers were etched deeply for improving coupler characteristics such as self-imaging quality, uniformity and fabrication tolerance. The proposed switch achieves good performances, including a low insertion loss of -11 .OdB, a fiber-waveguide coupling loss of -4.3dB and a fast response speed measured to be 3.5 and 8.8 μs for raise and fall switching time, respectively.

  9. An all-optical switch of Mach-Zehnder interferometer type using an active fibre ring resonator

    Institute of Scientific and Technical Information of China (English)

    Li Jun-Qing; Alireza Bananej; Li Qiang-Hua; Chen Qiang; Li Chun-Fei

    2004-01-01

    We propose an all-optical switch of the Mach-Zehnder interferometer type using an active nonlinear ring resonatorand analyse the significance of the parameter A, a product of gain and total loss, for performing an ideal 1 by 2switch. We found that in the range of 1 - κ≤ A ≤√/1 - k, the increment of A can compensate the losses insidethe ring, therefore increase the finesse of the ring and enhance the nonlinearity contribution to reduce the switchingpower threshold effectively. We also emphasize the importance of the initial switching point and discuss the feasibilityof utilizing a high-nonlinear fibre in the ring.

  10. Nonlinear optical switching behavior in the solid state: A theoretical investigation on anils

    KAUST Repository

    Ségerie, Audrey

    2011-09-13

    The linear (π(1)) and second-order nonlinear (π(2)) optical properties of two anil crystals, [N-(4-hydroxy)-salicylidene-amino-4-(methylbenzoate) and N-(3,5-di-tert- butylsalicylidene)-4-aminopyridine, denoted 4A and 4P, respectively], as well as the optical contrasts upon switching between their enol (E) and keto (K) forms, have been investigated by combining the molecular responses calculated using quantum chemistry methods and an electrostatic interaction scheme to account for the local field effects. It is found that intermolecular interactions impact differently the K/E optical contrasts in the two systems, which illustrates the importance of the supramolecular organization on the macroscopic responses. In 4A, the surrounding effects on the (hyper)polarizabilities are similar in the enol and keto forms, leading to optical contrasts very close to those of the isolated molecule. In contrast, an enhancement of the second-order susceptibility is observed in the keto form of 4P, leading to a large π(2)(K)/π(2)(E) contrast. Moreover, the π(2)(4A)/π(2)(4P) ratio for the most stable enol forms is obtained to be in good agreement with previous experimental investigations, which supports the reliability of the computational procedure. © 2011 American Chemical Society.

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

    Science.gov (United States)

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

    1991-01-01

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

  12. Fabrication of 2×2 Thermo-Optic Switches with Organic-Inorganic Hybrid Materials Prepared by Sol-Gel Technique

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    2×2 Mach-Zehnder interferometric thermo-optic switch was fabricated with organic/inorganic hybrid materials by sol-gel technique and direct UV patterning. The switching time of device was measured to be 4.2 ms and switching power 9.3 mW.

  13. Simulation of the viewing properties and optical compensation of the biaxial nematic in-plane switching mode.

    Science.gov (United States)

    Benzie, Philip W; Corbett, Daniel; Elston, Steve J

    2012-01-01

    Using Berreman 4 × 4 optical methods and continuum theory, we investigate the theoretical viewing properties of a potential homeotropically aligned biaxial nematic display switched with in-plane fields. We determine the isocontrast, isotransmission viewing characteristics for wide-angle viewing for in-plane switching and consider the necessary requirements for optical compensation to produce a high transmission in the bright state and low transmission in the dark state. We show how compensation can be achieved with biaxial compensation layers using a homogeneous biaxial film or from birefringence.

  14. Experimental validation of efficient methods for the prediction of patterning effects in SOA-based optical switches

    DEFF Research Database (Denmark)

    Xu, Jing; Ding, Yunhong; Xue, Weiqi

    2010-01-01

    We experimentally investigate and verify simple and efficient methods for characterizing the patterning effects (PE) of SOA-based optical switches. The onset of PE saturation is well predicted by the theory. an experimental method to capture the maximum PE is developed.......We experimentally investigate and verify simple and efficient methods for characterizing the patterning effects (PE) of SOA-based optical switches. The onset of PE saturation is well predicted by the theory. an experimental method to capture the maximum PE is developed....

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

    Science.gov (United States)

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

    2017-01-01

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

  16. Optical nonlinearities and ultrafast all-optical switching of m-plane GaN in the near-infrared

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yu; Zhou, Feng; Yang, Junyi; Yang, Yong [College of Physics, Optoelectronics and Energy, Soochow University, 215006 Suzhou (China); Xiao, Zhengguo; Wu, Xingzhi [Department of Physics, Harbin Institute of Technology, 150001 Harbin (China); Song, Yinglin, E-mail: ylsong@hit.edu.cn [College of Physics, Optoelectronics and Energy, Soochow University, 215006 Suzhou (China); Department of Physics, Harbin Institute of Technology, 150001 Harbin (China)

    2015-06-22

    We reported a systematic investigation on the three-photon absorption (3PA) spectra and wavelength dispersion of Kerr refraction of bulk m-plane GaN crystal with both polarization E⊥c and E//c by femtosecond Z-scan technique in the near-infrared region from 760 to 1030 nm. Both 3PA spectra and Kerr refraction dispersion were in good agreement with two-band models. The calculated nonlinear figure of merit and measured ultrafast nonlinear refraction dynamics via femtosecond pump-probe with phase object method revealed that m-plane GaN would be a promising candidate for ultrafast all-optical switching and autocorrelation applications at telecommunication wavelengths.

  17. Engineered materials for all-optical helicity-dependent magnetic switching

    Science.gov (United States)

    Mangin, S.; Gottwald, M.; Lambert, C.-H.; Steil, D.; Uhlíř, V.; Pang, L.; Hehn, M.; Alebrand, S.; Cinchetti, M.; Malinowski, G.; Fainman, Y.; Aeschlimann, M.; Fullerton, E. E.

    2014-03-01

    The possibility of manipulating magnetic systems without applied magnetic fields have attracted growing attention over the past fifteen years. The low-power manipulation of the magnetization, preferably at ultrashort timescales, has become a fundamental challenge with implications for future magnetic information memory and storage technologies. Here we explore the optical manipulation of the magnetization in engineered magnetic materials. We demonstrate that all-optical helicity-dependent switching (AO-HDS) can be observed not only in selected rare earth-transition metal (RE-TM) alloy films but also in a much broader variety of materials, including RE-TM alloys, multilayers and heterostructures. We further show that RE-free Co-Ir-based synthetic ferrimagnetic heterostructures designed to mimic the magnetic properties of RE-TM alloys also exhibit AO-HDS. These results challenge present theories of AO-HDS and provide a pathway to engineering materials for future applications based on all-optical control of magnetic order.

  18. All-optical switching via four-wave mixing Bragg scattering in a silicon platform

    CERN Document Server

    Zhao, Yun; Mathews, Jay; Agha, Imad

    2016-01-01

    We employ the process of non-degenerate four-wave mixing Bragg scattering (FWM-BS) to demonstrate all-optical control in a silicon platform. In our configuration, a strong, non-information-carrying pump is mixed with a weak control pump and an input signal in a silicon-on-insulator waveguide. Through the optical nonlinearity of this highly-confining waveguide, the weak pump controls the wavelength conversion process from the signal to an idler, leading to a controlled depletion of the signal. The strong pump, on the other hand, plays the role of a constant bias. In this work, we show experimentally that it is possible to implement this low-power switching technique as a first step towards universal optical logic gates, and test the performance with random binary data. Even at very low powers, where the signal and control pump levels are almost equal, the eye-diagrams remain open, indicating a successful operation of the logic gates.

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

    DEFF Research Database (Denmark)

    Nord, Martin

    2004-01-01

    This work proposes a quality of service differentiation algorithm, improving the service class granularity and isolation of our recently presented waveband plane based design. The design aims at overcoming potential hardware limitations and increasing the switch node dimensioning flexibility in c...

  20. Switch on or switch off: an optical DNA sensor based on poly(p-phenylenevinylene) grafted magnetic beads.

    Science.gov (United States)

    Srinivas, Anupama R Gulur; Peng, Hui; Barker, David; Travas-Sejdic, Jadranka

    2012-05-15

    There has been an enormous demand for commercial label-free DNA sensors in a diverse range of fields including pre-emptive medicine, diagnostics, environmental monitoring, and food industry. Addressing the need for sensitive, selective and facile DNA sensors, we demonstrate a novel switch on/off sensor design that utilizes sandwich hybridization between photoluminescent anionic conjugated polyelectrolyte (CPE) bound captureprobe coated onto magnetic beads, target and the signaling probe. The hybridization-readout in our sensor was monitored by either fluorescence resonance energy transfer (FRET, switch-on) or superquenching (switch-off) depending on the type of signaling probe used. Moreover recent designs that utilize beads for sensing DNA have been limited towards using electrostatic interactions or intercalation of dyes to observe FRET. To our knowledge this is the first report of a switch on/off sensor utilizing either FRET or superquenching thus providing flexibility for future development of such rapid, facile and sensitive DNA sensors. The FRET-based sensor was investigated by optimizing the reaction parameters and selectivity. A low detection limit of 240 fmol in 2 mL of SSC buffer was achieved.

  1. Performance analysis of a low-complexity and efficient QoS differentiation algorithm for bufferless optical packet switches with shared wavelength converters in asynchronous operation

    DEFF Research Database (Denmark)

    Nord, Martin

    2004-01-01

    This paper presents a simulation study of a low-complexity optical packet switching quality of service differentiation scheme, aiming at minimising the penalty of offering packet loss rate isolation in an optical packet switch with a wavelength converter pool. Special emphasis is given to potential...

  2. Modeling and Characterization of Modified Optical Burst Switching (OBS Ring Network Using Proxy Node

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Dutta

    2012-01-01

    Full Text Available This paper presents an analytical model of an optical burst switching  ring network capable of handling WDM traffic intelligently. The network protocol and efficient architecture increases the data transport capability of a congested network. Here we propose an architecture to ease the traffic congestion in a ring network. The backbone of the proposed model is the use of a proxy node which is connected to a particular number of nodes, depending upon the traffic, then diverting their traffic and thereby increasing throughput. A probabilistic model for the proposed network architecture is developed employing packet queuing control to estimate the average waiting time of packets in the buffer and the average number of packets in the buffer for different incoming traffic arrival rate.

  3. UNITED STABILIZING SCHEME FOR EDGE DELAY IN OPTICAL BURST SWITCHED NETWORKS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A novel scheme, namely united stabilizing scheme for edge delay, is introduced in optical burst switched networks. In the scheme, the limits of burst length and assembly time are both set according to certain qualifications. For executing the scheme, the conception for unit input bit rate is introduced to improve universality, and the assembly algorithm with a buffer safety space under the self-similar traffic model at each ingress edge router is proposed. Then, the components of burst and packet delay are concluded, and the equations that limits of burst length and assembly time should satisfy to stabilize the burst edge delay under different buffer offered loads are educed. The simulation results show that united stabilizing scheme stabilizes both burst and packet edge delay to a great extent when buffer offered load changes from 0.1 to 1, and the edge delay of burst and packet are near the limit values under larger offered load, respectively.

  4. A new burst assembly technique for supporting QoS in optical burst switching networks

    Institute of Scientific and Technical Information of China (English)

    Xiaolong Yang(阳小龙); Mingrui Dang(党明瑞); Youju Mao(毛幼菊); Lemin Li(李乐民)

    2003-01-01

    This letter proposes a new burst assembly technique for supporting QoS in optical burst switching (OBS)networks. It consists of the adaptive-threshold burst assembly mechanism and QoS-based random offset-time scheme. The assembly mechanism, which is fit well to multi-class burst assembly, not only matcheswith IP QoS mechanism based on packet classification, and also utilizes fairly and efficiently assemblycapacity. Based on token-bucket model and burst segment selective discard (BSSD), the offset-time schemecan smooth the traffic to support OBS QoS. The simulation results show that the technique can improvethe performance in terms of packet loss probability (PLP).

  5. A Novel Framework for IP DiffServ over Optical Burst Switching Networks

    Institute of Scientific and Technical Information of China (English)

    Ke-Ping Long; Yun Li; Rodney S.Tucker; Chong-Gang Wang

    2004-01-01

    This paper presents a novel framework for IP Differentiated Services (DiffServ) over optical burst switching (OBS), namely, DS-OBS. The network architecture, functional model of edge nodes and core nodes, the control packet format, a novel burst assembly scheme at ingress nodes and scheduling algorithm of core nodes are presented. The basic idea is to apply DiffServ capable burst assembly at ingress nodes and perform different per hop behavior (PHB) electronic treatments for control packets of different QoS class services at core nodes. Simulation results show that the proposed schemes can provide the best differentiated service for expedited forwarding (EF), assured forwarding (AF) and best effort (BE) services in terms of end-to-end deay, throughput and IP packet loss probability.

  6. An Intelligent Segmented Burst Assembly Mechanism in Optical Burst Switching Networks

    Institute of Scientific and Technical Information of China (English)

    XIE Yi-Yuan; ZHANG Jian-Guo

    2008-01-01

    We focus on the burst assembly mechanism and propose a new intelligent method in which the burst is assembled from several internet protocol (IP) packets in which the number of IP packets is changed according to the traffic load and the burst is segmented into several parts, called the ISOBS mechanism. The average burst assembly time of the ISOBS mechanism decreases as compared with the fixed-assembly-time and fixed-assembly-time-and-length mechanisms. The loss ratio decreases 50% as compared with the general optical burst switching (OBS) mechanism. The last segment can carry high quality of service (QOS) information. We can achieve that the loss ratio of the last segment is almost zero when the traffic load is less than 0.05. When the traffic load is 0.9, the loss ratio of the last segment is 0.0041. The ISOBS can support to transmit different QOS data.

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

    KAUST Repository

    Shihada, Basem

    2013-04-01

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

  8. An Arrangement of Channels and Transceivers in Optical Packet Switching Networks

    Institute of Scientific and Technical Information of China (English)

    Ming Hu

    2008-01-01

    Based on a media access and control (MAC) protocol, an arrangement of channels and transceivers in optical packet switching dense wavelength division multiplexing (DWDM) networks is proposed in this paper. In order to reduce the cost of nodes, fixed transmitters and receivers are used instead of tunable transmitters and receivers. Two fixed transmitters and many fixed receivers are used in each node in the scheme. The average waiting delay of this scheme is analyzed through mathematics and computer simulation. The result shows that the property of the scheme is almost the same as using tunable transmitter and receiver. Furthermore, if the tuning time of tunable transmitters is taken into account, the performance of the tunable transmitter scheme is poor than this scheme at the average waiting delay and throughput of the network.

  9. An Optic/Proton Dual-Controlled Fluorescence Switch based on Novel Photochromic Bithienylethene Derivatives

    Institute of Scientific and Technical Information of China (English)

    张佳琦; 靳家玉; 张隽佶; 邹雷

    2012-01-01

    A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds (4a, 4b, 4c) have been successfully synthesized through this simple method, and exhibit good photochromic properties with alternate irradiation of ultraviolet and visible light. Furthermore, the fluorescence of compound 4a, which bears a quinoline unit on the cyclopentene, can be modulated via optic and proton dual inputs. Upon excitation by 320 nm light, 4a emits a strong fluorescence at 404 nm. After irradiation with 254 nm light, the emission intensity is reduced due to the fluorescence resonance energy transfers (FRET) from quinoline unit to bithienylethene unit. Moreover, on addition of H~, the fluorescence is quenched completely due to the protonation of the quinoline. In addition, both the FRET and protonation process are reversi- ble, which indicates a potential application in molecular switches and logic gates.

  10. Performance analysis of an integrated scheme in optical burst switching high-speed networks

    Institute of Scientific and Technical Information of China (English)

    Amit Kumar Garg; R. S. Kaler

    2008-01-01

    @@ A new integrated scheme based on resource-reservation and adaptive network flow routing to alleviate contention in optical burst switching networks is proposed. The objective of the proposed scheme is to reduce the overall burst loss in the network and at the same time to avoid the packet out-of-sequence arrival problem. Simulations are carried out to assess the feasibility of the proposed scheme. Its performance is compared with that of contention resolution schemes based on conventional routing. Through extensive simulations, it is shown that the proposed scheme not only provides significantly better burst loss performance than the basic equal proportion and hop-length based traffic routing algorithms, but also is void of any packet re-orderings.

  11. Monolithic InP strictly non-blocking 8×8 switch for high-speed WDM optical interconnection.

    Science.gov (United States)

    Kwack, Myung-Joon; Tanemura, Takuo; Higo, Akio; Nakano, Yoshiaki

    2012-12-17

    A strictly non-blocking 8 × 8 switch for high-speed WDM optical interconnection is realized on InP by using the phased-array scheme for the first time. The matrix switch architecture consists of over 200 functional devices such as star couplers, phase-shifters and so on without any waveguide cross-section. We demonstrate ultra-broad optical bandwidth covering the entire C-band through several Input/Output ports combination with extinction ratio performance of more than 20dB. Also, nanoseconds reconfiguration time was successfully achieved by dynamic switching experiment. Error-free transmission was verified for 40-Gbps (10-Gbps × 4ch) WDM signal.

  12. Plasmonic nanoantennas as integrated coherent perfect absorbers on SOI waveguides for modulators and all-optical switches

    CERN Document Server

    Bruck, Roman

    2013-01-01

    The performance of plasmonic nanoantenna structures on top of SOI wire waveguides as coherent perfect absorbers for modulators and all-optical switches is explored. The absorption, scattering, reflection and transmission spectra of gold and aluminum nanoantenna-loaded waveguides were calculated by means of 3D finite-difference time-domain simulations for single waves propagating along the waveguide, as well as for standing wave scenarios composed from two counterpropagating waves. The investigated configurations showed losses of roughly 1% and extinction ratios greater than 25 dB for modulator and switching applications, as well as plasmon effects such as strong field enhancement and localization in the nanoantenna region. The proposed plasmonic coherent perfect absorbers can be utilized for ultracompact all-optical switches in coherent networks as well as modulators and can find applications in sensing or in increasing nonlinear effects.

  13. Reduction of pattern effects in SOA-based all-optical switches by using cross-gain modulated holding signal

    DEFF Research Database (Denmark)

    Bischoff, Svend; Mørk, Jesper

    2002-01-01

    , and reduces the fluctuations of the total energy injected into the interferometer within a bit-slot. Thus, we demonstrate a technique for reducing pattern effects in SOAs by employing a partially inverted holding beam. The method should be useful for increasing the data rates of all-optical switches....

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

    CERN Multimedia

    2003-01-01

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

  15. A QoS-Guanranteed Scheduling Algorithm with High Throughput for Edge Nodes of Optical Burst Switching Networks

    Institute of Scientific and Technical Information of China (English)

    Guiling Wu; Jianping Chen; Xinwang Li; Junfeng Chen

    2003-01-01

    A scheduling algorithm for the edge nodes of optical burst switching (OBS) networks is proposed to guarantee the delay re quirement of services with different CoS (Class of Service) and provide lower burst loss ratio at the same time. The performance of edge nodes based on the proposed algorithm is presented.

  16. Noise tolerance in wavelength-selective switching of optical differential quadrature-phase-shift-keying pulse train by collinear acousto-optic devices.

    Science.gov (United States)

    Goto, Nobuo; Miyazaki, Yasumitsu

    2014-06-01

    Optical switching of high-bit-rate quadrature-phase-shift-keying (QPSK) pulse trains using collinear acousto-optic (AO) devices is theoretically discussed. Since the collinear AO devices have wavelength selectivity, the switched optical pulse trains suffer from distortion when the bandwidth of the pulse train is comparable to the pass bandwidth of the AO device. As the AO device, a sidelobe-suppressed device with a tapered surface-acoustic-wave (SAW) waveguide and a Butterworth-type filter device with a lossy SAW directional coupler are considered. Phase distortion of optical pulse trains at 40 to 100  Gsymbols/s in QPSK format is numerically analyzed. Bit-error-rate performance with additive Gaussian noise is also evaluated by the Monte Carlo method.

  17. Non-Intrusive Magneto-Optic Detecting System for Investigations of Air Switching Arcs

    Science.gov (United States)

    Zhang, Pengfei; Zhang, Guogang; Dong, Jinlong; Liu, Wanying; Geng, Yingsan

    2014-07-01

    In current investigations of electric arc plasmas, experiments based on modern testing technology play an important role. To enrich the testing methods and contribute to the understanding and grasping of the inherent mechanism of air switching arcs, in this paper, a non-intrusive detecting system is described that combines the magneto-optic imaging (MOI) technique with the solution to inverse electromagnetic problems. The detecting system works in a sequence of main steps as follows: MOI of the variation of the arc flux density over a plane, magnetic field information extracted from the magneto-optic (MO) images, arc current density distribution and spatial pattern reconstruction by inverting the resulting field data. Correspondingly, in the system, an MOI set-up is designed based on the Faraday effect and the polarization properties of light, and an intelligent inversion algorithm is proposed that involves simulated annealing (SA). Experiments were carried out for high current (2 kA RMS) discharge cases in a typical low-voltage switchgear. The results show that the MO detection system possesses the advantages of visualization, high resolution and response, and electrical insulation, which provides a novel diagnostics tool for further studies of the arc.

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

    Science.gov (United States)

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

    2010-07-01

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

  19. An optically stabilized fast-switching light emitting diode as a light source for functional neuroimaging.

    Directory of Open Access Journals (Sweden)

    Daniel A Wagenaar

    Full Text Available Neuroscience research increasingly relies on optical methods for evoking neuronal activity as well as for measuring it, making bright and stable light sources critical building blocks of modern experimental setups. This paper presents a method to control the brightness of a high-power light emitting diode (LED light source to an unprecedented level of stability. By continuously monitoring the actual light output of the LED with a photodiode and feeding the result back to the LED's driver by way of a proportional-integral controller, drift was reduced to as little as 0.007% per hour over a 12-h period, and short-term fluctuations to 0.005% root-mean-square over 10 seconds. The LED can be switched on and off completely within 100 μs, a feature that is crucial when visual stimuli and light for optical recording need to be interleaved to obtain artifact-free recordings. The utility of the system is demonstrated by recording visual responses in the central nervous system of the medicinal leech Hirudo verbana using voltage-sensitive dyes.

  20. A robust and tuneable mid-infrared optical switch enabled by bulk Dirac fermions

    Science.gov (United States)

    Zhu, Chunhui; Wang, Fengqiu; Meng, Yafei; Yuan, Xiang; Xiu, Faxian; Luo, Hongyu; Wang, Yazhou; Li, Jianfeng; Lv, Xinjie; He, Liang; Xu, Yongbing; Liu, Junfeng; Zhang, Chao; Shi, Yi; Zhang, Rong; Zhu, Shining

    2017-01-01

    Pulsed lasers operating in the mid-infrared (3-20 μm) are important for a wide range of applications in sensing, spectroscopy, imaging and communications. Despite recent advances with mid-infrared gain platforms, the lack of a capable pulse generation mechanism remains a significant technological challenge. Here we show that bulk Dirac fermions in molecular beam epitaxy grown crystalline Cd3As2, a three-dimensional topological Dirac semimetal, constitutes an exceptional ultrafast optical switching mechanism for the mid-infrared. Significantly, we show robust and effective tuning of the scattering channels of Dirac fermions via an element doping approach, where photocarrier relaxation times are found flexibly controlled over an order of magnitude (from 8 ps to 800 fs at 4.5 μm). Our findings reveal the strong impact of Cr doping on ultrafast optical properties in Cd3As2 and open up the long sought parameter space crucial for the development of compact and high-performance mid-infrared ultrafast sources.

  1. Frequency-swept coherently detected spectral amplitude code for flexible implicit optical label switching

    Institute of Scientific and Technical Information of China (English)

    Yongsheng Cao; Fushen Chen; Zhigao Yang

    2011-01-01

    A new optical label switching system with coherently detected implicit spectral amplitude code(SAC)labels is proposed in this letter.The implicit SAC labels are recognized using a frequency-swept local light source oscillator.Intensity modulation payloads of 625 Mb/s and 1.25 Gb/s are considered.Label and pavload bit error rate(BER) performances are assessed and compared by simulations.The results reveal that,at a BER value of 10-9,-32.4dBm label received power can be obtained.In addition,8.3-dB optical signal-to-noise ratio(OSNR) is obtained when carrying a payload of 625 Mb/s.The label BER value hardly reaches 10-9 if the payload bit rate is at 1.25 Gb/s; however,a high payload bit rate only has little influence on received payload quality at a BER value of 10-9.Finally,a payload of 1.25 Gb/s could obtain-28.2 dBm received power and 9.5-dB OSNR.

  2. Frontoparietal traffic signals: a fast optical imaging study of preparatory dynamics in response mode switching.

    Science.gov (United States)

    Baniqued, Pauline L; Low, Kathy A; Fabiani, Monica; Gratton, Gabriele

    2013-06-01

    Coordination between networks of brain regions is important for optimal cognitive performance, especially in attention demanding tasks. With the event-related optical signal (a measure of changes in optical scattering because of neuronal activity) we can characterize rapidly evolving network processes by examining the millisecond-scale temporal correlation of activity in distinct regions during the preparatory period of a response mode switching task. Participants received a precue indicating whether to respond vocally or manually. They then saw or heard the letter "L" or "R," indicating a "left" or "right" response to be implemented with the appropriate response modality. We employed lagged cross-correlations to characterize the dynamic connectivity of preparatory processes. Our results confirmed coupling of frontal and parietal cortices and the trial-dependent relationship of the right frontal cortex with response preparation areas. The frontal-to-modality-specific cortex cross-correlations revealed a pattern in which first irrelevant regions were deactivated, and then relevant regions were activated. These results provide a window into the subsecond scale network interactions that flexibly tune to task demands.

  3. Performance and cost analysis of all-optical switching: OBS and OCS

    Directory of Open Access Journals (Sweden)

    Ekularn Dhavarudha

    2011-08-01

    Full Text Available This paper presents a study of performance and cost analysis of optical circuit switching (OCS and optical burstswitching (OBS by proposing the clear images of their node architectures and cost formulations. Then, we apply servicelevel agreement (SLA of the high quality of service application in the terms of network blocking probability and averagenetwork delay to demonstrate OCS and OBS performances, their investment costs, and network dimensioning methodology.Applying SLA to our studies can illustrate the impact of contention resolution and blocking resolution schemes to theperformances and costs of OBS and OCS, accordingly. The simulations illustrate that OBS applying WC gives the bestperformance among all architectures deploying the same offered bandwidth. The investigations also show that WC is a majortechnique contributing high performance gain to both OCS and OBS. Especially for OBS, WC is an important scheme allowingOBS high data grooming property as its performance gain contributing to OBS is much higher than those of OCS. For thecost analysis, OCS is the most economic among all architectures. BA provides the most cost effectiveness among all OBScontention resolution schemes. Lastly, FDL is the least cost effective scheme as it gives little performance enhancement butadds more cost to the network.

  4. Laser based analysis using a passively Q-switched laser employing analysis electronics and a means for detecting atomic optical emission of the laser media

    Science.gov (United States)

    Woodruff, Steven D.; Mcintyre, Dustin L.

    2016-03-29

    A device for Laser based Analysis using a Passively Q-Switched Laser comprising an optical pumping source optically connected to a laser media. The laser media and a Q-switch are positioned between and optically connected to a high reflectivity mirror (HR) and an output coupler (OC) along an optical axis. The output coupler (OC) is optically connected to the output lens along the optical axis. A means for detecting atomic optical emission comprises a filter and a light detector. The optical filter is optically connected to the laser media and the optical detector. A control system is connected to the optical detector and the analysis electronics. The analysis electronics are optically connected to the output lens. The detection of the large scale laser output production triggers the control system to initiate the precise timing and data collection from the detector and analysis.

  5. Evaluation of the potential of optical switching materials for overheating protection of thermal solar collectors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Huot, G.; Roecker, Ch.; Schueler, A.

    2008-01-15

    Providing renewable energy for domestic hot water production and space heating, thermal solar collectors are more and more widespread, and users' expectations with respect to performance and service lifetime are rising continuously. The durability of solar collector materials is a critical point as the collector lifetime should be at least 25 years. Overheating and the resulting stagnation of the collector is a common problem with solar thermal systems. During stagnation high temperatures lead to water evaporation, glycol degradation, and stresses in the collector with increasing pressure. Special precautions are necessary to release this pressure; only mechanical solutions exist nowadays. Additionally, the occurring elevated temperatures lead to degradation of the materials that compose collectors: seals, insulation materials, and also the selective coating which is the most important part of the collector. A promising way to achieve active cooling of collectors without any mechanical device for pressure release or collector emptying is to produce a selective coating which is able to switch its optical properties at a critical temperature Tc. An optical switch allows changing the selective coating efficiency; the goal is to obtain a coating with a poor selectivity above Tc (decreasing of absorptance, increasing of emittance). Obtaining self-cooling collectors will allow increasing collector surfaces on facades and roofs in order to get high efficiency and hot water production during winter without inconvenient overheating during summer. Optical switching of materials can be obtained by many ways. Inorganic and organic thermochromic compounds, and organic thermotropic coatings are the main types of switching coatings that have been studied at EPFL-LESO-PB. Aging studies of organic thermochromic paints fabricated at EPFL suggest that the durability of organic compounds might not be sufficient for glazed metallic collectors. First samples of inorganic coatings

  6. The Design of the M-B-Quadro Optical Switch and Its Access Control Strategies

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper proposes a new simple contention resolution switching architecture, M-B-Quadro, and its underlying access control strategies. By incorporating delay and buffer lines, the switching node can effectively obtain very low packet deflection probability.

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

    Science.gov (United States)

    Grichener, Alexander

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

  8. An acousto-optic Q-switched fiber laser using China-made double-cladding fiber

    Institute of Scientific and Technical Information of China (English)

    Hongming Zhao; Qihong Lou; Jun Zhou; Fangpei Zhang; Jingxing Dong; Yunrong Wei; Libo Li; Zhijiang Wang

    2007-01-01

    @@ A simple laser-diode pumped acoustic-optic Q-switched fiber laser is reported by using China-made largemode-area ytterbium-doped fiber. Q-switched pulses with a beam quality factor of M2 ≈ 2 and several hundred nanoseconds pulse duration are achieved at the repetition rate of 1 - 50 kHz. When the repetition rate is 1 kHz, the pulse energy is 0.93 mJ with the pulse duration of 132 ns. Meanwhile, the profile of laser pulses shows some mode-locking phenomena, the mechanism of the phenomena is discussed.

  9. Compact silicon-on-insulator-based 2 × 2 Mach-Zehnder interferometer electro-optic switch with low crosstalk

    Institute of Scientific and Technical Information of China (English)

    Jiejiang Xing; Zhiyong Li; Peiji Zhou; Yuanhao Gong; Yude Yu; Manqing Tan; Jinzhong Yu

    2015-01-01

    We report a compact 2 × 2 Mach-Zehnder interferometer (MZI) electro-optic switch fabricated on a siliconon-insulator using standard complementary metal-oxide semiconductor (CMOS) processes.With a short modulation arm length of 200 μm,the crosstalk is reduced to-22 dB by the new modulation scheme of push-pull modulation with a pre-biased π/2 phase shift.The new modulation scheme can also work with a fast switching time of about 5.4 ns.

  10. Investigation of patterning effect in ultrafast SOA-based optical switches

    DEFF Research Database (Denmark)

    Xu, Jing; Zhang, Xinliang; Mørk, Jesper

    2009-01-01

    A lower bound of PRBS length is derived considering patterning effects in ultrafast SOA-based switches. An effective method for simulating patterning effects is proposed, validated and applied to characterize the switches in large parameter regions.......A lower bound of PRBS length is derived considering patterning effects in ultrafast SOA-based switches. An effective method for simulating patterning effects is proposed, validated and applied to characterize the switches in large parameter regions....

  11. Experimental Demonstration of Multidimensional Switching Nodes for All-Optical Data Centre Networks

    DEFF Research Database (Denmark)

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

    t We experimentally demonstrate network nodes that enable SDM/WDM/TDM switching. 1 Tbit/s/core error-free performance is achieved for connections with different granularities being switched between three network nodes interconnected with 7-core multicore fibres.......t We experimentally demonstrate network nodes that enable SDM/WDM/TDM switching. 1 Tbit/s/core error-free performance is achieved for connections with different granularities being switched between three network nodes interconnected with 7-core multicore fibres....

  12. New types of 2×2 wavelength-switching blocks for optical cross-connects

    DEFF Research Database (Denmark)

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

    2001-01-01

    Two types of modular 2×2 wavelength-switching blocks are proposed in this letter. A 2×2 fixed wavelength-switching block can cross-connect two fixed channels between two fibers, and a 2×2 tunable wavelength-switching block can cross-connect any two channels between two fibers. These modular blocks...

  13. Injection of a Phase Modulated Source into the Z-Beamlet Laser for Increased Energy Extraction.

    Energy Technology Data Exchange (ETDEWEB)

    Rambo, Patrick K.; Armstrong, Darrell J.; Schwarz, Jens; Smith, Ian C; Shores, Jonathon; Speas, Christopher; Porter, John L.

    2014-11-01

    The Z-Beamlet laser has been operating at Sandia National Laboratories since 2001 to provide a source of laser-generated x-rays for radiography of events on the Z-Accelerator. Changes in desired operational scope have necessitated the increase in pulse duration and energy available from the laser system. This is enabled via the addition of a phase modulated seed laser as an alternative front-end. The practical aspects of deployment are discussed here.

  14. Ultra-compact and wide-spectrum-range thermo-optic switch based on silicon coupled photonic crystal microcavities

    Science.gov (United States)

    Zhang, Xingyu; Chakravarty, Swapnajit; Chung, Chi-Jui; Pan, Zeyu; Yan, Hai; Chen, Ray T.

    2015-11-01

    We design, fabricate, and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78 μm-long coupled L0-type photonic crystal microcavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystal microcavity. Coupling between identical microcavities gives rise to bonding and anti-bonding states of the coupled photonic molecules. The coupled photonic crystal microcavities are numerically simulated and experimentally verified with a 6 nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-optic switch is measured with an optical extinction ratio of 20 dB, an on-off switching power of 18.2 mW, a thermo-optic tuning efficiency of 0.63 nm/mW, a rise time of 14.8 μs, and a fall time of 18.5 μs. The measured on-chip loss on the transmission band is as low as 1 dB.

  15. Microheater-integrated silicon coupled photonic crystal microcavities for low-power thermo-optic switching over a wide spectrum

    Science.gov (United States)

    Zhang, Xingyu; Chakravarty, Swapnajit; Chung, Chi-Jui; Pan, Zeyu; Yan, Hai; Chen, Ray T.

    2016-03-01

    We design, fabricate and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78μm-long coupled L0-type photonic crystal microcavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystal microcavity. Coupling between identical microcavities gives rise to bonding and antibonding states of the coupled photonic molecules. The coupled photonic crystal microcavities are numerically simulated and experimentally verified with a 6nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-optic switch is measured with an optical extinction ratio of 20dB, an on-off switching power of 18.2mW, a therm-optic tuning efficiency of 0.63nm/mW, a rise time of 14.8μsec and a fall time of 18.5μsec. The measured on-chip loss on the transmission band is as low as 1dB.

  16. Ultra-compact and wide-spectrum-range thermo-optic switch based on silicon coupled photonic crystal microcavities

    CERN Document Server

    Zhang, Xingyu; Chung, Chi-Jui; Pan, Zeyu; Yan, Hai; Chen, Ray T

    2016-01-01

    We design, fabricate, and experimentally demonstrate a compact thermo-optic gate switch comprising a 3.78 um-long coupled L0-type photonic crystalmicrocavities on a silicon-on-insulator substrate. A nanohole is inserted in the center of each individual L0 photonic crystalmicrocavity. Coupling between identical microcavities gives rise to bonding and anti-bonding states of the coupled photonic molecules. The coupled photonic crystalmicrocavities are numerically simulated and experimentally verified with a 6 nm-wide flat-bottom resonance in its transmission spectrum, which enables wider operational spectrum range than microring resonators. An integrated micro-heater is in direct contact with the silicon core to efficiently drive the device. The thermo-optic switch is measured with an optical extinction ratio of 20 dB, an on-off switching power of 18.2 mW, a thermo-optic tuning efficiency of 0.63 nm/mW, a rise time of 14.8 us, and a fall time of 18.5 us. The measured on-chip loss on the transmission band is as l...

  17. Research Progress on Multimode Interference Switches

    Institute of Scientific and Technical Information of China (English)

    GAO Qing; SHENG Zhi-rui; JIANG Xiao-qing; WANG Ming-hua

    2005-01-01

    Optical switches are key components for constructing optical communication networks, so it is necessary to design optical switches and optical switch arrays with high performance and low cost. As one type of optical switches, the multimode interference(MMI) switches have received considerable attention due to their unique merits. The structures and operation principles of various types of MMI switches are introduced,and the recent progresses of MMI switches are also discussed.

  18. An Enhanced Mathematical Model for Performance Evaluation of Optical Burst Switched Networks

    CERN Document Server

    Morsy, Mohamed H S; Shalaby, Hossam M H

    2008-01-01

    An enhanced mathematical model is introduced to study and evaluate the performance of a core node in an optical burst switched network. In the proposed model, the exact Poisson traffic arrivals to the OBS node is approximated by assuming that the maximum allowed number of arrivals to the OBS node, in a given time slot, is two (instead of infinity). A detailed state diagram is outlined to illustrate the problem, and then a mathematical model based on the equilibrium point analysis (EPA) technique is presented. The steady-state system throughput is derived from the model which is built in the absence of wavelength conversion capability. Our proposed model is aided by a simulation work which studies the performance of an OBS core node under the assumption of Poisson traffic arrivals (the exact case) and calculates the steady-state system throughput. The results obtained from the proposed mathematical model are consistent with that of simulation when assuming Poisson traffic arrivals and this consistency holds fo...

  19. Broadband sensitive pump-probe setup for ultrafast optical switching of photonic nanostructures and semiconductors.

    Science.gov (United States)

    Euser, Tijmen G; Harding, Philip J; Vos, Willem L

    2009-07-01

    We describe an ultrafast time resolved pump-probe spectroscopy setup aimed at studying the switching of nanophotonic structures. Both femtosecond pump and probe pulses can be independently tuned over broad frequency range between 3850 and 21,050 cm(-1). A broad pump scan range allows a large optical penetration depth, while a broad probe scan range is crucial to study strongly photonic crystals. A new data acquisition method allows for sensitive pump-probe measurements, and corrects for fluctuations in probe intensity and pump stray light. We observe a tenfold improvement of the precision of the setup compared to laser fluctuations, allowing a measurement accuracy of better than DeltaR=0.07% in a 1 s measurement time. Demonstrations of the improved technique are presented for a bulk Si wafer, a three-dimensional Si inverse opal photonic bandgap crystal, and z-scan measurements of the two-photon absorption coefficient of Si, GaAs, and the three-photon absorption coefficient of GaP in the infrared wavelength range.

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

    KAUST Repository

    Shihada, Basem

    2010-07-01

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

  1. High optical and switching performance electrochromic devices based on a zinc oxide nanowire with poly(methyl methacrylate) gel electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Young Tea; Chu, Daping, E-mail: dpc31@cam.ac.uk [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 JJ Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Neeves, Matthew; Placido, Frank [Thin Film Centre, University of the West of Scotland, Paisley PA1 2BE (United Kingdom); Smithwick, Quinn [Disney Research, 521 Circle Seven Drive, Glendale, Los Angeles, California 91201 (United States)

    2014-11-10

    High performance electrochromic devices have been fabricated and demonstrated utilizing a solid polymer electrolyte and zinc oxide (ZnO) nanowire (NW) array counter electrode. The poly(methyl methacrylate) based polymer electrolyte was spin coated upon hydrothermally grown ZnO NW array counter electrodes, while electron beam evaporated NiO{sub x} thin films formed the working electrodes. Excellent optical contrast and switching speeds were observed in the fabricated devices with active areas of 2 cm{sup 2}, exhibiting an optical contrast of 73.11% at the wavelength of 470 nm, combined with a fast switching time of 0.2 s and 0.4 s for bleaching and coloration, respectively.

  2. Circular polarization switching and bistability in an optically injected 1300 nm spin-vertical cavity surface emitting laser

    Energy Technology Data Exchange (ETDEWEB)

    Alharthi, S. S., E-mail: ssmalh@essex.ac.uk; Henning, I. D.; Adams, M. J. [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Hurtado, A. [School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester CO4 3SQ (United Kingdom); Institute of Photonics, Physics Department, University of Strathclyde, Wolfson Centre, 106 Rottenrow East, Glasgow G4 0NW, Scotland (United Kingdom); Korpijarvi, V.-M.; Guina, M. [Optoelectronics Research Centre (ORC), Tampere University of Technology, P.O. Box 692, FIN-33101 Tampere (Finland)

    2015-01-12

    We report the experimental observation of circular polarization switching (PS) and polarization bistability (PB) in a 1300 nm dilute nitride spin-vertical cavity surface emitting laser (VCSEL). We demonstrate that the circularly polarized optical signal at 1300 nm can gradually or abruptly switch the polarization ellipticity of the spin-VCSEL from right-to-left circular polarization and vice versa. Moreover, different forms of PS and PB between right- and left-circular polarizations are observed by controlling the injection strength and the initial wavelength detuning. These results obtained at the telecom wavelength of 1300 nm open the door for novel uses of spin-VCSELs in polarization sensitive applications in future optical systems.

  3. Wideband digitally tunable lasers based on fiber Bragg grating external cavity array and 1×N optical switch

    Institute of Scientific and Technical Information of China (English)

    Haiwen Cai(蔡海文); Jianxin Geng(耿建新); Zuoren Dong(董作人); Gaoting Chen(陈高庭); Zujie Fang(方祖捷)

    2003-01-01

    A novel wideband digitally tunable laser based on fiber Bragg grating external cavities and 1 × N optical switch provides 5 ms fast tuning time with output power more than 1 dBm over whole C-band that is only limited by the laser emission bandwidth. Less than 50 pm wavelength drift over -10 to 55℃ temperature range make that the wavelength locker and monitor are not necessary in this tunable laser.

  4. Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4×4 switch matrix with spot size converters (SSCs) and a new driving circuit are designed and fabricated. The introduction of a spot size converter (SSC) has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than 1μs.

  5. Bidirectionally tunable all-optical switch based on multiple nano-structured resonators using backward quasi-phase-matching

    Institute of Scientific and Technical Information of China (English)

    Jun Xie; Yuping Chen; Wenjie Lu; Xianfeng Chen

    2011-01-01

    @@ Based on the second-order nonlinearity, we present a bidirectional tunable all-optical switch at C-band by introducing backward quasi-phase-matching technique in Mg-doped periodically poled lithium niobate (MgO:PPLN) waveguide with a nano-8tructure called multiple resonators.Two injecting forward lights and one backward propagating light interact with difference frequency generations.The transmission of forward signal and backward idler light can be modulated simultaneously with the variation of control light power based on the basic "phase shift" structure of a single resonator.In this scheme, all the results come from our simulation, The speed of tlus bidirectional optical switch can reach to femtosecond if a femtosecond laser is used as the control light.%Based on the second-order nonlinearity, we present a bidirectional tunable all-optical switch at C-band by introducing backward quasi-phase-matching technique in Mg-doped periodically poled lithium niobate (MgO:PPLN) waveguide with a nano-structure called multiple resonators.Two injecting forward lights and one backward propagating light interact with difference frequency generations.The transmission of forward signal and backward idler light can be modulated simultaneously with the variation of control light power based on the basic "phase shift" structure of a single resonator.In this scheme, all the results come from our simulation.The speed of this bidirectional optical switch can reach to femtosecond if a femtosecond laser is used as the control light.

  6. Impact of Bulk Aggregation on the Electronic Structure of Streptocyanines: Implications for the Solid-State Nonlinear Optical Properties and All-Optical Switching Applications

    KAUST Repository

    Gieseking, Rebecca L.

    2014-10-16

    Polymethine dyes in dilute solutions show many of the electronic and optical properties required for all-optical switching applications. However, in the form of thin films, their aggregation and interactions with counterions do generally strongly limit their utility. Here, we present a theoretical approach combining molecular-dynamics simulations and quantum-chemical calculations to describe the bulk molecular packing of streptocyanines (taken as representative of simple polymethines) with counterions of different hardness (Cl and BPh4 ) and understand the impact on the optical properties. The accuracy of the force field we use is verified by reproducing experimental crystal parameters as well as the configurations of polymethine/counterion complexes obtained from electronic-structure calculations. The aggregation characteristics can be understood in terms of both polymethinecounterion and polymethinepolymethine interactions. The counterions are found to localize near one end of the streptocyanine backbones, and the streptocyanines form a broad range of aggregates with significant electronic couplings between neighboring molecules. As a consequence, the linear and nonlinear optical properties are substantially modified in the bulk. By providing an understanding of the relationship between the molecular interactions and the bulk optical properties, our results point to a clear strategy for designing polymethine and counterion molecular structures and optimizing the materials properties for all-optical switching applications.

  7. Engineered materials for all-optical helicity-dependent magnetic switching

    Science.gov (United States)

    Fullerton, Eric

    2014-03-01

    The possibilities of manipulating magnetization without applied magnetic fields have attracted growing attention over the last fifteen years. The low-power manipulation of magnetization, preferably at ultra-short time scales, has become a fundamental challenge with implications for future magnetic information memory and storage technologies. Here we explore the optical manipulation of the magnetization of engineered materials and devices using 100 fs optical pulses. We demonstrate that all optical - helicity dependent switching (AO-HDS) can be observed not only in selected rare-earth transition-metal (RE-TM) alloy films but also in a much broader variety of materials, including alloys, multilayers, heterostructures and RE-free Co-Ir-based synthetic ferrimagnets. The discovery of AO-HDS in RE-free TM-based synthetic ferrimagnets can enable breakthroughs for numerous applications since it exploits materials that are currently used in magnetic data storage, memories and logic technologies. In addition, this materials study of AO-HDS offers valuable insight into the underlying mechanisms involved. Indeed the common denominator of the diverse structures showing AO-HDS in this study is that two ferromagnetic sub-lattices exhibit magnetization compensation (and therefore angular momentum compensation) at temperatures near or above room temperature. We are highlighting that compensation plays a major role and that this compensation can be established at the atomic level as in alloys but also over a larger nanometers scale as in the multilayers or in heterostructures. We will also discuss the potential to extend AO-HDS to new classes of magnetic materials. This work was done in collaboration with S. Mangin, M. Gottwald, C-H. Lambert, D. Steil, V. Uhlíř, L. Pang, M. Hehn, S. Alebrand, M. Cinchetti, G. Malinowski, Y. Fainman, and M. Aeschlimann. Supported by the ANR-10-BLANC-1005 ``Friends,'' a grant from the Advanced Storage Technology Consortium, Partner University Fund

  8. Theoretical and experimental study of fundamental differences in the noise suppression of high-speed SOA-based all-optical switches

    DEFF Research Database (Denmark)

    Nielsen, Mads Lønstrup; Mørk, Jesper; Suzuki, R.

    2005-01-01

    We identify a fundamental difference between the ASE noise filtering properties of different all-optical SOA-based switch configurations, and divide the switches into two classes. An in-band ASE suppression ratio quantifying the difference is derived theoretically and the impact of the ASE...

  9. Mach-Zehnder Interferometers with Asymmetric Modulation Arms in Applications of High Speed Silicon-on-Insulator Based Optical Switches

    Institute of Scientific and Technical Information of China (English)

    SUN Fei; YU Jin-Zhong

    2006-01-01

    @@ Modulation arms with different widths are introduced to Mach-Zehnder interferometers (MZIs) to obtain improved performance. Theoretical analysis and numerical simulation have shown that when the widths of the two arms are properly designed to achieve an inherent mπ/2 (m is an odd integer) optical phase difference between the arms, the asymmetric MZI presents higher modulation speed. Furthermore, the carrier-absorption induced divergence of insertion losses in silicon-on-insulator (SOI) based MZI optical switches can be obviously improved.

  10. Controllable Optical Switch in a One-Dimensional Resonator Waveguide Coupled to a Whispering-Gallery Resonator

    Institute of Scientific and Technical Information of China (English)

    LANG Jia-Hong

    2011-01-01

    Single photon transport properties in a one-dimensional array of coupled microcavities waveguide coupled to a whispering-gallery resonator interacting with a A-type system are theoretically investigated.The calculations reveal that the transport properties of single photons with arbitrary energy can be controlled by varying the Rabi frequency and detuning the control optical field.This phenomenon can be used for controllable optical switching.Single photon transport properties in a onedimensional waveguide coupled to a two-level[1-10] or multi-level[11-17] system have been studied theoretically and experimentally for their potential applications in quantum information and all-optical devices.A coupled cavity array is considered as a one-dimensional waveguide and the single photon transport properties in such a system coupled to a two-level and multi-level system have been studied.%Single photon transport properties in a one-dimensional array of coupled microcavities waveguide coupled to a whispering-gallery resonator interacting with a A-type system are theoretically investigated. The calculations reveal that the transport properties of single photons with arbitrary energy can be controlled by varying the Rabi frequency and detuning the control optical field. This phenomenon can be used for controllable optical switching.

  11. Polarization-Independent High-Speed Switching in a Standard Non-Linear Optical Loop Mirror

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Galili, Michael; Oxenløwe, Leif Katsuo

    2008-01-01

    We introduce a scheme which allows polarization-independent switching in a standard NOLM. Experimental verification is performed by switching 10 Gbit/s data with 0.2 dB polarization-dependence and by error-free demultiplexing of polarization-scrambled 320 Gbit/s OTDM data....

  12. All-optical signal processing using InP photonic-crystal nanocavity switches

    DEFF Research Database (Denmark)

    Yu, Yi; Vukovic, Dragana; Heuck, Mikkel

    2014-01-01

    In this paper, we present recent progress in experimental characterization of InP photonic-crystal nanocavity switches. Pump-probe measurements on an InP PhC H0 cavity show large-contrast ultrafast switching at low pulse energy. At large pulse energies, a large resonance shift passing across...

  13. Electro-optical switching at 1550 nm using a two-state GeSe phase-change layer.

    Science.gov (United States)

    Soref, Richard; Hendrickson, Joshua; Liang, Haibo; Majumdar, Arka; Mu, Jianwei; Li, Xun; Huang, Wei-Ping

    2015-01-26

    New designs for electro-optical free-space and waveguided 2 x 2 switches are presented and analyzed at the 1.55 μm telecoms wavelength. The proposed devices employ a ~10 nm film of GeSe that is electrically actuated to transition the layer forth-and-back from the amorphous to the crystal phase, yielding a switch with two self-sustaining states. This phase change material was selected for its very low absorption loss at the operation wavelength, along with its electro-refraction Δn ~0.6. All switches are cascadeable into N x M devices. The free-space prism-shaped structures use III-V prism material to match the GeSe crystal index. The Si/GeSe/Si "active waveguides" are quite suitable for directional-coupler switches as well as Mach-Zehnder devices-all of which have an active length 16x less than that in the free-carrier art.

  14. Thermo-optic switch device based on Norland optical adhesive%基于Norland紫外固化胶的热光开关器件

    Institute of Scientific and Technical Information of China (English)

    王旗; 王希斌; 孙小强; 田亮; 王菲; 张大明

    2012-01-01

    采用新型聚合物材料Norland紫外固化胶(NOA)制备了聚合物M-Z型热光开关器件。对NOA薄膜材料的光学性质进行了表征,采用感应耦合等离子体(ICP)方法制备出形貌良好的波导器件。测得在1 550 nm波长下,长2.2 cm的直波导插入损耗为8.3 dB。在电极上施加直流信号,测得热光开关的消光比为11 dB,驱动功率为85 mW。引入直流偏置网络,获得了器件的开关特性曲线,测得开关器件的上升时间为1.085 ms,下降时间为489.5μs。实验结果表明:NOA材料在热光开关及其它聚合物光波导集成器件的制备中具有很大的应用潜力。%Norland Optical Adhesive(NOA),a new type of polymer material,is used to fabricate the Mach-Zehnder thermo-optic switch in this paper.The optical properties of NOA film materials are characterized.The waveguides with good profiles are fabricated by the Inductively Coupled Plasma(ICP) method.The insertion loss of a 2.2 cm-length straight waveguide is 8.3 dB at 1 550 nm.The extinction ratio of the thermo-optic switch is 11 dB and the driving power is 83 mW when the DC bias is loaded on the electrodes.The switching property of the device is tested with DC bias,and the rise time and the fall time of the switch are 1.085 ms and 489.5 μs,respectively.Experimental results show that the NOA material has great potentials in fabricating thermo-optic switches and other polymer waveguide integrated devices.

  15. C2-Symmetric Dibenzosuberane-based Helicenes as Potential Chirochromic Optical Switches and Amorphous Hosts in OLED Applications

    Institute of Scientific and Technical Information of China (English)

    CHEN Chien-Tien; CHOU Y-Chen; KAO Jin-Y; LI Tai-Wei; LIU Chia-Cheng; LI Ying-Chieh; CHANG I-Hsin; LIN Jin-Sheng; YEN Chia-Wen

    2001-01-01

    @@ Three C2-symmetric (10R,11R)-diethyl substituted dibenzosuberane (DBS)-based helicenes with varying steric and conjugation demands of their bottom fragments were synthesized. Only the helicene-7a[with the bottom part derived from tetralone was found photo-switchable in reasonable time scale. Photoisomerization of the diastereomerically pure (10R,11R,P)-helicene (7a) at 280 nm led to virtually exclusive formation of the opposite M form-diastereomer 7a′ (7a′/7a = 99.6/0.4). The preferential return of 7a′ to 7a can be effected upon irradiation at 254 nm (7a′/7a = 3G/67) or thermally at 130 7a′/7a = 0/100). The photo-induced switching process amounts to a 133% difference in d.e. (from 99.2% to-34%). The concomitant change of helicene chirality between these two diastereomeric photostationary states augurs well for their potential application as an optical switch in LC materials. To our knowledge, our system serves as the best chirochromic optical switch as compared to the examples possessing similar photochromic properties.

  16. C2-Symmetric Dibenzosuberane-based Helicenes as Potential Chirochromic Optical Switches and Amorphous Hosts in OLED Applications

    Institute of Scientific and Technical Information of China (English)

    CHEN; Chien-Tien

    2001-01-01

    Three C2-symmetric (10R,11R)-diethyl substituted dibenzosuberane (DBS)-based helicenes with varying steric and conjugation demands of their bottom fragments were synthesized. Only the helicene-7a[with the bottom part derived from tetralone was found photo-switchable in reasonable time scale. Photoisomerization of the diastereomerically pure (10R,11R,P)-helicene (7a) at 280 nm led to virtually exclusive formation of the opposite M form-diastereomer 7a′ (7a′/7a = 99.6/0.4). The preferential return of 7a′ to 7a can be effected upon irradiation at 254 nm (7a′/7a = 3G/67) or thermally at 130 7a′/7a = 0/100). The photo-induced switching process amounts to a 133% difference in d.e. (from 99.2% to-34%). The concomitant change of helicene chirality between these two diastereomeric photostationary states augurs well for their potential application as an optical switch in LC materials. To our knowledge, our system serves as the best chirochromic optical switch as compared to the examples possessing similar photochromic properties.……

  17. Manufacture tolerance analysis and control for a polymer on-silicon Mach-Zehnder-interferometer-based electro-optic switch

    Institute of Scientific and Technical Information of China (English)

    ZHENG Chuan-tao; MA Chun-sheng; YAN Xin; CUI Zhan-chen; ZHANG Da-ming

    2011-01-01

    To enhance the electro-optic (EO) modulation efficiency and realize the impedance-matching, a polymer-on-silicon multi mode interference (MMI) Mach-Zehnder interferometer (MZI) -based electro-optic (EO) switch is designed and optimized.Under the central operation wavelength of 1550 nm, the driving voltages of the designed switch are O and ±1.375 V,respectively, with a short active region length of 5 mm, and the characteristic impedance of the electrode is about 49.6 Ω.The manufacture tolerance is analyzed for instructing the device fabrication. The results show that to realize ideal switching function, high fabrication accuracy on the buffer thickness, core thickness, electrode width and MMI wavegnide width is extremely required, and a small voltage drift of-0.03-0.05 V is also expected for reducing the crosstalk to less than -30 dB.The allowed 3 dB bandwidth is 60 nm, and within this spectrum range, the insertion loss and crosstalk are less than 6.71 dB and -30 dB, respectively.

  18. Porous silicon-VO{sub 2} based hybrids as possible optical temperature sensor: Wavelength-dependent optical switching from visible to near-infrared range

    Energy Technology Data Exchange (ETDEWEB)

    Antunez, E. E.; Salazar-Kuri, U.; Estevez, J. O.; Basurto, M. A.; Agarwal, V., E-mail: vagarwal@uaem.mx [Centro de Investigación en Ingeniería y Ciencias Aplicadas, Instituto de Investigación en Ciencias Básicas y Aplicadas, UAEM, Av. Universidad 1001, Col. Chamilpa, Cuernavaca, Mor. 62209 (Mexico); Campos, J. [Instituto de Energías Renovables, UNAM, Priv. Xochicalco S/N, Temixco, Mor. 62580 (Mexico); Jiménez Sandoval, S. [Laboratorio de Investigación en Materiales, Centro de Investigación y estudios Avanzados del Instituto Politécnico Nacional, Unidad Querétaro, Qro. 76001 (Mexico)

    2015-10-07

    Morphological properties of thermochromic VO{sub 2}—porous silicon based hybrids reveal the growth of well-crystalized nanometer-scale features of VO{sub 2} as compared with typical submicron granular structure obtained in thin films deposited on flat substrates. Structural characterization performed as a function of temperature via grazing incidence X-ray diffraction and micro-Raman demonstrate reversible semiconductor-metal transition of the hybrid, changing from a low-temperature monoclinic VO{sub 2}(M) to a high-temperature tetragonal rutile VO{sub 2}(R) crystalline structure, coupled with a decrease in phase transition temperature. Effective optical response studied in terms of red/blue shift of the reflectance spectra results in a wavelength-dependent optical switching with temperature. As compared to VO{sub 2} film over crystalline silicon substrate, the hybrid structure is found to demonstrate up to 3-fold increase in the change of reflectivity with temperature, an enlarged hysteresis loop and a wider operational window for its potential application as an optical temperature sensor. Such silicon based hybrids represent an exciting class of functional materials to display thermally triggered optical switching culminated by the characteristics of each of the constituent blocks as well as device compatibility with standard integrated circuit technology.

  19. 20-kHz watt-level green laser with LGS crystal electro-optic Q-switch

    Institute of Scientific and Technical Information of China (English)

    Hao Tang; Xiaolei Zhu; Junqing Meng; Huaguo Zang

    2009-01-01

    A diode-end-pumped electro-optic(EO)Q-switched green laser operating at the repetition rate of 20 kHz is reported.A block of La3Ga5SiO14(LGS)single crystal is used as a Q-switch and the type I phasematching LiB3O5(LBO)is used as the nonlinear crystal in the second harmonic generation.The 2.3-W average power of 532-nm green laser is obtained at the repetition rate of 20 kHz with the pulse width as short as 10 ns.When the output power is about 1.5 W,the measured power fluctuation is less than 1.4% (root-mean-square,RMS)with the beam quality factor of M2 < 2 in both orthogonal directions.

  20. Effective photoconductivity of exfoliated black phosphorus for optoelectronic switching under 1.55 μm optical excitation

    Energy Technology Data Exchange (ETDEWEB)

    Penillard, A., E-mail: anne.penillard@espci.fr; Tripon-Canseliet, C.; Maksimovic, I.; Géron, E. [Laboratoire de Physique et d' Etude des Matériaux, Ecole Supérieure de Physique et de Chimie Industrielle de la ville de Paris, UMR8213, 10 rue Vauquelin 75231 Paris Cedex 05 (France); Rosticher, M. [Laboratoire Pierre Aigrain, Département de Physique de l' Ecole Normale Supérieure, 24 rue Lhomond 75231 Paris Cedex 05 (France); Liu, Z. [School of Materials Science and Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)

    2016-01-14

    We present a microwave photoconductive switch based on exfoliated black phosphorus and strongly responding to a 1.55 μm optical excitation. According to its number of atomic layers, exfoliated black phosphorus presents unique properties for optoelectronic applications, like a tunable direct bandgap from 0.3 eV to 2 eV, strong mobilities, and strong conductivities. The switch shows a maximum ON/OFF ratio of 17 dB at 1 GHz, and 2.2 dB at 20 GHz under 1.55-μm laser excitation at 50 mW, never achieved with bidimensional materials.

  1. Silicon-on-insulator 1×2 Y-junction Optical Switch Based on Waveguide-vanishing Effect①②

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    The silicon-on-insulator(SOI)1×2Y-junction optical waveguide switch has been proposed and fabricated,which is based on the large cross-section single-mode rib waveguide condition,the waveguide-vanishing effect and the free-carrier plasma dispersion effect.In the switch,the SOI technique utilizer silicon and silicon dioxide thermal bonding and back-polishing.The insertion loss and extinction ratio of the device are measured to be less than 4.78dB and 20.8dB respectively at a wavelength of 1.3μm and an injection current of 45mA.Response time is about 160ns.

  2. Design considerations for multi-core optical fibers in nonlinear switching and mode-locking applications

    CERN Document Server

    Nazemosadat, Elham

    2014-01-01

    We explore the practical challenges which should be addressed when designing a multi-core fiber coupler for nonlinear switching or mode-locking applications. The inevitable geometric imperfections formed in these fiber couplers during the fabrication process affect the performance characteristics of the nonlinear switching device. Fabrication uncertainties are tolerable as long as the changes they impose on the propagation constant of the modes are smaller than the linear coupling between the cores. It is possible to reduce the effect of the propagation constant variations by bringing the cores closer to each other, hence, increasing the coupling. However, higher coupling translates into a higher switching power which may not be desirable in some practical situations. Therefore, fabrication errors limit the minimum achievable switching power in nonlinear couplers.

  3. Optical switching of protein interactions on photosensitive–electroactive polymers measured by atomic force microscopy

    OpenAIRE

    Gelmi, Amy; Zanoni, Michele; Higgins, Michael; Gambhir, Sanjeev; Officer, David; Diamond, Dermot; Wallace, Gordon

    2013-01-01

    The ability to switch the physico-chemical properties of conducting polymers opens up new possibilities for a range of new applications. Appropriately functionalised materials can provide routes to multi-modal switching, for example in response light and/or electrochemical stimuli; this capability is important in the field of bionics, wherein remote control of the properties of materials opens new possibilities. For example, the ability to actuate a film via photonic stimuli is particularly i...

  4. Ultrafast, low-power, all-optical switching via birefringent phase-matched transverse mode conversion in integrated waveguides.

    Science.gov (United States)

    Hellwig, Tim; Epping, Jörn P; Schnack, Martin; Boller, Klaus-J; Fallnich, Carsten

    2015-07-27

    We demonstrate the potential of birefringence-based, all-optical, ultrafast conversion between the transverse modes in integrated optical waveguides by modelling the conversion process by numerically solving the multi-mode coupled nonlinear Schroedinger equations. The observed conversion is induced by a control beam and due to the Kerr effect, resulting in a transient index grating which coherently scatters probe light from one transverse waveguide mode into another. We introduce birefringent phase matching to enable efficient all-optically induced mode conversion at different wavelengths of the control and probe beam. It is shown that tailoring the waveguide geometry can be exploited to explicitly minimize intermodal group delay as well as to maximize the nonlinear coefficient, under the constraint of a phase matching condition. The waveguide geometries investigated here, allow for mode conversion with over two orders of magnitude reduced control pulse energy compared to previous schemes and thereby promise nonlinear mode switching exceeding efficiencies of 90% at switching energies below 1 nJ.

  5. Coherent 40 Gb/s SP-16QAM and 80 Gb/s PDM-16QAM in an Optimal Supercomputer Optical Switch Fabric

    DEFF Research Database (Denmark)

    Karinou, Fotini; Borkowski, Robert; Zibar, Darko;

    2013-01-01

    We demonstrate, for the first time, the feasibility of using 40 Gb/s SP-16QAM and 80 Gb/s PDM-16QAM in an optimized cell switching supercomputer optical interconnect architecture based on semiconductor optical amplifiers as ON/OFF gates....

  6. All-optical Mach-Zehnder interferometer switching based on the phase-shift multiplication effect of an analog on the electromagnetically induced transparency effect

    Science.gov (United States)

    Wang, Boyun; Xiong, Liangbin; Zeng, Qingdong; Chen, Zhihong; Lv, Hao; Ding, Yaoming; Du, Jun; Yu, Huaqing

    2016-06-01

    We theoretically and numerically investigate all-optical Mach-Zehnder interferometer switching based on the phase-shift multiplication effect of an all-optical analog on the electromagnetically induced transparency effect. The free-carrier plasma dispersion effect modulation method is applied to improve the tuning rate with a response time of picoseconds. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Compared with no phase-shift multiplication effect, the average pump power of all-optical switching required to yield the π-phase shift difference decreases by 55.1%, and the size of the modulation region is reduced by 50.1% when the average pump power reaches 60.8 mW. This work provides a new direction for low-power consumption and miniaturization of microstructure integration light-controlled switching devices in optical communication and quantum information processing.

  7. Electro-optical characteristics of a chiral hybrid in-plane switching liquid crystal mode for high brightness.

    Science.gov (United States)

    Gwag, Jin Seog; Sohn, Kyunghwa; Kim, Young-Ki; Kim, Jae-Hoon

    2008-08-04

    We propose a new in-plane switching (IPS) nematic liquid crystal (LC) mode which uses a twist effect with a hybrid LC alignment and interdigitated electrodes as an approach for a high brightness. This is optimized to a normally white mode to minimize loss of transmittance at the electrode compared to the conventional IPS mode. The proposed mode shows an excellent dark state because the bulk LCs are aligned in parallel to the optic axis of the polarizer under low electric fields. Consequently, this proposed mode exhibits a much higher contrast ratio (980:1) than that of the conventional IPS mode (550:1).

  8. A Silicon-on-Insulator-Based Thermo-Optic Waveguide Switch with Low Insertion Loss and Fast Response

    Institute of Scientific and Technical Information of China (English)

    LI Yan-Ping; YU Jin-Zhong; CHEN Shao-Wu

    2005-01-01

    @@ A silicon-on-insulator-based thermo-optic waveguide switch integrated with spot size converters is designed and fabricated by inductively coupled plasma reactive ion etching. The device shows good characteristics, including low insertion loss of 8 ± 1 dB for wavelength 1530-1580nm and fast response times of 4.6 μs for rising edge and 1.9μs for falling edge. The extinction ratios of the two channels are 19.1 and 18 dB, respectively.

  9. Free-carrier contribution to all-optical switching in Mie-resonant hydrogenated amorphous silicon nanodisks

    Science.gov (United States)

    Vabishchevich, Polina P.; Shorokhov, Alexander S.; Shcherbakov, Maxim R.; Fedyanin, Andrey A.

    2016-03-01

    Conventionally, all-optical switching devices made out from bulk silicon and other semiconductors are limited by free-carrier relaxation time which spans from picoseconds to microseconds. In this work, we discuss the possibility to suppress the undesired long free-carrier relaxation in subwavelength dielectric nanostructures exhibiting localized magnetic Mie resonances. Numerical calculations show the unsymmetrical modification of the transmittance spectra of the nanodisks due the free carriers photo-injection. Such a spectral dependance allows to control temporal response of the nanostructure by varying the laser pulse spectum.

  10. Optical switching of electron transport in a waveguide-QED system

    Science.gov (United States)

    Abdullah, Nzar Rauf; Tang, Chi-Shung; Manolescu, Andrei; Gudmundsson, Vidar

    2016-10-01

    Electron switching in waveguides coupled to a photon cavity is found to be strongly influenced by the photon energy and polarization. Therefore, the charge dynamics in the system is investigated in two different regimes, for off-resonant and resonant photon fields. In the off-resonant photon field, the photon energy is smaller than the energy spacing between the first two lowest subbands of the waveguide system, the charge splits between the waveguides implementing a √{ NOT }-quantum logic gate action. In the resonant photon field, the charge is totally switched from one waveguide to the other due to the appearance of photon replica states of the first subband in the second subband region instigating a quantum-NOT transition. In addition, the importance of the photon polarization to control the charge motion in the waveguide system is demonstrated. The idea of charge switching in electronic circuits may serve to built quantum bits.

  11. 32 × 32 silicon electro-optic switch with built-in monitors and balanced-status units

    Science.gov (United States)

    Qiao, Lei; Tang, Weijie; Chu, Tao

    2017-02-01

    To construct large-scale silicon electro-optical switches for optical interconnections, we developed a method using a limited number of power monitors inserted at certain positions to detect and determine the optimum operating points of all switch units to eliminate non-uniform effects arising from fabrication errors. We also introduced an optical phase bias to one phase-shifter arm of a Mach–Zehnder interferometer (MZI)-type switch unit to balance the two operation statuses of a silicon electro-optical switch during push–pull operation. With these methods, a 32 × 32 MZI-based silicon electro-optical switch was successfully fabricated with 180-nm complementary metal–oxide–semiconductor (CMOS) process technology, which is the largest scale silicon electro-optical switch to the best of our knowledge. At a wavelength of 1520 nm, the on-chip insertion losses were 12.9 to 16.5 dB, and the crosstalk ranged from ‑17.9 to ‑24.8 dB when all units were set to the ‘Cross’ status. The losses were 14.4 to 18.5 dB, and the crosstalk ranged from ‑15.1 to ‑19.0 dB when all units were in the ‘Bar’ status. The total power consumptions of the 32 × 32 switch were 247.4 and 542.3 mW when all units were set to the ‘Cross’ and ‘Bar’ statuses, respectively.

  12. Light-switching-light optical transistor based on metallic nanoparticle cross-chains geometry incorporating Kerr nonlinearity

    Energy Technology Data Exchange (ETDEWEB)

    AbdelMalek, Fathi; Aroua, Walid [National Institute of Applied Science and Technology, University of Carthage, Tunis (Tunisia); Haxha, Shyqyri [Computer Science and Technology Department, Bedfordshire University, Luton (United Kingdom); Flint, Ian [Selex ES Ltd, Luton, Bedfordshire (United Kingdom)

    2016-08-15

    In this research work, we propose all-optical transistor based on metallic nanoparticle cross-chains geometry. The geometry of the proposed device consists of two silver nanoparticle chains arranged along the x- and z-axis. The x-chain contains a Kerr nonlinearity, the source beam is set at the left side of the later, while the control beam is located at the top side of the z-chain. The control beam can turn ON and OFF the light transmission of an incoming light. We report a theoretical model of a very small all-optical transistor proof-of-concept made of optical 'light switching light' concept. We show that the transmission efficiency strongly depends on the control beam and polarization of the incoming light. We investigate the influence of a perfect reflector and reflecting substrate on the transmission of the optical signal when the control beam is turned ON and OFF. These new findings make our unique design a potential candidate for future highly-integrated optical information processing chips. (copyright 2016 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Demonstration of Optically Controlled re-Routing in a Photonic Crystal Three-Port Switch

    DEFF Research Database (Denmark)

    Combrié, S.; Heuck, Mikkel; Xavier, S.

    2012-01-01

    We present an experimental demonstration of optically controlled re-routing of a signal in a photonic crystal cavity-waveguide structure with 3 ports. This represents a key functionality of integrated all-optical signal processing circuits....

  14. Optical properties and switching durability of TiO2 top-coated magnesium-nickel thin-film switchable mirrors

    Science.gov (United States)

    Bao, Shanhu; Zhang, Xiaoli; Jin, Ping; Yoshimura, Kazuki

    2015-04-01

    An amorphous TiO2 film (180 nm) was deposited as a protective layer on the surface of a triple-layer thin-film switchable mirror (Pd/Ti/Mg4Ni deposited on glass) by a sol-gel coating process, and its optical switching behavior and switching lifetime under 4% hydrogen gas loading were evaluated. The use of a TiO2 coating extended the switching durability to about 1600 cycles, which is a fourfold increase compared with that of uncoated mirrors. The switching response of the Pd/Ti/Mg4Ni thin film was not affected by the presence of the TiO2 film, with hydrogenation and dehydrogenation speeds being almost the same as those of uncoated mirrors. The optical properties of the TiO2-coated mirrors were improved in the hydrogenated state, and a diffuse reflection phenomenon was observed in the dehydrogenated state.

  15. Simulation of the Physical Performance of Optical Packet Switching Nodes%光分组交换节点物理性能仿真

    Institute of Scientific and Technical Information of China (English)

    王春华; 李力; 朱炳春; 贾潞华

    2002-01-01

    A graphical and visual simulation system for the study of optical packet switching (OPS) nodes is accomplished. With the simulation system, the effect on physical performance- bit error rate (BER) due to a variety of factors such as the crosstalk parameters of OPS nodes, number of cascaded OPS nodes, length of optical output buffer, traffic load and fluctuation of amplitude of optical signals are evaluated. Reliability of the simulation system is proved by the analytical results obtained in all the above cases.

  16. Multiple-Constraint-Aware RWA Algorithms Based on a Comprehensive Evaluation Model: Use in Wavelength-Switched Optical Networks%Multiple-Constraint-Aware RWA Algorithms Based on a Comprehensive Evaluation Model: Use in Wavelength-Switched Optical Networks

    Institute of Scientific and Technical Information of China (English)

    Hui Yang; YongliZhao; Shanguo Huang; Dajiang Wang; Xuping Cao; Xuefeng Lin

    2012-01-01

    Because of explosive growth in Internet traffic and high complexity of heterogeneous networks, improving the routing and wavelength assignment (RWA) algorithm in underlying optical networks has become very important. Where there are multiple links between different the node pairs, a traditional wavelength-assignment algorithm may be invalid for a wavelength-switched optical networks (WSON) that has directional blocking constraints. Also, impairments in network nodes and subsequent degradation of optical signals may cause modulation failure in the optical network. In this paper, we propose an RWA algorithm based on a novel evaluation model for a WSQN that has multiple constraints. The algorithm includes comprehensive evaluation model (CEM) and directional blocking constraint RWA based on CEM (DB-RWA). Diverse constraints are abstracted into various constraint conditions in order to better assign routing and wavelength. We propose using the novel CEM to optimize routing according to an assessed value of constraints on transmission performance. This eliminates the effects of physical transmission impairments in a WSON. DB-RWA based on CEM abstracts directional blocking conditions in multiple links between network nodes into directional blocking constraints. It also satisfies rigorous network specifications and provides flexibility, scalability, and first-fit rate for the backbone, especially in multiple links between WSON nodes.

  17. Mid-infrared ZGP optical parametric oscillator directly pumped by a lamp-pumped, Q-switched Cr,Tm,Ho:YAG laser

    NARCIS (Netherlands)

    Nieuwenhuis, Ab F.; Lee, Chris J.; Slot, van der Peter J.M.; Gross, Petra; Boller, Klaus-Jochen; Powers, Peter E.

    2007-01-01

    We generate mid-infrared pulsed light tunable between 5.6 μm and 6.6 μm using an optical parametric oscillator (OPO) directly pumped by a Cr,Tm,Ho:YAG, Q -switched laser operating at 2.1 μm. The Holmium laser uses a RTP Q -switch to produce pulses shorter than 100 ns and energies of up to 42 mJ in a

  18. Short pulse diode-pumped Tm:YAG slab laser electro-optically Q-switched by RbTiOPO4 crystal

    Science.gov (United States)

    Jin, Lin; Liu, Pian; Huang, Haitao; Liu, Xuan; Shen, Deyuan

    2016-10-01

    In this paper, a laser diode end pumped RbTiOPO4 (RTP) electro-optically Q-switched Tm:YAG slab laser was demonstrated. Stable Q-switched pulse with the shortest pulse width of 58 ns and an average output power of 7.5 W were realized at the repetition rate of 1 KHz, corresponding to the slope efficiency of 21.7%.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    the prospect of low latency and low-power consumption. The performance of the multidimensional switching nodes has been investigated in an experimental demonstration comprising three network nodes connected with multicore fibers. Both high capacity wavelength connections and time-shared subwavelength...

  20. Usage of mechanically switching devices for HV electrostatic elements of beam optics

    CERN Document Server

    Mikhailichenko, Alexander

    2015-01-01

    We are considering usage of gas-filled mechanical relays-Kilovacs and Gigavacs- for power supply of HV electrical dipoles, quadrupoles etc., where even a time dependent regime required. One can expect the physical switching time on few nanosecond level with such devices operating up to 70kV with currents~50A.

  1. Hollow fiber optics with improved durability for high-peak-power pulses of Q-switched Nd:YAG lasers.

    Science.gov (United States)

    Matsuura, Yuji; Tsuchiuchi, Akio; Noguchi, Hiroshi; Miyagi, Mitsunobu

    2007-03-10

    To improve the damage threshold of hollow optical waveguides for transmitting Q-switched Nd:YAG laser pulses, we optimize the metallization processes for the inner coating of fibers. For silver-coated hollow fiber as the base, second, and third Nd:YAG lasers, drying silver films at a moderate temperature and with inert gas flow is found to be effective. By using this drying process, the resistance to high-peak-power optical pulse radiation is drastically improved for fibers fabricated with and without the sensitizing process. The maximum peak power transmitted in the fiber is greater than 20 MW. To improve the energy threshold of aluminum-coated hollow fibers for the fourth and fifth harmonics of Nd:YAG lasers, a thin silver film is added between the aluminum film and the glass substrate to increase adhesion of the aluminum coating. By using this primer layer, the power threshold improves to 3 MW for the fourth harmonics of a Q-switched Nd:YAG laser light.

  2. All-optical spin switching: A new frontier in femtomagnetism — A short review and a simple theory

    Science.gov (United States)

    Zhang, G. P.; Latta, T.; Babyak, Z.; Bai, Y. H.; George, Thomas F.

    2016-08-01

    Using an ultrafast laser pulse to manipulate the spin degree of freedom has broad technological appeal. It allows one to control the spin dynamics on a femtosecond time scale. The discipline, commonly called femtomagnetism, started with the pioneering experiment by Beaurepaire and coworkers in 1996, who showed subpicosecond demagnetization occurs in magnetic Ni thin films. This finding has motivated extensive research worldwide. All-optical helicity-dependent spin switching (AO-HDS) represents a new frontier in femtomagnetism, where a single ultrafast laser pulse can permanently switch spin without any assistance from a magnetic field. This review summarizes some of the crucial aspects of this new discipline: key experimental findings, leading mechanisms, controversial issues, and possible future directions. The emphasis is on our latest investigation. We first develop the all-optical spin switching (AOS) rule that determines how the switchability depends on the light helicity. This rule allows one to understand microscopically how the spin is reversed and why the circularly polarized light appears more powerful than the linearly polarized light. Then we invoke our latest spin-orbit coupled harmonic oscillator model to simulate single spin reversal. We consider both continuous wave (cw) excitation and pulsed laser excitation. The results are in a good agreement with the experimental result (a MatLab code is available upon request from the author). We then extend the code to include the exchange interaction among different spin sites. We show where the “inverse-Faraday field” comes from and how the laser affects the spin reversal nonlinearly. Our hope is that this review will motivate new experimental and theoretical investigations and discussions.

  3. Novel Folding Large-Scale Optical Switch Matrix with Total Internal Reflection Mirrors on Silicon-on-Insulator by Anisotropy Chemical Etching

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-Wei; YU Jin-Zhong; CHEN Shao-Wu

    2005-01-01

    A compact optical switch matrix was designed, in which light circuits were folded by total internal reflective (TIR) mirrors. Two key elements, 2 × 2 switch and TIR mirror, have been fabricated on silicon-on-insulator wafer by anisotropy chemical etching. The 2 × 2 switch showed very low power consumption of 140mW and avery high speed of 8 ± 1 μs. An improved design for the TIR mirror was developed, and the fabricated mirror with smooth and vertical reflective facet showed low excess loss of 0.7 ± 0.3 dB at 1.55μm.

  4. LD end-pumped acousto-optic Q-switched 1319 nm/1338 nm dual-wavelength Nd:YAG laser

    Science.gov (United States)

    Wu, C. T.; Yu, M.; Wang, C.; Yu, K.; Yu, Y. J.; Chen, X. Y.; Jin, G. Y.

    2016-10-01

    Laser characteristics of acousto-optic Q-switched operation of 1319 nm/1338 nm dual-wavelength composite Nd:YAG laser were studied. Maximum output power of 5.77 W was achieved in CW operation. Under Q-switched operation, the maximum peak power of 3.96 kW and minimum pulse width of 65.6 ns was obtained at repetition frequency of 20 kHz with the duty ratio of 96%. The influence of the duration of the ultrasonic field acted on the Q-switch to the output characteristics of dual-wavelength composite Nd:YAG laser had been reported first time.

  5. Study of radiative blast waves generated on the Z-beamlet laser.

    Energy Technology Data Exchange (ETDEWEB)

    Edens, Aaron D.; Schwarz, Jens

    2012-02-01

    This document describes the original goals of the project to study the Vishniac Overstability on blast waves produced using the Z-Beamlet laser facility as well as the actual results. The proposed work was to build on earlier work on the facility and result in the best characterized set of data for such phenomena in the laboratory. To accomplish the goals it was necessary to modify the existing probe laser at the facility so that it could take multiple images over the course of 1-2 microseconds. Troubles with modifying the probe laser are detailed as well as the work that went into said modifications. The probe laser modification ended up taking the entire length of the project and were the major accomplishment of the research.

  6. Beamlet based direct aperture optimization for MERT using a photon MLC

    Energy Technology Data Exchange (ETDEWEB)

    Henzen, D., E-mail: henzen@ams.unibe.ch; Manser, P.; Frei, D.; Volken, W.; Born, E. J.; Joosten, A.; Lössl, K.; Aebersold, D. M.; Chatelain, C.; Fix, M. K. [Division of Medical Radiation Physics and Department of Radiation Oncology, Inselspital, Bern University Hospital, and University of Bern, Berne CH-3010 (Switzerland); Neuenschwander, H. [Clinic for Radiation-Oncology, Lindenhofspital, Berne CH-3012 (Switzerland); Stampanoni, M. F. M. [Institute for Biomedical Engineering, ETH Zürich and Paul Scherrer Institut, Villigen CH-5234 (Switzerland)

    2014-12-15

    Purpose: A beamlet based direct aperture optimization (DAO) for modulated electron radiotherapy (MERT) using photon multileaf collimator (pMLC) shaped electron fields is developed and investigated. Methods: The Swiss Monte Carlo Plan (SMCP) allows the calculation of dose distributions for pMLC shaped electron beams. SMCP is interfaced with the Eclipse TPS (Varian Medical Systems, Palo Alto, CA) which can thus be included into the inverse treatment planning process for MERT. This process starts with the import of a CT-scan into Eclipse, the contouring of the target and the organs at risk (OARs), and the choice of the initial electron beam directions. For each electron beam, the number of apertures, their energy, and initial shape are defined. Furthermore, the DAO requires dose–volume constraints for the structures contoured. In order to carry out the DAO efficiently, the initial electron beams are divided into a grid of beamlets. For each of those, the dose distribution is precalculated using a modified electron beam model, resulting in a dose list for each beamlet and energy. Then the DAO is carried out, leading to a set of optimal apertures and corresponding weights. These optimal apertures are now converted into pMLC shaped segments and the dose calculation for each segment is performed. For these dose distributions, a weight optimization process is launched in order to minimize the differences between the dose distribution using the optimal apertures and the pMLC segments. Finally, a deliverable dose distribution for the MERT plan is obtained and loaded back into Eclipse for evaluation. For an idealized water phantom geometry, a MERT treatment plan is created and compared to the plan obtained using a previously developed forward planning strategy. Further, MERT treatment plans for three clinical situations (breast, chest wall, and parotid metastasis of a squamous cell skin carcinoma) are created using the developed inverse planning strategy. The MERT plans are

  7. Fundamental mechanism for all-optical helicity-dependent switching of magnetization

    Science.gov (United States)

    Chen, Xiang-Jun

    2017-01-01

    Switching magnetizations with femtosecond circularly polarized lasers may have revolutionary impacts on magnetic data storage and relevant applications. Achievements in ferrimagnetic and ferromagnetic materials of various structures strongly imply a general phenomenon of fundamental atom-laser interaction. Rotating an atom’s wave function with the rotating electric field of a circularly polarized laser, I show the quantum mechanics for the atom is equivalent to that in a static electric field of the same magnitude and a tremendous static magnetic field which interacts with the atom in somewhat different ways. When some conditions are satisfied, transitions of atoms in these two crossed effective fields lead to a highly nonequilibrium state with orbital magnetic moments inclining to the effective magnetic field. The switching finally completes after the pulse duration via relaxation. PMID:28117460

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    End-to-end quality of service provisioning is still a challenging task despite many years of research and development in this area. Considering a generalized multi-protocol label switching based core/metro network and resource reservation protocol capable home gateways, it is the access part...... of the network where quality of service signaling is bridged. This article proposes strategies for generalized multi-protocol label switching control over next emerging passive optical network standard, i.e., the 10-gigabit-capable passive optical network. Node management and resource allocation approaches...

  9. 2.79 μm high peak power LGS electro-optically Q-switched Cr,Er:YSGG laser.

    Science.gov (United States)

    Wang, Li; Wang, Jintao; Yang, Jingwei; Wu, Xianyou; Sun, Dunlu; Yin, Shaotang; Jiang, Haihe; Wang, Jiyang; Xu, Changqing

    2013-06-15

    A flash lamp pumped Cr,Er:YSGG laser utilizing a langasite (LGS) crystal as an electro-optic Q-switch is proposed and demonstrated. It is proved that a LGS crystal with relatively high damage threshold can be used as the electro-optic Q-switch at 2.79 μm, and 216 mJ pulse energy with 14.36 ns pulse width is achieved. Its corresponding peak power of pulse can reach 15 MW, to our knowledge the best result at a 2.79 μm wavelength.

  10. Observation of transverse space charge effects in a multi-beamlet electron bunch produced in a photo-emission electron source

    Energy Technology Data Exchange (ETDEWEB)

    Rihaoui, M.; /Northern Illinois U. /NICADD, DeKalb; Gai, W.; /Argonne; Piot, P.; /Northern Illinois U. /NICADD, DeKalb /FERMILAB; Power, J.G.; /Argonne; Ysof, Z.; /Argonne

    2008-09-01

    A 'multiple beamlet' experiment aimed at investigating the transverse space charge effect was recently conducted at the Argonne Wakefield Accelerator. The experiment generated a symmetric pattern of 5 beamlets on the photocathode of the RF gun with the drive laser. We explored the evolution of the thereby produced 5 MeV, space-charge dominated electron beamlets in the 2m drift following the RF photocathode gun for various external focusing. Two important effects were observed and benchmarked using the particle-in-cell beam dynamics code IMPACT-T. In this paper, we present our experimental observation and their benchmarking with Impact-T.

  11. Optical label switching in telecommunication using semiconductor lasers, amplifiers and electro-absorption modulators

    DEFF Research Database (Denmark)

    Chi, Nan; Christiansen, Lotte Jin; Jeppesen, Palle;

    2004-01-01

    We demonstrate all-optical label encoding and updating for an orthogonally labeled signal in combined IM/FSK modulation format utilizing semiconductor lasers, semiconductor optical amplifiers and electro-absorption modulators. Complete functionality of a network node including two-hop transmissio...

  12. All-optical switching and strong coupling using tunable whispering-gallery-mode microresonators

    NARCIS (Netherlands)

    O'Shea, D.; Junge, C.; Poellinger, M.; Vogler, A.; Rauschenbeutel, A.

    2011-01-01

    We review our recent work on tunable, ultra-high quality factor whispering-gallery-mode bottle microresonators and highlight their applications in non-linear optics and in quantum optics experiments. Our resonators combine ultra-high quality factors of up to Q=3.6x10(8), a small mode volume, and nea

  13. COHERENT DETECTION FOR SPECTRAL AMPLITUDE-CODED OPTICAL LABEL SWITCHING SYSTEMS

    DEFF Research Database (Denmark)

    Osadchiy, Alexey Vladimirovich; Tafur Monroy, Idelfonso

    2010-01-01

    Coherent detection for spectrally encoded optical labels is proposed and experimentally demonstrated for three label tones spectrally spaced at 1 GHz. The proposed method utilizes a frequency swept local oscillator in a coherent receiver supported by digital signal processing for improved flexibi...... flexibility and upgradeability while reducing label detection subsystem complexity as compared with the conventional optical autocorrelation based approaches.......Coherent detection for spectrally encoded optical labels is proposed and experimentally demonstrated for three label tones spectrally spaced at 1 GHz. The proposed method utilizes a frequency swept local oscillator in a coherent receiver supported by digital signal processing for improved...

  14. Evaluation of the nonlinear optical properties for an expanded porphyrin Hückel-Möbius aromaticity switch

    Science.gov (United States)

    Torrent-Sucarrat, Miquel; Anglada, Josep M.; Luis, Josep M.

    2012-11-01

    The conformational flexibility of the expanded porphyrins allows them to achieve different topologies with distinct aromaticities and nonlinear optical properties (NLOP). For instance, it is possible to switch between Möbius and Hückel topologies applying only small changes in the external conditions or in the structure of the ring. In this work, we evaluate the electronic and vibrational contributions to static and dynamic NLOP of the Hückel and Möbius conformers of A,D-di-p-benzi[28]hexaphyrin(1.1.1.1.1.1) synthesized by Latos-Grażyński and co-workers [Angew. Chem., Int. Ed. 46, 7869 (2007), 10.1002/anie.200700555]. Calculations are performed at the HF, M052X, and CAM-B3LYP levels using the 6-31G, 6-311G(d), and 6-31+G(d) basis sets. Our results conclude that M052X/6-31G and CAM-B3LYP/6-31G methods provide a correct qualitative description of the electronic and vibrational contributions for the NLOP of expanded porphyrins. The studied systems show high NLOP with large differences between the Möbius and Hückel conformations (around 1 × 106 a.u. for bar γ). The obtained results indicate that the expanded porphyrins are promising systems to manufacture Hückel-to-Möbius topological switches.

  15. Diode-end-pumped electro-optically Q-switched Nd:YLF slab laser.

    Science.gov (United States)

    Zhang, Hengli; Du, Keming; Li, Daijun; Shi, Peng; Wang, Yongdong; Diart, Robert

    2004-05-10

    We report a very compact Nd:YLF slab laser that is end pumped by a quasi-continuous-wave diode stack. A hybrid resonator is used to generate high output power in a near-diffraction-limited beam (i.e., a beam propogation M2 factor of less than 1.2). A pulse energy of 14.3 mJ was obtained with a pulse width of 8.5 ns at a repetition rate of 500 Hz, which corresponds to a Q-switched peak power of 1.68 MW.

  16. Inversionless light amplification and optical switching controlled by state-dependent alignment of molecules

    CERN Document Server

    Popov, A K

    2003-01-01

    We propose a method to achieve amplification without population inversion by anisotropic molecules whose orientation by an external electric field is state-dependent. It is based on decoupling of the lower-state molecules from the resonant light while the excited ones remain emitting. The suitable class of molecules is discussed, the equation for the gain factor is derived, and the magnitude of the inversionless amplification is estimated for the typical experimental conditions. Such switching of the sample from absorbing to amplifying via transparent state is shown to be possible both with the aid of dc and ac control electric fields.

  17. Optical switching and inversionless amplification controlled by state-dependent alignment of molecules

    CERN Document Server

    Popov, A K

    2005-01-01

    Switching anisotropic molecules from strongly-absorbing to strongly-amplifying through a transparent state is shown to be possible by application of dc or ac control electric fields without the requirement of the population inversion. It is based on decoupling of the lower-level molecules from the resonant light while the excited ones remain emitting due to their state-dependent alignment. The amplification index may become dependent only on a number of excited molecules and not on the population of the lower state. A suitable class of molecules and applications in optoelectronics, fiberoptics and nanophotonics are outlined.

  18. Effect of bulky substituents on thiopyrylium polymethine aggregation in the solid state: A theoretical evaluation of the implications for all-optical switching applications

    KAUST Repository

    Gieseking, Rebecca L.

    2014-11-25

    Polymethine dyes in dilute solutions display many of the optical properties required for all-optical switching applications. However, in thin films, aggregation and polymethine-counterion interactions can substantially modify their properties and limit their utility. Here, we examine the impact of a series of bulky substituents on the solid-state molecular packing of thiopyrylium polymethines by using a theoretical approach combining molecular-dynamics simulations and quantum-chemical calculations. Importantly, it is found that the positions of the substituents near the center and/or ends of the dye determine the extent to which aggregation is reduced; in particular, substituents near the polymethine center primarily modify the type of aggregation that is observed, while substituents near the polymethine ends reduce aggregation and aid in maintaining solution-like properties in the solid state. Our theoretical study elucidates relationships between molecular structure and bulk optical properties and provides design guidelines for all-optical switching materials.

  19. Hydrogen-induced electrical and optical switching in Pd capped Pr nanoparticle layers

    Indian Academy of Sciences (India)

    Shubhra Kala; B R Mehta

    2008-06-01

    In this study, modification in the properties of hydrogen-induced switchable mirror based on Pr nanoparticle layers is reported. The reversible changes in hydrogen-induced electrical and optical properties of Pd capped Pr nanoparticle layers have been studied as a function of hydrogenation time and compared with the conventional device based on Pd capped Pr thin films. Faster electrical and optical response, higher optical contrast and presence of single absorption edge corresponding to Pr trihydride state in hydrogen loaded state have been observed in the case of nanoparticle layers. The improvement in the electrical and optical properties have been explained in terms of blue shift in the absorption edge due to quantum confinement effect, larger number of interparticle boundaries, presence of defects, loose adhesion to the substrate and enhanced surface to volume atom ratio at nanodimension.

  20. Magnetic layer thickness dependence of all-optical magnetization switching in GdFeCo thin films

    Science.gov (United States)

    Yoshikawa, Hiroki; El Moussaoui, Souliman; Terashita, Shinnosuke; Ueda, Ryohei; Tsukamoto, Arata

    2016-07-01

    To clarify the relationship between all-optical magnetization switching (AOS) and nonlocal and nonadiabatic energy dissipation process, we focus on the contribution from energy dissipation in the depth direction. Differently designed structure dependence of created magnetic domain is observed from the reversal phenomenon, AOS, or multidomains by thermomagnetic nucleation (TMN) in GdFeCo multilayer thin films. TMN depends on the shared absorbed energy throughout the continuous metallic volume. On the other hand, AOS critically depends on nonadiabatic energy dissipation process with the electron system in sub-picoseconds. Furthermore, the laser fluence dependence of AOS-created domain sizes indicates that the value of irradiated laser fluence threshold per magnetic domain volume is almost constant. However, a lower laser irradiation fluence below 1-2 mW has a larger value and thickness dependence. From these results, we suggest that AOS depends on energy dissipation from the incident surface in the depth direction for a few picoseconds.

  1. Comparison of laser performance of electro-optic Q-switched Nd:YAG ceramic/single crystal laser

    Institute of Scientific and Technical Information of China (English)

    Jianghua Ji; Xiaolei Zhu; Chunyu Wang; Yongwei Feng; Qihong Lou

    2006-01-01

    @@ An electro-optic Q-switched Nd:YAG ceramic laser operating at kHz repetition rate was demonstrated.Thermal induced lens' focus of ceramic rod was measured and compensated by plano-convex cavity structure. Depolarization loss at different output powers was measured in Nd:YAG single crystal and ceramic lasers. High-energy high-beam-quality laser pulse output was obtained in both laser structures. Pulse energy of about 20 mJ and pulse width of less than 12 ns were achieved, and the average power reached 20 W. The divergence of output laser beam was less than 1.2 mrad, and the beam propagation factor M2was about 1.4.

  2. A novel approach for generating flat optical frequency comb based on externally injected gain-switching distributed feedback semiconductor laser

    Science.gov (United States)

    Zhu, Huatao; Wang, Rong; Pu, Tao; Xiang, Peng; Zheng, Jilin; Fang, Tao

    2017-02-01

    In this paper, a novel approach for generating flat optical frequency comb (OFC) based on externally injected gain-switched distributed feedback (DFB) semiconductor laser is proposed and experimentally demonstrated. In the proposed system, the flatness, the number of OFC spectral lines, and the spectral line to background noise ratio can be tuned to their optimized values by adjusting the current of the modulation signal, the injection ratio and the detuning frequency. Since the frequency of the modulation signal decides the frequency spacing of the output spectral lines, OFC spectral lines of different spacing can be achieved. In the experiment, 10 spectral lines with 1.5 dB power variation are demonstrated to verify the proposed approach. In addition, the expansion of the spectral line is investigated.

  3. Polarization switching and injection locking in vertical-cavity surface-emitting lasers subject to parallel optical injection.

    Science.gov (United States)

    Quirce, Ana; Pérez, Pablo; Popp, Alexandra; Valle, Ángel; Pesquera, Luis; Hong, Yanhua; Thienpont, Hugo; Panajotov, Krassimir

    2016-06-01

    Polarization switching in a long-wavelength vertical-cavity surface-emitting laser (VCSEL) under parallel optical injection is analyzed in a theoretical and experimental way. For the first time, to our knowledge, we report experimentally a state in which injection locking of the parallel polarization and excitation of the free-running orthogonal polarization of the VCSEL are simultaneously obtained. We obtain very simple analytical expressions that describe both linear polarizations. We show that the power of both linear polarizations depend linearly on the injected power in such a way that the total power emitted by the VCSEL is constant. We perform a linear stability analysis of this solution to characterize the region of parameters in which it can be observed. Our measurements qualitatively confirm the previous theoretical predictions.

  4. Azobenzene liquid crystalline materials for efficient optical switching with pulsed and/or continuous wave laser beams.

    Science.gov (United States)

    Hrozhyk, Uladzimir A; Serak, Svetlana V; Tabiryan, Nelson V; Hoke, Landa; Steeves, Diane M; Kimball, Brian R

    2010-04-12

    This study compares optical switching capabilities of liquid crystal (LC) materials based on different classes of azobenzene dyes. LCs based on molecules containing benzene rings with nearly symmetrical pi-pi conjugation respond more efficiently to a cw beam than to a nanosecond laser pulse and maintain the changes induced by the beam for tens of hours. Using azo dye molecules containing two benzene rings with push-pull pi-pi conjugation we demonstrate high photosensitivity to both a cw beam as well as nanosecond laser pulse with only 1 s relaxation of light-induced changes in material properties. Even faster, 1 ms restoration time is obtained for azo dye molecules containing hetaryl (benzothiazole) ring with enhanced push-pull pi-pi conjugation. These materials respond most efficiently to pulsed excitation while discriminating cw radiation.

  5. Numerical investigation of high-contrast ultrafast all-optical switching in low-refractive-index polymeric photonic crystal nanobeam microcavities

    Science.gov (United States)

    Meng, Zi-Ming; Zhong, Xiao-Lan; Wang, Chen; Li, Zhi-Yuan

    2012-06-01

    With the development of micro- or nano-fabrication technologies, great interest has been aroused in exploiting photonic crystal nanobeam structures. In this article the design of high-quality-factor (Q) polymeric photonic crystal nanobeam microcavities suitable for realizing ultrafast all-optical switching is presented based on the three-dimensional finite-difference time-domain method. Adopting the pump-probe technique, the ultrafast dynamic response of the all-optical switching in a nanobeam microcavity with a quality factor of 1000 and modal volume of 1.22 (λ/n)3 is numerically studied and a switching time as fast as 3.6 picoseconds is obtained. Our results indicate the great promise of applying photonic crystal nanobeam microcavities to construct integrated ultrafast tunable photonic devices or circuits incorporating polymer materials with large Kerr nonlinearity and ultrafast response speed.

  6. Null Fiber Coupler with Ultra-high Splitting Ratio of 100000:1 for All-fiber Acousto-optic Switch

    Institute of Scientific and Technical Information of China (English)

    LI Tong; PENG Jiangde; LI Qun; LIU Xiaoming

    2000-01-01

    A fiber null coupler with very high splitting ratio of 100000: 1 and low excess loss of 0.1 dB is reported. The control of the maximum splitting ratio and loss of the null coupler is studied. Its switching function is experimentally demonstrated by acousto-optic modulation.

  7. On intra-node impairments and engineering rules for an optical label switching router supporting an FSK/IM labeling scheme

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Tafur Monroy, Idelfonso; Koonen, A.M.J.

    2006-01-01

    This paper presents a study on intranode impairments and engineering rules for a label switching router supporting intensity modulated (IM) optical payload data signals labeled by using frequency-shift key (FSK) modulation. Engineering rules and design guidelines are presented regarding the choice...

  8. A 200 kHz Q-Switched Adhesive-Free Bond Composite Nd:YVO4 Laser using a Double-Crystal RTP Electro-optic Modulator

    Institute of Scientific and Technical Information of China (English)

    YU Yong-Ji; CHEN Xin-Yu; WANG Chao; WU Chun-Ting; LIU Rui; JIN Guang-Yong

    2012-01-01

    A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported. A pair of RbTiOPOi (RTP) crystals are used as a high repetition EO Q-switch. At the repetition rate of 200kHz, the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65 ns are achieved at an incident pump power of 27 W, corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%, respectively. To the best of our knowledge, this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.%A diode-end-pumped electro-optic (EO) Q-switched adhesive-free bond composite Nd:YVO4 laser operating at a repetition rate of 200 kHz is reported.A pair of RbTiOPO4 (RTP) crystals are used as a high repetition EO Q-switch.At the repetition rate of 200kHz,the maximum average output power of 11.8 W at wavelength 1064 nm and full width at half maximum of pulses of 16.65ns are achieved at an incident pump power of 27 W,corresponding to an optical conversion efficiency of 43.7% and a slope efficiency of 44.6%,respectively.To the best of our knowledge,this is the highest repetition rate reported on the EO Q-switched laser by using RTP crystals.

  9. Femtosecond time-resolved optical and Raman spectroscopy of photoinduced spin crossover: temporal resolution of low-to-high spin optical switching.

    Science.gov (United States)

    Smeigh, Amanda L; Creelman, Mark; Mathies, Richard A; McCusker, James K

    2008-10-29

    A combination of femtosecond electronic absorption and stimulated Raman spectroscopies has been employed to determine the kinetics associated with low-spin to high-spin conversion following charge-transfer excitation of a FeII spin-crossover system in solution. A time constant of tau = 190 +/- 50 fs for the formation of the 5T2 ligand-field state was assigned based on the establishment of two isosbestic points in the ultraviolet in conjunction with changes in ligand stretching frequencies and Raman scattering amplitudes; additional dynamics observed in both the electronic and vibrational spectra further indicate that vibrational relaxation in the high-spin state occurs with a time constant of ca. 10 ps. The results set an important precedent for extremely rapid, formally forbidden (DeltaS = 2) nonradiative relaxation as well as defining the time scale for intramolecular optical switching between two electronic states possessing vastly different spectroscopic, geometric, and magnetic properties.

  10. Adaptive beamlet-based finite-size pencil beam dose calculation for independent verification of IMRT and VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Park, Justin C.; Li, Jonathan G.; Arhjoul, Lahcen; Yan, Guanghua; Lu, Bo; Fan, Qiyong; Liu, Chihray, E-mail: liucr@ufl.edu [Department of Radiation Oncology, University of Florida, Gainesville, Florida 32610-0385 (United States)

    2015-04-15

    Purpose: The use of sophisticated dose calculation procedure in modern radiation therapy treatment planning is inevitable in order to account for complex treatment fields created by multileaf collimators (MLCs). As a consequence, independent volumetric dose verification is time consuming, which affects the efficiency of clinical workflow. In this study, the authors present an efficient adaptive beamlet-based finite-size pencil beam (AB-FSPB) dose calculation algorithm that minimizes the computational procedure while preserving the accuracy. Methods: The computational time of finite-size pencil beam (FSPB) algorithm is proportional to the number of infinitesimal and identical beamlets that constitute an arbitrary field shape. In AB-FSPB, dose distribution from each beamlet is mathematically modeled such that the sizes of beamlets to represent an arbitrary field shape no longer need to be infinitesimal nor identical. As a result, it is possible to represent an arbitrary field shape with combinations of different sized and minimal number of beamlets. In addition, the authors included the model parameters to consider MLC for its rounded edge and transmission. Results: Root mean square error (RMSE) between treatment planning system and conventional FSPB on a 10 × 10 cm{sup 2} square field using 10 × 10, 2.5 × 2.5, and 0.5 × 0.5 cm{sup 2} beamlet sizes were 4.90%, 3.19%, and 2.87%, respectively, compared with RMSE of 1.10%, 1.11%, and 1.14% for AB-FSPB. This finding holds true for a larger square field size of 25 × 25 cm{sup 2}, where RMSE for 25 × 25, 2.5 × 2.5, and 0.5 × 0.5 cm{sup 2} beamlet sizes were 5.41%, 4.76%, and 3.54% in FSPB, respectively, compared with RMSE of 0.86%, 0.83%, and 0.88% for AB-FSPB. It was found that AB-FSPB could successfully account for the MLC transmissions without major discrepancy. The algorithm was also graphical processing unit (GPU) compatible to maximize its computational speed. For an intensity modulated radiation therapy (

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    With the advent of TCP/IP protocol suite the overall era of communication technologies had been redefined. Now, we can’t ignore the presence of huge amount of IP traffic; data, voice or video increasing day by day creating more pressure on existing communicating media and supporting back bone...... cross connects based on translation of wavelength when an IP packet is crossing the optical cross connect. Adding the concepts of layer 3 routing protocols along with the wavelength translation scheme, will help in spanning the overall optical network for a larger area....

  12. All-optical switching in granular ferromagnets caused by magnetic circular dichroism

    Science.gov (United States)

    Ellis, Matthew O. A.; Fullerton, Eric E.; Chantrell, Roy W.

    2016-07-01

    Magnetic recording using circularly polarised femto-second laser pulses is an emerging technology that would allow write speeds much faster than existing field driven methods. However, the mechanism that drives the magnetisation switching in ferromagnets is unclear. Recent theories suggest that the interaction of the light with the magnetised media induces an opto-magnetic field within the media, known as the inverse Faraday effect. Here we show that an alternative mechanism, driven by thermal excitation over the anisotropy energy barrier and a difference in the energy absorption depending on polarisation, can create a net magnetisation over a series of laser pulses in an ensemble of single domain grains. Only a small difference in the absorption is required to reach magnetisation levels observed experimentally and the model does not preclude the role of the inverse Faraday effect but removes the necessity that the opto-magnetic field is 10 s of Tesla in strength.

  13. Thomson develops new optical reader, digital switching system: Gigadisc reader recorder

    Science.gov (United States)

    Levy, D.

    1984-01-01

    A digital optical disk, newly developed by Thomson of France, is announced. The disk, which has a greatly enhanced data storage capacity, is capable of capturing a leading position in information processing and business communications systems by overtaking the share of the market now held by the flexible magnetic disk. A marketing strategy is presented.

  14. Domain size criterion for the observation of all-optical helicity-dependent switching in magnetic thin films

    Science.gov (United States)

    El Hadri, Mohammed Salah; Hehn, Michel; Pirro, Philipp; Lambert, Charles-Henri; Malinowski, Grégory; Fullerton, Eric E.; Mangin, Stéphane

    2016-08-01

    To understand the necessary condition for the observation of all-optical helicity-dependent switching (AO-HDS) of magnetization in thin films, we investigated ferromagnetic Co/Pt and Co/Ni multilayers as well as ferrimagnetic TbCo alloys as a function of magnetic layer compositions and thicknesses. We show that both ferro- and ferrimagnets with high saturation magnetization show AO-HDS if their magnetic thickness is strongly reduced below a material-dependent threshold thickness. By taking into account the demagnetizing energy and the domain wall energy, we are able to define a criterion to predict whether AO-HDS or thermal demagnetization (TD) will be observed. This criterion for the observation of AO-HDS is that the equilibrium size of magnetic domains forming during the cooling process should be larger than the laser spot size. From these results we anticipate that more magnetic materials are expected to show AO-HDS. However, the effect of the optical pulses' helicity is hidden by the formation of small magnetic domains during the cooling process.

  15. Bundled hollow optical fibers for transmission of high-peak-power Q-switched Nd:YAG laser pulses.

    Science.gov (United States)

    Yilmaz, Ozgur; Miyagi, Mitsunobu; Matsuura, Yuji

    2006-09-20

    A hollow-fiber bundle was designed and used to deliver high-peak-power pulses from a Q-switched Nd:YAG laser. An 80 cm long bundle with a total diameter of 5.5 mm was composed of 37 glass capillaries with bore diameters of 0.7 mm. Beam-resizing optics with two lenses were used to couple the laser beam into the bundle. The measured coupling loss due to the limited aperture ratio of the bundle was 2.3 dB, and the transmission loss at wavelengths of 1064 and 532 nm was 0.3 dB. When an inert gas flowed through the bores of the capillaries, the maximum output pulse energy was 200 mJ, which was the limit of the laser used in the experiment. Hollow-fiber bundles withstand irradiation better than single hollow fibers and silica-glass optical fibers do. They are suitable for many dermatological applications because they can be used to irradiate a large area.

  16. Fast response and low power consumption 1×2 thermo-optic switch based on dielectric-loaded surface plasmon polariton waveguides

    Science.gov (United States)

    Qi, Zhipeng; Hu, Guohua; Yun, Binfeng; Zhang, Xiong; Cui, Yiping

    2016-08-01

    In this paper, we present a 1 × 2 thermo-optic (TO) switch based on the integration of the dielectric-loaded surface plasmon polariton (SPP) waveguides with the silicon nanowires. Liquid-curable fluorinated resin (LFR) made of perfluorinated polymer was adopted as the ridge, which has a TO coefficient twice more than that of polymethyl methacrylate, leading to a significant decrease in the power consumption. It was shown that the response time of the dielectric-loaded SPP waveguide could be improved through optimizing the dimensions of the LFR polymer ridge without loss of relative high figure of merit and large confinement factor. Performance characteristics of such a 1 × 2 TO switch operating at a telecom wavelength of 1550 nm was investigated theoretically from the analysis of both heat and optical fields. The results reveal that a switching power as low as 7 mW and an extremely short switching time (with rise time of 3 μs and fall time of 6.7 μs) could be achieved with the proposed dielectric-loaded SPP-based 1 × 2 TO switch. In addition, the crosstalk could be enhanced to at least 40 dB with the applied power of 7 mW at the wavelength of 1550 nm, and it could be retained to be above 20 dB in the wavelength spectrum of 1500-1600 nm during the on/off state.

  17. Solitary pulse-on-demand production by optical injection locking of passively Q-switched InGaN diode laser near lasing threshold

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, X., E-mail: xi.zeng@csem.ch, E-mail: dmitri.boiko@csem.ch; Stadelmann, T.; Grossmann, S.; Hoogerwerf, A. C.; Boïko, D. L., E-mail: xi.zeng@csem.ch, E-mail: dmitri.boiko@csem.ch [Centre Suisse d' Electronique et de Microtechnique SA (CSEM), CH-2002 Neuchâtel (Switzerland); Sulmoni, L.; Lamy, J.-M.; Grandjean, N. [Institute of Condensed Matter Physics (ICMP), École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland)

    2015-02-16

    In this letter, we investigate the behavior of a Q-switched InGaN multi-section laser diode (MSLD) under optical injection from a continuous wave external cavity diode laser. We obtain solitary optical pulse generation when the slave MSLD is driven near free running threshold, and the peak output power is significantly enhanced with respect to free running configuration. When the slave laser is driven well above threshold, optical injection reduces the peak power. Using standard semiconductor laser rate equation model, we find that both power enhancement and suppression effects are the result of partial bleaching of the saturable absorber by externally injected photons.

  18. Universal dynamics and controlled switching of dissipative Kerr solitons in optical microresonators

    CERN Document Server

    Karpov, M; Lucas, E; Kordts, A; Pfeiffer, M H P; Lichachev, G; Lobanov, V E; Gorodetsky, M L; Kippenberg, T J

    2016-01-01

    Dissipative temporal Kerr solitons in optical microresonators enable to convert a continuous wave laser into a train of femtosecond pulses. Of particular interest are single soliton states, whose $\\mathrm{sech}^{2}$ spectral envelope provides a spectrally smooth and low noise optical frequency comb, and that recently have been generated in crystalline, silica, and silicon-nitride resonators. Here, we study the dynamics of multiple soliton states containing ${N}$ solitons and report the discovery of a novel, yet simple mechanism which makes it possible to reduce deterministically the number of solitons, one by one, i.e. ${N\\! \\to\\! N\\!-\\!1\\! \\to\\! \\dots \\!\\to\\! 1}$. By applying weak phase modulation, we directly characterize the soliton state via a double-resonance response. The dynamical probing demonstrates that transitions occur in a predictable way, and thereby enables us to map experimentally the underlying multi-stability diagram of dissipative Kerr solitons. These measurements reveal the "lifted" degene...

  19. Ultrafast optical switching of infrared plasmon polaritons in high-mobility graphene

    Science.gov (United States)

    Ni, G. X.; Wang, L.; Goldflam, M. D.; Wagner, M.; Fei, Z.; McLeod, A. S.; Liu, M. K.; Keilmann, F.; Özyilmaz, B.; Castro Neto, A. H.; Hone, J.; Fogler, M. M.; Basov, D. N.

    2016-04-01

    The success of metal-based plasmonics for manipulating light at the nanoscale has been empowered by imaginative designs and advanced nano-fabrication. However, the fundamental optical and electronic properties of elemental metals, the prevailing plasmonic media, are difficult to alter using external stimuli. This limitation is particularly restrictive in applications that require modification of the plasmonic response at sub-picosecond timescales. This handicap has prompted the search for alternative plasmonic media, with graphene emerging as one of the most capable candidates for infrared wavelengths. Here we visualize and elucidate the properties of non-equilibrium photo-induced plasmons in a high-mobility graphene monolayer. We activate plasmons with femtosecond optical pulses in a specimen of graphene that otherwise lacks infrared plasmonic response at equilibrium. In combination with static nano-imaging results on plasmon propagation, our infrared pump-probe nano-spectroscopy investigation reveals new aspects of carrier relaxation in heterostructures based on high-purity graphene.

  20. Optical injection induced polarization mode switching and correlation analysis on a VCSEL

    CERN Document Server

    Damodarakurup, Sajeev; Vudayagiri, Ashok

    2015-01-01

    Vertical cavity Surface Emitting Laser (VCSEL) diodes emit light in two polarization modes. The amount of optical feedback is found to influence the intensities of the emitted modes. We investigate the effect of the amount of total output polarization feedback and polarization selective feedback on the intensities of the two emitted polarization modes. A 40 micro seconds resolution time series correlation analysis is done for different feedback conditions and investigate the power spectral continuity and onset of chaos on two polarization modes

  1. Electrodynamics analysis on coherent perfect absorber and phase-controlled optical switch.

    Science.gov (United States)

    Chen, Tianjie; Duan, Shaoguang; Chen, Y C

    2012-05-01

    A coherent perfect absorber is essentially a specially designed Fabry-Perot interferometer, which completely extinguishes the incident coherent light. The one- and two-beam coherent perfect absorbers have been analyzed using classical electrodynamics by considering index matching in layered structures to totally suppress reflections. This approach presents a clear and physically intuitive picture for the principle of operation of a perfect absorber. The results show that the incident beam(s) must have correct phases and amplitudes, and the real and imaginary parts of the refractive indices of the media in the interferometer must satisfy a well-defined relation. Our results are in agreement with those obtained using the S-matrix analysis. However, the results were obtained solely based on the superposition of waves from multiple reflections without invoking the concept of time reversal as does the S-matrix approach. Further analysis shows that the two-beam device can be configured to function as a phase-controlled three-state switch.

  2. Developing a Pre-Heat Platform for MagLIF with Z-Beamlet

    Science.gov (United States)

    Geissel, Matthias; Harvey-Thompson, Adam J.; Awe, T. J.; Bliss, D. E.; Glinsky, M. E.; Campbell, E. M.; Gomez, M. R.; Harding, E.; Hansen, S. B.; Jennings, C. A.; Kimmel, M. W.; Knapp, P. F.; Lewis, S. M.; McBride, R. D.; Peterson, K.; Schollmeier, M.; Scoglietti, D. J.; Sefkow, A. B.; Shores, J. E.; Sinars, D. B.; Rochau, G. A.; Slutz, S. A.; Smith, I. C.; Weiss, M. R.; Porter, J. L.

    2016-10-01

    Sandia's Magnetized Liner Inertial Fusion Program has put one of the main objectives towards developing standard platform for a `preconditioned' target, providing a scenario that reproducibly delivers pre-heated fuel. The majority of this effort has been done at the ``Pecos'' Target Area using Sandia's Z-Beamlet laser to provide the pre-heat energy, just like for fully integrated MagLIF experiments. The nature and magnitude of Laser-Plasma-Instabilities during this process are particularly important, since they can lead to less energy in the fuel (backscatter processes) or to energy deposition in less desirable areas (filamentation/scatter). We present results for Stimulated Brillouin Backscatter and forward scatter, and show the effect of the laser pulse shape to laser-entrance-hole transmission and blast wave propagation in the fuel. Sandia is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corp., for the U.S. DOE's Nat'l Nucl. Sec. Admin. under contract DE-AC04-94AL85000.

  3. Analysis of laser preconditioning experiments on Z Beamlet Laser for MagLIF

    Science.gov (United States)

    Glinsky, Michael; Weis, Matthew; Harvey-Thompson, Adam; Geissel, Matthias; Jennings, Christopher; Nagayama, Taisuke; Peterson, Kyle

    2016-10-01

    Presented is an analysis of a series of laser preconditioning experiments on the Z Beamlet Laser (ZBL). These experiments examine the penetration of the laser through the plastic window (a few microns thick), the energy deposition into a gas behind the window, and the resulting density variations in the gas. The ZBL is a glass laser, frequency doubled to 527 μm, capable of delivering up to 4 kJ on target with a pulse length of a few ns. This is the same laser that is used to preheat the fuel in the MagLIF scheme before it is magnetically imploded on the Z generator. The design space for the laser pulse is explored in a series of experiments. Diagnostics include transmitted energy, backscattered energy, x-ray self emission images, and density shadowgrams at several times. These results are matched against HYDRA simulations using the uncertainty quantification engine Dakota. The potential for SBS, SRS, and filamentation are evaluated. Estimates of the energy deposition profile and disposition of the window (important because of potential mix with the fuel) are obtained with uncertainty. Work was performed by Sandia National Laboratories for USDoE under contract DE-AC04-94AL85000. SAND NO. 2016-6689C.

  4. Laser Pre-Heat Studies for MagLIF with Z-Beamlet

    Science.gov (United States)

    Geissel, Matthias; Harvey-Thompson, Adam J.; Awe, T. J.; Gomez, M. R.; Harding, E.; Jennings, C.; Kimmel, M. W.; Knapp, P.; Peterson, K.; Schollmeier, M.; Sefkow, A. B.; Shores, J. E.; Sinars, D. B.; Slutz, S. A.; Smith, I. C.; Speas, C. S.; Vesey, R. A.; Porter, J. L.; Campbell, E. M.; Lewis, S. M.

    2015-11-01

    Magnetized Liner Inertial Confinement Fusion (MagLIF) relies on strong pre-heat of the fuel, typically hundreds of eV. Z-Beamlet delivers up to 4 kJ of laser energy to the target to achieve this goal. Over the last year, several experimental campaigns at the Pecos target area of Sandia's Z-Backlighter Facility and in the center section of the Z-Accelerator have been performed to investigate pre-heat. Primary objectives of these campaigns were the transmission through the laser entrance hole (LEH) in dependence of window thicknesses and focus parameters (including phase plate smoothing), as well as energy coupling to the gaseous fuel. The applied diagnostic suite included a wide range of time integrated and time-resolved X-ray imaging devices, spectrometers, backscatter monitors, a full-beam laser transmission calorimeter, and X-ray diodes.We present the findings of these studies, looking ahead towards a standard pre-heat platform. Sandia National Labs is a multi-program laboratory managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Dept. of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. Establishment of Quantum Communication Network and Design of Quantum Switch Based on Automatic Switch Optical Network%基于ASON的量子通信网络构建和量子交换机设计

    Institute of Scientific and Technical Information of China (English)

    刘晓慧; 聂敏; 裴昌幸

    2011-01-01

    Based on current quantum communication technology,the core technique in automatic switch optical network(ASON)is introduced into quantum communication network,the 3 layers quantum communication network (QCN) model is proposed,in which transmission plane and control plane are separated each other. At the same time,the quantum switch based on the proposed 3 layers quantum communication network model is presented in the paper. Finally the scheme of quantum switch,which is as a key technology of carrying out quantum switching is presented in the paper. This scheme of QCN may play an important role in the establishment of quantum communication network in the large scale in the future.%在目前量子通信技术的基础上,将自动交换光网络核心思想引入量子通信网络中,提出一个传输面与控制面相分离的三层量子通信网络模型和基于该模型的量子交换机结构,并给出了作为实现量子交换机关键技术的基于纠缠的量子交换方案.研究结果表明,该网络模型对于未来大规模量子通信系统的构建具有十分重要的意义.

  6. Optically switched magnetism in photovoltaic perovskite CH3NH3(Mn:Pb)I3

    Science.gov (United States)

    Náfrádi, B.; Szirmai, P.; Spina, M.; Lee, H.; Yazyev, O. V.; Arakcheeva, A.; Chernyshov, D.; Gibert, M.; Forró, L.; Horváth, E.

    2016-11-01

    The demand for ever-increasing density of information storage and speed of manipulation boosts an intense search for new magnetic materials and novel ways of controlling the magnetic bit. Here, we report the synthesis of a ferromagnetic photovoltaic CH3NH3(Mn:Pb)I3 material in which the photo-excited electrons rapidly melt the local magnetic order through the Ruderman-Kittel-Kasuya-Yosida interactions without heating up the spin system. Our finding offers an alternative, very simple and efficient way of optical spin control, and opens an avenue for applications in low-power, light controlling magnetic devices.

  7. Optical design for excellent contrast ratio in a reflective horizontal-switching liquid crystal cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung-Mi; Ji, Seung-Hoon; Lee, Gi-Dong [Department of Electronics Engineering, Dong-A University, Busan 604-714 (Korea, Republic of); Lee, Joun-Ho [LG.Philips LCD, 642-3 Jinpyung-dong, Gumi-city, Kyungbuk 730-350 (Korea, Republic of); Lee, Seung Hee [Research Center for Advanced Materials Development, School of Advanced Materials Engineering, Chonbuk National University, Chonju, Chonbuk 561-756 (Korea, Republic of)], E-mail: gdlee@dau.ac.kr, E-mail: lsh1@chonbuk.ac.kr

    2008-06-07

    In this paper, we propose an optical configuration for a reflective liquid crystal (LC) cell with a single polarizer that can show an excellent contrast ratio by effectively eliminating phase dispersion. The proposed configuration consists of a half-wave retarder, two A-plates, a quarter-wave LC cell and a reflector; the configuration was designed on a Poincare sphere with the trigonometric method. From the calculation, we confirm that this configuration can show a high contrast ratio as compared with the conventional configuration due to the excellent dark state.

  8. 光梯度力驱动的纳米硅基光开关∗%A nano-silicon-photonic switch driven by an optical gradient force

    Institute of Scientific and Technical Information of China (English)

    林建潇; 吴九汇; 刘爱群; 陈喆; 雷浩

    2015-01-01

    通过一道光改变另一道光的传输路线是光子集成网络中重要而长远的目标,然而,由于硅材料的光学非线性较弱,在硅材料上实现开关的全光控制难以实现.因此本文提出了一种由光梯度力驱动的纳米硅基光开关,实现了硅基光开关的全光控制.该光开关由一个部分悬空的微环谐振器和一个交叉波导结构构成,当通入一道控制光时,悬空的微环谐振器在光梯度力的作用下发生弯曲,微环谐振器的谐振波长随之发生变化,从而实现光信号的传输路线发生改变.该光开关利用纳米光子制造技术在标准绝缘体上硅晶圆上制造,实验数据得出其最小消光比为10.67 dB,最大串扰为−11.01 dB,开关时间分别为180 ns和170 ns.该光开关具有尺寸小,响应速度快,低损耗和可拓展等优点,在片上集成光路、高速信号处理以及下一代光纤通信网络中具有潜在应用.%Using light to dynamically and stably redirect the flow of another beam of light is a long-term goal for photonic-integrated circuits. However, it is challenging to realize a practically all-optical switching device in silicon owing to its weak optical nonlinearity. Major published work on all-optical switches were using single-photon absorption and two-photon absorption, which requires ultrahigh switching energy. This paper presents a nano-silicon-photonic all-optical switch driven by an optical gradient force, in which a fast switching speed with low power consumption is obtained. Each switching element is composed of a waveguide crossing connection and a micro-ring resonator. The ring resonator is side-coupled to a double-etched waveguide crossing, while the micro-ring resonator is partially released from the substrate and becomes free-standing. When the“drop”port is in“OFF”state, the wavelength of the signal light from the“input”port does not satisfy the resonant condition in the micro-ring. Therefore, light is

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

    Directory of Open Access Journals (Sweden)

    Gerald Franzl

    2011-01-01

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

  10. Ferrimagnetic Tb-Fe Alloy Thin Films: Composition and Thickness Dependence of Magnetic Properties and All-Optical Switching

    Directory of Open Access Journals (Sweden)

    Birgit eHebler

    2016-02-01

    Full Text Available Ferrimagnetic rare earth - transition metal Tb-Fe alloy thin films exhibit a variety of different magnetic properties, which depends strongly on composition and temperature. In this study, first the influence of the film thickness (5 - 85 nm on the sample magnetic properties was investigated in a wide composition range between 15 at.% and 38 at.% of Tb. From our results, we find that the compensation point, remanent magnetization, and magnetic anisotropy of the Tb-Fe films depend not only on the composition but also on the thickness of the magnetic film up to a critical thickness of about 20-30 nm. Beyond this critical thickness, only slight changes in magnetic properties are observed. This behavior can be attributed to a growth-induced modification of the microstructure of the amorphous films, which affects the short range order. As a result, a more collinear alignment of the distributed magnetic moments of Tb along the out-of-plane direction with film thickness is obtained. This increasing contribution of the Tb sublattice magnetization to the total sample magnetization is equivalent to a sample becoming richer in Tb and can be referred to as an effective composition. Furthermore, the possibility of all-optical switching, where the magnetization orientation of Tb-Fe can be reversed solely by circularly polarized laser pulses, was analyzed for a broad range of compositions and film thicknesses and correlated to the underlying magnetic properties.

  11. Spatial-phase code-division multiple-access system with multiplexed Fourier holography switching for reconfigurable optical interconnection.

    Science.gov (United States)

    Takasago, K; Takekawa, M; Shirakawa, A; Kannari, F

    2000-05-10

    A new, to our knowledge, space-variant optical interconnection system based on a spatial-phase code-division multiple-access technique with multiplexed Fourier holography is described. In this technique a signal beam is spread over wide spatial frequencies by an M-sequence pseudorandom phase code. At a receiver side a selected signal beam is properly decoded, and at the same time its spatial pattern is shaped with a Fourier hologram, which is recorded by light that is encoded with the same M-sequence phase mask as the desired signal beam and by light whose spatial beam pattern is shaped to a signal routing pattern. Using the multiplexed holography, we can simultaneously route multisignal flows into individually specified receiver elements. The routing pattern can also be varied by means of switching the encoding phase code or replacing the hologram. We demonstrated a proof-of-principle experiment with a doubly multiplexed hologram that enables simultaneous routing of two signal beams. Using a numerical model, we showed that the proposed scheme can manage more than 250 routing patterns for one signal flow with one multiplexed hologram at a signal-to-noise ratio of ~5.

  12. Structure and optical properties of polycrystalline NiO films and its resistive switching behavior in Au/NiO/Pt structures

    Energy Technology Data Exchange (ETDEWEB)

    Lai, J.C. [Tianjin Key Laboratory of Film Electronic & Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Wang, X.C., E-mail: wangxccn@126.com [Tianjin Key Laboratory of Film Electronic & Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Mi, W.B. [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparation Technology, Faculty of Science, Tianjin University, Tianjin 300072 (China); Ding, Y.H.; Yang, B.H. [Tianjin Key Laboratory of Film Electronic & Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China)

    2015-12-01

    Structure and optical of polycrystalline NiO films fabricated by reactive sputtering and its resistive switching properties in Au/NiO/Pt structures are investigated. The size of surface uniform pyramid-like islands and average surface roughness increase with the increase of NiO film thickness (t). The NiO films grow with the preferred (111) orientation at 400 °C, but both (100) and (110)-oriented grains exist in the films fabricated at room temperature. Raman results reveal that the crystallinity of the films fabricated at 400 °C becomes good by comparing with that at room temperature. The optical band gap monotonically decreases from 4.44 eV at t=22 nm to 3.55 eV at t=800 nm. The resistance of the Au/NiO/Pt/Ti/glass structures could be switched between two stable states including low and high resistance states. The bipolar endurance performance of the resistive switching remains nondegradable after 200 cycles. The resistive switching can be ascribed to the carrier trapping and detrapping induced by the electric field, which can change the thickness of the depletion layer at Au/NiO interface.

  13. A reconfigurable optical switch exploiting ultrafast control of shaped wavefronts in a multimode nanowire scattering medium

    CERN Document Server

    Strudley, Tom; Mills, Ben; Muskens, Otto L

    2013-01-01

    Wavefront shaping of light fields has opened up a wealth of new applications in imaging and communication in highly multimode environments [1-11]. By mixing of the modes with optimized phases and amplitudes it is possible to focus light through - or even inside - opaque scattering media [1,2]. Here we present work demonstrating ultrafast control of such an optimized wavefront transmitted through a dense disordered mat of semiconductor nanowires by exploiting their inherent nonlinearity. Modulations of the peak intensity of up to 63% (4.3 dB) are induced by optical pumping as a result of a combination of multimode dephasing and induced absorption. Next to ultrafast dephasing of the shaped field, we show that it is possible to dynamically rephase the light fields into an optimized spot by means of pulsed nonlinear excitation of the medium. We obtain an enhancement of the peak to background ratio of the optimized spot resulting from rephasing of up to 18%. While our results are obtained for three dimensional med...

  14. A proposal for digital electro-optic switches with free-carrier dispersion effect and Goos-Hanchen shift in silicon-on-insulator waveguide corner mirror

    Science.gov (United States)

    Sun, DeGui

    2013-09-01

    In a silicon-on-insulator (SOI) waveguide corner mirror (WCM) structure, with the quantum process of a frustrated total internal reflection (FTIR) phenomenon and the time delay principle in the two-dimensional potential barrier tunneling process of a mass of particles, we derive an accurate physical model for the Goos-Hanchen (GH) shift of optical guided-mode in the FTIR process, and in principle match the GH shift jumping states with the independent guided-modes. Then, we propose and demonstrate a new regime of 1 × N digital optical switches with a matching state between the free-carrier dispersion (FCD) based refractive index modulation (RIM) of silicon to create a GH shift jumping function of a photonic signal at the reflecting interface and the independent guided-modes in the FTIR process, where a MOS-capacitor type electro-optic modulation regime is proposed and discussed to realize an effective FCD-based RIM. At the critical matching state, i.e., the incident of an optical beam is at the vicinity of Brewster angle in the WCM, a mini-change of refractive index of waveguide material can cause a great jump of GH shift along the FTIR reflecting interface, and further a 1 × N digital optical switching process could be realized. For a 350-500 nm single-mode rib waveguide made on the 220 nm CMOS-compatible SOI substrate and with the FCD effect based RIM of silicon crystal, a concentration variation of 1018-1019 cm-3 has caused a 0.5-2.5 μm GH shift of reflected beam, which is at 2-5 times of a mode-size and hence radically convinces an optical switching function with a 1 × 3-1 × 10 scale.

  15. General Strategy for Broadband Coherent Perfect Absorption and Multi-wavelength All-optical Switching Based on Epsilon-Near-Zero Multilayer Films

    Science.gov (United States)

    Kim, Tae Young; Badsha, Md. Alamgir; Yoon, Junho; Lee, Seon Young; Jun, Young Chul; Hwangbo, Chang Kwon

    2016-03-01

    We propose a general, easy-to-implement scheme for broadband coherent perfect absorption (CPA) using epsilon-near-zero (ENZ) multilayer films. Specifically, we employ indium tin oxide (ITO) as a tunable ENZ material, and theoretically investigate CPA in the near-infrared region. We first derive general CPA conditions using the scattering matrix and the admittance matching methods. Then, by combining these two methods, we extract analytic expressions for all relevant parameters for CPA. Based on this theoretical framework, we proceed to study ENZ CPA in a single layer ITO film and apply it to all-optical switching. Finally, using an ITO multilayer of different ENZ wavelengths, we implement broadband ENZ CPA structures and investigate multi-wavelength all-optical switching in the technologically important telecommunication window. In our design, the admittance matching diagram was employed to graphically extract not only the structural parameters (the film thicknesses and incident angles), but also the input beam parameters (the irradiance ratio and phase difference between two input beams). We find that the multi-wavelength all-optical switching in our broadband ENZ CPA system can be fully controlled by the phase difference between two input beams. The simple but general design principles and analyses in this work can be widely used in various thin-film devices.

  16. Controllable transmission photonic band gap and all-optical switching behaviors of 1-D InAs/GaAs quantum-dot photonic crystal

    Science.gov (United States)

    Hu, Zhenhua; Xiang, Bowen; Xing, Yunsheng

    2016-12-01

    Transmission optical properties of one-dimensional (1-D) InAs/GaAs quantum-dot photonic crystal (QD-PC), composed of 400 elementary cells, were analyzed by using transfer matrix method. In our calculations, a homogeneous broadening with temperature and other inhomogeneous broadening with quantum dot (QD) size fluctuations are introduced. Our results show that a large optical Stark shift occurs at the high energy edge of the transmission photonic band-gap (TPBG) when, which exhibits the function of light with light, an external laser field acts resonantly on the excitons in the InAs QDs. Utilized this TPBG based on the pump-probe geometry, an all-optical switch can be constructed and the on-off switching extinction ratio (SER) is varied with both the temperature and the inhomogeneity of QDs. Significantly, it still maintains switching behavior and can process the data sequence of return-to-zero codes of 250 Gb/s even if the QD standard deviation of relative size fluctuations (SD-RSF) is up to 3% and the temperature is at 100 K.

  17. Development of an ultra-widely tunable DFG-THz source with switching between organic nonlinear crystals pumped with a dual-wavelength BBO optical parametric oscillator.

    Science.gov (United States)

    Notake, Takashi; Nawata, Kouji; Kawamata, Hiroshi; Matsukawa, Takeshi; Qi, Feng; Minamide, Hiroaki

    2012-11-01

    We developed a difference frequency generation (DFG) source with an organic nonlinear optical crystal of DAST or BNA selectively excited by a dual-wavelength β-BaB(2)O(4) optical parametric oscillator (BBO-OPO). The dual-wavelength BBO-OPO can independently oscillate two lights with different wavelengths from 800 to 1800 nm in a cavity. THz-wave generation by using each organic crystal covers ultrawide range from 1 to 30 THz with inherent intensity dips by crystal absorption modes. The reduced outputs can be improved by switching over the crystals with adequately tuned pump wavelengths of the BBO-OPO.

  18. 支持波长突发和波带突发的光交换研究%Research on optical switching with wavelength burst and waveband burst

    Institute of Scientific and Technical Information of China (English)

    黄胜; 孙丽琴; 吴艳秋; 李玲霞; 庞洪丰

    2012-01-01

    随着网络中业务量的增加,OBS(optical burst switching)网络的核心节点进行交换的端口数增多,交换矩阵规模增大,节点成本增加.为了减小交换矩阵的规模并降低节点成本,将波带思想引入光突发交换中,设计了支持波长突发和波带突发交换的OBS网络节点结构,并提出了支持波长突发和波带突发的汇聚算法和信道调度算法.仿真分析了端口数目及波带粒度对网络性能的影响.仿真结果表明,在满足一定丢包率要求下,可以通过选择合适的端口比和波带粒度来减少交换矩阵端口数目,降低节点成本.%With the increasing of traffic in the networks, the switching port number and the switching matrix scale, as well as the cost in the core nodes, are growing. In order to reduce the switching matrix scale and the node cost, the waveband switching idea is introduced to the OBS( optical burst switching) networks. New architectures of OBS network nodes are designed to support wavelength burst and waveband burst switching in the paper. An assembly algorithm and a channel scheduling algorithm are proposed for the OBS networks to support wavelength burst and waveband burst. The simulation analyses the impact of the number of ports and waveband granularity on the performance of the OBS network. The simulation results show that under the condition of a certain packet loss probability of propose architectures and algorithms could decrease the switching port number and reduce the cost of nodes through the appropriate proportion of ports and waveband granularity.

  19. 0.48Tb/s (12x40Gb/s) WDM transmission and high-quality thermo-optic switching in dielectric loaded plasmonics

    DEFF Research Database (Denmark)

    Kalavrouziotis, Dimitrios; Papaioannou, S.; Giannoulis, Giannis;

    2012-01-01

    through BER measurements by exploiting the heterointegration of a 60 mu m-long straight DLSPPW on a Silicon-on-Insulator waveguide platform, showing error-free performance for six out of the twelve channels. High-quality thermo-optic tuning has been achieved by utilizing Cycloaliphatic......We demonstrate Wavelength Division Multiplexed (WDM)-enabled transmission of 480Gb/s aggregate data traffic (12x40Gb/s) as well as high-quality 1x2 thermo-optic tuning in Dielectric-Loaded Surface Plasmon Polariton Waveguides (DLSPPWs). The WDM transmission characteristics have been verified......-Acrylate-Polymer as an efficient thermo-optic polymer loading employed in a dual-resonator DLSPPW switching structure, yielding a 9nm wavelength shift and extinction ratio values higher than 10dB at both output ports when heated to 90 degrees C. (C)2012 Optical Society of America...

  20. Efficient Compound-Cavity Eye-Safe KTP OPO at 1.57 μm Pumped by an Electro-Optic Q-Switched Nd: YAG Laser

    Institute of Scientific and Technical Information of China (English)

    ZHONG Kai; WANG Yu-Ye; XU De-Gang; GENG You-Fu; WANG Jing-Li; WANG Peng; YAO Jian-Quan

    2009-01-01

    An efficient high-energy eye-safe optical parametric oscillator (OPO) based on a type-Ⅱ non-critically phasematched KTP crystal is demonstrated.The KTP OPO is pumped by a quasi-cw diode side-pumped electrooptic Q-switched Nd:YAG laser in a compound-cavity configuration.The maximum output energy of the signal wavelength at 1.57 μm is 66.5 m J,corresponding to an electrical- to-optical conversion efficiency of 4.47% and an optical-to-optical conversion efficiency of 12.1%.The pulse width (FWHM) is about 3.6 ns with a peak power of 18.5 MW.The output energy is insensitive to repetition rate and demonstrates good stability.

  1. Fast phase switching within the bunch train of the PHIN photo-injector at CERN using fiber-optic modulators on the drive laser

    CERN Document Server

    Divall Csatari, M; Bolzon, B; Bravin, E; Chevallay, E; Dobert, S; Drozdy, A; Fedosseev, V; Hessler, C; Lefevre, T; Livesley, S; Losito, R; Mete, O; Petrarca, M; Rabiller, A N

    2011-01-01

    The future Compact Linear Collider (CLIC) e^-/e^+ collider is based on the two-beam acceleration concept, whereby interleaving electron bunches of the drive beam through a delay loop and combiner rings as well as high peak RF power at 12GHz are created locally to accelerate a second beam, the main beam. One of the main objectives of the currently operational CLIC Test Facility (CTF3) is to demonstrate beam combination from 1.5GHz to 12GHz, which requires satellite-free fast phase-switching of the drive beam with sub-ns speed. The PHIN photo-injector, with the photo-injector laser, provides flexibility in the time structure of the electron bunches produced, by direct manipulation of the laser pulses. A novel fiber modulator-based phase-switching technique allows clean and fast phase-switch at 1.5GHz. This paper describes the switching system based on fiber-optic modulators, and the measurements carried out on both the laser and the electron beam to verify the scheme.

  2. Highly efficient, versatile, self-Q-switched, high-repetition-rate microchip laser generating Ince-Gaussian modes for optical trapping

    Science.gov (United States)

    Dong, Jun; He, Yu; Zhou, Xiao; Bai, Shengchuang

    2016-03-01

    Lasers operating in the Ince-Gaussian (IG) mode have potential applications for optical manipulation of microparticles and formation of optical vortices, as well as for optical trapping and optical tweezers. Versatile, self-Q-switched, high-peak-power, high-repetition-rate Cr, Nd:YAG microchip lasers operating in the IG mode are implemented under tilted, tightly focused laser-diode pumping. An average output power of over 2 W is obtained at an absorbed pump power of 6.4 W. The highest optical-to-optical efficiency of 33.2% is achieved at an absorbed pump power of 3.9 W. Laser pulses with a pulse energy of 7.5 μJ, pulse width of 3.5 ns and peak power of over 2 kW are obtained. A repetition rate up to 335 kHz is reached at an absorbed pump power of 5.8 W. Highly efficient, versatile, IG-mode lasers with a high repetition rate and a high peak power ensure a better flexibility in particle manipulation and optical trapping.

  3. Nonlinear switching in a two-concentric-core chalcogenide glass optical fiber for passively mode-locking a fiber laser.

    Science.gov (United States)

    Nazemosadat, Elham; Mafi, Arash

    2014-08-15

    We propose an all-fiber mode-locking device, which operates based on nonlinear switching in a novel two-concentric-core fiber structure. The design is particularly attractive given the ease of fabrication and coupling to other components in a mode-locked fiber laser cavity. The nonlinear switching in this coupler is studied, and the relative power transmission is obtained. The analysis shows that this nonlinear switch is practical for mode-locking fiber lasers and is forgiving to fabrication errors.

  4. Sub-terahertz microsecond optically controlled switch with GaAs active element beyond the photoelectric threshold

    Science.gov (United States)

    Kulygin, M.; Denisov, G.; Vlasova, K.; Andreev, N.; Shubin, S.; Salahetdinov, S.

    2016-01-01

    We study an unusual working regime of a recently developed sub-terahertz microwave cavity-based switch. The resonator cavity includes a semiconductor plate which is illuminated by laser emission beyond the photoelectric threshold. Despite a significant change to the conventional process of photoelectric effect we have found that the switch works. Typical switching performance rate is about 1 μs for the regime. A process of carrier density relaxation beyond the photoelectric threshold is discussed. An idea of diagnostic method for the semiconductor's quality is proposed.

  5. All-optical SR flip-flop based on SOA-MZI switches monolithically integrated on a generic InP platform

    Science.gov (United States)

    Pitris, St.; Vagionas, Ch.; Kanellos, G. T.; Kisacik, R.; Tekin, T.; Broeke, R.; Pleros, N.

    2016-03-01

    At the dawning of the exaflop era, High Performance Computers are foreseen to exploit integrated all-optical elements, to overcome the speed limitations imposed by electronic counterparts. Drawing from the well-known Memory Wall limitation, imposing a performance gap between processor and memory speeds, research has focused on developing ultra-fast latching devices and all-optical memory elements capable of delivering buffering and switching functionalities at unprecedented bit-rates. Following the master-slave configuration of electronic Flip-Flops, coupled SOA-MZI based switches have been theoretically investigated to exceed 40 Gb/s operation, provided a short coupling waveguide. However, this flip-flop architecture has been only hybridly integrated with silica-on-silicon integration technology exhibiting a total footprint of 45x12 mm2 and intra-Flip-Flop coupling waveguide of 2.5cm, limited at 5 Gb/s operation. Monolithic integration offers the possibility to fabricate multiple active and passive photonic components on a single chip at a close proximity towards, bearing promises for fast all-optical memories. Here, we present for the first time a monolithically integrated all-optical SR Flip-Flop with coupled master-slave SOA-MZI switches. The photonic chip is integrated on a 6x2 mm2 die as a part of a multi-project wafer run using library based components of a generic InP platform, fiber-pigtailed and fully packaged on a temperature controlled ceramic submount module with electrical contacts. The intra Flip-Flop coupling waveguide is 5 mm long, reducing the total footprint by two orders of magnitude. Successful flip flop functionality is evaluated at 10 Gb/s with clear open eye diagram, achieving error free operation with a power penalty of 4dB.

  6. LD-pumped high repetition rate Q-switched Nd:YVO4 laser by using La3Ga5SiO14 single crystal electro-optic modulator

    Institute of Scientific and Technical Information of China (English)

    Chunyu Wang; Huaguo Zang; Xiaoli Li; Yutian Lu; Xiaolei Zhu

    2006-01-01

    A diode-end-pumped electro-optic (EO) Q-switched Nd:YVO4 laser operating at repetition rate of 10 kpps (pulses per second) was reported. A block of La3Ga5SiO14 (LGS) single crystal was used as a Q-switch and the driver was a metal oxide semiconductor field effect transistor (MOS-FET) pulser of high repetition rate and high voltage. At continuous wave (CW) operation, the slope efficiency of the laser was 46%, and maximum optical-to-optical efficiency was 38.5%. Using an output coupler with transmission of 70%, a 10-kpps Q-switched pulse train with 0.4-mJ monopulse energy and 8.2-ns pulse width was achieved, the optical conversion efficiency was around 15%, and the beam quality M2 factor was less than 1.2.

  7. Optimization of Key Parameters in 622-Mb/s Amplitude Shift Keying Labeled 40-Gb/s Return to Zero Differential Phase Shift Keying Optical Switching Network

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jun-yan; XIN Xiang-jun; YU Chong-xiu; XU Da-xiong

    2008-01-01

    Optimized are the label extinction ratio and dispersion compensation of an optical label switching transmission system, which employs 40-Gb/s return to zero differential phase shift keying(RZ-DPSK) payload labeled with 622-Mb/s amplitude shift keying(ASK) control data. In our scheme, the receiver sensitivities of payload and label achieves -27.8 dBm and -33.5 dBm, respectively. After transmitted over 40 km, 60 km and 80 km single mode fiber(SMF)(with dispersion compensation) respectively, the payload can be recovered with no power penalty, while the label can be recovered with less than 2 dB penalty.

  8. Precise calculation of the KTP crystal used as both an intracavity electro-optic Q-switch and a second harmonic generator

    Institute of Scientific and Technical Information of China (English)

    Yuye Wang; Jianquan Yao; Degang Xu; Pu Zhao; Peng Wang

    2006-01-01

    @@ A method of precisely calculating the external applied voltage and the optimum type-Ⅱ phase matching angles for KTP crystal, which is used as both an intracavity electro-optic (EO) Q-switch and a frequency doubler, is presented. The effective EO coefficient along the phase-matching direction is defined to calculate the half-wave voltage and the quarter-wave voltage, and the precise calculation for the phase matching angles in the condition of KTP crystal optimum second harmonic phase matching is theoretically realized.

  9. 光分组交换节点中串扰特性的研究%Study of Crosstalk Property in an Optical Packet Switching Node

    Institute of Scientific and Technical Information of China (English)

    王春华; 李力; 贾潞华; 黄肇明

    2002-01-01

    The effect of queuing delay of output buffer on the crosstalk property in optical packet switching nodes is investigated. The relationship between crosstalk and buffer length is obtained. From the calculation and simulation results, it is concluded that the crosstalk power penalty predominantly depends on the buffer length, the longer the buffer, the greater the penalty, as well as the random range of the penalty. While comparing with the effect of queuing delay, the effect of random routing path delay takes very little proportion in the total power penalty.

  10. Advanced conceptual design report for the Z-Beamlet laser backlighter

    Energy Technology Data Exchange (ETDEWEB)

    Caird, J

    1999-05-31

    The Z-accelerator facility at Sandia National Laboratories (SNL) in Albuquerque, New Mexico, performs critical experiments on the physics of matter at extremely high energy density as part of the Department of Energy's nuclear weapons Stockpile Stewardship Program. In order to augment and enhance the value of experiments performed at this facility, the construction of a new x-ray backlighting diagnostic system is required. New information would be obtained by recording images and/or spectra of x-ray radiation transmitted through target materials as they evolve during Z-accelerator-driven experiments (or ''shots''). In this application, we generally think of the diagnostic x-rays as illumination produced behind the target materials and detected after passing through the Z-target. Hence the x-ray source is commonly called a ''backlighter.'' The methodology is a specific implementation of the general science known as x-ray radiography and/or x-ray spectroscopy. X-ray backlighter experiments have been performed in inertial confinement fusion (ICF) facilities in many countries. On Nova, experience with backlighters has been obtained since about 1986. An intense source of x-rays is produced by focusing one of its beams on a backlighter target nearby, while the other beams are used to create the high-energy-density conditions to be studied in the experiment. This conceptual design report describes how a laser-backlighter similar to one beam of Nova could be constructed for use at Sandia's Z-accelerator facility. The development of such a facility at Sandia is timely for two major reasons. First, at LLNL the Beamlet laser was decommissioned in FY98, and the Nova laser will be decommissioned in FY99, in preparation for activation of the National Ignition Facility (NIF). This will provide several million dollars worth of subsystems and components from which to construct other lasers, such as the Z-backlighter. Second, the new

  11. Latitude-energy structure of multiple ion beamlets in Polar/TIMAS data in plasma sheet boundary layer and boundary plasma sheet below 6 RE radial distance: basic properties and statistical analysis

    Directory of Open Access Journals (Sweden)

    W. K. Peterson

    2005-03-01

    Full Text Available Velocity dispersed ion signatures (VDIS occurring at the plasma sheet boundary layer (PSBL are a well reported feature. Theory has, however, predicted the existence of multiple ion beamlets, similar to VDIS, in the boundary plasma sheet (BPS, i.e. at latitudes below the PSBL. In this study we show evidence for the multiple ion beamlets in Polar/TIMAS ion data and basic properties of the ion beamlets will be presented. Statistics of the occurrence frequency of ion multiple beamlets show that they are most common in the midnight MLT sector and for altitudes above 4 RE, while at low altitude (≤3 RE, single beamlets at PSBL (VDIS are more common. Distribution functions of ion beamlets in velocity space have recently been shown to correspond to 3-dimensional hollow spheres, containing a large amount of free energy. We also study correlation with ~100 Hz waves and electron anisotropies and consider the possibility that ion beamlets correspond to stable auroral arcs.

  12. Kerr-induced all-optical switching in a GaInP photonic crystal Fabry-Perot resonator.

    Science.gov (United States)

    Eckhouse, V; Cestier, I; Eisenstein, G; Combrié, S; Lehoucq, G; De Rossi, A

    2012-04-09

    We describe nonlinear properties of a GaInP photonic crystal Fabry-Perot resonator containing integrated reflectors. The device exhibits an extremely large static nonlinearity due to a thermal effect. Dynamical measurements were used to discriminate between the thermal and Kerr contributions to the nonlinearity. The high frequency nonlinear response is strictly due to the Kerr effect and the efficiency is similar to that obtained in self-phase modulation and four wave mixing experiments. The waveguide dispersion and the wavelength dependent integrated reflectors yield a series of transmission peaks with varying widths which determine the maximum speed at which the device can operate. Switching and wavelength conversion experiments with 92ps and 30ps wide pulses were demonstrated using pulse energies of a few pJ. The switching process is Kerr dominated with the fundamental response being essentially instantaneous so that the obtainable switching speed is strictly determined by the resonator structure.

  13. Studies on structural, optical, magnetic, and resistive switching properties of doped BiFe1-xCrxO3 thin films

    Science.gov (United States)

    Sharma, Y.; Martinez, R.; Agarwal, R.; Barrionuevo, D.; Katiyar, R. K.; Kumar, A.; Katiyar, R. S.

    2016-11-01

    We report the effect of multivalent Cr-ion doping on the structural, optical, magnetic, and resistive switching properties of BiFe1-xCrxO3 (BFCO) thin films (where, 0 ≤ x ≤ 0.15). BFCO thin films were deposited on Pt/TiO2/SiO2/Si (100) substrate using pulsed laser deposition technique. X-ray diffraction and micro-Raman analysis revealed the presence of a secondary phase in BFCO thin films, above 5% Cr doping concentrations. Enhanced magnetization was observed in BFCO films owing to ferromagnetic superexchange interaction between Fe and Cr-ions. X-ray photoelectron spectroscopy measurements revealed the multivalent states of Cr and Fe-ions, where suppression of oxygen vacancies due to Cr-ion doping in BFCO films was discussed based on the defect chemistry viewpoint. Moreover, current conduction and resistive switching properties were studied and the dominant switching mechanism was explained in the light of oxygen vacancies assisted filamentary conduction model.

  14. Band edge tailoring of InGaAs/AlAsSb coupled double quantum wells for a monolithically integrated all-optical switch.

    Science.gov (United States)

    Feng, Jijun; Akimoto, Ryoichi; Gozu, Shin-ichiro; Mozume, Teruo; Hasama, Toshifumi; Ishikawa, Hiroshi

    2013-07-01

    We demonstrate a compact all-optical Michelson interferometer (MI) gating switch with monolithic integration of two different bandgap energies. Based on the ion-induced intermixing in InGaAs/AlAsSb coupled double quantum wells, the blueshift of the band edge can be tailored. Through phosphorus ion implantation with a dose of 5 × 10(14) cm(-2) and subsequent annealing at 720 °C for 60 s, an implanted sample can acquire a high transmittance compared with the as-grown one. Meanwhile, the cross-phase modulation (XPM) efficiency of a non-implanted sample undergoing the same annealing process decreases little. An implanted part for signal propagation and a non-implanted section for XPM are thus monolithically integrated for an MI switch by an area-selective manner. Full switching of a π-rad nonlinear phase shift is achieved with pump pulse energy of 5.6 pJ at a 10-GHz repetition rate.

  15. 基于热光效应的1×4聚合物数字光开关%A 1 × 4 Polymeric Digital Optical Switch Based on the Thermo-Optic Effect

    Institute of Scientific and Technical Information of China (English)

    唐奕; 张昊; 杨建义; 王明华; 江晓清

    2006-01-01

    We present a 1 × 4 Y-branch digital optical switch in which S-bend variable optical attenuators are integrated. The S-bend waveguides, which are always introduced to connect the switch and the standard fiber array, are made use of and designed as variable optical attenuators. A compact device with low crosstalk and larger branching-angle is obtained. The device is fabricated on the thermo-optic polymer materials,and the performance of the device is measured. With an applied driving power of less than 200mW, the device has a low crosstalk of less than - 35dB at a wavelength of 1.55μm.%提出了基于热光型聚合物的集成有S弯曲光衰减器的1×4 Y分叉数字光开关.利用开关与光纤阵列耦合用的S弯曲,将其设计成可变光衰减器,这使得器件更紧凑,并获得低串扰和大分叉角.在小于200mW的驱动功耗下,器件串扰可低至-35dB.

  16. Laser diode structures with a saturable absorber for high-energy picosecond optical pulse generation by combined gain-and Q-switching

    Science.gov (United States)

    Ryvkin, B. S.; Avrutin, E. A.; Kostamovaara, J. E. K.; Kostamovaara, J. T.

    2017-02-01

    The performance of gain-switched Fabry-Perot asymmetric-waveguide semiconductor lasers with a large equivalent spot size and an intracavity saturable absorber was investigated experimentally and theoretically. The laser with a short (˜20 μm) absorber emitted high-energy afterpulse-free optical pulses in a broad range of injection current pulse amplitudes; optical pulses with a peak power of about 35 W and a duration of about 80 ps at half maximum were achieved with a current pulse with an amplitude of just 8 A and a duration of 1.5 ns. Good quality pulsations were observed in a broad range of elevated temperatures. The introduction of a substantially longer absorber section leads to strong spectral broadening of the output without a significant improvement to pulse energy and peak power.

  17. Switching the direction of spin accumulation in the spin Hall effect of light by adjusting the optical axis of an uniaxial crystal

    Institute of Scientific and Technical Information of China (English)

    Tang Ming; Zhou Xin-Xing; Xiao Zhi-Cheng; Luo Hai-Lu; Wen Shuang-Chun

    2013-01-01

    We theoretically and experimentally investigate a switchable spin Hall effect (SHE) of light in reflection near the Brewster angle at an air-uniaxial crystal interface.We find a large transverse spin splitting near the Brewster angle,whose sign can be altered by rotating the optical axis.As an analogy of the SHE in an electronic system,a switchable spin accumulation in the SHE of light is detected.We are able to switch the direction of the spin accumulation by adjusting the optical axis angle of the uniaxial crystal.These findings may give opportunities for photon spin manipulating and developing a new generation of nano-photonic devices.

  18. Single Atom Plasmonic Switch

    CERN Document Server

    Emboras, Alexandros; Ma, Ping; Haffner, Christian; Luisier, Mathieu; Hafner, Christian; Schimmel, Thomas; Leuthold, Juerg

    2015-01-01

    The atom sets an ultimate scaling limit to Moores law in the electronics industry. And while electronics research already explores atomic scales devices, photonics research still deals with devices at the micrometer scale. Here we demonstrate that photonic scaling-similar to electronics-is only limited by the atom. More precisely, we introduce an electrically controlled single atom plasmonic switch. The switch allows for fast and reproducible switching by means of the relocation of an individual or at most - a few atoms in a plasmonic cavity. Depending on the location of the atom either of two distinct plasmonic cavity resonance states are supported. Experimental results show reversible digital optical switching with an extinction ration of 10 dB and operation at room temperature with femtojoule (fJ) power consumption for a single switch operation. This demonstration of a CMOS compatible, integrated quantum device allowing to control photons at the single-atom level opens intriguing perspectives for a fully i...

  19. Photonics in switching

    CERN Document Server

    Midwinter, John E; Kelley, Paul

    1993-01-01

    Photonics in Switching provides a broad, balanced overview of the use of optics or photonics in switching, from materials and devices to system architecture. The chapters, each written by an expert in the field, survey the key technologies, setting them in context and highlighting their benefits and possible applications. This book is a valuable resource for those working in the communications industry, either at the professional or student level, who do not have extensive background knowledge or the underlying physics of the technology.

  20. Manipulation of the coherent spatial and angular shifts of Goos-Hänchen effect to realize the digital optical switch in silicon-on-insulator waveguide corner

    Science.gov (United States)

    Sun, DeGui

    2016-11-01

    In this work, based on the quantum process of the Goos-Hänchen (GH) spatial shift, a quantum process of the GH angular shift is also theoretically investigated. Then, the coherence between spatial and angular shifts in the GH effect is discovered and developed to manipulate the final total displacement for a digital optical switch. It is found that a waveguide corner structure always makes the reflected guide-mode have a GH angular shift in the minus direction when the incident beam is in the Brewster angle vicinity, while it always makes the spatial shift in the plus direction. Meanwhile, the coherence of these two GH shifts has an interesting distribution with the incident angle, and only in the common linear response area to the incident angle, the two GH shifts are mutually enhancing, and then a mini refractive index modulation of the guided-mode at the reflecting interface can create a great stable jump of reflected beam displacement at an eigenstate under the GH effect. As a result, on the 220 nm CMOS-compatible silicon-on-insulator waveguide platform, with a tapered multimode interference (MMI) waveguide, a 5 × 1018cm-3 concentration variation of free carriers can create an absolute digital total displacement of 8-25 μm of the reflected beam on the MMI waveguide output end, leading to a 1 × 5 scale digital optical switching function.