WorldWideScience

Sample records for division multiplexed transmission

  1. Recent Progress in Space-Division Multiplexed Transmission Technologies

    DEFF Research Database (Denmark)

    Morioka, Toshio

    2013-01-01

    Recent development of transmission technologies based on space-division multiplexing is described with future perspectives including a recent achievement of one Pb/s transmission in a single strand of fiber....

  2. Three mode Er3+ ring-doped fiber amplifier for mode-division multiplexed transmission

    NARCIS (Netherlands)

    Jung, Y.; Kang, Q.; Sleiffer, V.A.J.M.; Inan, B.; Kuschnerov, M.; Veljanovski, V.; Corbett, B.; Winfield, R.; Li, Z.; Teh, P.S.; Dhar, A.; Sahu, J.K.; Poletti, F.; Alam, S.U.; Richardson, D.J.

    2013-01-01

    We successfully fabricate three-mode erbium doped fiber with a confined Er3+ doped ring structure and experimentally characterize the amplifier performance with a view to mode-division multiplexed (MDM) transmission. The differential modal gain was effectively mitigated by controlling the relative

  3. Transmission performance of a 400 Gbit s−1 all-optical orthogonal frequency division multiplexing system

    International Nuclear Information System (INIS)

    Tang, Jing; Xia, Min; Li, Wei; Yang, Kecheng; Liu, Deming; Huang, Benxiong

    2013-01-01

    The performance of a 400 Gbit s −1 all-optical orthogonal frequency division multiplexing (AO-OFDM) transmission system is researched with the effects of chromatic dispersion, fiber nonlinearities and amplified spontaneous emission (ASE) noise. The numerical simulation results show that the AO-OFDM system can provide a higher spectral efficiency (SE) and a better sensitivity than a dense wavelength division multiplexing (DWDM) system. The accumulated dispersion tolerance of the system reaches 330 ps nm −1 . When transmitted over single-span 80 km single-mode fiber (SMF), AO-OFDM signals have a 1.5 dB power penalty at BER=10 −3 due to the fiber Kerr nonlinearities, and the receiver sensitivity of the AO-OFDM system is obviously degraded with increasing incident optical power. In multispan transmission, the interaction of the fiber Kerr nonlinearity with the ASE noise is analyzed. A 1320 km maximum transmission distance is realized at 0 dBm incident optical power. The transmission discount due to the ASE noise and fiber nonlinearities in the AO-OFDM system is calculated. Fiber Kerr nonlinearities impose a greater limitation on the performance of the AO-OFDM system for long-distance transmission. All results clearly indicate the feasibility of AO-OFDM technology for next generation 400 Gbit s −1 fiber communication and multiservice networks. (paper)

  4. Experimental demonstration of optical stealth transmission over wavelength-division multiplexing network.

    Science.gov (United States)

    Zhu, Huatao; Wang, Rong; Pu, Tao; Fang, Tao; Xiang, Peng; Zheng, Jilin; Tang, Yeteng; Chen, Dalei

    2016-08-10

    We propose and experimentally demonstrate an optical stealth transmission system over a 200 GHz-grid wavelength-division multiplexing (WDM) network. The stealth signal is processed by spectral broadening, temporal spreading, and power equalizing. The public signal is suppressed by multiband notch filtering at the stealth channel receiver. The interaction between the public and stealth channels is investigated in terms of public-signal-to-stealth-signal ratio, data rate, notch-filter bandwidth, and public channel number. The stealth signal can transmit over 80 km single-mode fiber with no error. Our experimental results verify the feasibility of optical steganography used over the existing WDM-based optical network.

  5. Optical power allocation for adaptive transmissions in wavelength-division multiplexing free space optical networks

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    2015-08-01

    Full Text Available Attracting increasing attention in recent years, the Free Space Optics (FSO technology has been recognized as a cost-effective wireless access technology for multi-Gigabit rate wireless networks. Radio on Free Space Optics (RoFSO provides a new approach to support various bandwidth-intensive wireless services in an optical wireless link. In an RoFSO system using wavelength-division multiplexing (WDM, it is possible to concurrently transmit multiple data streams consisting of various wireless services at very high rate. In this paper, we investigate the problem of optical power allocation under power budget and eye safety constraints for adaptive WDM transmission in RoFSO networks. We develop power allocation schemes for adaptive WDM transmissions to combat the effect of weather turbulence on RoFSO links. Simulation results show that WDM RoFSO can support high data rates even over long distance or under bad weather conditions with an adequate system design.

  6. Long-Haul Dense Space Division Multiplexed Transmission over Low-Crosstalk Heterogeneous 32-Core Transmission Line Using Partial Recirculating Loop System

    DEFF Research Database (Denmark)

    Mizuno, Takayuki; Shibahara, Kohki; Ye, Feihong

    2017-01-01

    In this paper, we present long-haul 32-core dense space division multiplexed (DSDM) unidirectional transmission over a single-mode multicore transmission line. We developed a low-crosstalk heterogeneous 32-core fiber with a square lattice arrangement, and a novel partial recirculating loop system...

  7. An amplified coarse wavelength division multiplexing self-referencing sensor network based on phase-shifted FBGs in transmissive configuration

    International Nuclear Information System (INIS)

    Elosua, C; Perez-Herrera, R A; Lopez-Amo, M; Bariain, C; Garcia-Olcina, R; Sales, S; Capmany, J

    2009-01-01

    A new amplified CWDM (coarse wavelength division multiplexing) self-referencing sensor network using phase-shifted fibre Bragg gratings (PS-FBGs) is experimentally demonstrated in this work. The network uses the PS-FBGs to address intensity sensors in a transmissive configuration, obtaining simultaneously in reflection a wavelength encoded reference signal. In order to enable the remote operation of the sensors, we have introduced optical amplification at the interrogation header of the network, using highly doped erbium fibre

  8. Two-mode PLC-based mode multi/demultiplexer for mode and wavelength division multiplexed transmission.

    Science.gov (United States)

    Hanzawa, Nobutomo; Saitoh, Kuimasa; Sakamoto, Taiji; Matsui, Takashi; Tsujikawa, Kyozo; Koshiba, Masanori; Yamamoto, Fumihiko

    2013-11-04

    We proposed a PLC-based mode multi/demultiplexer (MUX/DEMUX) with an asymmetric parallel waveguide for mode division multiplexed (MDM) transmission. The mode MUX/DEMUX including a mode conversion function with an asymmetric parallel waveguide can be realized by matching the effective indices of the LP(01) and LP(11) modes of two waveguides. We report the design of a mode MUX/DEMUX that can support C-band WDM-MDM transmission. The fabricated mode MUX/DEMUX realized a low insertion loss of less than 1.3 dB and high a mode extinction ratio that exceeded 15 dB. We used the fabricated mode MUX/DEMUX to achieve a successful 2 mode x 4 wavelength x 10 Gbps transmission over a 9 km two-mode fiber with a penalty of less than 1 dB.

  9. Channel estimation in few mode fiber mode division multiplexing transmission system

    Science.gov (United States)

    Hei, Yongqiang; Li, Li; Li, Wentao; Li, Xiaohui; Shi, Guangming

    2018-03-01

    It is abundantly clear that obtaining the channel state information (CSI) is of great importance for the equalization and detection in coherence receivers. However, to the best of the authors' knowledge, in most of the existing literatures, CSI is assumed to be perfectly known at the receiver. So far, few literature discusses the effects of imperfect CSI on MDM system performance caused by channel estimation. Motivated by that, in this paper, the channel estimation in few mode fiber (FMF) mode division multiplexing (MDM) system is investigated, in which two classical channel estimation methods, i.e., least square (LS) method and minimum mean square error (MMSE) method, are discussed with the assumption of the spatially white noise lumped at the receiver side of MDM system. Both the capacity and BER performance of MDM system affected by mode-dependent gain or loss (MDL) with different channel estimation errors have been studied. Simulation results show that the capacity and BER performance can be further deteriorated in MDM system by the channel estimation, and an 1e-3 variance of channel estimation error is acceptable in MDM system with 0-6 dB MDL values.

  10. Effects of fourth-order dispersion in very high-speed optical time-division multiplexed transmission.

    Science.gov (United States)

    Capmany, J; Pastor, D; Sales, S; Ortega, B

    2002-06-01

    We present a closed-form expression for computation of the output pulse's rms time width in an optical fiber link with up to fourth-order dispersion (FOD) by use of an optical source with arbitrary linewidth and chirp parameters. We then specialize the expression to analyze the effect of FOD on the transmission of very high-speed linear optical time-division multiplexing systems. By suitable source chirping, FOD can be compensated for to an upper link-length limit above which other techniques must be employed. Finally, a design formula to estimate the maximum attainable bit rate limited by FOD as a function of the link length is also presented.

  11. Feasibility of space-division-multiplexed transmission of IEEE 802.11 n/ac-compliant wireless MIMO signals over OM3 multimode fiber

    NARCIS (Netherlands)

    Lei, Yi; Li, Jianqiang; Meng, Ziyi; Wu, Rui; Wan, Zhiquan; Fan, Yuting; Zhang, Wenjia; Yin, Feifei; Dai, Yitang; Xu, Kun

    2018-01-01

    In this paper, we have experimentally demonstrated the feasibility of space-division-multiplexed 3 × 3 multiple-input multiple-output (MIMO) transmission over a single OM3 multimode fiber (MMF) using commercial IEEE 802.11 n/ac access points. Throughput performance for different fiber length links

  12. Space-division-multiplexed transmission of 3x3 multiple-input multiple-output wireless signals over conventional graded-index multimode fiber

    NARCIS (Netherlands)

    Lei, Yi; Li, Jianqiang; Fan, Yuting; Yu, Dawei; Fu, Songnian; Yin, Feifei; Dai, Yitang; Xu, Kun

    2016-01-01

    In this paper, we experimentally demonstrate space-division-multiplexed (SDM) transmission of IEEE 802.11ac-compliant 3-spatial-stream WLAN signals over 3 spatial modes of conventional 50um graded-index (GI) multimode fiber (MMF) employing non-mode-selective 3D-waveguide photonic lantern. Two kinds

  13. In-service crosstalk monitoring for dense space division multiplexed multi-core fiber transmission systems

    DEFF Research Database (Denmark)

    Mizuno, T.; Isoda, A.; Shibahara, K.

    2017-01-01

    We present in-service inter-core crosstalk monitoring for MCF transmission systems. We transmit 54-WDM PDM-16QAM signals over 111.6-km 32-core DSDM transmission line incorporating cladding-pumped 32-core MC-EYDFA, and demonstrate -30 dB crosstalk monitoring without affecting transmission...

  14. Dispersion-optimized optical fiber for high-speed long-haul dense wavelength division multiplexing transmission

    Science.gov (United States)

    Wu, Jindong; Chen, Liuhua; Li, Qingguo; Wu, Wenwen; Sun, Keyuan; Wu, Xingkun

    2011-07-01

    Four non-zero-dispersion-shifted fibers with almost the same large effective area (Aeff) and optimized dispersion properties are realized by novel index profile designing and modified vapor axial deposition and modified chemical vapor deposition processes. An Aeff of greater than 71 μm2 is obtained for the designed fibers. Three of the developed fibers with positive dispersion are improved by reducing the 1550nm dispersion slope from 0.072ps/nm2/km to 0.063ps/nm2/km or 0.05ps/nm2/km, increasing the 1550nm dispersion from 4.972ps/nm/km to 5.679ps/nm/km or 7.776ps/nm/km, and shifting the zero-dispersion wavelength from 1500nm to 1450nm. One of these fibers is in good agreement with G655D and G.656 fibers simultaneously, and another one with G655E and G.656 fibers; both fibers are beneficial to high-bit long-haul dense wavelength division multiplexing systems over S-, C-, and L-bands. The fourth developed fiber with negative dispersion is also improved by reducing the 1550nm dispersion slope from 0.12ps/nm2/km to 0.085ps/nm2/km, increasing the 1550nm dispersion from -4ps/nm/km to -6.016ps/nm/km, providing facilities for a submarine transmission system. Experimental measurements indicate that the developed fibers all have excellent optical transmission and good macrobending and splice performances.

  15. 73.7 Tb/s (96x3x256-Gb/s) mode-division-multiplexed DP-16QAM transmission with inline MM-EDFA

    NARCIS (Netherlands)

    Sleiffer, V.A.J.M.; Jung, Y.; Veljanovski, V.; Uden, van R.G.H.; Kuschnerov, M.; Kang, Q.; Grüner-Nielsen, L.; Sun, Y.; Richardson, D.J.; Alam, S.U.; Poletti, F.; Sahu, J.K.; Dhar, A.; Chen, H.; Inan, B.; Koonen, A.M.J.; Corbett, B.; Winfield, R.; Ellis, A.D.; Waardt, de H.

    2012-01-01

    We show transmission of a 73.7 Tb/s (96x3x256-Gb/s) DP-16QAM mode-division- multiplexed signal over 119km of few-mode fiber with inline multi-mode EDFA, using 6x6 MIMO digital signal processing. The total demonstrated net capacity is 57.6 Tb/s (SE 12 bits/s/Hz).

  16. Space-division-multiplexed transmission of 3x3 multiple-input multiple-output wireless signals over conventional graded-index multimode fiber.

    Science.gov (United States)

    Lei, Yi; Li, Jianqiang; Fan, Yuting; Yu, Dawei; Fu, Songnian; Yin, Feifei; Dai, Yitang; Xu, Kun

    2016-12-12

    In this paper, we experimentally demonstrate space-division-multiplexed (SDM) transmission of IEEE 802.11ac-compliant 3-spatial-stream WLAN signals over 3 spatial modes of conventional 50um graded-index (GI) multimode fiber (MMF) employing non-mode-selective 3D-waveguide photonic lantern. Two kinds of scenarios, including fiber-only transmission and fiber-wireless hybrid transmission, were investigated by measuring error vector magnitude (EVM) performance for each stream and condition number (CN) of the channel matrix. The experimental results show that, SDM-based MMF link could offer a CNwireless MIMO signals over existing in-building commercially-available MMFs with enormous cost-saving.

  17. Image secure transmission for optical orthogonal frequency-division multiplexing visible light communication systems using chaotic discrete cosine transform

    Science.gov (United States)

    Wang, Zhongpeng; Zhang, Shaozhong; Chen, Fangni; Wu, Ming-Wei; Qiu, Weiwei

    2017-11-01

    A physical encryption scheme for orthogonal frequency-division multiplexing (OFDM) visible light communication (VLC) systems using chaotic discrete cosine transform (DCT) is proposed. In the scheme, the row of the DCT matrix is permutated by a scrambling sequence generated by a three-dimensional (3-D) Arnold chaos map. Furthermore, two scrambling sequences, which are also generated from a 3-D Arnold map, are employed to encrypt the real and imaginary parts of the transmitted OFDM signal before the chaotic DCT operation. The proposed scheme enhances the physical layer security and improves the bit error rate (BER) performance for OFDM-based VLC. The simulation results prove the efficiency of the proposed encryption method. The experimental results show that the proposed security scheme not only protects image data from eavesdroppers but also keeps the good BER and peak-to-average power ratio performances for image-based OFDM-VLC systems.

  18. Investigation into constant envelope orthogonal frequency division multiplexing for polarization-division multiplexing coherent optical communication

    Science.gov (United States)

    Li, Yupeng; Ding, Ding

    2017-09-01

    Benefiting from the high spectral efficiency and low peak-to-average power ratio, constant envelope orthogonal frequency division multiplexing (OFDM) is a promising technique in coherent optical communication. Polarization-division multiplexing (PDM) has been employed as an effective way to double the transmission capacity in the commercial 100 Gb/s PDM-QPSK system. We investigated constant envelope OFDM together with PDM. Simulation results show that the acceptable maximum launch power into the fiber improves 10 and 6 dB for 80- and 320-km transmission, respectively (compared with the conventional PDM OFDM system). The maximum reachable distance of the constant envelope OFDM system is able to reach 800 km, and even 1200 km is reachable if an ideal erbium doped fiber amplifier is employed.

  19. On-chip mode division multiplexing technologies

    DEFF Research Database (Denmark)

    Ding, Yunhong; Frellsen, Louise Floor; Guan, Xiaowei

    2016-01-01

    Space division multiplexing (SDM) is currently widely investigated in order to provide enhanced capacity thanks to the utilization of space as a new degree of multiplexing freedom in both optical fiber communication and on-chip interconnects. Basic components allowing the processing of spatial...... photonic integrated circuit mode (de) multiplexer for few-mode fibers (FMFs)....

  20. Demonstration of hybrid orbital angular momentum multiplexing and time-division multiplexing passive optical network.

    Science.gov (United States)

    Wang, Andong; Zhu, Long; Liu, Jun; Du, Cheng; Mo, Qi; Wang, Jian

    2015-11-16

    Mode-division multiplexing passive optical network (MDM-PON) is a promising scheme for next-generation access networks to further increase fiber transmission capacity. In this paper, we demonstrate the proof-of-concept experiment of hybrid mode-division multiplexing (MDM) and time-division multiplexing (TDM) PON architecture by exploiting orbital angular momentum (OAM) modes. Bidirectional transmissions with 2.5-Gbaud 4-level pulse amplitude modulation (PAM-4) downstream and 2-Gbaud on-off keying (OOK) upstream are demonstrated in the experiment. The observed optical signal-to-noise ratio (OSNR) penalties for downstream and upstream transmissions at a bit-error rate (BER) of 2 × 10(-3) are less than 2.0 dB and 3.0 dB, respectively.

  1. Mode Division Multiplexing Exploring Hollow-Core Photonic Bandgap Fibers

    DEFF Research Database (Denmark)

    Xu, Jing; Lyngso, Jens Kristian; Leick, Lasse

    2013-01-01

    We review our recent exploratory investigations on mode division multiplexing using hollow-core photonic bandgap fibers (HC-PBGFs). Compared with traditional multimode fibers, HC-PBGFs have several attractive features such as ultra-low nonlinearities, low-loss transmission window around 2 µm etc....... After having discussed the potential and challenges of using HC-PBGFs as transmission fibers for mode multiplexing applications, we will report a number of recent proof-of-concept results obtained in our group using direct detection receivers. The first one is the transmission of two 10.7 Gbit/s non...

  2. Equalizer complexity of mode division multiplexed coherent receivers

    NARCIS (Netherlands)

    Inan, B.; Spinnler, B.; Ferreira, F.; Lobato, A.; Adhikari, S.; Sleiffer, V.A.J.M.; Borne, van den D.; Hanik, N.; Jansen, S.L.

    2012-01-01

    We show that OFDM requires the lowest equalizer complexity for crosstalk compensation in a mode-division-multiplexing receiver. For a 2000-km transmission distance and less than 10% ODFM-specific overhead, the modal dispersion must be below 12 ps/km

  3. Transmission of 20 channels over 238 km of non-zero dispersion shifted fibre using distributed time-division multiplexing-pumped Raman amplification

    Czech Academy of Sciences Publication Activity Database

    Karásek, Miroslav; Radil, J.; Vojtěch, J.

    2010-01-01

    Roč. 4, č. 2 (2010), s. 78-84 ISSN 1751-8768 R&D Projects: GA AV ČR 1ET300670503 Institutional research plan: CEZ:AV0Z20670512 Keywords : optical fibre amplifiers * Raman amplification * wavelength – division - multiplexing Subject RIV: JA - Electronics ; Optoelectronics , Electrical Engineering Impact factor: 1.105, year: 2010

  4. High core count single-mode multicore fiber for dense space division multiplexing

    DEFF Research Database (Denmark)

    Aikawa, K.; Sasaki, Y.; Amma, Y.

    2016-01-01

    Multicore fibers and few-mode fibers have the potential to realize dense-space-division multiplexing systems. Several dense-space-division multiplexing system transmission experiments over multicore fibers and few-mode fibers have been demonstrated so far. Multicore fibers, including recent resul...

  5. Optical Code-Division Multiple-Access and Wavelength Division Multiplexing: Hybrid Scheme Review

    OpenAIRE

    P. Susthitha Menon; Sahbudin Shaari; Isaac A.M. Ashour; Hesham A. Bakarman

    2012-01-01

    Problem statement: Hybrid Optical Code-Division Multiple-Access (OCDMA) and Wavelength-Division Multiplexing (WDM) have flourished as successful schemes for expanding the transmission capacity as well as enhancing the security for OCDMA. However, a comprehensive review related to this hybrid system are lacking currently. Approach: The purpose of this paper is to review the literature on OCDMA-WDM overlay systems, including our hybrid approach of one-dimensional coding of SAC OCDMA with WDM si...

  6. Implementation of orthogonal frequency division multiplexing (OFDM) and advanced signal processing for elastic optical networking in accordance with networking and transmission constraints

    Science.gov (United States)

    Johnson, Stanley

    An increasing adoption of digital signal processing (DSP) in optical fiber telecommunication has brought to the fore several interesting DSP enabled modulation formats. One such format is orthogonal frequency division multiplexing (OFDM), which has seen great success in wireless and wired RF applications, and is being actively investigated by several research groups for use in optical fiber telecom. In this dissertation, I present three implementations of OFDM for elastic optical networking and distributed network control. The first is a field programmable gate array (FPGA) based real-time implementation of a version of OFDM conventionally known as intensity modulation and direct detection (IMDD) OFDM. I experimentally demonstrate the ability of this transmission system to dynamically adjust bandwidth and modulation format to meet networking constraints in an automated manner. To the best of my knowledge, this is the first real-time software defined networking (SDN) based control of an OFDM system. In the second OFDM implementation, I experimentally demonstrate a novel OFDM transmission scheme that supports both direct detection and coherent detection receivers simultaneously using the same OFDM transmitter. This interchangeable receiver solution enables a trade-off between bit rate and equipment cost in network deployment and upgrades. I show that the proposed transmission scheme can provide a receiver sensitivity improvement of up to 1.73 dB as compared to IMDD OFDM. I also present two novel polarization analyzer based detection schemes, and study their performance using experiment and simulation. In the third implementation, I present an OFDM pilot-tone based scheme for distributed network control. The first instance of an SDN-based OFDM elastic optical network with pilot-tone assisted distributed control is demonstrated. An improvement in spectral efficiency and a fast reconfiguration time of 30 ms have been achieved in this experiment. Finally, I

  7. Silicon Chip-to-Chip Mode-Division Multiplexing

    DEFF Research Database (Denmark)

    Baumann, Jan Markus; Porto da Silva, Edson; Ding, Yunhong

    2018-01-01

    A chip-to-chip mode-division multiplexing connection is demonstrated using a pair of multiplexers/demultiplexers fabricated on the silicon-on-insulator platform. Successful mode multiplexing and demultiplexing is experimentally demonstrated, using the LP01, LP11a and LP11b modes.......A chip-to-chip mode-division multiplexing connection is demonstrated using a pair of multiplexers/demultiplexers fabricated on the silicon-on-insulator platform. Successful mode multiplexing and demultiplexing is experimentally demonstrated, using the LP01, LP11a and LP11b modes....

  8. λ-Selection Strategy in C+L Band 1-Pbit/s (448 WDM/19-Core/128 Gbit/s/channel) Flex-Grid Space Division Multiplexed Transmission

    DEFF Research Database (Denmark)

    Asif, Rameez; Ye, Feihong; Morioka, Toshio

    2015-01-01

    In this paper, an inter-core crosstalk based wavelength selection scheme has been proposed for flex-grid superchannels in space division multiplexed transmission. The two λ-selection strategies are categorized as: (a) aligned wavelength super-channels (Aλ-SCs), where all super-channels are placed...... at same λ in all the cores and (b) interleaved wavelength super-channels (Iλ-SCs), where all super-channels are placed at different λ in all the neighboring cores. It is depicted that system performance is improved for DP-16QAM channels in 1-Pbit/s (448 WDM/19 Core/128 Gbit/s/channel) 60 km fiber link...

  9. Wavelength division multiplexing a practical engineering guide

    CERN Document Server

    Grobe, Klaus

    2013-01-01

    In this book, Optical Wavelength Division Multiplexing (WDM) is approached from a strictly practical and application-oriented point of view. Based on the characteristics and constraints of modern fiber-optic components, transport systems and fibers, the text provides relevant rules of thumb and practical hints for technology selection, WDM system and link dimensioning, and also for network-related aspects such as wavelength assignment and resilience mechanisms. Actual 10/40 Gb/s WDM systems are considered, and a preview of the upcoming 100 Gb/s systems and technologies for even higher bit rate

  10. Analysis of subsystems in wavelength-division-multiplexing networks

    DEFF Research Database (Denmark)

    Liu, Fenghai

    2001-01-01

    Wavelength division multiplexing (WDM) technology together with optical amplification has created a new era for optical communication. Transmission capacity is greatly increased by adding more and more wavelength channels into a single fiber, as well as by increasing the line rate of each channel...... in semiconductor optical amplifiers (SOAs), and dispersion managed fiber sections. New subsystems are also proposed in the thesis: a modular 2×2 multiwavelength cross-connect using wavelength switching blocks, a wavelength converter based on cross phase modulation in a semiconductor modulator, a wavelength...

  11. A Survivable Wavelength Division Multiplexing Passive Optical Network with Both Point-to-Point Service and Broadcast Service Delivery

    Science.gov (United States)

    Ma, Xuejiao; Gan, Chaoqin; Deng, Shiqi; Huang, Yan

    2011-11-01

    A survivable wavelength division multiplexing passive optical network enabling both point-to-point service and broadcast service is presented and demonstrated. This architecture provides an automatic traffic recovery against feeder and distribution fiber link failure, respectively. In addition, it also simplifies the protection design for multiple services transmission in wavelength division multiplexing passive optical networks.

  12. High-Capacity Multi-Core Fibers for Space-Division Multiplexing

    DEFF Research Database (Denmark)

    Ye, Feihong

    The transmission capacity of the present optical fiber communication systems based on time division multiplexing (TDM) and wavelength-division multiplexing (WDM) using single-mode fibers (SMFs) is reaching its limit of around 100 Tbit/s per fiber due to the fiber nonlinearities, fiber fuse...... phenomenon and the optical amplifier bandwidth. To meet the ever increasing global data traffic growth and to overcome the looming capacity crunch, a new multiplexing technology using new optical fibers is urgently needed. Space-division multiplexing (SDM) is a promising scheme to overcome the capacity limit...... of the present SMF-based systems. Among the proposed SDM schemes, the one based on uncoupled multi-core fibers (MCFs) having multiple cores in a mutual cladding has proven effective in substantially increasing the transmission capacity per fiber with least system complexity as demonstrated in several state...

  13. Mode division multiplexing over 19-cell hollow-core photonic bandgap fibre by employing integrated mode multiplexer

    NARCIS (Netherlands)

    Chen, H.; Uden, van R.G.H.; Okonkwo, C.M.; Jung, Y.; Wheeler, N.V.; Fokoua, E.N.; Baddela, N.; Petrovich, M.N.; Poletti, F.; Richardson, D.J.; Raz, O.; Waardt, de H.; Koonen, A.M.J.

    2014-01-01

    A photonic integrated mode coupler based on silicon-on-insulator is employed for mode division multiplexing (MDM) over a 193 m 19-cell hollow-core photonic bandgap fibre (HC-PBGF) with a -3 dB bandwidth >120 nm. Robust MDM transmissions using LP01 and LP11 modes, and two degenerate LP11 modes (LP11a

  14. Low-peak-to-average power ratio and low-complexity asymmetrically clipped optical orthogonal frequency-division multiplexing uplink transmission scheme for long-reach passive optical network.

    Science.gov (United States)

    Zhou, Ji; Qiao, Yaojun

    2015-09-01

    In this Letter, we propose a discrete Hartley transform (DHT)-spread asymmetrically clipped optical orthogonal frequency-division multiplexing (DHT-S-ACO-OFDM) uplink transmission scheme in which the multiplexing/demultiplexing process also uses the DHT algorithm. By designing a simple encoding structure, the computational complexity of the transmitter can be reduced from O(Nlog(2)(N)) to O(N). At the probability of 10(-3), the peak-to-average power ratio (PAPR) of 2-ary pulse amplitude modulation (2-PAM)-modulated DHT-S-ACO-OFDM is approximately 9.7 dB lower than that of 2-PAM-modulated conventional ACO-OFDM. To verify the feasibility of the proposed scheme, a 4-Gbit/s DHT-S-ACO-OFDM uplink transmission scheme with a 1∶64 way split has been experimentally implemented using 100-km standard single-mode fiber (SSMF) for a long-reach passive optical network (LR-PON).

  15. A SURVEY ON WAVELENGTH DIVISION MULTIPLEXING (WDM NETWORKS

    Directory of Open Access Journals (Sweden)

    G. Ramesh

    2010-03-01

    Full Text Available Communication networks have emerged as a source of empowerment in today’s society. At the global level, the Internet is becoming the backbone of the modern economy. The new generations in developed countries cannot even conceive of a world without broadband access to the Internet. The inability of the current Internet infrastructure to cope with the wide variety and ever growing number of users, emerging networked applications, usage patterns and business models is increasingly being recognized worldwide. The dynamic growth of Internet traffic and its bursty nature requires high transmission rate. With the advances and the progress in Wavelength Division Multiplexing (WDM technology, the amount of raw bandwidth available in fiber links has increased to high magnitude. This paper presents a survey on WDM networks from its development to the current status. Also an analysis on buffer size in optical networks for real time traffic was performed.

  16. Time-division multiplexing vs network calculus: A comparison

    DEFF Research Database (Denmark)

    Puffitsch, Wolfgang; Sørensen, Rasmus Bo; Schoeberl, Martin

    2015-01-01

    that time-division multiplexing leads to better worst-case latencies, while network calculus supports higher bandwidths. Furthermore, time-division multiplexing leads to a simpler hardware implementation, while dynamically scheduled networks-on-chip allow the integration of best-effort traffic in the on......Networks-on-chip are increasingly common in modern multicore architectures. However, general-purpose networks-on-chip are not always well suited for real-time applications that require bandwidth and latency guarantees. Two approaches to provide real-time guarantees have emerged: time......-chip network in a more natural way....

  17. Space division multiplexing chip-to-chip quantum key distribution

    DEFF Research Database (Denmark)

    Bacco, Davide; Ding, Yunhong; Dalgaard, Kjeld

    2017-01-01

    nodes of the quantum keys to their respective destinations. In this paper we present an experimental demonstration of a photonic integrated silicon chip quantum key distribution protocols based on space division multiplexing (SDM), through multicore fiber technology. Parallel and independent quantum...

  18. Integrated optical delay lines for time-division multiplexers

    NARCIS (Netherlands)

    Stopinski, S.T.; Malinowski, M.; Piramidowicz, R.; Kleijn, E.; Smit, M.K.; Leijtens, X.J.M.

    2013-01-01

    In this paper, we present a study of integrated optical delay lines (DLs) for application in optical time-division multiplexers. The investigated DLs are formed by spirally folded waveguides. The components were designed in a generic approach and fabricated in multi-project wafer runs on an

  19. 12-core x 3-mode Dense Space Division Multiplexed Transmission over 40 km Employing Multi-carrier Signals with Parallel MIMO Equalization

    DEFF Research Database (Denmark)

    Mizuno, T.; Kobayashi, T.; Takara, H.

    2014-01-01

    We demonstrate dense SDM transmission of 20-WDM multi-carrier PDM-32QAM signals over a 40-km 12-core x 3-mode fiber with 247.9-b/s/Hz spectral efficiency. Parallel MIMO equalization enables 21-ns DMD compensation with 61 TDE taps per subcarrier....

  20. Interferometric characterization of few-mode fibers (FMF) for mode-division multiplexing (MDM)

    OpenAIRE

    Muliar, Olena; Usuga Castaneda, Mario A.; Rottwitt, Karsten; Lægsgaard, Jesper

    2015-01-01

    The rapid growth of global data traffic demands the continuous search for new technologies and systems that could increase transmission capacity in optical links and recent experiments show that to do so, it is advantageous to explore new degrees of freedom such as polarization, wavelength or optical modes. Mode division multiplexing (MDM) appears in this context as a promising and viable solution for such capacity increase, since it utilizes multiple spatial modes of an optical fiber as indi...

  1. Phase division multiplexed EIT for enhanced temporal resolution.

    Science.gov (United States)

    Dowrick, T; Holder, D

    2018-03-29

    The most commonly used EIT paradigm (time division multiplexing) limits the temporal resolution of impedance images due to the need to switch between injection electrodes. Advances have previously been made using frequency division multiplexing (FDM) to increase temporal resolution, but in cases where a fixed range of frequencies is available, such as imaging fast neural activity, an upper limit is placed on the total number of simultaneous injections. The use of phase division multiplexing (PDM) where multiple out of phase signals can be injected at each frequency is investigated to increase temporal resolution. TDM, FDM and PDM were compared in head tank experiments, to compare transfer impedance measurements and spatial resolution between the three techniques. A resistor phantom paradigm was established to investigate the imaging of one-off impedance changes, of magnitude 1% and with durations as low as 500 µs (similar to those seen in nerve bundles), using both PDM and TDM approaches. In head tank experiments, a strong correlation (r  >  0.85 and p  EIT injections.

  2. A simple wavelength division multiplexing system for active learning teaching

    Science.gov (United States)

    Zghal, Mourad; Ghalila, Hassen; Ben Lakhdar, Zohra

    2009-06-01

    The active learning project consists in a series of workshops for educators, researchers and students and promotes an innovative method of teaching physics using simple, inexpensive materials that can be fabricated locally. The objective of the project is to train trainers and inspire students to learn physics. The workshops are based on the use of laboratory work and hands-on activities in the classroom. The interpretation of these experiments is challenging for some students, and the experiments can lead to a significant amount of discussion. The workshops are organized within the framework of the project ``Active Learning in Optics and Photonics" (ALOP) mainly funded by UNESCO, with the support of ICTP (Abdus Salam International Centre for Theoretical Physics) and SPIE. ALOP workshops offer high school, college or university physics teachers the opportunity to improve their conceptual understanding of optics. These workshops usually run for five days and cover several of the topics usually found in any introductory university physics program. Optics and photonics are used as subject matter because it is relevant as well as adaptable to research and educational conditions in many developing countries [1]. In this paper, we will mainly focus on a specific topic of the ALOP workshops, namely optical communications and Wavelength Division Multiplexing technology (WDM). This activity was originally developed by Mazzolini et al [2]. WDM is a technology used in fibre-optic communications for transmitting two or more separate signals over a single fibre optic cable by using a separate wavelength for each signal. Multiple signals are carried together as separate wavelengths of light in a multiplexed signal. Simple and inexpensive WDM system was implemented in our laboratory using light emitting diodes or diode lasers, plastic optical fibres, a set of optical filters and lenses, prism or grating, and photodiodes. Transmission of audio signals using home-made, simple

  3. A novel MUX/DEMUX based on few-mode FBG for mode division multiplexing system

    Science.gov (United States)

    Han, Yueyu; Hu, Guijun

    2016-05-01

    In this paper, a novel mode multiplexer/demultiplexer (MUX/DEMUX) based on few-mode fiber Bragg gratings (FBG) has been proposed. The principle of the MUX/DEMUX based on few-mode FBG has been described in detail, and crosstalk of better than -20 dB is obtained experimentally. Then a 2×2 division multiplexing (MDM) system has been established with the MUX/DEMUX we proposed. The transmission experiment of 2×10 Gbps PRBS has been achieved successfully, which are carried by LP01 mode and LP11 mode, respectively. When the receiver sensitivity is greater than -14 dB m and -10 dB m, the BER can both reach 10-3 for B2B and 10 km transmission, respectively.

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

    Science.gov (United States)

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

    2017-07-01

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

  5. Pulse patterning effect in optical pulse division multiplexing for flexible single wavelength multiple access optical network

    Science.gov (United States)

    Jung, Sun-Young; Kim, Chang-Hun; Han, Sang-Kook

    2018-05-01

    A demand for high spectral efficiency requires multiple access within a single wavelength, but the uplink signals are significantly degraded because of optical beat interference (OBI) in intensity modulation/direct detection system. An optical pulse division multiplexing (OPDM) technique was proposed that could effectively reduce the OBI via a simple method as long as near-orthogonality is satisfied, but the condition was strict, and thus, the number of multiplexing units was very limited. We propose pulse pattern enhanced OPDM (e-OPDM) to reduce the OBI and improve the flexibility in multiple access within a single wavelength. The performance of the e-OPDM and patterning effect are experimentally verified after 23-km single mode fiber transmission. By employing pulse patterning in OPDM, the tight requirement was relaxed by extending the optical delay dynamic range. This could support more number of access with reduced OBI, which could eventually enhance a multiple access function.

  6. Frequency-division multiplexer and demultiplexer for terahertz wireless links.

    Science.gov (United States)

    Ma, Jianjun; Karl, Nicholas J; Bretin, Sara; Ducournau, Guillaume; Mittleman, Daniel M

    2017-09-28

    The development of components for terahertz wireless communications networks has become an active and growing research field. However, in most cases these components have been studied using a continuous or broadband-pulsed terahertz source, not using a modulated data stream. This limitation may mask important aspects of the performance of the device in a realistic system configuration. We report the characterization of one such device, a frequency multiplexer, using modulated data at rates up to 10 gigabits per second. We also demonstrate simultaneous error-free transmission of two signals at different carrier frequencies, with an aggregate data rate of 50 gigabits per second. We observe that the far-field spatial variation of the bit error rate is different from that of the emitted power, due to a small nonuniformity in the angular detection sensitivity. This is likely to be a common feature of any terahertz communication system in which signals propagate as diffracting beams not omnidirectional broadcasts.There is growing interest in the development of components to facilitate wireless communications in the terahertz but the characterization of these systems involve an unmodulated input. Here the authors demonstrate multiplexing and demultiplexing of data streams in the terahertz range using a real data link.

  7. Gain transient control for wavelength division multiplexed access networks using semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Osadchiy, Alexey Vladimirovich; Kjær, Rasmus

    2009-01-01

    Gain transients can severely hamper the upstream network performance in wavelength division multiplexed (WDM) access networks featuring erbium doped fiber amplifiers (EDFAs) or Raman amplification. We experimentally demonstrate for the first time using 10 Gb/s fiber transmission bit error rate...... measurements how a near-saturated semiconductor optical amplifier (SOA) can be used to control these gain transients. An SOA is shown to reduce the penalty of transients originating in an EDFA from 2.3 dB to 0.2 dB for 10 Gb/s transmission over standard single mode fiber using a 231-1 PRBS pattern. The results...... suggest that a single SOA integrated within a WDM receiver at the metro node could offer a convenient all-optical solution for upstream transient controlin WDM access networks....

  8. High-Speed Turbo-TCM-Coded Orthogonal Frequency-Division Multiplexing Ultra-Wideband Systems

    Directory of Open Access Journals (Sweden)

    Wang Yanxia

    2006-01-01

    Full Text Available One of the UWB proposals in the IEEE P802.15 WPAN project is to use a multiband orthogonal frequency-division multiplexing (OFDM system and punctured convolutional codes for UWB channels supporting a data rate up to 480 Mbps. In this paper, we improve the proposed system using turbo TCM with QAM constellation for higher data rate transmission. We construct a punctured parity-concatenated trellis codes, in which a TCM code is used as the inner code and a simple parity-check code is employed as the outer code. The result shows that the system can offer a much higher spectral efficiency, for example, 1.2 Gbps, which is 2.5 times higher than the proposed system. We identify several essential requirements to achieve the high rate transmission, for example, frequency and time diversity and multilevel error protection. Results are confirmed by density evolution.

  9. Interferometric characterization of few-mode fibers (FMF) for mode-division multiplexing (MDM)

    DEFF Research Database (Denmark)

    Muliar, Olena; Usuga Castaneda, Mario A.; Rottwitt, Karsten

    2015-01-01

    ), commonly used in a MDM scenario. This experimental technique requires the use of a Mach-Zehnder interferometer, where the reference's path length is controlled by an optical delay line. The interference between the output beams of reference and fiber under test (FUT) is recorded on a CCD camera......The rapid growth of global data traffic demands the continuous search for new technologies and systems that could increase transmission capacity in optical links and recent experiments show that to do so, it is advantageous to explore new degrees of freedom such as polarization, wavelength...... or optical modes. Mode division multiplexing (MDM) appears in this context as a promising and viable solution for such capacity increase, since it utilizes multiple spatial modes of an optical fiber as individual communication channels for data transmission. In order to evaluate its performance, a MDM system...

  10. Doubling transmission capacity in optical wireless system by antenna horizontal- and vertical-polarization multiplexing.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Zhang, Junwen; Dong, Ze; Chi, Nan

    2013-06-15

    We experimentally demonstrate 2×56 Gb/s two-channel polarization-division-multiplexing quadrature-phase-shift-keying signal delivery over 80 km single-mode fiber-28 and 2 m Q-band (33-50 GHz) wireless link, adopting antenna horizontal- (H-) and vertical-polarization (V-polarization) multiplexing. At the wireless receiver, classic constant-modulus-algorithm equalization based on digital signal processing can realize polarization demultiplexing and remove the crosstalk at the same antenna polarization. By adopting antenna polarization multiplexing, the signal baud rate and performance requirements for optical and wireless devices can be reduced but at the cost of double antennas and devices, while wireless transmission capacity can also be increased but at the cost of stricter requirements for V-polarization. The isolation is only about 19 dB when V-polarization deviation approaches 10°, which will affect high-speed (>50 Gb/s) wireless delivery.

  11. PLC-based mode multi/demultiplexers for mode division multiplexing

    Science.gov (United States)

    Saitoh, Kunimasa; Hanzawa, Nobutomo; Sakamoto, Taiji; Fujisawa, Takeshi; Yamashita, Yoko; Matsui, Takashi; Tsujikawa, Kyozo; Nakajima, Kazuhide

    2017-02-01

    Recently developed PLC-based mode multi/demultiplexers (MUX/DEMUXs) for mode division multiplexing (MDM) transmission are reviewed. We firstly show the operation principle and basic characteristics of PLC-based MUX/DEMUXs with an asymmetric directional coupler (ADC). We then demonstrate the 3-mode (2LP-mode) multiplexing of the LP01, LP11a, and LP11b modes by using fabricated PLC-based mode MUX/DEMUX on one chip. In order to excite LP11b mode in the same plane, a PLC-based LP11 mode rotator is introduced. Finally, we show the PLC-based 6-mode (4LP-mode) MUX/DEMUX with a uniform height by using ADCs, LP11 mode rotators, and tapered waveguides. It is shown that the LP21a mode can be excited from the LP11b mode by using ADC, and the two nearly degenerated LP21b and LP02 modes can be (de)multiplexed separately by using tapered mode converter from E13 (E31) mode to LP21b (LP02) mode.

  12. Time-division-multiplex control scheme for voltage multiplier rectifiers

    Directory of Open Access Journals (Sweden)

    Bin-Han Liu

    2017-03-01

    Full Text Available A voltage multiplier rectifier with a novel time-division-multiplexing (TDM control scheme for high step-up converters is proposed in this study. In the proposed TDM control scheme, two full-wave voltage doubler rectifiers can be combined to realise a voltage quadrupler rectifier. The proposed voltage quadrupler rectifier can reduce transformer turn ratio and transformer size for high step-up converters and also reduce voltage stress for the output capacitors and rectifier diodes. An N-times voltage rectifier can be straightforwardly produced by extending the concepts from the proposed TDM control scheme. A phase-shift full-bridge (PSFB converter is adopted in the primary side of the proposed voltage quadrupler rectifier to construct a PSFB quadrupler converter. Experimental results for the PSFB quadrupler converter demonstrate the performance of the proposed TDM control scheme for voltage quadrupler rectifiers. An 8-times voltage rectifier is simulated to determine the validity of extending the proposed TDM control scheme to realise an N-times voltage rectifier. Experimental and simulation results show that the proposed TDM control scheme has great potential to be used in high step-up converters.

  13. Multi-client quantum key distribution using wavelength division multiplexing

    International Nuclear Information System (INIS)

    Grice, Warren P.; Bennink, Ryan S.; Earl, Dennis Duncan; Evans, Philip G.; Humble, Travis S.; Pooser, Raphael C.; Schaake, Jason; Williams, Brian P.

    2011-01-01

    Quantum Key Distribution (QKD) exploits the rules of quantum mechanics to generate and securely distribute a random sequence of bits to two spatially separated clients. Typically a QKD system can support only a single pair of clients at a time, and so a separate quantum link is required for every pair of users. We overcome this limitation with the design and characterization of a multi-client entangled-photon QKD system with the capacity for up to 100 clients simultaneously. The time-bin entangled QKD system includes a broadband down-conversion source with two unique features that enable the multi-user capability. First, the photons are emitted across a very large portion of the telecom spectrum. Second, and more importantly, the photons are strongly correlated in their energy degree of freedom. Using standard wavelength division multiplexing (WDM) hardware, the photons can be routed to different parties on a quantum communication network, while the strong spectral correlations ensure that each client is linked only to the client receiving the conjugate wavelength. In this way, a single down-conversion source can support dozens of channels simultaneously--and to the extent that the WDM hardware can send different spectral channels to different clients, the system can support multiple client pairings. We will describe the design and characterization of the down-conversion source, as well as the client stations, which must be tunable across the emission spectrum.

  14. Testbed for Multi-Wavelength Optical Code Division Multiplexing Based on Passive Linear Unitary Filters

    National Research Council Canada - National Science Library

    Yablonovitch, Eli

    2000-01-01

    .... The equipment purchased under this grant has permitted UCLA to purchase a number of broad-band optical components, including especially some unique code division multiplexing filters that permitted...

  15. Capacity of Wavelength and Time Division Multiplexing for Quasi-Distributed Measurement Using Fiber Bragg Gratings

    Directory of Open Access Journals (Sweden)

    Marcel Fajkus

    2015-01-01

    Full Text Available In this paper, an analysis of the use of wavelength and time division multiplexing techniques for quasi-distributed measurement in uniform fiber Bragg gratings is presented. To date, publications have concentrated on the determination of the maximum number of fiber Bragg gratings on one optical fiber using wavelength and time division multiplexing. In this paper, these techniques will be extended to determine the spectral width of wavelength division multiplexing in terms of the spectral width of the light emitting diode, the spectral width of the Bragg gratings, the measurement ranges of the individual sensors, and the guard band between two adjacent Bragg gratings. For time division multiplexing, a description of the time and power conditions are given. In particular the reflected power, first order crosstalk and chromatic dispersion have been considered. Finally, these relationships were applied to verify a design in a simulation using OptiSystem software.

  16. Telemetry Standards, RCC Standard 106-17. Chapter 3. Frequency Division Multiplexing Telemetry Standards

    Science.gov (United States)

    2017-07-01

    Standard 106-17 Chapter 3, July 2017 3-5 Table 3-4. Constant-Bandwidth FM Subcarrier Channels Frequency Criteria\\Channels: A B C D E F G H Deviation ...Telemetry Standards , RCC Standard 106-17 Chapter 3, July 2017 3-i CHAPTER 3 Frequency Division Multiplexing Telemetry Standards Acronyms...Frequency Division Multiplexing Telemetry Standards ................................ 3-1 3.1 General

  17. 2x2 MIMO-OFDM Gigabit fiber-wireless access system based on polarization division multiplexed WDM-PON

    DEFF Research Database (Denmark)

    Deng, Lei; Pang, Xiaodan; Zhao, Ying

    2012-01-01

    We propose a spectral efficient radio over wavelength division multiplexed passive optical network (WDM-PON) system by combining optical polarization division multiplexing (PDM) and wireless multiple input multiple output (MIMO) spatial multiplexing techniques. In our experiment, a training-based...

  18. Fine-filter method for Raman lidar based on wavelength division multiplexing and fiber Bragg grating.

    Science.gov (United States)

    Wang, Jun; Zheng, Jiao; Lu, Hong; Yan, Qing; Wang, Li; Liu, Jingjing; Hua, Dengxin

    2017-11-01

    Atmospheric temperature is one of the important parameters for the description of the atmospheric state. Most of the detection approaches to atmospheric temperature monitoring are based on rotational Raman scattering for better understanding atmospheric dynamics, thermodynamics, atmospheric transmission, and radiation. In this paper, we present a fine-filter method based on wavelength division multiplexing, incorporating a fiber Bragg grating in the visible spectrum for the rotational Raman scattering spectrum. To achieve high-precision remote sensing, the strong background noise is filtered out by using the secondary cascaded light paths. Detection intensity and the signal-to-noise ratio are improved by increasing the utilization rate of return signal form atmosphere. Passive temperature compensation is employed to reduce the temperature sensitivity of fiber Bragg grating. In addition, the proposed method provides a feasible solution for the filter system with the merits of miniaturization, high anti-interference, and high stability in the space-based platform.

  19. Development of authentication code for multi-access optical code division multiplexing based quantum key distribution

    Science.gov (United States)

    Taiwo, Ambali; Alnassar, Ghusoon; Bakar, M. H. Abu; Khir, M. F. Abdul; Mahdi, Mohd Adzir; Mokhtar, M.

    2018-05-01

    One-weight authentication code for multi-user quantum key distribution (QKD) is proposed. The code is developed for Optical Code Division Multiplexing (OCDMA) based QKD network. A unique address assigned to individual user, coupled with degrading probability of predicting the source of the qubit transmitted in the channel offer excellent secure mechanism against any form of channel attack on OCDMA based QKD network. Flexibility in design as well as ease of modifying the number of users are equally exceptional quality presented by the code in contrast to Optical Orthogonal Code (OOC) earlier implemented for the same purpose. The code was successfully applied to eight simultaneous users at effective key rate of 32 bps over 27 km transmission distance.

  20. Integrated cladding-pumped multicore few-mode erbium-doped fibre amplifier for space-division-multiplexed communications

    Science.gov (United States)

    Chen, H.; Jin, C.; Huang, B.; Fontaine, N. K.; Ryf, R.; Shang, K.; Grégoire, N.; Morency, S.; Essiambre, R.-J.; Li, G.; Messaddeq, Y.; Larochelle, S.

    2016-08-01

    Space-division multiplexing (SDM), whereby multiple spatial channels in multimode and multicore optical fibres are used to increase the total transmission capacity per fibre, is being investigated to avert a data capacity crunch and reduce the cost per transmitted bit. With the number of channels employed in SDM transmission experiments continuing to rise, there is a requirement for integrated SDM components that are scalable. Here, we demonstrate a cladding-pumped SDM erbium-doped fibre amplifier (EDFA) that consists of six uncoupled multimode erbium-doped cores. Each core supports three spatial modes, which enables the EDFA to amplify a total of 18 spatial channels (six cores × three modes) simultaneously with a single pump diode and a complexity similar to a single-mode EDFA. The amplifier delivers >20 dBm total output power per core and <7 dB noise figure over the C-band. This cladding-pumped EDFA enables combined space-division and wavelength-division multiplexed transmission over multiple multimode fibre spans.

  1. Tailoring Chirped Moiré Fiber Bragg Gratings for Wavelength-Division-Multiplexing and Optical Code-Division Multiple-Access Applications

    Science.gov (United States)

    Chen, Lawrence R.; Smith, Peter W. E.

    The design and fabrication of chirped Moiré fiber Bragg gratings (CMGs) are presented, which can be used in either (1) transmission as passband filters for providing wavelength selectivity in wavelength-division-multiplexed (WDM) systems or (2) reflection as encoding/decoding elements to decompose short broadband pulses in both wavelength and time in order to implement an optical code-division multiple-access (OCDMA) system. In transmission, the fabricated CMGs have single or multiple flattened passbands ( 12 dB isolation and near constant in-band group delay. It is shown that these filters do not produce any measurable dispersion-induced power penalties when used to provide wavelength selectivity in 2.5 Gbit/s systems. It is also demonstrated how CMGs can be used in reflection to encode/decode short pulses from a wavelength-tunable mode-locked Er-doped fiber laser.

  2. Frequency division multiplexed multi-color fluorescence microscope system

    Science.gov (United States)

    Le, Vu Nam; Yang, Huai Dong; Zhang, Si Chun; Zhang, Xin Rong; Jin, Guo Fan

    2017-10-01

    Grayscale camera can only obtain gray scale image of object, while the multicolor imaging technology can obtain the color information to distinguish the sample structures which have the same shapes but in different colors. In fluorescence microscopy, the current method of multicolor imaging are flawed. Problem of these method is affecting the efficiency of fluorescence imaging, reducing the sampling rate of CCD etc. In this paper, we propose a novel multiple color fluorescence microscopy imaging method which based on the Frequency division multiplexing (FDM) technology, by modulating the excitation lights and demodulating the fluorescence signal in frequency domain. This method uses periodic functions with different frequency to modulate amplitude of each excitation lights, and then combine these beams for illumination in a fluorescence microscopy imaging system. The imaging system will detect a multicolor fluorescence image by a grayscale camera. During the data processing, the signal obtained by each pixel of the camera will be processed with discrete Fourier transform, decomposed by color in the frequency domain and then used inverse discrete Fourier transform. After using this process for signals from all of the pixels, monochrome images of each color on the image plane can be obtained and multicolor image is also acquired. Based on this method, this paper has constructed and set up a two-color fluorescence microscope system with two excitation wavelengths of 488 nm and 639 nm. By using this system to observe the linearly movement of two kinds of fluorescent microspheres, after the data processing, we obtain a two-color fluorescence dynamic video which is consistent with the original image. This experiment shows that the dynamic phenomenon of multicolor fluorescent biological samples can be generally observed by this method. Compared with the current methods, this method can obtain the image signals of each color at the same time, and the color video's frame

  3. Advanced Spatial-Division Multiplexed Measurement Systems Propositions—From Telecommunication to Sensing Applications: A Review

    Directory of Open Access Journals (Sweden)

    Yi Weng

    2016-08-01

    Full Text Available The concepts of spatial-division multiplexing (SDM technology were first proposed in the telecommunications industry as an indispensable solution to reduce the cost-per-bit of optical fiber transmission. Recently, such spatial channels and modes have been applied in optical sensing applications where the returned echo is analyzed for the collection of essential environmental information. The key advantages of implementing SDM techniques in optical measurement systems include the multi-parameter discriminative capability and accuracy improvement. In this paper, to help readers without a telecommunication background better understand how the SDM-based sensing systems can be incorporated, the crucial components of SDM techniques, such as laser beam shaping, mode generation and conversion, multimode or multicore elements using special fibers and multiplexers are introduced, along with the recent developments in SDM amplifiers, opto-electronic sources and detection units of sensing systems. The examples of SDM-based sensing systems not only include Brillouin optical time-domain reflectometry or Brillouin optical time-domain analysis (BOTDR/BOTDA using few-mode fibers (FMF and the multicore fiber (MCF based integrated fiber Bragg grating (FBG sensors, but also involve the widely used components with their whole information used in the full multimode constructions, such as the whispering gallery modes for fiber profiling and chemical species measurements, the screw/twisted modes for examining water quality, as well as the optical beam shaping to improve cantilever deflection measurements. Besides, the various applications of SDM sensors, the cost efficiency issue, as well as how these complex mode multiplexing techniques might improve the standard fiber-optic sensor approaches using single-mode fibers (SMF and photonic crystal fibers (PCF have also been summarized. Finally, we conclude with a prospective outlook for the opportunities and challenges of

  4. Advanced Spatial-Division Multiplexed Measurement Systems Propositions—From Telecommunication to Sensing Applications: A Review

    Science.gov (United States)

    Weng, Yi; Ip, Ezra; Pan, Zhongqi; Wang, Ting

    2016-01-01

    The concepts of spatial-division multiplexing (SDM) technology were first proposed in the telecommunications industry as an indispensable solution to reduce the cost-per-bit of optical fiber transmission. Recently, such spatial channels and modes have been applied in optical sensing applications where the returned echo is analyzed for the collection of essential environmental information. The key advantages of implementing SDM techniques in optical measurement systems include the multi-parameter discriminative capability and accuracy improvement. In this paper, to help readers without a telecommunication background better understand how the SDM-based sensing systems can be incorporated, the crucial components of SDM techniques, such as laser beam shaping, mode generation and conversion, multimode or multicore elements using special fibers and multiplexers are introduced, along with the recent developments in SDM amplifiers, opto-electronic sources and detection units of sensing systems. The examples of SDM-based sensing systems not only include Brillouin optical time-domain reflectometry or Brillouin optical time-domain analysis (BOTDR/BOTDA) using few-mode fibers (FMF) and the multicore fiber (MCF) based integrated fiber Bragg grating (FBG) sensors, but also involve the widely used components with their whole information used in the full multimode constructions, such as the whispering gallery modes for fiber profiling and chemical species measurements, the screw/twisted modes for examining water quality, as well as the optical beam shaping to improve cantilever deflection measurements. Besides, the various applications of SDM sensors, the cost efficiency issue, as well as how these complex mode multiplexing techniques might improve the standard fiber-optic sensor approaches using single-mode fibers (SMF) and photonic crystal fibers (PCF) have also been summarized. Finally, we conclude with a prospective outlook for the opportunities and challenges of SDM

  5. Survivable architectures for time and wavelength division multiplexed passive optical networks

    Science.gov (United States)

    Wong, Elaine

    2014-08-01

    The increased network reach and customer base of next-generation time and wavelength division multiplexed PON (TWDM-PONs) have necessitated rapid fault detection and subsequent restoration of services to its users. However, direct application of existing solutions for conventional PONs to TWDM-PONs is unsuitable as these schemes rely on the loss of signal (LOS) of upstream transmissions to trigger protection switching. As TWDM-PONs are required to potentially use sleep/doze mode optical network units (ONU), the loss of upstream transmission from a sleeping or dozing ONU could erroneously trigger protection switching. Further, TWDM-PONs require its monitoring modules for fiber/device fault detection to be more sensitive than those typically deployed in conventional PONs. To address the above issues, three survivable architectures that are compliant with TWDM-PON specifications are presented in this work. These architectures combine rapid detection and protection switching against multipoint failure, and most importantly do not rely on upstream transmissions for LOS activation. Survivability analyses as well as evaluations of the additional costs incurred to achieve survivability are performed and compared to the unprotected TWDM-PON. Network parameters that impact the maximum achievable network reach, maximum split ratio, connection availability, fault impact, and the incremental reliability costs for each proposed survivable architecture are highlighted.

  6. Penalty-free transmission at 10 Gbit/s through 40 cascaded 1-nm arrayed waveguide multiplexers

    DEFF Research Database (Denmark)

    Nissov, Morten; Jørgensen, Bo Foged; Pedersen, Rune Johan Skullerud

    1997-01-01

    Cascaded optical add-drop multiplexers (OADM) and optical cross connects (OXC) are key components in optical wavelength-division multiplex networks. OADMs with filtering of the passing signals and OXCs can be constructed by the use of wavelength-division multiplexers. Cascadability of multiplexers...

  7. A polarization-division multiplexing SSB-OFDM system with beat interference cancellation receivers

    Science.gov (United States)

    Yang, Peiling; Ma, Jianxin; Zhang, Junyi

    2018-06-01

    In this paper, we have proposed a polarization-division multiplexing (PDM) single-sideband optical orthogonal frequency division multiplexing (SSB-OOFDM) scheme with signal-signal beat interference cancellation receivers with balanced detection (ICRBD). This system can double channel capacity and improve spectrum efficiency (SE) with the reduced guard band (GB) due to the PDM. Multiple input multiple output (MIMO) technique is used to solve polarization mode dispersion (PMD) associated with channel estimation and equalization. By simulation, we demonstrate the efficacy of the proposed technique for a 2 ×40 Gbit/s 16-QAM SSB-PDM-OOFDM system according to the error vector magnitude (EVM) and the constellation diagrams.

  8. An analog method of cross-talk compensation for a RGB wavelength division multiplexed optical link

    Science.gov (United States)

    Chisholm, George; Leveneur, Jérôme; Futter, John; Kennedy, John

    2018-06-01

    Pulse-width modulation (PWM) over optical fiber can be a very advantageous data transmission approach when an electrically isolated data link is required. The use of wavelength division multiplexing allows multiple data streams to be sent through a single fiber independently. The present investigation aims to demonstrate a novel approach to reduce cross-talk in a three-channel RGB optical link without the need for complex optical componentry. An op-amp circuit is developed to reduce the cross-talk so that the resolution of the PWM data is preserved. An iterative Monte-Carlo simulation approach is used to optimize the op-amp circuit. The approach is developed for a set of three PWM Hall effect magnetometers with 12-bit resolution and 128 Hz sampling rate. We show that, in these conditions, the loss of resolution due to cross-talk is prevented. We also show that the cross-talk compensation allows the RGB PWM link to outperform other transmission schemes.

  9. 100G shortwave wavelength division multiplexing solutions for multimode fiber data links

    DEFF Research Database (Denmark)

    Cimoli, Bruno; Estaran Tolosa, Jose Manuel; Rodes Lopez, Guillermo Arturo

    2016-01-01

    We investigate an alternative 100G solution for optical short-range data center links. The presented solution adopts wavelength division multiplexing technology to transmit four channels of 25G over a multimode fiber. A comparative performance analysis of the wavelength-grid selection for the wav...

  10. Phased-array-based photonic integrated circuits for wavelength division multiplexing applications

    NARCIS (Netherlands)

    Staring, A.A.M.; Smit, M.K.

    1997-01-01

    Wavelength division multiplexing (WDM) technology provides many options to the design of flexible all-optical networks. In order to exploit these options to their full potential, photonic integrated circuits (PICs) for wavelength routing and switching will be indispensable. One of the basic building

  11. A Statically Scheduled Time-Division-Multiplexed Network-on-Chip for Real-Time Systems

    DEFF Research Database (Denmark)

    Schoeberl, Martin; Brandner, Florian; Sparsø, Jens

    2012-01-01

    This paper explores the design of a circuit-switched network-on-chip (NoC) based on time-division-multiplexing (TDM) for use in hard real-time systems. Previous work has primarily considered application-specific systems. The work presented here targets general-purpose hardware platforms. We...

  12. Power transients in time-division multiplexed discrete Raman fibre amplifier

    Czech Academy of Sciences Publication Activity Database

    Karásek, Miroslav; Radil, J.; Vojtěch, J.

    2009-01-01

    Roč. 282, č. 14 (2009), s. 2944-2949 ISSN 0030-4018 R&D Projects: GA AV ČR 1ET300670503 Institutional research plan: CEZ:AV0Z20670512 Keywords : optical communications * optical fibre * time division multiplexing Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.316, year: 2009

  13. High-Spatial-Multiplicity Multicore Fibers for Future Dense Space-Division-Multiplexing Systems

    DEFF Research Database (Denmark)

    Matsuo, Shoichiro; Takenaga, Katsuhiro; Sasaki, Yusuke

    2016-01-01

    Multicore fibers and few-mode fibers have potential application in realizing dense-space-division multiplexing systems. However, there are some tradeoff requirements for designing the fibers. In this paper, the tradeoff requirements such as spatial channel count, crosstalk, differential mode dela...

  14. Performance Analysis of Optical Code Division Multiplex System

    Science.gov (United States)

    Kaur, Sandeep; Bhatia, Kamaljit Singh

    2013-12-01

    This paper presents the Pseudo-Orthogonal Code generator for Optical Code Division Multiple Access (OCDMA) system which helps to reduce the need of bandwidth expansion and improve spectral efficiency. In this paper we investigate the performance of multi-user OCDMA system to achieve data rate more than 1 Tbit/s.

  15. Quantum metropolitan optical network based on wavelength division multiplexing.

    Science.gov (United States)

    Ciurana, A; Martínez-Mateo, J; Peev, M; Poppe, A; Walenta, N; Zbinden, H; Martín, V

    2014-01-27

    Quantum Key Distribution (QKD) is maturing quickly. However, the current approaches to its application in optical networks make it an expensive technology. QKD networks deployed to date are designed as a collection of point-to-point, dedicated QKD links where non-neighboring nodes communicate using the trusted repeater paradigm. We propose a novel optical network model in which QKD systems share the communication infrastructure by wavelength multiplexing their quantum and classical signals. The routing is done using optical components within a metropolitan area which allows for a dynamically any-to-any communication scheme. Moreover, it resembles a commercial telecom network, takes advantage of existing infrastructure and utilizes commercial components, allowing for an easy, cost-effective and reliable deployment.

  16. Quantum key distribution for 10 Gb/s dense wavelength division multiplexing networks

    International Nuclear Information System (INIS)

    Patel, K. A.; Dynes, J. F.; Lucamarini, M.; Choi, I.; Sharpe, A. W.; Yuan, Z. L.; Shields, A. J.; Penty, R. V.

    2014-01-01

    We demonstrate quantum key distribution (QKD) with bidirectional 10 Gb/s classical data channels in a single fiber using dense wavelength division multiplexing. Record secure key rates of 2.38 Mbps and fiber distances up to 70 km are achieved. Data channels are simultaneously monitored for error-free operation. The robustness of QKD is further demonstrated with a secure key rate of 445 kbps over 25 km, obtained in the presence of data lasers launching conventional 0 dBm power. We discuss the fundamental limit for the QKD performance in the multiplexing environment

  17. In-plane wavelength division de-multiplexing using photonic crystals

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Harpøth, Anders; Hede, K. K.

    We demonstrate a novel concept for in-plane coarse wavelength division de-multiplexing in integrated photonic circuits utilizing planar photonic crystal waveguides (PhCWs) fabricated in a silicon-on-insulator material. The filtering of wavelength channels is realized by shifting the cut......-off frequency of the fundamental photonic bandgap mode. The shift is obtained by modifying the size of the border holes in consecutive sections of the PhCW1. Simulations and experimental proof-of-principle of the four-channel de-multiplexer will be presented. 1A. Adibi et al., Electron. Lett. 36, 1376...

  18. Synchronization, retiming and time-division multiplexing of an asynchronous 10 gigabit NRZ Ethernet packet to Terabit Ethernet

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Mulvad, Hans Christian Hansen

    2011-01-01

    An asynchronous 10 Gb/s Ethernet packet with maximum packet size of 1518 bytes is synchronized and retimed to a master clock with 200 kHz frequency offset using a time lens. The NRZ packet is simultaneously converted into an RZ packet, then further pulse compressed to a FWHM of 400 fs and finally...... time-division multiplexed with a serial 1.28 Tb/s signal including a vacant time slot, thus forming a 1.29 Tb/s time-division multiplexed serial signal. Error-free performance of synchronizing, retiming, time-division multiplexing to a Terabit data stream and finally demultiplexing back to 10 Gb...

  19. Single-mode multicore fiber for dense space division multiplexing

    DEFF Research Database (Denmark)

    Sasaki, Yusuke; Amma, Yoshimichi; Takenaga, Katsuhiro

    2016-01-01

    Single-mode multicore fiber (SM-MCF) is attractive for high-capacity transmission. Our fabricated SM-MCFs achieve high core count and low crosstalk with a cladding diameter of 230 µm. Characteristics of fan-in/fan-out for the SM-MCFs are also investigated....

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

    DEFF Research Database (Denmark)

    2014-01-01

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

  1. Novel Equalization Techniques for Space Division Multiplexing Based on Stokes Space Update Rule

    Directory of Open Access Journals (Sweden)

    Francisco Javier Vaquero Caballero

    2017-02-01

    Full Text Available Space division multiplexing (SDM is a promising technology that aims to overcome the capacity crunch of optical communications. In this paper, we introduce the multiple-input multiple-output (MIMO Stokes Space Algorithm (SSA implemented in frequency domain, a novel equalization technique for space division multiplexing (SDM. Although different papers have been published about the SSA and its MIMO implementation, we provide for the first time an analysis of the of the convergence speed and frequency offset of the SSA compared to the least mean square (LMS. SSA algorithm can deal with higher frequency offsets and linewidths than LMS, being suitable for optical communications with higher phase noise. SSA does not need pre-compensation of frequency offset, which can be compensated after equalization without penalties. On the other hand, due to reduced convergence speed, SSA requires longer training sequences than LMS.

  2. Visible Wavelength Division Multiplex System for use as a Instructional Lab System for Higher Education

    OpenAIRE

    Fischer, Ulrich H. P.; Schmidt, Michael; Volmer, Tino; Weigl, Bjoern; Just, Jens-Uwe

    2007-01-01

    The demand for high-speed digital communication such as data, video, and the broadband Internet increases, the required throughput of the modules in communications systems will also increase. In this paper we present an instruction system, which works on the basis of a wavelength division multiplex (WDM) system in the visible spectrum. It is specialised for the academic training at universities to demonstrate the principles of the WDM techniques. It works platform independent in combination w...

  3. Simulation Performance of Multiple-Input Multiple-Output Systems Employing Single-Carrier Modulation and Orthogonal Frequency Division Multiplexing

    National Research Council Canada - National Science Library

    Saglam, Halil D

    2004-01-01

    ...) systems utilizing Alamouti-based space-time block coding (STBC) technique. The MIMO communication systems using STBC technique employing both single-carrier modulation and orthogonal frequency division multiplexing (OFDM...

  4. Threshold-Based Multiple Optical Signal Selection Scheme for Free-Space Optical Wavelength Division Multiplexing Systems

    KAUST Repository

    Nam, Sung Sik; Alouini, Mohamed-Slim; Zhang, Lin; Ko, Young-Chai

    2017-01-01

    We propose a threshold-based multiple optical signal selection scheme (TMOS) for free-space optical wavelength division multiplexing systems. With this scheme, we can obtain higher spectral efficiency while reducing the possible complexity

  5. Improved Encrypted-Signals-Based Reversible Data Hiding Using Code Division Multiplexing and Value Expansion

    Directory of Open Access Journals (Sweden)

    Xianyi Chen

    2018-01-01

    Full Text Available Compared to the encrypted-image-based reversible data hiding (EIRDH method, the encrypted-signals-based reversible data hiding (ESRDH technique is a novel way to achieve a greater embedding rate and better quality of the decrypted signals. Motivated by ESRDH using signal energy transfer, we propose an improved ESRDH method using code division multiplexing and value expansion. At the beginning, each pixel of the original image is divided into several parts containing a little signal and multiple equal signals. Next, all signals are encrypted by Paillier encryption. And then a large number of secret bits are embedded into the encrypted signals using code division multiplexing and value expansion. Since the sum of elements in any spreading sequence is equal to 0, lossless quality of directly decrypted signals can be achieved using code division multiplexing on the encrypted equal signals. Although the visual quality is reduced, high-capacity data hiding can be accomplished by conducting value expansion on the encrypted little signal. The experimental results show that our method is better than other methods in terms of the embedding rate and average PSNR.

  6. Dense Wavelength Division (De Multiplexers Based on Fiber Bragg Gratings

    Directory of Open Access Journals (Sweden)

    S. BENAMEUR

    2014-05-01

    Full Text Available This study is to measure the impact of demultiplexers based on Fiber Bragg Grating (FBG filter on performance of DWDM system for optical access network. An optical transmission link has been established in which we have inserted a demultiplexer based on four different FBG filters. The first step will be the characterization of FBG’s filters (i.e. uniform FBG, Gaussian apodized Grating, chirped FBG to explain their behavior in the optical link. The simulations were conducted for different fiber’s lengths, filter bandwidth and different received power to get the best system performance. This helped to assess their impact on the link performance in terms of Bit Error Rate (BER.

  7. Stresses and Temperature Stability of Dense Wavelength Division Multiplexing Filters Prepared by Reactive Ion-Assisted E-Gun Evaporation

    Science.gov (United States)

    Wei, Chao-Tsang; Shieh, Han-Ping D.

    2005-10-01

    In this paper, we report the in situ measurement of the temperature stability of narrow-band-pass filters on different types of substrate, for dense wavelength division multiplexing (DWDM) filters in optical-fiber transmission systems. The DWDM filters were designed as all-dielectric Fabry-Perot filters and fabricated by reactive ion-assisted deposition. Ta2O5 and SiO2 were used as high- and low-refractive-index layers, respectively, for constructing the DWDM filters. The accuracy and stability of the coating process were evaluated for fabricating the DWDM filters for the temperature stability of the center wavelength. The center wavelength shift was determined to be greatly dependent on the coefficient of thermal expansion of the substrate on which the filter is deposited.

  8. Mode-multiplexed transmission over conventional graded-index multimode fibers

    NARCIS (Netherlands)

    Ryf, R.; Fontaine, N.K.; Chen, H.; Guan, B.; Huang, B.; Esmaeelpour, M.; Gnauck, A.H.; Randel, S.; Yoo, S.J.B.; Koonen, A.M.J.; Shubochkin, R.; Sun, Yi; Lingle, R.

    2015-01-01

    We present experimental results for combined mode-multiplexed and wavelength multiplexed transmission over conventional graded-index multimode fibers. We use mode-selective photonic lanterns as mode couplers to precisely excite a subset of the modes of the multimode fiber and additionally to

  9. Shared protection based virtual network mapping in space division multiplexing optical networks

    Science.gov (United States)

    Zhang, Huibin; Wang, Wei; Zhao, Yongli; Zhang, Jie

    2018-05-01

    Space Division Multiplexing (SDM) has been introduced to improve the capacity of optical networks. In SDM optical networks, there are multiple cores/modes in each fiber link, and spectrum resources are multiplexed in both frequency and core/modes dimensions. Enabled by network virtualization technology, one SDM optical network substrate can be shared by several virtual networks operators. Similar with point-to-point connection services, virtual networks (VN) also need certain survivability to guard against network failures. Based on customers' heterogeneous requirements on the survivability of their virtual networks, this paper studies the shared protection based VN mapping problem and proposes a Minimum Free Frequency Slots (MFFS) mapping algorithm to improve spectrum efficiency. Simulation results show that the proposed algorithm can optimize SDM optical networks significantly in terms of blocking probability and spectrum utilization.

  10. Direction-division multiplexed holographic free-electron-driven light sources

    Science.gov (United States)

    Clarke, Brendan P.; MacDonald, Kevin F.; Zheludev, Nikolay I.

    2018-01-01

    We report on a free-electron-driven light source with a controllable direction of emission. The source comprises a microscopic array of plasmonic surface-relief holographic domains, each tailored to direct electron-induced light emission at a selected wavelength into a collimated beam in a prescribed direction. The direction-division multiplexed source is tested by driving it with the 30 kV electron beam of a scanning electron microscope: light emission, at a wavelength of 800 nm in the present case, is switched among different output angles by micron-scale repositioning of the electron injection point among domains. Such sources, with directional switching/tuning possible at picosecond timescales, may be applied to field-emission and surface-conduction electron-emission display technologies, optical multiplexing, and charged-particle-beam position metrology.

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

    Science.gov (United States)

    Xin, Wei

    1997-10-01

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

  12. Interfacing Hardware Accelerators to a Time-Division Multiplexing Network-on-Chip

    DEFF Research Database (Denmark)

    Pezzarossa, Luca; Sørensen, Rasmus Bo; Schoeberl, Martin

    2015-01-01

    This paper addresses the integration of stateless hardware accelerators into time-predictable multi-core platforms based on time-division multiplexing networks-on-chip. Stateless hardware accelerators, like floating-point units, are typically attached as co-processors to individual processors in ...... implementation. The design evaluation is carried out using the open source T-CREST multi-core platform implemented on an Altera Cyclone IV FPGA. The size of the proposed design, including a floating-point accelerator, is about two-thirds of a processor....

  13. The performance of orthogonal frequency division multiplexing in the weak turbulence regime of free space optics communication systems

    International Nuclear Information System (INIS)

    Selvi, M; Murugesan, K

    2012-01-01

    Radio on free space optics—RoFSO—has gained momentum in research because of its cost effectiveness and efficiency in transferring data at a high rate that is comparable to that for optical fiber media. While the transmission data rate is limited in fiber due to dispersion and nonlinearity, such effects do not prevail in FSO communication links. The data rate depends mainly on the switching speed of the optoelectronic devices. With the characteristics of free space being random in nature, the performance of RoFSO is primarily governed by atmospheric conditions. In this paper, we evaluate the performance of the orthogonal frequency division multiplexing (OFDM) signal in free space and compare against its counterpart radio frequency (RF) wireless communication systems. Simulations have been done on the atmospheric conditions by means of modeling the scintillation effect using log-normal distribution. The performance of the proposed system under two different base-band modulations, namely OFDM–PSK (phase shift keying) and QAM (quadrature amplitude modulation) in weak turbulence conditions is studied. It is found that PSK performs better than QAM. Also the M-ary performance analysis shows that 3–5 dB improvement in the signal to noise ratio is obtained for OFDM based FSO transmission compared to RF based wireless transmission. (paper)

  14. Demonstration of an 8 × 25-Gb/s optical time-division multiplexing system

    Science.gov (United States)

    Wang, Dong; Huo, Li; Li, Yunbo; Wang, Lei; Li, Han; Jiang, Xiangyu; Chen, Xin; Lou, Caiyun

    2017-11-01

    An 8 × 25-Gb/s optical time-division multiplexing (OTDM) system is demonstrated experimentally. The optical pulse source is based on optical frequency comb (OFC) generation and pulse shaping, which can generate nearly chirp-free 25-GHz 1.6-ps optical Gaussian pulse. The eightfold optical time-division demultiplexer consists of a single-driven dual-parallel Mach-Zehnder modulator (DPMZM) and a Mamyshev reshaper. Error-free demultiplexing of 8 × 25-Gb/s back-to-back (B2B) signal with a power penalty of 4.1 dB to 4.4 dB at a bit error rate (BER) of 10-9 is achieved to confirm the performance of the proposed system.

  15. Eliminating four-wave-mixing crosstalk in wavelength-division-multiplexing systems

    Science.gov (United States)

    Kwong, Wing C.; Yang, Guu-Chang

    1996-11-01

    To reduce four-wave-mixing crosstalk in long-haul wavelength-division multiplexing (WDM) lightwave systems, the use of unequally spaced channels has recently been proposed. Instead of being solved y integer linear programming, the unequal-spaced channel-allocation problem is here treated as constructing suitable optical orthogonal codes in optical code-division multiple-access (CDMA). Three 'algebraic' algorithms on finding the frequency locations of unequally spaced WDM channels are reported. The constructions are based on generating optical CDMA codewords with a predetermined pulse separation and 'aperiodic' autocorrelation sidelobes no greater than one. The algorithms potentially provide a fast and simple alternative to solve the problem, besides the recently reported computer-search method.

  16. Rapid, Time-Division Multiplexed, Direct Absorption- and Wavelength Modulation-Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alexander Klein

    2014-11-01

    Full Text Available We present a tunable diode laser spectrometer with a novel, rapid time multiplexed direct absorption- and wavelength modulation-spectroscopy operation mode. The new technique allows enhancing the precision and dynamic range of a tunable diode laser absorption spectrometer without sacrificing accuracy. The spectroscopic technique combines the benefits of absolute concentration measurements using calibration-free direct tunable diode laser absorption spectroscopy (dTDLAS with the enhanced noise rejection of wavelength modulation spectroscopy (WMS. In this work we demonstrate for the first time a 125 Hz time division multiplexed (TDM-dTDLAS-WMS spectroscopic scheme by alternating the modulation of a DFB-laser between a triangle-ramp (dTDLAS and an additional 20 kHz sinusoidal modulation (WMS. The absolute concentration measurement via the dTDLAS-technique allows one to simultaneously calibrate the normalized 2f/1f-signal of the WMS-technique. A dTDLAS/WMS-spectrometer at 1.37 µm for H2O detection was built for experimental validation of the multiplexing scheme over a concentration range from 50 to 3000 ppmV (0.1 MPa, 293 K. A precision of 190 ppbV was achieved with an absorption length of 12.7 cm and an averaging time of two seconds. Our results show a five-fold improvement in precision over the entire concentration range and a significantly decreased averaging time of the spectrometer.

  17. Dense wavelength division multiplexing devices for metropolitan-area datacom and telecom networks

    Science.gov (United States)

    DeCusatis, Casimer M.; Priest, David G.

    2000-12-01

    Large data processing environments in use today can require multi-gigabyte or terabyte capacity in the data communication infrastructure; these requirements are being driven by storage area networks with access to petabyte data bases, new architecture for parallel processing which require high bandwidth optical links, and rapidly growing network applications such as electronic commerce over the Internet or virtual private networks. These datacom applications require high availability, fault tolerance, security, and the capacity to recover from any single point of failure without relying on traditional SONET-based networking. These requirements, coupled with fiber exhaust in metropolitan areas, are driving the introduction of dense optical wavelength division multiplexing (DWDM) in data communication systems, particularly for large enterprise servers or mainframes. In this paper, we examine the technical requirements for emerging nextgeneration DWDM systems. Protocols for storage area networks and computer architectures such as Parallel Sysplex are presented, including their fiber bandwidth requirements. We then describe two commercially available DWDM solutions, a first generation 10 channel system and a recently announced next generation 32 channel system. Technical requirements, network management and security, fault tolerant network designs, new network topologies enabled by DWDM, and the role of time division multiplexing in the network are all discussed. Finally, we present a description of testing conducted on these networks and future directions for this technology.

  18. Effect of Shot Noise on Simultaneous Sensing in Frequency Division Multiplexed Diffuse Optical Tomographic Imaging Process.

    Science.gov (United States)

    Jang, Hansol; Lim, Gukbin; Hong, Keum-Shik; Cho, Jaedu; Gulsen, Gultekin; Kim, Chang-Seok

    2017-11-28

    Diffuse optical tomography (DOT) has been studied for use in the detection of breast cancer, cerebral oxygenation, and cognitive brain signals. As optical imaging studies have increased significantly, acquiring imaging data in real time has become increasingly important. We have developed frequency-division multiplexing (FDM) DOT systems to analyze their performance with respect to acquisition time and imaging quality, in comparison with the conventional time-division multiplexing (TDM) DOT. A large tomographic area of a cylindrical phantom 60 mm in diameter could be successfully reconstructed using both TDM DOT and FDM DOT systems. In our experiment with 6 source-detector (S-D) pairs, the TDM DOT and FDM DOT systems required 6.18 and 1 s, respectively, to obtain a single tomographic data set. While the absorption coefficient of the reconstruction image was underestimated in the case of the FDM DOT, we experimentally confirmed that the abnormal region can be clearly distinguished from the background phantom using both methods.

  19. Enhanced Next Generation Millimeter-Wave Multicarrier System with Generalized Frequency Division Multiplexing

    Directory of Open Access Journals (Sweden)

    Hidekazu Shimodaira

    2016-01-01

    Full Text Available Orthogonal Frequency Division Multiplexing (OFDM is a popular multicarrier technique used to attain high spectral efficiencies. It also has other advantages such as multipath tolerance and ease of implementation. However, OFDM based systems suffer from high Peak-to-Average Power Ratio (PAPR problem. Because of the nonlinearity of the power amplifiers, the high PAPR causes significant distortion in the transmitted signal for millimeter-wave (mmWave systems. To alleviate the high PAPR problem, this paper utilizes Generalized Frequency Division Multiplexing (GFDM which can achieve high spectral efficiency as well as low PAPR. In this paper, we show the performance of GFDM using the IEEE 802.11ad multicarrier frame structures. IEEE 802.11ad is considered one of the most successful industry standards utilizing unlicensed mmWave frequency band. In addition, this paper indicates the feasibility of using GFDM for the future standards such as IEEE 802.11ay. This paper studies the performance improvements in terms of PAPR reduction for GFDM. Based on the performance results, the optimal numbers of subcarriers and subsymbols are calculated for PAPR reduction while minimizing the Bit Error Rate (BER performance degradation. Moreover, transmitter side ICI (Intercarrier Interference reduction is introduced to reduce the receiver load.

  20. Effect of Shot Noise on Simultaneous Sensing in Frequency Division Multiplexed Diffuse Optical Tomographic Imaging Process

    Directory of Open Access Journals (Sweden)

    Hansol Jang

    2017-11-01

    Full Text Available Diffuse optical tomography (DOT has been studied for use in the detection of breast cancer, cerebral oxygenation, and cognitive brain signals. As optical imaging studies have increased significantly, acquiring imaging data in real time has become increasingly important. We have developed frequency-division multiplexing (FDM DOT systems to analyze their performance with respect to acquisition time and imaging quality, in comparison with the conventional time-division multiplexing (TDM DOT. A large tomographic area of a cylindrical phantom 60 mm in diameter could be successfully reconstructed using both TDM DOT and FDM DOT systems. In our experiment with 6 source-detector (S-D pairs, the TDM DOT and FDM DOT systems required 6.18 and 1 s, respectively, to obtain a single tomographic data set. While the absorption coefficient of the reconstruction image was underestimated in the case of the FDM DOT, we experimentally confirmed that the abnormal region can be clearly distinguished from the background phantom using both methods.

  1. Ultra high speed optical transmission using subcarrier-multiplexed four-dimensional LDPC-coded modulation.

    Science.gov (United States)

    Batshon, Hussam G; Djordjevic, Ivan; Schmidt, Ted

    2010-09-13

    We propose a subcarrier-multiplexed four-dimensional LDPC bit-interleaved coded modulation scheme that is capable of achieving beyond 480 Gb/s single-channel transmission rate over optical channels. Subcarrier-multiplexed four-dimensional LDPC coded modulation scheme outperforms the corresponding dual polarization schemes by up to 4.6 dB in OSNR at BER 10(-8).

  2. On the Efficient Broadcasting of Heterogeneous Services over Band-Limited Channels: Unequal Power Allocation for Wavelet Packet Division Multiplexing

    Directory of Open Access Journals (Sweden)

    Maurizio Murroni

    2008-01-01

    Full Text Available Multiple transmission of heterogeneous services is a central aspect of broadcasting technology. Often, in this framework, the design of efficient communication systems is complicated by stringent bandwidth constraint. In wavelet packet division multiplexing (WPDM, the message signals are waveform coded onto wavelet packet basis functions. The overlapping nature of such waveforms in both time and frequency allows improving the performance over the commonly used FDM and TDM schemes, while their orthogonality properties permit to extract the message signals by a simple correlator receiver. Furthermore, the scalable structure of WPDM makes it suitable for broadcasting heterogeneous services. This work investigates unequal error protection (UEP of data which exhibit different sensitivities to channel errors to improve the performance of WPDM for transmission over band-limited channels. To cope with bandwidth constraint, an appropriate distribution of power among waveforms is proposed which is driven by the channel error sensitivities of the carried message signals in case of Gaussian noise. We address this problem by means of the genetic algorithms (GAs, which allow flexible suboptimal solution with reduced complexity. The mean square error (MSE between the original and the decoded message, which has a strong correlation with subjective perception, is used as an optimization criterion.

  3. Group-Orthogonal Code-Division Multiplex: A Physical-Layer Enhancement for IEEE 802.11n Networks

    Directory of Open Access Journals (Sweden)

    Felip Riera-Palou

    2010-01-01

    Full Text Available The new standard for wireless local area networks (WLANs, named IEEE 802.11n, has been recently released. This new norm builds upon and remains compatible with the previous WLANs standards IEEE 802.11a/g while it is able to achieve transmission rates of up to 600 Mbps. These increased data rates are mainly a consequence of two important new features: (1 multiple antenna technology at transmission and reception, and (2 optional doubling of the system bandwidth thanks to the availability of an additional 20 MHz band. This paper proposes the use of Group-Orthogonal Code Division Multiplex (GO-CDM as a means to improve the performance of the 802.11n standard by further exploiting the inherent frequency diversity. It is explained why GO-CDM synergistically matches with the two aforementioned new features and the performance gains it can offer under different configurations is illustrated. Furthermore, the effects that group-orthogonal has on key implementation issues such as channel estimation, carrier frequency offset, and peak-to-average power ratio (PAPR are also considered.

  4. Three-Phase Time-Multiplexed Planar Power Transmission to Distributed Implants.

    Science.gov (United States)

    Lee, Byunghun; Ahn, Dukju; Ghovanloo, Maysam

    2016-03-01

    A platform has been presented for wireless powering of receivers (Rx's) that are arbitrarily distributed over a large area. A potential application could be powering of small Rx implants, distributed over large areas of the brain. The transmitter (Tx) consists of three overlapping layers of hexagonal planar spiral coils (hex-PSC) that are horizontally shifted to provide the strongest and most homogeneous electromagnetic flux coverage. The three-layer hex-PSC array is driven by a three-phase time-division-multiplexed power Tx that takes the advantage of the carrier phase shift, coil geometries, and Rx time constant to homogeneously power the arbitrarily distributed Rx's regardless of their misalignments. The functionality of the proposed three-phase power transmission concept has been verified in a detailed scaled-up high-frequency structure simulator Advanced Design System simulation model and measurement setup, and compared with a conventional Tx. The new Tx delivers 5.4 mW to each Rx and achieves, on average, 5.8% power transfer efficiency to the Rx at the worst case 90° angular misalignment, compared with 1.4% by the conventional Tx.

  5. A Study of Dispersion Compensation of Polarization Multiplexing-Based OFDM-OCDMA for Radio-over-Fiber Transmissions.

    Science.gov (United States)

    Yen, Chih-Ta; Chen, Wen-Bin

    2016-09-07

    Chromatic dispersion from optical fiber is the most important problem that produces temporal skews and destroys the rectangular structure of code patterns in the spectra-amplitude-coding-based optical code-division multiple-access (SAC-OCDMA) system. Thus, the balance detection scheme does not work perfectly to cancel multiple access interference (MAI) and the system performance will be degraded. Orthogonal frequency-division multiplexing (OFDM) is the fastest developing technology in the academic and industrial fields of wireless transmission. In this study, the radio-over-fiber system is realized by integrating OFDM and OCDMA via polarization multiplexing scheme. The electronic dispersion compensation (EDC) equalizer element of OFDM integrated with the dispersion compensation fiber (DCF) is used in the proposed radio-over-fiber (RoF) system, which can efficiently suppress the chromatic dispersion influence in long-haul transmitted distance. A set of length differences for 10 km-long single-mode fiber (SMF) and 4 km-long DCF is to verify the compensation scheme by relative equalizer algorithms and constellation diagrams. In the simulation result, the proposed dispersion mechanism successfully compensates the dispersion from SMF and the system performance with dispersion equalizer is highly improved.

  6. A Study of Dispersion Compensation of Polarization Multiplexing-Based OFDM-OCDMA for Radio-over-Fiber Transmissions

    Directory of Open Access Journals (Sweden)

    Chih-Ta Yen

    2016-09-01

    Full Text Available Chromatic dispersion from optical fiber is the most important problem that produces temporal skews and destroys the rectangular structure of code patterns in the spectra-amplitude-coding-based optical code-division multiple-access (SAC-OCDMA system. Thus, the balance detection scheme does not work perfectly to cancel multiple access interference (MAI and the system performance will be degraded. Orthogonal frequency-division multiplexing (OFDM is the fastest developing technology in the academic and industrial fields of wireless transmission. In this study, the radio-over-fiber system is realized by integrating OFDM and OCDMA via polarization multiplexing scheme. The electronic dispersion compensation (EDC equalizer element of OFDM integrated with the dispersion compensation fiber (DCF is used in the proposed radio-over-fiber (RoF system, which can efficiently suppress the chromatic dispersion influence in long-haul transmitted distance. A set of length differences for 10 km-long single-mode fiber (SMF and 4 km-long DCF is to verify the compensation scheme by relative equalizer algorithms and constellation diagrams. In the simulation result, the proposed dispersion mechanism successfully compensates the dispersion from SMF and the system performance with dispersion equalizer is highly improved.

  7. Time-Predictable Communication on a Time-Division Multiplexing Network-on-Chip Multicore

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Bo

    This thesis presents time-predictable inter-core communication on a multicore platform with a time-division multiplexing (TDM) network-on-chip (NoC) for hard real-time systems. The thesis is structured as a collection of papers that contribute within the areas of: reconfigurable TDM NoCs, static...... TDM scheduling, and time-predictable inter-core communication. More specifically, the work presented in this thesis investigates the interaction between hardware and software involved in time-predictable inter-core communication on the multicore platform. The thesis presents: a new generation...... of the Argo NoC network interface (NI) that supports instantaneous reconfiguration, a TDM traffic scheduler that generates virtual circuit (VC) configurations for the Argo NoC, and software functions for two types of intercore communication. The new generation of the Argo NoC adds the capability...

  8. Distributed MIMO chaotic radar based on wavelength-division multiplexing technology.

    Science.gov (United States)

    Yao, Tingfeng; Zhu, Dan; Ben, De; Pan, Shilong

    2015-04-15

    A distributed multiple-input multiple-output chaotic radar based on wavelength-division multiplexing technology (WDM) is proposed and demonstrated. The wideband quasi-orthogonal chaotic signals generated by different optoelectronic oscillators (OEOs) are emitted by separated antennas to gain spatial diversity against the fluctuation of a target's radar cross section and enhance the detection capability. The received signals collected by the receive antennas and the reference signals from the OEOs are delivered to the central station for joint processing by exploiting WDM technology. The centralized signal processing avoids precise time synchronization of the distributed system and greatly simplifies the remote units, which improves the localization accuracy of the entire system. A proof-of-concept experiment for two-dimensional localization of a metal target is demonstrated. The maximum position error is less than 6.5 cm.

  9. Increase of nonlinear signal distortions due to linear mode coupling in space division multiplexed systems

    DEFF Research Database (Denmark)

    Kutluyarov, Ruslan V.; Bagmanov, Valeriy Kh; Antonov, Vyacheslav V.

    2017-01-01

    This paper is focused on the analysis of linear and nonlinear mode coupling in space division multiplexed (SDM) optical communications over step-index fiber in few-mode regime. Linear mode coupling is caused by the fiber imperfections, while the nonlinear coupling is caused by the Kerr......-nonlinearities. Therefore, we use the system of generalized coupled nonlinear Schrödinger equations (GCNLSE) to describe the signal propagation. We analytically show that the presence of linear mode coupling may cause increasing of the nonlinear signal distortions. For the detailed study we solve GCNLSE numerically...... for the standard step index fiber at the wavelength of 850 nm in the basis of spatial modes with helical phase front (vortex modes) and for a special kind of few-mode fiber with enlarged core, providing propagation of five spatial modes at 1550 nm. Simulation results confirm that the linear mode coupling may lead...

  10. Dynamic segment shared protection for multicast traffic in meshed wavelength-division-multiplexing optical networks

    Science.gov (United States)

    Liao, Luhua; Li, Lemin; Wang, Sheng

    2006-12-01

    We investigate the protection approach for dynamic multicast traffic under shared risk link group (SRLG) constraints in meshed wavelength-division-multiplexing optical networks. We present a shared protection algorithm called dynamic segment shared protection for multicast traffic (DSSPM), which can dynamically adjust the link cost according to the current network state and can establish a primary light-tree as well as corresponding SRLG-disjoint backup segments for a dependable multicast connection. A backup segment can efficiently share the wavelength capacity of its working tree and the common resources of other backup segments based on SRLG-disjoint constraints. The simulation results show that DSSPM not only can protect the multicast sessions against a single-SRLG breakdown, but can make better use of the wavelength resources and also lower the network blocking probability.

  11. Filter multiplexing by use of spatial Code Division Multiple Access approach.

    Science.gov (United States)

    Solomon, Jonathan; Zalevsky, Zeev; Mendlovic, David; Monreal, Javier Garcia

    2003-02-10

    The increasing popularity of optical communication has also brought a demand for a broader bandwidth. The trend, naturally, was to implement methods from traditional electronic communication. One of the most effective traditional methods is Code Division Multiple Access. In this research, we suggest the use of this approach for spatial coding applied to images. The approach is to multiplex several filters into one plane while keeping their mutual orthogonality. It is shown that if the filters are limited by their bandwidth, the output of all the filters can be sampled in the original image resolution and fully recovered through an all-optical setup. The theoretical analysis of such a setup is verified in an experimental demonstration.

  12. Quasidistributed temperature sensor based on dense wavelength-division multiplexing optical fiber delay

    Science.gov (United States)

    Su, Jun; Yang, Ning; Fan, Zhiqiang; Qiu, Qi

    2017-10-01

    We report on a fiber-optic delay-based quasidistributed temperature sensor with high precision. The device works by detecting the delay induced by the temperature instead of the spectrum. To analyze the working principle of this sensor, the thermal dependence of the fiber-optic delay was theoretically investigated and the delay-temperature coefficient was measured to be 42.2 ps/km°C. In this sensor, quasidistributed measurement of temperature could be easily realized by dense wavelength-division multiplexing and wavelength addressing. We built and tested a prototype quasidistributed temperature sensor with eight testing points equally distributed along a 32.61-km-long fiber. The experimental results demonstrate an average error of economic temperature measurements.

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

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia; Sparsø, Jens

    2014-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  15. Feasibility of quantum key distribution through a dense wavelength division multiplexing network

    International Nuclear Information System (INIS)

    Qi Bing; Qian Li; Lo, Hoi-Kwong; Zhu Wen

    2010-01-01

    In this paper, we study the feasibility of conducting quantum key distribution (QKD) together with classical communication through the same optical fiber by employing dense-wavelength-division-multiplexing (DWDM) technology at telecom wavelength. The impact of classical channels on the quantum channel has been investigated for both QKD based on single-photon detection and QKD based on homodyne detection. Our studies show that the latter can tolerate a much higher level of contamination from classical channels than the former. This is because the local oscillator used in the homodyne detector acts as a 'mode selector', which can suppress noise photons effectively. We have performed simulations based on both the decoy BB84 QKD protocol and the Gaussian-modulated coherent state (GMCS) QKD protocol. While the former cannot tolerate even one classical channel (with a power of 0 dBm), the latter can be multiplexed with 38 classical channels (0 dBm power per channel) and still has a secure distance around 10 km. A preliminary experiment has been conducted based on a 100 MHz bandwidth homodyne detector.

  16. Modular time division multiplexer: Efficient simultaneous characterization of fast and slow transients in multiple samples

    Science.gov (United States)

    Kim, Stephan D.; Luo, Jiajun; Buchholz, D. Bruce; Chang, R. P. H.; Grayson, M.

    2016-09-01

    A modular time division multiplexer (MTDM) device is introduced to enable parallel measurement of multiple samples with both fast and slow decay transients spanning from millisecond to month-long time scales. This is achieved by dedicating a single high-speed measurement instrument for rapid data collection at the start of a transient, and by multiplexing a second low-speed measurement instrument for slow data collection of several samples in parallel for the later transients. The MTDM is a high-level design concept that can in principle measure an arbitrary number of samples, and the low cost implementation here allows up to 16 samples to be measured in parallel over several months, reducing the total ensemble measurement duration and equipment usage by as much as an order of magnitude without sacrificing fidelity. The MTDM was successfully demonstrated by simultaneously measuring the photoconductivity of three amorphous indium-gallium-zinc-oxide thin films with 20 ms data resolution for fast transients and an uninterrupted parallel run time of over 20 days. The MTDM has potential applications in many areas of research that manifest response times spanning many orders of magnitude, such as photovoltaics, rechargeable batteries, amorphous semiconductors such as silicon and amorphous indium-gallium-zinc-oxide.

  17. Multi element synthetic aperture transmission using a frequency division approach

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt

    2003-01-01

    transmitted into the tissue is low. This paper describes a novel method in which the available spectrum is divided into 2N overlapping subbands. This will assure a smooth broadband high resolution spectrum when combined. The signals are grouped into two subsets in which all signals are fully orthogonal...... can therefore be used for flow imaging, unlike with Hadamard and Golay coding. The frequency division approach increases the SNR by a factor of N2 compared to conventional pulsed synthetic aperture imaging, provided that N transmission centers are used. Simulations and phantom measurements...

  18. Low-latency optical parallel adder based on a binary decision diagram with wavelength division multiplexing scheme

    Science.gov (United States)

    Shinya, A.; Ishihara, T.; Inoue, K.; Nozaki, K.; Kita, S.; Notomi, M.

    2018-02-01

    We propose an optical parallel adder based on a binary decision diagram that can calculate simply by propagating light through electrically controlled optical pass gates. The CARRY and CARRY operations are multiplexed in one circuit by a wavelength division multiplexing scheme to reduce the number of optical elements, and only a single gate constitutes the critical path for one digit calculation. The processing time reaches picoseconds per digit when we use a 100-μm-long optical path gates, which is ten times faster than a CMOS circuit.

  19. New Compensation Technique for Fiber Impairments in Ultra High Capacity Super channel Based on (QDPASK Dense wavelength division multiplex (DWDM systems

    Directory of Open Access Journals (Sweden)

    Ibrahim A.Murdas

    2017-07-01

    Full Text Available In this paper we want to increase the data rate and to get larger transmission distance, therefore we use the Advanced modulation technique QDPASK in DWDM system with low channels space. In case of long transmission distance and multi channels system both giving rise to inter channel crosstalk induced by fiber nonlinearities as a result the use of advanced modulation technique becomes difficult. In this paper Quaternary differential phase amplitude shift keying (QDPASK is designed for 32 dense wavelength division multiplexing (DWDM channels, therefore we proposed a new cascade compensation system consist of optical and digital back propagation techniques (ODBP for compensate the linear and nonlinear effects . A performance of the system was reported using QDPASK DWDM fiber-optic system for various system parameters. The research is tested in VPI maker environment.

  20. Coherent optical DFT-spread OFDM transmission using orthogonal band multiplexing.

    Science.gov (United States)

    Yang, Qi; He, Zhixue; Yang, Zhu; Yu, Shaohua; Yi, Xingwen; Shieh, William

    2012-01-30

    Coherent optical OFDM (CO-OFDM) combined with orthogonal band multiplexing provides a scalable and flexible solution for achieving ultra high-speed rate. Among many CO-OFDM implementations, digital Fourier transform spread (DFT-S) CO-OFDM is proposed to mitigate fiber nonlinearity in long-haul transmission. In this paper, we first illustrate the principle of DFT-S OFDM. We then experimentally evaluate the performance of coherent optical DFT-S OFDM in a band-multiplexed transmission system. Compared with conventional clipping methods, DFT-S OFDM can reduce the OFDM peak-to-average power ratio (PAPR) value without suffering from the interference of the neighboring bands. With the benefit of much reduced PAPR, we successfully demonstrate 1.45 Tb/s DFT-S OFDM over 480 km SSMF transmission.

  1. Subcarrier multiplexing tolerant dispersion transmission system employing optical broadband sources.

    Science.gov (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José

    2009-03-16

    This paper presents a novel SCM optical transmission system for next-generation WDM-PONs combining broadband optical sources and a Mach-Zehnder interferometric structure. The approach leeds to transport RF signals up to 50 GHz being compatible with RoF systems since a second configuration has been proposed in order to overcome dispersion carrier suppression effect using DSB modulation. The theoretical analysis validates the potentiality of the system also considering the effects of the dispersion slope over the transmission window. (c) 2009 Optical Society of America

  2. Multiplexing storage using angular variation in a transmission holographic polymer dispersed liquid crystal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Hee; Jung, Yeon-Gil, E-mail: jungyg@changwon.ac.kr

    2015-12-01

    Simultaneous angular multiplexing of transmission gratings in a holographic polymer dispersed liquid crystal (HPDLC) film as a function of resin and film compositions, irradiation intensity, and cell thickness has been studied by exposing the material to three coherent laser beams. It was found that the diffraction efficiency monotonically increases with irradiation intensity and cell gap, whereas a maximum of 43% is obtained at specific compositions of trimethylolpropane triacrylate (TMPTA)/N-vinylpyrrolidone (NVP) = 8/1 and polymer/LC = 65/35. The multiplexed gratings have been captured using SEM imaging and the reconstructed images using a charge-coupled device camera, showing successful reconstructed images of gratings. - Highlights: • Multiplex images were well recorded using simultaneous angular method. • The periodic structures of the LC and polymer regions were well prepared. • The angular selectivity was variable nevertheless fabrication by three beams. • The images were successfully reconstructed in gratings of same spot.

  3. Multiplexing storage using angular variation in a transmission holographic polymer dispersed liquid crystal

    International Nuclear Information System (INIS)

    Kim, Eun-Hee; Jung, Yeon-Gil

    2015-01-01

    Simultaneous angular multiplexing of transmission gratings in a holographic polymer dispersed liquid crystal (HPDLC) film as a function of resin and film compositions, irradiation intensity, and cell thickness has been studied by exposing the material to three coherent laser beams. It was found that the diffraction efficiency monotonically increases with irradiation intensity and cell gap, whereas a maximum of 43% is obtained at specific compositions of trimethylolpropane triacrylate (TMPTA)/N-vinylpyrrolidone (NVP) = 8/1 and polymer/LC = 65/35. The multiplexed gratings have been captured using SEM imaging and the reconstructed images using a charge-coupled device camera, showing successful reconstructed images of gratings. - Highlights: • Multiplex images were well recorded using simultaneous angular method. • The periodic structures of the LC and polymer regions were well prepared. • The angular selectivity was variable nevertheless fabrication by three beams. • The images were successfully reconstructed in gratings of same spot.

  4. Security analysis of orthogonal-frequency-division-multiplexing-based continuous-variable quantum key distribution with imperfect modulation

    Science.gov (United States)

    Zhang, Hang; Mao, Yu; Huang, Duan; Li, Jiawei; Zhang, Ling; Guo, Ying

    2018-05-01

    We introduce a reliable scheme for continuous-variable quantum key distribution (CV-QKD) by using orthogonal frequency division multiplexing (OFDM). As a spectrally efficient multiplexing technique, OFDM allows a large number of closely spaced orthogonal subcarrier signals used to carry data on several parallel data streams or channels. We place emphasis on modulator impairments which would inevitably arise in the OFDM system and analyze how these impairments affect the OFDM-based CV-QKD system. Moreover, we also evaluate the security in the asymptotic limit and the Pirandola-Laurenza-Ottaviani-Banchi upper bound. Results indicate that although the emergence of imperfect modulation would bring about a slight decrease in the secret key bit rate of each subcarrier, the multiplexing technique combined with CV-QKD results in a desirable improvement on the total secret key bit rate which can raise the numerical value about an order of magnitude.

  5. On-chip two-mode division multiplexing using tapered directional coupler-based mode multiplexer and demultiplexer

    DEFF Research Database (Denmark)

    Ding, Yunhong; Xu, Jing; Da Ros, Francesco

    2013-01-01

    ), and large fabrication tolerance (20 nm) are measured. An on-chip mode multiplexing experiment is carried out on the fabricated circuit with non return-to-zero (NRZ) on-off keying (OOK) signals at 40 Gbit/s. The experimental results show clear eye diagrams and moderate power penalty for both TE0 and TE1...

  6. Wavelength-stepped, actively mode-locked fiber laser based on wavelength-division-multiplexed optical delay lines

    Science.gov (United States)

    Lee, Eunjoo; Kim, Byoung Yoon

    2017-12-01

    We propose a new scheme for an actively mode-locked wavelength-swept fiber laser that produces a train of discretely wavelength-stepped pulses from a short fiber cavity. Pulses with different wavelengths are split and combined by standard wavelength division multiplexers with fiber delay lines. As a proof of concept, we demonstrate a laser using an erbium doped fiber amplifier and commercially available wavelength-division multiplexers with wavelength spacing of 0.8 nm. The results show simultaneous mode-locking at three different wavelengths. Laser output parameters in time domain, optical and radio frequency spectral domain, and the noise characteristics are presented. Suggestions for the improved design are discussed.

  7. Fabrication of dense wavelength division multiplexing filters with large useful area

    Science.gov (United States)

    Lee, Cheng-Chung; Chen, Sheng-Hui; Hsu, Jin-Cherng; Kuo, Chien-Cheng

    2006-08-01

    Dense Wavelength Division Multiplexers (DWDM), a kind of narrow band-pass filter, are extremely sensitive to the optical thickness error in each composite layer. Therefore to have a large useful coating area is extreme difficult because of the uniformity problem. To enlarge the useful coating area it is necessary to improve their design and their fabrication. In this study, we discuss how the tooling factors at different positions and for different materials are related to the optical performance of the design. 100GHz DWDM filters were fabricated by E-gun evaporation with ion-assisted deposition (IAD). To improve the coating uniformity, an analysis technique called shaping tooling factor (STF) was used to analyze the deviation of the optical thickness in different materials so as to enlarge the useful coating area. Also a technique of etching the deposited layers with oxygen ions was introduced. When the above techniques were applied in the fabrication of 100 GHz DWDM filters, the uniformity was better than +/-0.002% over an area of 72 mm in diameter and better than +/-0.0006% over 20mm in diameter.

  8. Algorithm for protecting light-trees in survivable mesh wavelength-division-multiplexing networks

    Science.gov (United States)

    Luo, Hongbin; Li, Lemin; Yu, Hongfang

    2006-12-01

    Wavelength-division-multiplexing (WDM) technology is expected to facilitate bandwidth-intensive multicast applications such as high-definition television. A single fiber cut in a WDM mesh network, however, can disrupt the dissemination of information to several destinations on a light-tree based multicast session. Thus it is imperative to protect multicast sessions by reserving redundant resources. We propose a novel and efficient algorithm for protecting light-trees in survivable WDM mesh networks. The algorithm is called segment-based protection with sister node first (SSNF), whose basic idea is to protect a light-tree using a set of backup segments with a higher priority to protect the segments from a branch point to its children (sister nodes). The SSNF algorithm differs from the segment protection scheme proposed in the literature in how the segments are identified and protected. Our objective is to minimize the network resources used for protecting each primary light-tree such that the blocking probability can be minimized. To verify the effectiveness of the SSNF algorithm, we conduct extensive simulation experiments. The simulation results demonstrate that the SSNF algorithm outperforms existing algorithms for the same problem.

  9. Secure Communications in High Speed Fiber Optical Networks Using Code Division Multiple Access (CDMA) Transmission

    Energy Technology Data Exchange (ETDEWEB)

    Han, I; Bond, S; Welty, R; Du, Y; Yoo, S; Reinhardt, C; Behymer, E; Sperry, V; Kobayashi, N

    2004-02-12

    This project is focused on the development of advanced components and system technologies for secure data transmission on high-speed fiber optic data systems. This work capitalizes on (1) a strong relationship with outstanding faculty at the University of California-Davis who are experts in high speed fiber-optic networks, (2) the realization that code division multiple access (CDMA) is emerging as a bandwidth enhancing technique for fiber optic networks, (3) the realization that CDMA of sufficient complexity forms the basis for almost unbreakable one-time key transmissions, (4) our concepts for superior components for implementing CDMA, (5) our expertise in semiconductor device processing and (6) our Center for Nano and Microtechnology, which is where the majority of the experimental work was done. Here we present a novel device concept, which will push the limits of current technology, and will simultaneously solve system implementation issues by investigating new state-of-the-art fiber technologies. This will enable the development of secure communication systems for the transmission and reception of messages on deployed commercial fiber optic networks, through the CDMA phase encoding of broad bandwidth pulses. CDMA technology has been developed as a multiplexing technology, much like wavelength division multiplexing (WDM) or time division multiplexing (TDM), to increase the potential number of users on a given communication link. A novel application of the techniques created for CDMA is to generate secure communication through physical layer encoding. Physical layer encoding devices are developed which utilize semiconductor waveguides with fast carrier response times to phase encode spectral components of a secure signal. Current commercial technology, most commonly a spatial light modulator, allows phase codes to be changed at rates of only 10's of Hertz ({approx}25ms response). The use of fast (picosecond to nanosecond) carrier dynamics of semiconductors

  10. DFT based spatial multiplexing and maximum ratio transmission for mm-wawe large MIMO

    DEFF Research Database (Denmark)

    Phan-Huy, D.-T.; Tölli, A.; Rajatheva, N.

    2014-01-01

    -SM-MRT). When the DFT-SM scheme alone is used, the data streams are either mapped onto different angles of departures in the case of aligned linear arrays, or mapped onto different orbital angular momentums in the case of aligned circular arrays. Maximum ratio transmission pre-equalizes the channel......By using large point-to-point multiple input multiple output (MIMO), spatial multiplexing of a large number of data streams in wireless communications using millimeter-waves (mm-waves) can be achieved. However, according to the antenna spacing and transmitter-receiver distance, the MIMO channel...... is likely to be ill-conditioned. In such conditions, highly complex schemes such as the singular value decomposition (SVD) are necessary. In this paper, we propose a new low complexity system called discrete Fourier transform based spatial multiplexing (DFT-SM) with maximum ratio transmission (DFT...

  11. An order of magnitude improvement in optical fiber bandwidth using spatial domain multiplexing/space division multiplexing (SDM) in conjunction with orbital angular momentum (OAM)

    Science.gov (United States)

    Murshid, Syed; Alanzi, Saud; Hridoy, Arnob; Lovell, Greg; Parhar, Gurinder; Chakravarty, Abhijit; Chowdhury, Bilas

    2014-09-01

    Spatial Domain Multiplexing/Space Division Multiplexing (SDM) can increase the bandwidth of existing and futuristic optical fibers by an order of magnitude or more. In the SDM technique, we launch multiple single mode pigtail laser sources of same wavelength into a carrier fiber at different angles. The launching angles decide the output of the carrier fiber by allocating separate spatial locations for each channel. Each channel follows a helical trajectory while traversing the length of the carrier fiber, thereby allowing spatial reuse of optical frequencies. In this endeavor we launch light from five different single mode pigtail laser sources at different angles (with respect to the axis of the carrier fiber) into the carrier fiber. Owing to helical propagation we get five distinct concentric donut shaped rings with negligible crosstalk at the output end of the fiber. These SDM channels also exhibit Orbital Angular Momentum (OAM), thereby adding an extra degree of photon freedom. We present the experimental data of five spatially multiplexed channels and compare them with simulated results to show that this technique can potentially improve the data capacity of optical fibers by an order of magnitude: A factor of five using SDM and another factor of two using OAM.

  12. Ultrahigh-Spectral-Efficiency WDM/SDM Transmission Using PDM-1024-QAM Probabilistic Shaping With Adaptive Rate

    DEFF Research Database (Denmark)

    Hu, Hao; Yankov, Metodi Plamenov; Da Ros, Francesco

    2018-01-01

    We demonstrate wavelength-division-multiplexed (WDM) and space-division-multiplexed (SDM) transmission of probabilistically shaped polarization-division-multiplexed (PDM) 1024-state quadrature amplitude modulation (QAM) channels over a 9.7-km single-mode 30-core fiber, achieving aggregated spectr...

  13. An in-building network based on community access television integration with quadrature phase-shift keying orthogonal frequency-division multiplexing

    International Nuclear Information System (INIS)

    Chen, Chia-Yi; Lin, Ying-Pyng; Lu, Hai-Han; Wu, Po-Yi; Lin, Huang-Chang; Wu, Hsiao-Wen

    2012-01-01

    An in-building network based on cable television (CATV) integration with quadrature phase-shift keying (QPSK) orthogonal frequency-division multiplexing (OFDM) transport over a combination of single-mode fibers (SMF) and perfluorinated graded-index plastic optical fibers (GI-POF) is proposed and experimentally demonstrated. In this system, a 1558.5 nm optical signal is directly transmitted along two fiber spans (20 km SMF + 25 m GI-POF). An optimum guard band is carefully established to ensure that no very substantial signal interference is induced between the CATV and QPSK OFDM bands. Error free transmission with sufficiently low bit error rate values was achieved for 1.25 Gbps/771.5 MHz QPSK OFDM signals; also, acceptable carrier-to-noise ratio, composite second-order, and composite triple-beat performances were obtained for CATV signals. This proposed network is significant because it is economical and convenient to install. (paper)

  14. Advanced time and wavelength division multiplexing for metropolitan area optical data communication networks

    Science.gov (United States)

    Watford, M.; DeCusatis, C.

    2005-09-01

    With the advent of new regulations governing the protection and recovery of sensitive business data, including the Sarbanes-Oxley Act, there has been a renewed interest in business continuity and disaster recovery applications for metropolitan area networks. Specifically, there has been a need for more efficient bandwidth utilization and lower cost per channel to facilitate mirroring of multi-terabit data bases. These applications have further blurred the boundary between metropolitan and wide area networks, with synchronous disaster recovery applications running up to 100 km and asynchronous solutions extending to 300 km or more. In this paper, we discuss recent enhancements in the Nortel Optical Metro 5200 Dense Wavelength Division Multiplexing (DWDM) platform, including features recently qualified for data communication applications such as Metro Mirror, Global Mirror, and Geographically Distributed Parallel Sysplex (GDPS). Using a 10 Gigabit/second (Gbit/s) backbone, this solution transports significantly more Fibre Channel protocol traffic with up to five times greater hardware density in the same physical package. This is also among the first platforms to utilize forward error correction (FEC) on the aggregate signals to improve bit error rate (BER) performance beyond industry standards. When combined with encapsulation into wide area network protocols, the use of FEC can compensate for impairments in BER across a service provider infrastructure without impacting application level performance. Design and implementation of these features will be discussed, including results from experimental test beds which validate these solutions for a number of applications. Future extensions of this environment will also be considered, including ways to provide configurable bandwidth on demand, mitigate Fibre Channel buffer credit management issues, and support for other GDPS protocols.

  15. Frequency-Division Multiplexing for Electrical Impedance Tomography in Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Yair Granot

    2007-01-01

    Full Text Available Electrical impedance tomography (EIT produces an image of the electrical impedance distribution of tissues in the body, using electrodes that are placed on the periphery of the imaged area. These electrodes inject currents and measure voltages and from these data, the impedance can be computed. Traditional EIT systems usually inject current patterns in a serial manner which means that the impedance is computed from data collected at slightly different times. It is usually also a time-consuming process. In this paper, we propose a method for collecting data concurrently from all of the current patterns in biomedical applications of EIT. This is achieved by injecting current through all of the current injecting electrodes simultaneously, and measuring all of the resulting voltages at once. The signals from various current injecting electrodes are separated by injecting different frequencies through each electrode. This is called frequency-division multiplexing (FDM. At the voltage measurement electrodes, the voltage related to each current injecting electrode is isolated by using Fourier decomposition. In biomedical applications, using different frequencies has important implications due to dispersions as the tissue's electrical properties change with frequency. Another significant issue arises when we are recording data in a dynamic environment where the properties change very fast. This method allows simultaneous measurements of all the current patterns, which may be important in applications where the tissue changes occur in the same time scale as the measurement. We discuss the FDM EIT method from the biomedical point of view and show results obtained with a simple experimental system.

  16. A large capacity time division multiplexed (TDM) laser beam combining technique enabled by nanosecond speed KTN deflector

    Science.gov (United States)

    Yin, Stuart (Shizhuo); Chao, Ju-Hung; Zhu, Wenbin; Chen, Chang-Jiang; Campbell, Adrian; Henry, Michael; Dubinskiy, Mark; Hoffman, Robert C.

    2017-08-01

    In this paper, we present a novel large capacity (a 1000+ channel) time division multiplexing (TDM) laser beam combining technique by harnessing a state-of-the-art nanosecond speed potassium tantalate niobate (KTN) electro-optic (EO) beam deflector as the time division multiplexer. The major advantages of TDM approach are: (1) large multiplexing capability (over 1000 channels), (2) high spatial beam quality (the combined beam has the same spatial profile as the individual beam), (3) high spectral beam quality (the combined beam has the same spectral width as the individual beam, and (4) insensitive to the phase fluctuation of individual laser because of the nature of the incoherent beam combining. The quantitative analyses show that it is possible to achieve over one hundred kW average power, single aperture, single transverse mode solid state and/or fiber laser by pursuing this innovative beam combining method, which represents a major technical advance in the field of high energy lasers. Such kind of 100+ kW average power diffraction limited beam quality lasers can play an important role in a variety of applications such as laser directed energy weapons (DEW) and large-capacity high-speed laser manufacturing, including cutting, welding, and printing.

  17. Spatial-phase code-division multiple-access system with multiplexed Fourier holography switching for reconfigurable optical interconnection

    Science.gov (United States)

    Takasago, Kazuya; Takekawa, Makoto; Shirakawa, Atsushi; Kannari, Fumihiko

    2000-05-01

    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.

  18. Iterative normalization technique for reference sequence generation for zero-tail discrete fourier transform spread orthogonal frequency division multiplexing

    DEFF Research Database (Denmark)

    2017-01-01

    Systems, methods, apparatuses, and computer program products for generating sequences for zero-tail discrete fourier transform (DFT)-spread-orthogonal frequency division multiplexing (OFDM) (ZT DFT-s-OFDM) reference signals. One method includes adding a zero vector to an input sequence...... of each of the elements, converting the sequence to time domain, generating a zero-padded sequence by forcing a zero head and tail of the sequence, and repeating the steps until a final sequence with zero-tail and flat frequency response is obtained....

  19. Free-space optics mode-wavelength division multiplexing system using LG modes based on decision feedback equalization

    Science.gov (United States)

    Amphawan, Angela; Ghazi, Alaan; Al-dawoodi, Aras

    2017-11-01

    A free-space optics mode-wavelength division multiplexing (MWDM) system using Laguerre-Gaussian (LG) modes is designed using decision feedback equalization for controlling mode coupling and combating inter symbol interference so as to increase channel diversity. In this paper, a data rate of 24 Gbps is achieved for a FSO MWDM channel of 2.6 km in length using feedback equalization. Simulation results show significant improvement in eye diagrams and bit-error rates before and after decision feedback equalization.

  20. A real-time multi-gases detection and concentration measurements based-on time-division multiplexed-lasers

    Science.gov (United States)

    Yazdandoust, Fatemeh; Tatenguem Fankem, Hervé; Milde, Tobias; Jimenez, Alvaro; Sacher, Joachim

    2018-02-01

    We report the development of a platform, based-on a Field-Programmable Gate Arrays (FPGAs) and suitable for Time-Division-Multiplexed DFB lasers. The designed platform is subsequently combined with a spectroscopy setup, for detection and quantification of species in a gas mixture. The experimental results show a detection limit of 460 ppm, an uncertainty of 0.1% and a computation time of less than 1000 clock cycles. The proposed system offers a high level of flexibility and is applicable to arbitrary types of gas-mixtures.

  1. Free-space optics mode-wavelength division multiplexing system using LG modes based on decision feedback equalization

    Directory of Open Access Journals (Sweden)

    Amphawan Angela

    2017-01-01

    Full Text Available A free-space optics mode-wavelength division multiplexing (MWDM system using Laguerre-Gaussian (LG modes is designed using decision feedback equalization for controlling mode coupling and combating inter symbol interference so as to increase channel diversity. In this paper, a data rate of 24 Gbps is achieved for a FSO MWDM channel of 2.6 km in length using feedback equalization. Simulation results show significant improvement in eye diagrams and bit-error rates before and after decision feedback equalization.

  2. Diversity-Multiplexing Trade-off for Coordinated Relayed Uplink and Direct Downlink Transmissions

    DEFF Research Database (Denmark)

    Thai, Chan; Popovski, Petar; Sun, Fan

    2013-01-01

    Abstract—There are two basic principles used in wireless network coding to design throughput-efficient schemes: (1) aggregation of communication flows and (2) interference is embraced and subsequently cancelled or mitigated. These principles inspire design of Coordinated Direct/Relay (CDR) schemes......, where each basic transmission involves two flows to a direct and a relayed user. Considering a scenario with relayed uplink and direct downlink, we analyze the Diversity-Multiplexing Tradeoff (DMT) calculating either the exact value or both upper/lower bounds. The CDR scheme is shown to have a higher...

  3. Reflective variable optical attenuators and fibre ring lasers for wavelength-division multiplexing systems

    Science.gov (United States)

    Liu, He Liang

    Wavelength division multiplexing (WDM) optical fibre system is an important enabling technology to fulfill the demands for bandwidth in the modern information age. The main objective of this project is to study novel devices with the potential to enhance the performance of WDM systems. In particular, a novel reflective variable optical attenuator (RVOA) used for dynamic gain equalization (DGE) and fibre lasers based on an entirely new type of erbium-doped fibres with ultrawide tuning range were investigated theoretically and experimentally. We proposed a new type of RVOA device which could be potentially integrated with arrayed waveguide grating (AWG) to reduce the cost of DGE substantially. Initially, fibre-based RVOAs, fabricated with optical fibre components such as fibre coupler and Faraday rotator mirror, were investigated theoretically and experimentally. Larger attenuation range up to 22 dB was realized for fibre coupler-based ROVA with a Faraday rotator mirror and its polarization-dependent loss is about 0.5 dB. Then polymeric waveguide-based RVOAs were investigated theoretically and experimentally. Using an epoxy Novolak resin as core material and an UV-cured resin (Norland's NOA61) as cladding material, a polymeric waveguide RVOA was successfully fabricated. The dynamic 15 dB attenuation range was achieved and the PDL was less than 0.2 dB. The measured insertion loss of the polymeric waveguide RVOA was too large (about 18 dB) and was mainly induced by coupling loss, material loss and poor alignment. In the second part of the study, fibre ring lasers with continuous wavelength tuning over wide wavelength range and fibre ring lasers with discrete wavelength tuning were investigated. Tunable lasers are important devices in WDM systems because they could be employed as reserved sources and therefore avoiding the need to stock large inventory of lasers to cover the ITU-wavelength grid. In this project, erbium ions doped bismuth oxide glass fibres instead of

  4. Optical Synchronization of a 10-G Ethernet Packet and Time-Division Multiplexing to a 50-Gb/s Signal Using an Optical Time Lens

    DEFF Research Database (Denmark)

    Hu, Hao; Laguardia Areal, Janaina; Palushani, Evarist

    2010-01-01

    A 10-G Ethernet packet with maximum packet size of 1518 bytes is synchronized to a master clock with 200-kHz frequency offset using a time lens. The input 10-Gb/s non-return-to-zero packet is at the same time converted into a return-to-zero (RZ) packet with a pulsewidth of 10 ps and then time......-division multiplexed with four 10-Gb/s optical time-division-multiplexing (OTDM) channels, thus constituting a 50-Gb/s OTDM serial signal. Error-free performances of the synchronized RZ packet and demultiplexed packet from the aggregated 50-Gb/s OTDM signal are achieved....

  5. Fabrication and optical characteristics of silicon-based two-dimensional wavelength division multiplexing splitter with photonic crystal directional waveguide couplers

    International Nuclear Information System (INIS)

    Liu, Cheng-Yang

    2011-01-01

    Photonic crystals have many potential applications because of their ability to control lightwave propagation. We report on the fabrication and optical properties of quasi-two-dimensional photonic crystals with triangular lattice of dielectric rods in air. Rod-type photonic crystal structures were fabricated in silicon by electron beam lithography and dry-etching techniques. Wavelength division multiplexing splitters were fabricated from two-dimensional photonic crystal directional waveguide couplers. Transmission spectra were measured and device operation was shown to be in agreement with theoretical calculations. The splitters can be used in visible light region. Such an approach to photonic element systems should enable new applications for designing components in photonic integrated circuits. -- Highlights: → We report the fabrication and optical properties of rod-type photonic crystal. → The splitter was fabricated by electron beam lithography and dry-etching techniques. → The splitter was composed of directional waveguide couplers. → Measured transmission spectra are in agreement with theoretical calculations. → The splitters can be used in visible light region.

  6. 1 λ × 1.44 Tb/s free-space IM-DD transmission employing OAM multiplexing and PDM.

    Science.gov (United States)

    Zhu, Yixiao; Zou, Kaiheng; Zheng, Zhennan; Zhang, Fan

    2016-02-22

    We report the experimental demonstration of single wavelength terabit free-space intensity modulation direct detection (IM-DD) system employing both orbital angular momentum (OAM) multiplexing and polarization division multiplexing (PDM). In our experiment, 12 OAM modes with two orthogonal polarization states are used to generate 24 channels for transmission. Each channel carries 30 Gbaud Nyquist PAM-4 signal. Therefore an aggregate gross capacity record of 1.44 Tb/s (12 × 2 × 30 × 2 Gb/s) is acheived with a modulation efficiency of 48 bits/symbol. After 0.8m free-space transmission, the bit error rates (BERs) of all the channels are below the 20% hard-decision forward error correction (HD-FEC) threshold of 1.5 × 10(-2). After applying the decision directed recursive least square (DD-RLS) based filter and post filter, the BERs of two polarizations can be reduced from 5.3 × 10(-3) and 7.3 × 10(-3) to 2.2 × 10(-3) and 3.4 × 10(-3), respectively.

  7. Threshold-Based Multiple Optical Signal Selection Scheme for Free-Space Optical Wavelength Division Multiplexing Systems

    KAUST Repository

    Nam, Sung Sik

    2017-11-13

    We propose a threshold-based multiple optical signal selection scheme (TMOS) for free-space optical wavelength division multiplexing systems. With this scheme, we can obtain higher spectral efficiency while reducing the possible complexity of implementation caused by the beam-selection scheme and without a considerable performance loss. To characterize the performance of our scheme, we statistically analyze the operation characteristics under conventional detection conditions (i.e., heterodyne detection and intensity modulation/direct detection techniques) with log-normal turbulence while taking into consideration the impact of pointing error. More specifically, we derive exact closed-form expressions for the outage probability, the average bit error rate, and the average spectral efficiency while adopting an adaptive modulation. Some selected results show that TMOS increases the average spectral efficiency while maintaining a minimum average bit error rate requirement.

  8. Frequency division transmission imaging and synthetic aperture reconstruction

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt

    2006-01-01

    In synthetic transmit aperture imaging only a few transducer elements are used in every transmission, which limits the signal-to-noise ratio (SNR). The penetration depth can be increased by using all transmitters in every transmission. In this paper, a method for exciting all transmitters in every...... corresponding to the excitation waveforms, the different transmitters can be decoded at the receiver. The matched filter of a specific waveform will allow information only from this waveform to pass through, thereby separating it from the other waveforms. This means that all transmitters can be used in every...... transmission, and the information from the different transmitters can be separated instantaneously. Compared to traditional synthetic transmit aperture (STA) imaging, in which the different transmitters are excited sequentially, more energy is transmitted in every transmission, and a better signal...

  9. Audit of EDF generation and transmission division suppliers

    International Nuclear Information System (INIS)

    Leconte, J.P.

    1993-01-01

    This paper presents the process for acceptance by EDF/production and transmission group of suppliers, industrial equipment manufacturers and providers of repair activities or services for the maintenance of nuclear plants. 1 tab

  10. Photonic crystal ring resonator-based four-channel dense wavelength division multiplexing demultiplexer on silicon on insulator platform: design and analysis

    Science.gov (United States)

    Sreenivasulu, Tupakula; Bhowmick, Kaustav; Samad, Shafeek A.; Yadunath, Thamerassery Illam R.; Badrinarayana, Tarimala; Hegde, Gopalkrishna; Srinivas, Talabattula

    2018-04-01

    A micro/nanofabrication feasible compact photonic crystal (PC) ring-resonator-based channel drop filter has been designed and analyzed for operation in C and L bands of communication window. The four-channel demultiplexer consists of ring resonators of holes in two-dimensional PC slab. The proposed assembly design of dense wavelength division multiplexing setup is shown to achieve optimal quality factor, without altering the lattice parameters or resonator size or inclusion of scattering holes. Transmission characteristics are analyzed using the three-dimensional finite-difference time-domain simulation approach. The radiation loss of the ring resonator was minimized by forced cancelation of radiation fields by fine-tuning the air holes inside the ring resonator. An average cross talk of -34 dB has been achieved between the adjacent channels maintaining an average quality factor of 5000. Demultiplexing is achieved by engineering only the air holes inside the ring, which makes it a simple and tolerant design from the fabrication perspective. Also, the device footprint of 500 μm2 on silicon on insulator platform makes it easy to fabricate the device using e-beam lithography technique.

  11. Coherent Detection of Wavelength Division Multiplexed Phase-Modulated Radio-over-Fibre Signals

    DEFF Research Database (Denmark)

    Zibar, Darko; Yu, Xianbin; Peucheret, Christophe

    2008-01-01

    A WDM phase-modulated Radio-over-Fibre link using digital coherent detection is experimentally demonstrated. 3 times 50 Mb/s WDM transmission of a BPSK modulated 5 GHz RF carrier is achieved over 25 km.......A WDM phase-modulated Radio-over-Fibre link using digital coherent detection is experimentally demonstrated. 3 times 50 Mb/s WDM transmission of a BPSK modulated 5 GHz RF carrier is achieved over 25 km....

  12. Novel secure and bandwidth efficient optical code division multiplexed system for future access networks

    Science.gov (United States)

    Singh, Simranjit

    2016-12-01

    In this paper, a spectrally coded optical code division multiple access (OCDMA) system using a hybrid modulation scheme has been investigated. The idea is to propose an effective approach for simultaneous improvement of the system capacity and security. Data formats, NRZ (non-return to zero), DQPSK (differential quadrature phase shift keying), and PoISk (polarisation shift keying) are used to get the orthogonal modulated signal. It is observed that the proposed hybrid modulation provides efficient utilisation of bandwidth, increases the data capacity and enhances the data confidentiality over existing OCDMA systems. Further, the proposed system performance is compared with the current state-of-the-art OCDMA schemes.

  13. Orbital Angular Momentum-based Space Division Multiplexing for High-capacity Underwater Optical Communications

    Science.gov (United States)

    Ren, Yongxiong; Li, Long; Wang, Zhe; Kamali, Seyedeh Mahsa; Arbabi, Ehsan; Arbabi, Amir; Zhao, Zhe; Xie, Guodong; Cao, Yinwen; Ahmed, Nisar; Yan, Yan; Liu, Cong; Willner, Asher J.; Ashrafi, Solyman; Tur, Moshe; Faraon, Andrei; Willner, Alan E.

    2016-09-01

    To increase system capacity of underwater optical communications, we employ the spatial domain to simultaneously transmit multiple orthogonal spatial beams, each carrying an independent data channel. In this paper, we show up to a 40-Gbit/s link by multiplexing and transmitting four green orbital angular momentum (OAM) beams through a single aperture. Moreover, we investigate the degrading effects of scattering/turbidity, water current, and thermal gradient-induced turbulence, and we find that thermal gradients cause the most distortions and turbidity causes the most loss. We show systems results using two different data generation techniques, one at 1064 nm for 10-Gbit/s/beam and one at 520 nm for 1-Gbit/s/beam; we use both techniques since present data-modulation technologies are faster for infrared (IR) than for green. For the 40-Gbit/s link, data is modulated in the IR, and OAM imprinting is performed in the green using a specially-designed metasurface phase mask. For the 4-Gbit/s link, a green laser diode is directly modulated. Finally, we show that inter-channel crosstalk induced by thermal gradients can be mitigated using multi-channel equalisation processing.

  14. Optical-wireless-optical full link for polarization multiplexing quadrature amplitude/phase modulation signal transmission.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Chi, Nan; Zhang, Junwen

    2013-11-15

    We propose and experimentally demonstrate an optical wireless integration system at the Q-band, in which up to 40 Gb/s polarization multiplexing multilevel quadrature amplitude/phase modulation (PM-QAM) signal can be first transmitted over 20 km single-mode fiber-28 (SMF-28), then delivered over a 2 m 2 × 2 multiple-input multiple-output wireless link, and finally transmitted over another 20 km SMF-28. The PM-QAM modulated wireless millimeter-wave (mm-wave) signal at 40 GHz is generated based on the remote heterodyning technique, and demodulated by the radio-frequency transparent photonic technique based on homodyne coherent detection and baseband digital signal processing. The classic constant modulus algorithm equalization is used at the receiver to realize polarization demultiplexing of the PM-QAM signal. For the first time, to the best of our knowledge, we realize the conversion of the PM-QAM modulated wireless mm-wave signal to the optical signal as well as 20 km fiber transmission of the converted optical signal.

  15. Performance of Coarse Timing Synchronization in Orthogonal Frequency Division Multiplexing System

    Science.gov (United States)

    Bruno; Xuping, Zhai

    2018-01-01

    A novel symbol timing synchronization based on training symbols for OFDM system was designed and presented in this paper. The performance of the proposed method is tested in terms of the timing metric and mean square error (MSE), indoor no-noise, and Rayleigh fading channel, obtained by simulation. The over the air transmission of the proposed timing metric is evaluated by implementing a software defined radio based on the GNU Radio and universal software radio peripheral communication platforms. The simulation results show that the proposed timing metric indexed at the correct time point, which has smaller MSE than others methods, particularly at high signal-to-noise ratio. Therefore the proposed method works well, even in transmission through the air indoor laboratory environment.

  16. An Asynchronous Time-Division-Multiplexed Network-on-Chip for Real-Time Systems

    DEFF Research Database (Denmark)

    Kasapaki, Evangelia

    is an important part of the T-CREST paltform and used in a number of configurations. The flexible timing organization of Argo combines asynchronous routers with mesochronous NIs, which are connected to individually clocked cores, supporting a GALS system organization. The mesochronous NIs operate at the same......Multi-processor architectures using networks-on-chip (NOCs) for communication are becoming the standard approach in the development of embedded systems and general purpose platforms. Typically, multi-processor platforms follow a globally asynchronous locally synchronous (GALS) timing organization....... This thesis focuses on the design of Argo, a NOC targeted at hard real-time multi-processor platforms with a GALS timing organization. To support real-time communication, NOCs establish end-to-end connections and provide latency and throughput guarantees for these connections. Argo uses time division...

  17. Investigation of Orthogonal Frequency Division Multiplexing Based Power Line Communication Systems

    OpenAIRE

    Hosseinpour, Ali

    2015-01-01

    Power Line Communication (PLC) has the potential to become the preferred technique for providing broadband to homes and offices with the advantage of eliminating the need for new wiring infrastructure and reducing the cost. Power line grids, however, present a hostile channel for data communication, since the fundamental purpose of the power line channel was only the transmission of electric power at 50/60 Hz frequencies. The development of PLC systems for providing broadband applications req...

  18. Blind identification of the number of sub-carriers for orthogonal frequency division multiplexing-based elastic optical networking

    Science.gov (United States)

    Zhao, Lei; Xu, Hengying; Bai, Chenglin

    2018-03-01

    In orthogonal frequency division multiplexing (OFDM)-based elastic optical networking (EON), it is imperative to identify unknown parameters of OFDM-based EON signals quickly, intelligently and robustly. Because the number of sub-carriers determines the size of the sub-carriers spacing and then affects the symbol period of the OFDM and the anti-dispersion capability of the system, the identification of the number of sub-carriers has a profound effect on the identification of other key parameters of the system. In this paper, we proposed a method of number identification for sub-carriers of OFDM-based EON signals with help of high-order cyclic cumulant. The specific fourth-order cyclic cumulant exists only at the location of its sub-carriers frequencies. So the identification of the number of sub-carriers can be implemented by detecting the cyclic-frequencies. The proposed scheme in our study can be divided into three sub-stages, i.e. estimating the spectral range, calculating the high-order cyclic cumulant and identifying the number of sub-carriers. When the optical signal-to-noise ratios (OSNR) varied from 16dB to 22dB, the number of sub-carriers (64-512) was successfully identified in the experiment, and from the statistical point of view, the average identification absolute accuracy (IAAs) exceeded 94%.

  19. Short-range remote spectral sensor using mid-infrared semiconductor lasers with orthogonal code-division multiplexing approach

    Science.gov (United States)

    Morbi, Zulfikar; Ho, D. B.; Ren, H.-W.; Le, Han Q.; Pei, Shin Shem

    2002-09-01

    Demonstration of short-range multispectral remote sensing, using 3 to 4-micrometers mid- infrared Sb semiconductor lasers based on code-division multiplexing (CDM) architecture, is described. The system is built on a principle similar to intensity- modulated/direct-detection optical-CDMA for communications, but adapted for sensing with synchronous, orthogonal codes to distinguish different wavelength channels with zero interchannel correlation. The concept is scalable for any number of channels, and experiments with a two-wavelength system are conducted. The CDM-signal processing yielded a white-Gaussian-like system noise that is found to be near the theoretical level limited by the detector fundamental intrinsic noise. With sub-mW transmitter average power, the system was able to detect an open-air acetylene gas leak of 10-2 STP ft3/hr from 10-m away with time-varying, random, noncooperative backscatters. A similar experiment detected and positively distinguished hydrocarbon oil contaminants on water from bio-organic oils and detergents. Projection for more advanced systems suggests a multi-kilometer-range capability for watt-level transmitters, and hundreds of wavelength channels can also be accommodated for active hyperspectral remote sensing application.

  20. Simultaneous frequency stabilization and high-power dense wavelength division multiplexing (HP-DWDM) using an external cavity based on volume Bragg gratings (VBGs)

    Science.gov (United States)

    Hengesbach, Stefan; Klein, Sarah; Holly, Carlo; Witte, Ulrich; Traub, Martin; Hoffmann, Dieter

    2016-03-01

    Multiplexing technologies enable the development of high-brightness diode lasers for direct industrial applications. We present a High-Power Dense Wavelength Division Multiplexer (HP-DWDM) with an average channel spacing of 1.7 (1.5) nm and a subsequent external cavity mirror to provide feedback for frequency stabilization and multiplexing in one step. The "self-optimizing" multiplexing unit consists of four reflective Volume Bragg Gratings (VBGs) with 99% diffraction efficiency and seven dielectric mirrors to overlay the radiation of five input channels with an adjustable channel spacing of 1-2 nm. In detail, we focus on the analysis of the overall optical efficiency, the change of the beam parameter product and the spectral width. The performance is demonstrated using five 90 μm multimode 9xx single emitters with M2angular intensity distribution changes strongly and the beam parameter product decreases by a factor of 1.2 to 1.9. Thereby the angular intensity distribution is more affected than the width of the beam waist. The spectral width per emitter decreases to 3-200 pm (FWHM) depending on the injection current and the reflectance of the feedback mirror (0.75%, 1.5%, 4%, 6% or 8%). The overall optical multiplexing efficiency ranges between 77% and 86%. With some modifications (e.g. enhanced AR-coatings) we expect 90-95%.

  1. Transmission of Multilevel 60 Gbit/s Polarization Multiplexed RZ-D8PSK using only 10 Gbit/s equipment

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee; Tokle, Torger; Peucheret, Christophe

    2007-01-01

    By combining differential 8-ary phase shift keying with polarization multiplexing, we present transmission of multilevel modulation with 6 bits per symbol through a 100 km fiber span with a receiver bit-error-ratio better than 10-9.......By combining differential 8-ary phase shift keying with polarization multiplexing, we present transmission of multilevel modulation with 6 bits per symbol through a 100 km fiber span with a receiver bit-error-ratio better than 10-9....

  2. A new material platform of Si photonics for implementing architecture of dense wavelength division multiplexing on Si bulk wafer

    Science.gov (United States)

    Zhang, Ziyi; Yako, Motoki; Ju, Kan; Kawai, Naoyuki; Chaisakul, Papichaya; Tsuchizawa, Tai; Hikita, Makoto; Yamada, Koji; Ishikawa, Yasuhiko; Wada, Kazumi

    2017-12-01

    A new materials group to implement dense wavelength division multiplexing (DWDM) in Si photonics is proposed. A large thermo-optic (TO) coefficient of Si malfunctions multiplexer/demultiplexer (MUX/DEMUX) on a chip under thermal fluctuation, and thus DWDM implementation, has been one of the most challenging targets in Si photonics. The present study specifies an optical materials group for DWDM by a systematic survey of their TO coefficients and refractive indices. The group is classified as mid-index contrast optics (MiDex) materials, and non-stoichiometric silicon nitride (SiNx) is chosen to demonstrate its significant thermal stability. The TO coefficient of non-stoichiometric SiNx is precisely measured in the temperature range 24-76 °C using the SiNx rings prepared by two methods: chemical vapor deposition (CVD) and physical vapor deposition (PVD). The CVD-SiNx ring reveals nearly the same TO coefficient reported for stoichiometric CVD-Si3N4, while the value for the PVD-SiNx ring is slightly higher. Both SiNx rings lock their resonance frequencies within 100 GHz in this temperature range. Since CVD-SiNx needs a high temperature annealing to reduce N-H bond absorption, it is concluded that PVD-SiNx is suited as a MiDex material introduced in the CMOS back-end-of-line. Further stabilization is required, considering the crosstalk between two channels; a 'silicone' polymer is employed to compensate for the temperature fluctuation using its negative TO coefficient, called athermalization. This demonstrates that the resonance of these SiNx rings is locked within 50 GHz at the same temperature range in the wavelength range 1460-1620 nm (the so-called S, C, and L bands in optical fiber communication networks). A further survey on the MiDex materials strongly suggests that Al2O3, Ga2O3 Ta2O5, HfO2 and their alloys should provide even more stable platforms for DWDM implementation in MiDex photonics. It is discussed that the MiDex photonics will find various applications

  3. A new material platform of Si photonics for implementing architecture of dense wavelength division multiplexing on Si bulk wafer.

    Science.gov (United States)

    Zhang, Ziyi; Yako, Motoki; Ju, Kan; Kawai, Naoyuki; Chaisakul, Papichaya; Tsuchizawa, Tai; Hikita, Makoto; Yamada, Koji; Ishikawa, Yasuhiko; Wada, Kazumi

    2017-01-01

    A new materials group to implement dense wavelength division multiplexing (DWDM) in Si photonics is proposed. A large thermo-optic (TO) coefficient of Si malfunctions multiplexer/demultiplexer (MUX/DEMUX) on a chip under thermal fluctuation, and thus DWDM implementation, has been one of the most challenging targets in Si photonics. The present study specifies an optical materials group for DWDM by a systematic survey of their TO coefficients and refractive indices. The group is classified as mid-index contrast optics (MiDex) materials, and non-stoichiometric silicon nitride (SiN x ) is chosen to demonstrate its significant thermal stability. The TO coefficient of non-stoichiometric SiN x is precisely measured in the temperature range 24-76 °C using the SiN x rings prepared by two methods: chemical vapor deposition (CVD) and physical vapor deposition (PVD). The CVD-SiN x ring reveals nearly the same TO coefficient reported for stoichiometric CVD-Si 3 N 4 , while the value for the PVD-SiN x ring is slightly higher. Both SiN x rings lock their resonance frequencies within 100 GHz in this temperature range. Since CVD-SiN x needs a high temperature annealing to reduce N-H bond absorption, it is concluded that PVD-SiN x is suited as a MiDex material introduced in the CMOS back-end-of-line. Further stabilization is required, considering the crosstalk between two channels; a 'silicone' polymer is employed to compensate for the temperature fluctuation using its negative TO coefficient, called athermalization. This demonstrates that the resonance of these SiN x rings is locked within 50 GHz at the same temperature range in the wavelength range 1460-1620 nm (the so-called S, C, and L bands in optical fiber communication networks). A further survey on the MiDex materials strongly suggests that Al 2 O 3 , Ga 2 O 3 Ta 2 O 5 , HfO 2 and their alloys should provide even more stable platforms for DWDM implementation in MiDex photonics. It is discussed that the MiDex photonics

  4. Ultra-thin silicon (UTSi) on insulator CMOS transceiver and time-division multiplexed switch chips for smart pixel integration

    Science.gov (United States)

    Zhang, Liping; Sawchuk, Alexander A.

    2001-12-01

    We describe the design, fabrication and functionality of two different 0.5 micron CMOS optoelectronic integrated circuit (OEIC) chips based on the Peregrine Semiconductor Ultra-Thin Silicon on insulator technology. The Peregrine UTSi silicon- on-sapphire (SOS) technology is a member of the silicon-on- insulator (SOI) family. The low-loss synthetic sapphire substrate is optically transparent and has good thermal conductivity and coefficient of thermal expansion properties, which meet the requirements for flip-chip bonding of VCSELs and other optoelectronic input-output components. One chip contains transceiver and network components, including four channel high-speed CMOS transceiver modules, pseudo-random bit stream (PRBS) generators, a voltage controlled oscillator (VCO) and other test circuits. The transceiver chips can operate in both self-testing mode and networking mode. An on- chip clock and true-single-phase-clock (TSPC) D-flip-flop have been designed to generate a PRBS at over 2.5 Gb/s for the high-speed transceiver arrays to operate in self-testing mode. In the networking mode, an even number of transceiver chips forms a ring network through free-space or fiber ribbon interconnections. The second chip contains four channel optical time-division multiplex (TDM) switches, optical transceiver arrays, an active pixel detector and additional test devices. The eventual applications of these chips will require monolithic OEICs with integrated optical input and output. After fabrication and testing, the CMOS transceiver array dies will be packaged with 850 nm vertical cavity surface emitting lasers (VCSELs), and metal-semiconductor- metal (MSM) or GaAs p-i-n detector die arrays to achieve high- speed optical interconnections. The hybrid technique could be either wire bonding or flip-chip bonding of the CMOS SOS smart-pixel arrays with arrays of VCSELs and photodetectors onto an optoelectronic chip carrier as a multi-chip module (MCM).

  5. Timing system for TRISTAN AR using time division multiplexed serial transmission

    International Nuclear Information System (INIS)

    Ishii, Kazuhiro; Kadokura, Eiichi.

    1984-10-01

    The global timing signals of standard clock pulse, event code and time code for TRISTAN AR are transmitted by means of a single coaxial cable. The timing system is composed of the CAMAC system with a microcomputer (LSI-11) and the control computers (Hidic 80 E's). The CAMAC modules and the softwares for the timing system have been developed, and so the flexible and extensible system has been completed. (author)

  6. PLC-based LP₁₁ mode rotator for mode-division multiplexing transmission.

    Science.gov (United States)

    Saitoh, Kunimasa; Uematsu, Takui; Hanzawa, Nobutomo; Ishizaka, Yuhei; Masumoto, Kohei; Sakamoto, Taiji; Matsui, Takashi; Tsujikawa, Kyozo; Yamamoto, Fumihiko

    2014-08-11

    A PLC-based LP11 mode rotator is proposed. The proposed mode rotator is composed of a waveguide with a trench that provides asymmetry of the waveguide. Numerical simulations show that converting LP11a (LP11b) mode to LP11b (LP11a) mode can be achieved with high conversion efficiency (more than 90%) and little polarization dependence over a wide wavelength range from 1450 nm to 1650 nm. In addition, we fabricate the proposed LP11 mode rotator using silica-based PLC. It is confirmed that the fabricated mode rotator can convert LP11a mode to LP11b mode over a wide wavelength range.

  7. 32-core Inline Multicore Fiber Amplifier for Dense Space Division Multiplexed Transmission Systems

    DEFF Research Database (Denmark)

    Jain, S.; Mizuno, T.; Jung, Y.

    2016-01-01

    We present a high-core-count SDM amplifier, i.e. 32-core multicore-fiber amplifier, in a cladding-pumped configuration. An average gain of 17dB and NF of 7dB is obtained for -5dBm input signal power in the wavelength range 1544nm-1564nm....

  8. Compact 35μm fiber coupled diode laser module based on dense wavelength division multiplexing of NBA mini-bars

    Science.gov (United States)

    Witte, U.; Traub, M.; Di Meo, A.; Hamann, M.; Rubel, D.; Hengesbach, S.; Hoffmann, D.

    2016-03-01

    We present a compact, modular and cross talk free approach for dense wavelength division multiplexing of high power diode lasers based on ultra-steep dielectric filters. The mini bars consist of 5 narrow stripe broad area emitters with a beam parameter product in the range of 2 mm mrad and a wavelength spacing of 2.5 nm between 2 adjacent emitters. Experimental results for fiber coupling (35 μm core diameter, NA < 0.2) of internally and externally stabilized diode lasers are presented. Optical losses are analyzed and alternative optical designs to overcome the current limitations of the setup are discussed.

  9. 320 Gb/s Single polarization OTDM Transmission over 80 km Standard Transmission Fiber

    DEFF Research Database (Denmark)

    Siahlo, Andrei; Seoane, Jorge; Clausen, Anders

    2005-01-01

    Optical time-division multiplexing (OTDM) is an attractive technique for increasing the capacity of optical transmission systems. 320 Gbit/s single-channel and single-polarization error-free transmission over continuous spans of either 80 km SMF or 77 km NZDSF are realized.......Optical time-division multiplexing (OTDM) is an attractive technique for increasing the capacity of optical transmission systems. 320 Gbit/s single-channel and single-polarization error-free transmission over continuous spans of either 80 km SMF or 77 km NZDSF are realized....

  10. Terawatt power division and combination using self-magnetically insulated transmission lines

    International Nuclear Information System (INIS)

    Crow, J.T.; Peterson, G.D.

    1980-01-01

    Self-magnetically insulated transmission lines are necessary for the efficient transport of the terawatt pulses used in electron and ion accelerators. For some applications it is desirable to divide one transmission line into two, or to combine outputs of two or more lines into one, by means of self-magnetically insulated convolutes. Tests have been made on a coaxial-to-triaxial convolute in which connections between negative inner and outer lines are made by pins passing through holes in the intermediate positive conductor. Measurements in the 2 MV, 400 kA, 40 ns pulse Mite facility indicate virtually 100% current transport through the convolute and the ability to vary the division of current between the inner and outer lines of the triax by choice of inner line impedance. These measurements, and results obtained with this convolute connected to the ion diode for which it was designed, will be presented

  11. Gigabit Ethernet signal transmission using asynchronous optical code division multiple access.

    Science.gov (United States)

    Ma, Philip Y; Fok, Mable P; Shastri, Bhavin J; Wu, Ben; Prucnal, Paul R

    2015-12-15

    We propose and experimentally demonstrate a novel architecture for interfacing and transmitting a Gigabit Ethernet (GbE) signal using asynchronous incoherent optical code division multiple access (OCDMA). This is the first such asynchronous incoherent OCDMA system carrying GbE data being demonstrated to be working among multi-users where each user is operating with an independent clock/data rate and is granted random access to the network. Three major components, the GbE interface, the OCDMA transmitter, and the OCDMA receiver are discussed in detail. The performance of the system is studied and characterized through measuring eye diagrams, bit-error rate and packet loss rate in real-time file transfer. Our Letter also addresses the near-far problem and realizes asynchronous transmission and detection of signal.

  12. Image transmission in multicore-fiber code-division multiple access network

    Science.gov (United States)

    Yang, Guu-Chang; Kwong, Wing C.

    1997-01-01

    Recently, two-dimensional (2-D) signature patterns were proposed to encode binary digitized image pixels in optical code-division multiple-access (CDMA) networks with 'multicore' fiber. The new technology enables parallel transmission and simultaneous access of 2-D images in multiple-access environment, where these signature patterns are defined as optical orthogonal signature pattern codes (OOSPCs). However, previous work on OOSPCs assumed that the weight of each signature pattern was the same. In this paper, we construct a new family of OOSPCs with the removal of this assumption. Since varying the weight of a user's signature pattern affects that user's performance, this approach is useful for CDMA optical systems with multiple performance requirements.

  13. A Data Transmission Algorithm Based on Dynamic Grid Division for Coal Goaf Temperature Monitoring

    Directory of Open Access Journals (Sweden)

    Qingsong Hu

    2014-01-01

    Full Text Available WSN (wireless sensor network is a perfect tool of temperature monitoring in coal goaf. Based on the three-zone theory of goaf, the GtmWSN model is proposed, and its dynamic features are analyzed. Accordingly, a data transmission scheme, named DTDGD, is worked out. Firstly, sink nodes conduct dynamic grid division on the GtmWSN according to virtual semicircle. Secondly, each node will confirm to which grid it belongs based on grid number. Finally, data will be delivered to sink nodes with greedy forward and hole avoidance. Simulation results and field data showed that the GtmWSN and DTDGD satisfied the lifetime need of goaf temperature monitoring.

  14. The effect of structural design parameters on FPGA-based feed-forward space-time trellis coding-orthogonal frequency division multiplexing channel encoders

    Science.gov (United States)

    Passas, Georgios; Freear, Steven; Fawcett, Darren

    2010-08-01

    Orthogonal frequency division multiplexing (OFDM)-based feed-forward space-time trellis code (FFSTTC) encoders can be synthesised as very high speed integrated circuit hardware description language (VHDL) designs. Evaluation of their FPGA implementation can lead to conclusions that help a designer to decide the optimum implementation, given the encoder structural parameters. VLSI architectures based on 1-bit multipliers and look-up tables (LUTs) are compared in terms of FPGA slices and block RAMs (area), as well as in terms of minimum clock period (speed). Area and speed graphs versus encoder memory order are provided for quadrature phase shift keying (QPSK) and 8 phase shift keying (8-PSK) modulation and two transmit antennas, revealing best implementation under these conditions. The effect of number of modulation bits and transmit antennas on the encoder implementation complexity is also investigated.

  15. Energy-efficient orthogonal frequency division multiplexing-based passive optical network based on adaptive sleep-mode control and dynamic bandwidth allocation

    Science.gov (United States)

    Zhang, Chongfu; Xiao, Nengwu; Chen, Chen; Yuan, Weicheng; Qiu, Kun

    2016-02-01

    We propose an energy-efficient orthogonal frequency division multiplexing-based passive optical network (OFDM-PON) using adaptive sleep-mode control and dynamic bandwidth allocation. In this scheme, a bidirectional-centralized algorithm named the receiver and transmitter accurate sleep control and dynamic bandwidth allocation (RTASC-DBA), which has an overall bandwidth scheduling policy, is employed to enhance the energy efficiency of the OFDM-PON. The RTASC-DBA algorithm is used in an optical line terminal (OLT) to control the sleep mode of an optical network unit (ONU) sleep and guarantee the quality of service of different services of the OFDM-PON. The obtained results show that, by using the proposed scheme, the average power consumption of the ONU is reduced by ˜40% when the normalized ONU load is less than 80%, compared with the average power consumption without using the proposed scheme.

  16. An auxiliary graph based dynamic traffic grooming algorithm in spatial division multiplexing enabled elastic optical networks with multi-core fibers

    Science.gov (United States)

    Zhao, Yongli; Tian, Rui; Yu, Xiaosong; Zhang, Jiawei; Zhang, Jie

    2017-03-01

    A proper traffic grooming strategy in dynamic optical networks can improve the utilization of bandwidth resources. An auxiliary graph (AG) is designed to solve the traffic grooming problem under a dynamic traffic scenario in spatial division multiplexing enabled elastic optical networks (SDM-EON) with multi-core fibers. Five traffic grooming policies achieved by adjusting the edge weights of an AG are proposed and evaluated through simulation: maximal electrical grooming (MEG), maximal optical grooming (MOG), maximal SDM grooming (MSG), minimize virtual hops (MVH), and minimize physical hops (MPH). Numeric results show that each traffic grooming policy has its own features. Among different traffic grooming policies, an MPH policy can achieve the lowest bandwidth blocking ratio, MEG can save the most transponders, and MSG can obtain the fewest cores for each request.

  17. Improved MIMO radar GMTI via cyclic-shift transmission of orthogonal frequency division signals

    Science.gov (United States)

    Li, Fuyou; He, Feng; Dong, Zhen; Wu, Manqing

    2018-05-01

    Minimum detectable velocity (MDV) and maximum detectable velocity are both important in ground moving target indication (GMTI) systems. Smaller MDV can be achieved by longer baseline via multiple-input multiple-output (MIMO) radar. Maximum detectable velocity is decided by blind velocities associated with carrier frequencies, and blind velocities can be mitigated by orthogonal frequency division signals. However, the scattering echoes from different carrier frequencies are independent, which is not good for improving MDV performance. An improved cyclic-shift transmission is applied in MIMO GMTI system in this paper. MDV performance is improved due to the longer baseline, and maximum detectable velocity performance is improved due to the mitigation of blind velocities via multiple carrier frequencies. The signal model for this mode is established, the principle of mitigating blind velocities with orthogonal frequency division signals is presented; the performance of different MIMO GMTI waveforms is analysed; and the performance of different array configurations is analysed. Simulation results by space-time-frequency adaptive processing proves that our proposed method is a valid way to improve GMTI performance.

  18. Integrated photonics : compact multiplexing

    NARCIS (Netherlands)

    Pile, D.; Chen, H.; Uden, van R.G.H.; Okonkwo, C.M.; Koonen, A.M.J.

    2015-01-01

    Spatial multiplexers (SMUXs) for mode division multiplexing often involve multiple strategies for mode-selective excitation and the minimization of insertion and other losses. Haoshuo Chen, Roy van Uden, Chigo Okonkwo and Ton Koonen, working at the COBRA Institute at the Eindhoven University of

  19. Orbital angular momentum mode groups multiplexing transmission over 2.6-km conventional multi-mode fiber.

    Science.gov (United States)

    Zhu, Long; Wang, Andong; Chen, Shi; Liu, Jun; Mo, Qi; Du, Cheng; Wang, Jian

    2017-10-16

    Twisted light carrying orbital angular momentum (OAM) is a special kind of structured light that has a helical phase front, a phase singularity, and a doughnut intensity profile. Beyond widespread developments in manipulation, microscopy, metrology, astronomy, nonlinear and quantum optics, OAM-carrying twisted light has seen emerging application of optical communications in free space and specially designed fibers. Instead of specialty fibers, here we show the direct use of a conventional graded-index multi-mode fiber (MMF) for OAM communications. By exploiting fiber-compatible mode exciting and filtering elements, we excite the first four OAM mode groups in an MMF. We demonstrate 2.6-km MMF transmission using four data-carrying OAM mode groups (OAM 0,1 , OAM +1,1 /OAM -1,1 , OAM +2,1 , OAM +3,1 ). Moreover, we demonstrate two data-carrying OAM mode groups multiplexing transmission over the 2.6-km MMF with low-level crosstalk free of multiple-input multiple-output digital signal processing (MIMO-DSP). The demonstrations may open up new perspectives to fiber-based OAM communication/non-communication applications using already existing conventional fibers.

  20. Management of sexually transmissible infections in the era of multiplexed molecular diagnostics: a primary care survey.

    Science.gov (United States)

    Brosh-Nissimov, Tal; Kedem, Ron; Ophir, Nimrod; Shental, Omri; Keller, Nathan; Amit, Sharon

    2018-04-30

    Background: Data regarding sexually transmissible infections (STI) often originate from STI clinics, screening programs or laboratory-based studies, thus are biased for specific risk groups or lack clinical details. This real-life observational study presents sample data of most young adult Israeli population by exploiting the centralised diagnostic and documentation platforms resulting from a mandatory military service at the age of 18 years for both genders. Methods: All STI diagnoses of Israeli Defence Forces soldiers during a 6-month period were reviewed. Patients with Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) (major-STI) and Ureaplasma urealyticum (UU), Ureaplasma parvum (UP) and Mycoplasma hominis (MH) (equivocal STI) were compared with STI-negative controls. Results: Sexually transmissible infection positivity rates (n=2816) were as follows: CT 6.6%; MG 1.9%; NG 0.7%; TV 0.5%; UU 15.7%; UP 28.2%; and MH 6.2%. The CT+MG coinfection rate was 4.1%, yet CT+NG coinfections were rare (≈0.5%). More than half of the patients with ureaplasmas and/or MH were treated; 40% of them were recommended partner treatment. Most antibiotics were prescribed to patients with equivocal infections. Classic STI symptoms in males were linked to major-STI and UU, while females were asymptomatic or presented non-specific symptoms. Conclusions: The judicious use of antibiotics in the era of antimicrobial resistance necessitates re-evaluating the significance of equivocal pathogen detection and reporting (MH, UU, UP). Likewise, universal empiric treatment for NG should be reconsidered in light of its low rates in non-high-risk groups. Conversely, a high MG rate, a pathogen with potential resistance to common STI protocols, requires evaluation of guidelines adequacy.

  1. 60 Gbit/s 400 GHz Wireless Transmission

    DEFF Research Database (Denmark)

    Yu, Xianbin; Asif, Rameez; Piels, Molly

    2015-01-01

    We experimentally demonstrate a 400 GHz carrier wireless transmission system with real-time capable detection and demonstrate transmission of a 60 Gbit/s signal derived from optical Nyquist channels in a 12.5 GHz ultra-dense wavelength division multiplexing (UD-WDM) grid and carrying QPSK...

  2. Combined peak-to-average power ratio reduction and physical layer security enhancement in optical orthogonal frequency division multiplexing visible-light communication systems

    Science.gov (United States)

    Wang, Zhongpeng; Chen, Shoufa

    2016-07-01

    A physical encryption scheme for discrete Hartley transform (DHT) precoded orthogonal frequency division multiplexing (OFDM) visible-light communication (VLC) systems using frequency domain chaos scrambling is proposed. In the scheme, the chaos scrambling, which is generated by a modified logistic mapping, is utilized to enhance the physical layer of security, and the DHT precoding is employed to reduce of OFDM signal for OFDM-based VLC. The influence of chaos scrambling on peak-to-average power ratio (PAPR) and bit error rate (BER) of systems is studied. The experimental simulation results prove the efficiency of the proposed encryption method for DHT-precoded, OFDM-based VLC systems. Furthermore, the influence of the proposed encryption to the PAPR and BER of systems is evaluated. The experimental results show that the proposed security scheme can protect the DHT-precoded, OFDM-based VLC from eavesdroppers, while keeping the good BER performance of DHT-precoded systems. The BER performance of the encrypted and DHT-precoded system is almost the same as that of the conventional DHT-precoded system without encryption.

  3. Design and characterization of 16-mode PANDA polarization-maintaining few-mode ring-core fiber for spatial division multiplexing

    Science.gov (United States)

    Cao, Yuan; Zhao, Yongli; Yu, Xiaosong; Han, Jiawei; Zhang, Jie

    2017-11-01

    A PANDA polarization-maintaining few-mode ring-core fiber (PM-FM-RCF) structure with two air holes around the ring core is proposed. The relative mode multiplicity factor (RMMF) is defined to evaluate the spatial efficiency of the designed PM-FM-RCF. The performance analysis and comparison of the proposed PANDA PM-FM-RCFs considering three different types of step-index profiles are detailed. Through modal characteristic analysis and numerical simulation, the PM-FM-RCF with a lower refractive index difference (Δnoi=1.5%) between the ring core and the inner central circle can support up to 16 polarization modes with large RMMF at C-band, which shows the optimum modal properties compared with the PM-FM-RCF with higher Δnoi. All the supported polarization modes are effectively separated from their adjacent polarization modes with effective refractive index differences (Δn) larger than 10-4, which also show relatively small chromatic dispersion (-20 to 25 ps/nm/km), low attenuation (<1.4 dB/km), and small bending radius (˜8 mm) over the C-band. The designed PM-FM-RCF can be compatible with standard single-mode fibers and applied in multiple-input multiple-output-free spatial division multiplexing optical networks for short-reach optical interconnection.

  4. Peak-to-average power ratio reduction in orthogonal frequency division multiplexing-based visible light communication systems using a modified partial transmit sequence technique

    Science.gov (United States)

    Liu, Yan; Deng, Honggui; Ren, Shuang; Tang, Chengying; Qian, Xuewen

    2018-01-01

    We propose an efficient partial transmit sequence technique based on genetic algorithm and peak-value optimization algorithm (GAPOA) to reduce high peak-to-average power ratio (PAPR) in visible light communication systems based on orthogonal frequency division multiplexing (VLC-OFDM). By analysis of hill-climbing algorithm's pros and cons, we propose the POA with excellent local search ability to further process the signals whose PAPR is still over the threshold after processed by genetic algorithm (GA). To verify the effectiveness of the proposed technique and algorithm, we evaluate the PAPR performance and the bit error rate (BER) performance and compare them with partial transmit sequence (PTS) technique based on GA (GA-PTS), PTS technique based on genetic and hill-climbing algorithm (GH-PTS), and PTS based on shuffled frog leaping algorithm and hill-climbing algorithm (SFLAHC-PTS). The results show that our technique and algorithm have not only better PAPR performance but also lower computational complexity and BER than GA-PTS, GH-PTS, and SFLAHC-PTS technique.

  5. Implementasi dan Evaluasi Kinerja Multi Input SingleOutput Orthogonal Frequency Division Multiplexing (MISO OFDM Menggunakan Wireless Open Access Research Platform (WARP

    Directory of Open Access Journals (Sweden)

    Galih Permana Putra

    2017-01-01

    Full Text Available Teknologi komunikasi nirkabel terus berkembang untuk memenuhi kebutuhan manusia akan koneksi informasi yang cepat, pengiriman data yang berkapasitas besar dan dapat diandalkan. Di dalam proses tersebut banyak sekali gangguan yang dapat mempengaruhi penurunan kinerja komunikasi diantaranya adalah multipath fading [1]. Multi Input Single Output (MISO merupakan salah satu teknik space diversity yang menggunakan banyak antena dengan tujuan untuk mengatasi multipath fading. Adapun pada proses transmisi digunakan teknik Orthogonal Frequency-Division Multiplexing (OFDM yang bertujuan memberikan keuntungan dalam hal efisiensi pada saat transmisi data dan mampu menghindari Inter Simbol Interference (ISI. Pada penelitian ini akan dibandingkan kinerja sistem MISO OFDM dan SISO OFDM yang akan disimulasikan dan di implementasikan pada modul Wireless Open Access Penelitian Platform (WARP untuk mengevaluasi kinerja BER sebagai fungsi dari daya pancar dan jarak variasi. Parameter yang digunakan di dalam pengukuran berdasarkan IEEE 802.11 a/g karena menggunakan frekuensi 2,4 Ghz. Terdapat dua skema pengukuran yaitu SISO OFDM dan MISO OFDM dengan variasi jarak 4,6 dan 8 meter dengan variasi daya pancar -35 s/d -4 dBm dengan peningkatan gain 5 kali secara berkala. Dari dua skema yang dilaksanakan dapat disimpulkan bahwa semakin jauh jarak antara pemancar dan penerima maka dibutuhkan penambahan gain untuk menjaga kualitas data yang dikirimkan. Disamping itu, terdapat perbedaan nilai gain untuk mencapai nilai BER = dibutuhkan penambahan gain = - 33 sedangkan pada SISO OFM dibutuhkan penambahan gain = -18.

  6. 32 X 2.5 Gb/s Optical Code Division Multiplexing (O-CDM) For Agile Optical Networking (Phase II) Final Report CRADA No. TC02051.0

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C. V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mendez, A. J. [Mendez R & D Associates, El Segundo, CA (United States)

    2017-09-08

    This was a collaborative effort between Lawrence Livermore National Security, LLC (formerly The Regents of the University of California)/Lawrence Livermore National Laboratory (LLNL) and Mendez R & D Associates (MRDA) to develop and demonstrate a reconfigurable and cost effective design for optical code division multiplexing (O-CDM) with high spectral efficiency and throughput, as applied to the field of distributed computing, including multiple accessing (sharing of communication resources) and bidirectional data distribution in fiber-to-the-premise (FTTx) networks.

  7. A Comparative Study of Multiplexing Schemes for Next Generation Optical Access Networks

    Science.gov (United States)

    Imtiaz, Waqas A.; Khan, Yousaf; Shah, Pir Mehar Ali; Zeeshan, M.

    2014-09-01

    Passive optical network (PON) is a high bandwidth, economical solution which can provide the necessary bandwidth to end-users. Wavelength division multiplexed passive optical networks (WDM PONs) and time division multiplexed passive optical networks (TDM PONs) are considered as an evolutionary step for next-generation optical access (NGOA) networks. However they fail to provide highest transmission capacity, efficient bandwidth access, and robust dispersion tolerance. Thus future PONs are considered on simpler, efficient and potentially scalable, optical code division multiplexed (OCDM) PONs. This paper compares the performance of existing PONs with OCDM PON to determine a suitable scheme for NGOA networks. Two system parameter are used in this paper: fiber length, and bit rate. Performance analysis using Optisystem shows that; for a sufficient system performance parameters i.e. bit error rate (BER) ≤ 10-9, and maximum quality factor (Q) ≥ 6, OCDMA PON efficiently performs upto 50 km with 10 Gbit/s per ONU.

  8. Dual-drive Mach-Zehnder modulator-based reconfigurable and transparent spectral conversion for dense wavelength division multiplexing transmissions

    Science.gov (United States)

    Mao, Mingzhi; Qian, Chen; Cao, Bingyao; Zhang, Qianwu; Song, Yingxiong; Wang, Min

    2017-09-01

    A digital signal process enabled dual-drive Mach-Zehnder modulator (DD-MZM)-based spectral converter is proposed and extensively investigated to realize dynamically reconfigurable and high transparent spectral conversion. As another important innovation point of the paper, to optimize the converter performance, the optimum operation conditions of the proposed converter are deduced, statistically simulated, and experimentally verified. The optimum conditions supported-converter performances are verified by detail numerical simulations and experiments in intensity-modulation and direct-detection-based network in terms of frequency detuning range-dependent conversion efficiency, strict operation transparency for user signal characteristics, impact of parasitic components on the conversion performance, as well as the converted component waveform are almost nondistortion. It is also found that the converter has the high robustness to the input signal power, optical signal-to-noise ratio variations, extinction ratio, and driving signal frequency.

  9. 32-core erbium/ytterbium-doped multicore fiber amplifier for next generation space-division multiplexed transmission system

    DEFF Research Database (Denmark)

    Jain, Saurabh; Castro, Carlos; Jung, Yongmin

    2017-01-01

    We present a high-core-count 32-core multicore erbium/ytterbium-doped fiber amplifier (32c-MC-EYDFA) in a cladding pumped configuration. A side pumping technique is employed for ease of pump coupling in this monolithic all-fiber amplifier. A minimum gain of >17 dB and an average noise figure (NF)...

  10. Clock-distribution with instantaneous synchronisation for 160 Gbit/s optical time-domain multiplexed packet transmission

    NARCIS (Netherlands)

    Gomez-Agis, F.; Calabretta, N.; Albores Mejia, A.; Dorren, H.J.S.

    2010-01-01

    We demonstrate for the first time, to our knowledge, a clock-distribution method for ultra-high-speed optical time-domain multiplexed systems data packets that provides instantaneous synchronization, fast locking/unlocking times, and a highly stable bursty clock, enabling error-free operation of 160

  11. Coherence Multiplex System Topologies

    NARCIS (Netherlands)

    Meijerink, Arjan; Taniman, R.O.; Heideman, G.H.L.M.; van Etten, Wim

    2007-01-01

    Coherence multiplexing is a potentially inexpensive form of optical code-division multiple access, which is particularly suitable for short-range applications with moderate bandwidth requirements, such as access networks, LANs, or interconnects. Various topologies are known for constructing an

  12. Design and numerical optimization of a mode multiplexer based on few-mode fiber couplers

    International Nuclear Information System (INIS)

    Xie, Yiwei; Fu, Songnian; Liu, Hai; Zhang, Hailiang; Tang, Ming; Liu, Deming; Shum, P

    2013-01-01

    Mode division multiplexing (MDM) transmission based on few-mode fibers (FMFs) appears to be an alternative solution for overcoming the capacity limit of single-mode fibers (SMFs). A FMF coupler-based mode division multiplexer/demultiplexer (MMUX/DeMMUX) is proposed and theoretically investigated after the fabricated FMF is characterized. MMUXs/DeMMUXs with a mode contrast ratio (MCR) of more than 20 dB can be obtained for two-mode multiplexing and three-mode multiplexing over a wavelength span of 60 and 10 nm, respectively. We numerically verify the proposed MMUX/DeMMUX which has the advantages of high MCR, easy fabrication and maintenance, and low wavelength dependence. (paper)

  13. OAM-enhanced transmission for multimode short-range links

    DEFF Research Database (Denmark)

    Tatarczak, Anna; Usuga Castaneda, Mario A.; Tafur Monroy, Idelfonso

    2015-01-01

    We propose, experimentally demonstrate, and evaluate the performance of a multimode (MM) transmission fiber data link which is based on orbital angular momentum (OAM) modes. The proposed scheme uses OAM modes to increase capacity or reach without recurring to mode division multiplexing (MDM...

  14. Transmission of persistent ionizing radiation-induced foci through cell division in human primary cells

    Energy Technology Data Exchange (ETDEWEB)

    Vaurijoux, Aurelie, E-mail: aurelie.vaurijoux@irsn.fr [Institut de Radioprotection et de Sureté Nucléaire (IRSN), Laboratoire de Dosimétrie Biologique, BP 17, 92262 Fontenay aux roses cedex (France); Voisin, Pascale; Freneau, Amelie [Institut de Radioprotection et de Sureté Nucléaire (IRSN), Laboratoire de Dosimétrie Biologique, BP 17, 92262 Fontenay aux roses cedex (France); Barquinero, Joan Francesc [Universitat Autònoma de Barcelona, Faculty of Biosciences, 08193 Cerdanyola del Vallès (Spain); Gruel, Gaetan [Institut de Radioprotection et de Sureté Nucléaire (IRSN), Laboratoire de Dosimétrie Biologique, BP 17, 92262 Fontenay aux roses cedex (France)

    2017-03-15

    Highlights: • Persistent IRIF do not permanently block cell proliferation. • Persistent IRIF are transmitted in part and sometimes asymmetrically to daughter cells. • IRIF differ in their nature before and after the first cell division. - Abstract: Unrepaired DNA double-strand breaks (DSBs) induced by ionizing radiation are associated with lethal effects and genomic instability. After the initial breaks and chromatin destabilization, a set of post-translational modifications of histones occurs, including phosphorylation of serine 139 of histone H2AX (γH2AX), which leads to the formation of ionizing radiation-induced foci (IRIF). DSB repair results in the disappearance of most IRIF within hours after exposure, although some remain 24 h after irradiation. Their relation to unrepaired DSBs is generally accepted but still controversial. This study evaluates the frequency and kinetics of persistent IRIF and analyzes their impact on cell proliferation. We observed persistent IRIF up to 7 days postirradiation, and more than 70% of cells exposed to 5 Gy had at least one of these persistent IRIF 24 h after exposure. Moreover we demonstrated that persistent IRIF did not block cell proliferation definitively. The frequency of IRIF was lower in daughter cells, due to asymmetric distribution of IRIF between some of them. We report a positive association between the presence of IRIF and the likelihood of DNA missegregation. Hence, the structure formed after the passage of a persistent IRI focus across the S and G2 phases may impede the correct segregation of the affected chromosome's sister chromatids. The ensuing abnormal resolution of anaphase might therefore cause the nature of IRIF in daughter-cell nuclei to differ before and after the first cell division. The resulting atypical chromosomal assembly may be lethal or result in a gene dosage imbalance and possibly enhanced genomic instability, in particular in the daughter cells.

  15. Transmission of persistent ionizing radiation-induced foci through cell division in human primary cells

    International Nuclear Information System (INIS)

    Vaurijoux, Aurelie; Voisin, Pascale; Freneau, Amelie; Barquinero, Joan Francesc; Gruel, Gaetan

    2017-01-01

    Highlights: • Persistent IRIF do not permanently block cell proliferation. • Persistent IRIF are transmitted in part and sometimes asymmetrically to daughter cells. • IRIF differ in their nature before and after the first cell division. - Abstract: Unrepaired DNA double-strand breaks (DSBs) induced by ionizing radiation are associated with lethal effects and genomic instability. After the initial breaks and chromatin destabilization, a set of post-translational modifications of histones occurs, including phosphorylation of serine 139 of histone H2AX (γH2AX), which leads to the formation of ionizing radiation-induced foci (IRIF). DSB repair results in the disappearance of most IRIF within hours after exposure, although some remain 24 h after irradiation. Their relation to unrepaired DSBs is generally accepted but still controversial. This study evaluates the frequency and kinetics of persistent IRIF and analyzes their impact on cell proliferation. We observed persistent IRIF up to 7 days postirradiation, and more than 70% of cells exposed to 5 Gy had at least one of these persistent IRIF 24 h after exposure. Moreover we demonstrated that persistent IRIF did not block cell proliferation definitively. The frequency of IRIF was lower in daughter cells, due to asymmetric distribution of IRIF between some of them. We report a positive association between the presence of IRIF and the likelihood of DNA missegregation. Hence, the structure formed after the passage of a persistent IRI focus across the S and G2 phases may impede the correct segregation of the affected chromosome's sister chromatids. The ensuing abnormal resolution of anaphase might therefore cause the nature of IRIF in daughter-cell nuclei to differ before and after the first cell division. The resulting atypical chromosomal assembly may be lethal or result in a gene dosage imbalance and possibly enhanced genomic instability, in particular in the daughter cells.

  16. Design and fabrication of three-dimensional polymer mode multiplexer based on asymmetric waveguide couplers

    Science.gov (United States)

    He, Guobing; Gao, Yang; Xu, Yan; Ji, Lanting; Sun, Xiaoqiang; Wang, Xibin; Yi, Yunji; Chen, Changming; Wang, Fei; Zhang, Daming; Wu, Yuanda

    2018-05-01

    A polymer mode multiplexer based on asymmetric couplers is theoretically designed and experimentally demonstrated. The proposed X-junction coupler is formed by waveguides overlapped with different crossing angles in the vertical direction. A beam propagation method is adopted to optimize the dimensional parameters of the mode multiplexer to convert LP01 mode of two lower waveguides to LP11a and LP21a mode of the upper waveguide. The ultraviolet lithography and wet chemical etching are used in the fabrication process. A conversion ratio over 98% for both LP11a and LP21a mode in the wavelength range from 1530 to 1570 nm are experimentally demonstrated. This mode multiplexer has potential in broadband mode-division multiplexing transmission systems.

  17. Dielectric multilayer beam splitter with differential phase shift on transmission and reflection for division-of-amplitude photopolarimeter.

    Science.gov (United States)

    Yuan, Wenjia; Shen, Weidong; Zhang, Yueguang; Liu, Xu

    2014-05-05

    Dielectric multilayer beam splitter with differential phase shift on transmission and reflection for division-of-amplitude photopolarimeter (DOAP) was presented for the first time to our knowledge. The optimal parameters for the beam splitter are Tp = 78.9%, Ts = 21.1% and Δr - Δt = π/2 at 532nm at an angle of incidence of 45°. Multilayer anti-reflection coating with low phase shift was applied to reduce the backside reflection. Different design strategies that can achieve all optimal targets at the wavelength were tested. Two design methods were presented to optimize the differential phase shift. The samples were prepared by ion beam sputtering (IBS). The experimental results show good agreement with those of the design. The ellipsometric parameters of samples were measured in reflection (ψr, Δr) = (26.5°, 135.1°) and (28.2°, 133.5°), as well as in transmission (ψt, Δt) = (62.5°, 46.1°) and (63.5°, 46°) at 532.6nm. The normalized determinant of instrument matrix to evaluate the performance of samples is respectively 0.998 and 0.991 at 532.6nm.

  18. Recent advances in high-capacity free-space optical and radio-frequency communications using orbital angular momentum multiplexing

    Science.gov (United States)

    Ren, Yongxiong; Xie, Guodong; Yan, Yan; Li, Long; Zhao, Zhe; Wang, Jian; Tur, Moshe; Molisch, Andreas F.; Ashrafi, Solyman

    2017-01-01

    There is a continuing growth in the demand for data bandwidth, and the multiplexing of multiple independent data streams has the potential to provide the needed data capacity. One technique uses the spatial domain of an electromagnetic (EM) wave, and space division multiplexing (SDM) has become increasingly important for increased transmission capacity and spectral efficiency of a communication system. A subset of SDM is mode division multiplexing (MDM), in which multiple orthogonal beams each on a different mode can be multiplexed. A potential modal basis set to achieve MDM is to use orbital angular momentum (OAM) of EM waves. In such a system, multiple OAM beams each carrying an independent data stream are multiplexed at the transmitter, propagate through a common medium and are demultiplexed at the receiver. As a result, the total capacity and spectral efficiency of the communication system can be multiplied by a factor equal to the number of transmitted OAM modes. Over the past few years, progress has been made in understanding the advantages and limitations of using multiplexed OAM beams for communication systems. In this review paper, we highlight recent advances in the use of OAM multiplexing for high-capacity free-space optical and millimetre-wave communications. We discuss different technical challenges (e.g. atmospheric turbulence and crosstalk) as well as potential techniques to mitigate such degrading effects. This article is part of the themed issue ‘Optical orbital angular momentum’. PMID:28069770

  19. The radio-on-fiber-wavelength-division-multiplexed-passive-optical network (WDM-RoF-PON) for wireless and wire layout with linearly-polarized dual-wavelength fiber laser and carrier reusing

    Science.gov (United States)

    Ji, Wei; Chang, Jun

    2013-07-01

    In this paper, we design a WDM-RoF-PON based on linearly-polarized dual-wavelength fiber laser and CSRZ-DPSK, which can achieve wire-line and wireless access synchronously. With the CSRZ-DPSK modulation, the wireless access in ONU can save RF source and the frequency of radio carrier can be controlled by OLT. The dual-wavelength fiber laser is the union light source of WDM-PON with polarization multiplexing. By the RSOA and downstream light source reusing, the ONU can save omit laser source and makes the WDM-PON to be colorless. The networking has the credible transmission property, including wireless access and fiber transmission. The networking also has excellent covering range.

  20. Polarization-multiplexing ghost imaging

    Science.gov (United States)

    Dongfeng, Shi; Jiamin, Zhang; Jian, Huang; Yingjian, Wang; Kee, Yuan; Kaifa, Cao; Chenbo, Xie; Dong, Liu; Wenyue, Zhu

    2018-03-01

    A novel technique for polarization-multiplexing ghost imaging is proposed to simultaneously obtain multiple polarimetric information by a single detector. Here, polarization-division multiplexing speckles are employed for object illumination. The light reflected from the objects is detected by a single-pixel detector. An iterative reconstruction method is used to restore the fused image containing the different polarimetric information by using the weighted sum of the multiplexed speckles based on the correlation coefficients obtained from the detected intensities. Next, clear images of the different polarimetric information are recovered by demultiplexing the fused image. The results clearly demonstrate that the proposed method is effective.

  1. Seamless Translation of Optical Fiber PolMux-OFDM into a 2x2 MIMO Wireless Transmission Enabled by Digital Training-Based Fiber-Wireless Channel Estimation

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Zhao, Ying; Deng, Lei

    2011-01-01

    We propose and demonstrate a 2 × 2 multiple-input multiple-output (MIMO) wireless over fiber transmission system. Seamless translation of two orthogonal frequency division multiplexing (OFDM) signals on dual optical polarization states into wireless MIMO transmission at 795.5 Mbit/s net data rate...

  2. 32-core Dense SDM Unidirectional Transmission of PDM-16QAM Signals Over 1600 km Using Crosstalk-managed Single-mode Heterogeneous Multicore Transmission Line

    DEFF Research Database (Denmark)

    Mizuno, Takayuki; Shibahara, K.; Ono, Hirotaka

    2016-01-01

    We demonstrate 32-core dense space-division multiplexed (DSDM) unidirectional transmission of PDM-16QAM 20-WDM signals over 1644.8 km employing a low-crosstalk single-mode heterogeneous 32-core fiber in a partial recirculating-loop system....

  3. Strain measurement using multiplexed fiber optic sensors

    International Nuclear Information System (INIS)

    Kwon, Il Bum; Kim, Chi Yeop; Yoon, Dong Jin; Lee, Seung Seok

    2003-01-01

    FBG(Fiber Bragg grating) sensor, which is one of the fiber optic sensors for the application of smart structures, can not only measure one specific point but also multiple points by multiplexing techniques. We have proposed a novel multiplexing technique of FBG sensor by the intensity modulation of light source. This technique is applicable to WDM(Wavelength Division Multiplexing) technique and number of sensors in this system can be increased by using this technique with WDM technique.

  4. Optical Time-Division Multiplexing of 10 Gbit/s Ethernet Signals Synchronized by All-Optical Signal Processing Based on a Time-Lens

    DEFF Research Database (Denmark)

    Areal, Janaina Laguardia

    This Thesis presents 3 years work of an optical circuit that performs both pulse compression and frame synchronization and retiming. Our design aims at directly multiplexing several 10G Ethernet data packets (frames) to a high-speed OTDM link. This scheme is optically transparent and does not req...... coupler, completing the OTDM signal generation. We demonstrate the effectiveness of the design by laboratory experiments and simulations with VPI and MatLab....... not require clock recovery, resulting in a potentially very efficient solution. The scheme uses a time-lens, implemented through a sinusoidally driven optical phase modulation, combined with a linear dispersion element. As time-lenses are also used for pulse compression, we design the circuit also to perform...

  5. Division Multiplexing of 10 Gbit/s Ethernet Signals Synchronized by All-Optical Signal Processing Based on a Time-Lens

    DEFF Research Database (Denmark)

    Areal, Janaina Laguardia

    This Thesis presents 3 years work of an optical circuit that performs both pulse compression and frame synchronization and retiming. Our design aims at directly multiplexing several 10G Ethernet data packets (frames) to a high-speed OTDM link. This scheme is optically trans-parent and does not re...... coupler, completing the OTDM signal generation. We demonstrate the effectiveness of the design by laboratory experi-ments and simulations with VPI and MatLab....... not require clock recovery, resulting in a potentially very efficient solution. The scheme uses a time-lens, implemented through a sinusoidally driven optical phase modulation, combined with a linear dispersion element. As time-lenses are also used for pulse compression, we de-sign the circuit also to perform...

  6. All optical OFDM transmission for passive optical networks

    Science.gov (United States)

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

    2017-06-01

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

  7. Power-efficient method for IM-DD optical transmission of multiple OFDM signals.

    Science.gov (United States)

    Effenberger, Frank; Liu, Xiang

    2015-05-18

    We propose a power-efficient method for transmitting multiple frequency-division multiplexed (FDM) orthogonal frequency-division multiplexing (OFDM) signals in intensity-modulation direct-detection (IM-DD) optical systems. This method is based on quadratic soft clipping in combination with odd-only channel mapping. We show, both analytically and experimentally, that the proposed approach is capable of improving the power efficiency by about 3 dB as compared to conventional FDM OFDM signals under practical bias conditions, making it a viable solution in applications such as optical fiber-wireless integrated systems where both IM-DD optical transmission and OFDM signaling are important.

  8. Analogue multiplexer

    International Nuclear Information System (INIS)

    Gorshkov, V.A.; Kuznetsov, A.N.

    1980-01-01

    In systems of signal recording from several parallel spectrometric channels one can considerably reduce the total apparatus volume using a special unit - an analog multiplexer. A description of the multiplexer in the CAMAC system on the base of fast linear gating circuits which allows one analog-to-code converter to attend four spectrometric channels is given. On the example of the 4-channel spectrometer the logics of interaction of the multiple with analog-to-digital coxernver and signal recorder is shown. Electrical and functional multiplexer flow-sheets are given and its main characteristics are presented

  9. Dense SDM (12-Core × 3-Mode) Transmission Over 527 km With 33.2-ns Mode-Dispersion Employing Low-Complexity Parallel MIMO Frequency-Domain Equalization

    DEFF Research Database (Denmark)

    Shibahara, Kohki; Lee, Doohwan; Kobayashi, Takayuki

    2016-01-01

    We propose long-haul space-division-multiplexing (SDM) transmission systems employing parallel multiple-input multiple-output (MIMO) frequency-domain equalization (FDE) and transmission fiber with low differential mode delay (DMD). We first discuss the advantages of parallel MIMO FDE technique in...

  10. Crosstalk Analysis of 32-Core Dense Space Division Multiplexed System for Higher Order Modulation Formats Using an Integrated Cladding-Pumped Amplifier

    DEFF Research Database (Denmark)

    Castro, C.; Jain, S.; Jung, Y.

    2017-01-01

    We analyse the crosstalk performance of a fully integrated inline amplified 32-core link for 100G QPSK, 150G 8QAM, 200G 16-QAM, and 250G 32QAM in a recirculating loop. Transmission distances over 1000 km are confirmed for 8-QAM and QPSK channels.......We analyse the crosstalk performance of a fully integrated inline amplified 32-core link for 100G QPSK, 150G 8QAM, 200G 16-QAM, and 250G 32QAM in a recirculating loop. Transmission distances over 1000 km are confirmed for 8-QAM and QPSK channels....

  11. Theoretical analysis and simulation of a code division multiple access system (cdma for secure signal transmission in wideband channels

    Directory of Open Access Journals (Sweden)

    Stevan M. Berber

    2014-06-01

    Code Division Multiple Access (CDMA technique which allows communications of multiple users in the same communication system. This is achieved in such a way that each user is assigned a unique code sequence, which is used at the receiver side to discover the information dedicated to that user. These systems belong to the group of communication systems for direct sequence spread spectrum systems. Traditionally, CDMA systems use binary orthogonal spreading codes. In this paper, a mathematical model and simulation of a CDMA system based on the application of non-binary, precisely speaking, chaotic spreading sequences. In their nature, these sequences belong to random sequences with infinite periodicity, and due to that they are appropriate for applications in the systems that provide enhanced security against interception and secrecy in signal transmission. Numerous papers are dedicated to the development of CDMA systems in flat fading channels. This paper presents the results of these systems analysis for the case when frequency selective fading is present in the channel. In addition, the paper investigates a possibility of using interleaving techniques to mitigate fading in a wideband channel with the frequency selective fading. Basic structure of a CDMA communication system and its operation In this paper, a CDMA system block schematic is ppresented and the function of all blocks is explained. Notation  to be used in the paper is introduced. Chaotic sequences are defined and explained in accordance with the method of their generation. A wideband channel with frequency selective fading is defined by its impulse response function. Theoretical analysis of a CDMA system with flat fading in a narrowband channel A narrowband channel and flat fading are defined. A mathematical analysis of the system is conducted by presenting the signal expressions at vital points in the transmitter and receiver. The expression of the signal at the output of the sequence correlator is

  12. Transmission analysis in WDM networks

    DEFF Research Database (Denmark)

    Rasmussen, Christian Jørgen

    1999-01-01

    This thesis describes the development of a computer-based simulator for transmission analysis in optical wavelength division multiplexing networks. A great part of the work concerns fundamental optical network simulator issues. Among these issues are identification of the versatility and user...... the different component models are invoked during the simulation of a system. A simple set of rules which makes it possible to simulate any network architectures is laid down. The modelling of the nonlinear fibre and the optical receiver is also treated. The work on the fibre concerns the numerical solution...

  13. Fully Integrated, Multiport, Planar-Waveguide, Spectral Comparators and Multiplexers Based on Lithographic Holography

    National Research Council Canada - National Science Library

    Mossberg, Thomas; Greiner, Christoph

    2005-01-01

    .... for the first time the successful application of HBRs to wavelength division multiplexing. Measured device performance indicates that the photolithographic fabrication process has reduced multiplexer designs to practice essentially perfectly...

  14. Ultra-High Capacity Silicon Photonic Interconnects through Spatial Multiplexing

    Science.gov (United States)

    Chen, Christine P.

    The market for higher data rate communication is driving the semiconductor industry to develop new techniques of writing at smaller scales, while continuing to scale bandwidth at low power consumption. Silicon photonic (SiPh) devices offer a potential solution to the electronic interconnect bandwidth bottleneck. SiPh leverages the technology commensurate of decades of fabrication development with the unique functionality of next-generation optical interconnects. Finer fabrication techniques have allowed for manufacturing physical characteristics of waveguide structures that can support multiple modes in a single waveguide. By refining modal characteristics in photonic waveguide structures, through mode multiplexing with the asymmetric y-junction and microring resonator, higher aggregate data bandwidth is demonstrated via various combinations of spatial multiplexing, broadening applications supported by the integrated platform. The main contributions of this dissertation are summarized as follows. Experimental demonstrations of new forms of spatial multiplexing combined together exhibit feasibility of data transmission through mode-division multiplexing (MDM), mode-division and wavelength-division multiplexing (MDM-WDM), and mode-division and polarization-division multiplexing (MDM-PDM) through a C-band, Si photonic platform. Error-free operation through mode multiplexers and demultiplexers show how data can be viably scaled on multiple modes and with existing spatial domains simultaneously. Furthermore, we explore expanding device channel support from two to three arms. Finding that a slight mismatch in the third arm can increase crosstalk contributions considerably, especially when increasing data rate, we explore a methodical way to design the asymmetric y-junction device by considering its angles and multiplexer/demultiplexer arm width. By taking into consideration device fabrication variations, we turn towards optimizing device performance post

  15. Advanced Silicon Photonic Transceivers - the Case of a Wavelength Division and Polarization Multiplexed Quadrature Phase Shift Keying Receiver for Terabit/s Optical Transmission

    Science.gov (United States)

    2017-03-10

    formats by the co- integration of a passive 90 degree optical hybrid, highspeed balanced Ge photodetectors and a high-speed two-channel transimpedance...40 Gbaud and can handle advanced modulation formats by the co-integration of a passive 90 degree optical hybrid, high- speed balanced Ge...reached at an OSNR of 12.4 dB. The hard -decision FEC (HD-FEC) threshold (BER of 3.8 × 10-3 for 7% overhead) requires 14 dB OSNR. For 16-QAM this requires

  16. Equalizer Complexity for 6-LP Mode 112 Gbit/s m-ary DP-QAM Space Division Multiplexed Transmission in Strongly Coupled Few-Mode-Fibers

    DEFF Research Database (Denmark)

    Asif, Rameez; Ye, Feihong; Morioka, Toshio

    2015-01-01

    12×12 multiple-input multiple-output (MIMO) adaptive digital signal processing (DSP). Time domain equalization (TDE) is realized to implement the linear adaptive MIMO module that is implemented in blind mode using conventional constant-modulusalgorithm (CMA) for finite impulse response (FIR) adaptive......We have quantified equalizer complexity for transmitting dual-polarized 6-LP modes (LP01, LP11a, LP11b, LP21a, LP21b and LP02) of 112 Gbit/s m-ary QAM (m=4, 16, 32, 64, 256) single carrier signals over 20 km step-index few-mode fiber. The transmitted signals are strongly coupled and recovered using...

  17. A simple electron multiplexer

    International Nuclear Information System (INIS)

    Dobrzynski, L; Akjouj, A; Djafari-Rouhani, B; Al-Wahsh, H; Zielinski, P

    2003-01-01

    We present a simple multiplexing device made of two atomic chains coupled by two other transition metal atoms. We show that this simple atomic device can transfer electrons at a given energy from one wire to the other, leaving all other electron states unaffected. Closed-form relations between the transmission coefficients and the inter-atomic distances are given to optimize the desired directional electron ejection. Such devices can be adsorbed on insulating substrates and characterized by current surface technologies. (letter to the editor)

  18. IQ imbalance tolerable parallel-channel DMT transmission for coherent optical OFDMA access network

    Science.gov (United States)

    Jung, Sang-Min; Mun, Kyoung-Hak; Jung, Sun-Young; Han, Sang-Kook

    2016-12-01

    Phase diversity of coherent optical communication provides spectrally efficient higher-order modulation for optical communications. However, in-phase/quadrature (IQ) imbalance in coherent optical communication degrades transmission performance by introducing unwanted signal distortions. In a coherent optical orthogonal frequency division multiple access (OFDMA) passive optical network (PON), IQ imbalance-induced signal distortions degrade transmission performance by interferences of mirror subcarriers, inter-symbol interference (ISI), and inter-channel interference (ICI). We propose parallel-channel discrete multitone (DMT) transmission to mitigate transceiver IQ imbalance-induced signal distortions in coherent orthogonal frequency division multiplexing (OFDM) transmissions. We experimentally demonstrate the effectiveness of parallel-channel DMT transmission compared with that of OFDM transmission in the presence of IQ imbalance.

  19. Carcinoma multiplex

    International Nuclear Information System (INIS)

    Shah, S. A.; Riaz, U.; Zahoor, I.; Jalil, A.; Zubair, M.

    2013-01-01

    Multiple primaries in a single patient are uncommon, though not very rare. The existence of such cancers in two un-related, non-paired organs is even more un-common. Here, we present a case of 55 years old male who presented to us with a mucoepidermoid carcinoma of the parotid gland and was operated. Later on, he presented with a large cystic swelling in the pelvis which turned out to be pseudomyxoma peritonei. A review of slides and immunohistochemistry indicated it to be adenocarcinoma colon. He presented again with recurrent mucoepidermoid carcinoma of the parotid which was operated successfully with the use of myocutaneous flap for wound closure. He is currently undergoing chemotherapy. In order to establish a separate mono-clonal etiology of both tumours, immunohistochemistry was performed. To the best of our knowledge, carcinoma multiplex in the colon and the parotid has never been reported before. (author)

  20. Coherence-Multiplexed Optical RF Feeder Networks

    NARCIS (Netherlands)

    Meijerink, Arjan; Taniman, R.O.; van Etten, Wim

    2007-01-01

    An optical RF feeding system for wireless access is proposed, in which the radio access points are distinguished by means of coherence multiplexing (CM). CM is a rather unknown and potentially inexpensive optical code division multiple access technique, which is particularly suitable for relatively

  1. 160 Gb/s OFDM transmission utilizing an all-optical symbol generator based on PLC

    Science.gov (United States)

    Liang, Xiaojun; Qiao, Yaojun; Li, Wei; Mei, Junyao; Qin, Yi

    2009-11-01

    We demonstrate a 160 Gb/s orthogonal frequency division multiplexing (OFDM) system using an all-optical symbol generator based on planar light circuit (PLC) technology. Excellent bit error rate (BER) is observed after long-distance transmission. The proposed symbol generator fundamentally eliminates the processing speed limits introduced by electronics and is suitable for high integration, making it physically realizable to build high-speed all-optical OFDM systems with a large number of subcarriers.

  2. Single channel and WDM transmission of 28 Gbaud zero-guard-interval CO-OFDM.

    Science.gov (United States)

    Zhuge, Qunbi; Morsy-Osman, Mohamed; Mousa-Pasandi, Mohammad E; Xu, Xian; Chagnon, Mathieu; El-Sahn, Ziad A; Chen, Chen; Plant, David V

    2012-12-10

    We report on the experimental demonstration of single channel 28 Gbaud QPSK and 16-QAM zero-guard-interval (ZGI) CO-OFDM transmission with only 1.34% overhead for OFDM processing. The achieved transmission distance is 5120 km for QPSK assuming a 7% forward error correction (FEC) overhead, and 1280 km for 16-QAM assuming a 20% FEC overhead. We also demonstrate the improved tolerance of ZGI CO-OFDM to residual inter-symbol interference compared to reduced-guard-interval (RGI) CO-OFDM. In addition, we report an 8-channel wavelength-division multiplexing (WDM) transmission of 28 Gbaud QPSK ZGI CO-OFDM signals over 4160 km.

  3. One-step Multiplex RT-PCR Method for Simultaneous Detection of Seed Transmissible Bacteria and Viruses in Pepper and Tomato Seeds

    Directory of Open Access Journals (Sweden)

    Kyusik Jeong

    2011-04-01

    Full Text Available The aim of this study was to develop specific and sensitive PCR-based procedures for simultaneous detection of economically important plant seed infection pathogenic bacteria and virus, Xanthomonns campestris pv. vesicatoria (Xcv, Clavibacter michiganensis subsp. michiganensis (Cmm, Erwinia carotovora subsp. carotovora (Ecc, Pepper mild mottle virus (PMMoV and Tobacco mild green mosaic virus (TMGMV in pepper and tomato seeds. Most of pepper and tomato bacterial and virus diseases are responsible for germination and growth obstruction. PCR with arbitral primers: selection of specific primers, performance of PCR with specific primers and determination of the threshold level for pathogens detection. To detect simultaneously the Xcv, Cmm, Ecc, PMMoV and TMGMV in pepper and tomato seeds, five pairs (Cmm-F/R, Ecc-F/R, Xcv-F/R, PMMoV-F/R, TMGMV-F/R of specific primer were synthesized by primer-blast program. The multiplex PCR for the five pathogens in pepper and tomato seeds could detect specially without interference among primers and/or cDNA of plant seeds and other plant pathogens. The PCR result for pathogen detection using 20 commercial pepper and 10 tomato seed samples, Ecc was detected from 4 pepper and 2 tomato seed samples, PMMoV was detected from 1 pepper seed sample, and PMMoV and TMGMV were simultaneously detected from 1 pepper seed sample.

  4. One-step Multiplex RT-PCR Method for Simultaneous Detection of Seed Transmissible Bacterium and Virus Occurring on Brassicaceae Crop Seeds

    Directory of Open Access Journals (Sweden)

    Kyusik Jeong

    2011-04-01

    Full Text Available The aim of this research was to develop specific and sensitive PCR-based procedures for simultaneous detection of economically important plant pathogenic bacteria and seed borne virus in commercial Brassicaceae crop seeds, Xanthomonns campestris pv. campestris (Xcc and Lettuce Mosaic Virus (LMV. Bacterial and virus diseases of Brassicaceae leaves are responsible for heavy losses. PCR with arbitral primers: selection of specific primers, performance of PCR with specific primers and determination of the threshold level for pathogens detection. To detect simultaneously the Xcc and LMV in commercial Brassicaceae crop seeds (lettuce, kohlrabi, radish, chinese cabbage and cabbage, two pairs of specific primer (LMV-F/R, Xcc-F/R were synthesized by using primer-blast program (http://www.ncbi.nlm.nih.gov/tools/ primer-blast/. The multiplex PCR for the two pathogens in Brassicaceae crop seeds could detect specifically without interference among primers and/or cDNA of other plant pathogens. The pathogen detection limit was determined at 1 ng of RNA extracted from pathogens. In the total PCR results for pathogen detection using commercial kohlrabi (10 varieties, lettuce (50 varieties, radish (20 varieties, chinese cabbage (20 varieties and cabbage (20 varieties, LMV and Xcc were detected from 39 and 2 varieties, respectively. In the PCR result of lettuce, LMV and Xcc were simultaneously detected in 8 varieties.

  5. Conversion of asynchronous 10 Gbit/s Ethernet NRZ frame into a synchronous RZ frame and multiplexing to 170 Gbit/s

    DEFF Research Database (Denmark)

    Laguardia Areal, Janaina; Hu, Hao; Palushani, Evarist

    2010-01-01

    This paper presents an optical circuit for frame synchronization and pulse compression of 10G Ethernet frames with 12000 bits and multiplexing to a 170 Gbit/s optical time division multiplexed data stream.......This paper presents an optical circuit for frame synchronization and pulse compression of 10G Ethernet frames with 12000 bits and multiplexing to a 170 Gbit/s optical time division multiplexed data stream....

  6. Evaluation of PLC Channel Capacity and ABER Performances for OFDM-Based Two-Hop Relaying Transmission

    OpenAIRE

    Ezzine, Sana; Abdelkefi, Fatma; Cances, Jean Pierre; Meghdadi, Vahid; Bouallégue, Ammar

    2017-01-01

    Powerline network is recognized as a favorable infrastructure for Smart Grid to transmit information in the network thanks to its broad coverage and low cost deployment. The existing works are trying to improve and adapt transmission techniques to reduce Powerline Communication (PLC) channel attenuation and exploit the limited bandwidth to support high data rate over long distances. Two-hop relaying BroadBand PLC (BB-PLC) system, in which Orthogonal Frequency Division Multiplexing (OFDM) is u...

  7. Experimental evaluation of prefiltering for 56 Gbaud DP-QPSK signal transmission in 75 GHz WDM grid

    DEFF Research Database (Denmark)

    Borkowski, Robert; de Carvalho, Luis Henrique H.; Silva, Edson Porto da

    2014-01-01

    We investigate optical prefiltering for 56Gbaud (224Gbit/s) electrical time-division multiplexed (ETDM) dual polarization (DP) quaternary phase shift keying (QPSK) transmission. Different transmitter-side optical filter shapes are tested and their bandwidths are varied. Comparison of studied filter...... shapes shows an advantage of a pre-emphasis filter. Subsequently, we perform a fiber transmission of the 56Gbaud DP QPSK signal filtered with the 65GHz pre-emphasis filter to fit the 75GHz transmission grid. Bit error rate (BER) of the signal remains below forward error correction (FEC) limit after 300km...

  8. Multi-LED parallel transmission for long distance underwater VLC system with one SPAD receiver

    Science.gov (United States)

    Wang, Chao; Yu, Hong-Yi; Zhu, Yi-Jun; Wang, Tao; Ji, Ya-Wei

    2018-03-01

    In this paper, a multiple light emitting diode (LED) chips parallel transmission (Multi-LED-PT) scheme for underwater visible light communication system with one photon-counting single photon avalanche diode (SPAD) receiver is proposed. As the lamp always consists of multi-LED chips, the data rate could be improved when we drive these multi-LED chips parallel by using the interleaver-division-multiplexing technique. For each chip, the on-off-keying modulation is used to reduce the influence of clipping. Then a serial successive interference cancellation detection algorithm based on ideal Poisson photon-counting channel by the SPAD is proposed. Finally, compared to the SPAD-based direct current-biased optical orthogonal frequency division multiplexing system, the proposed Multi-LED-PT system could improve the error-rate performance and anti-nonlinearity performance significantly under the effects of absorption, scattering and weak turbulence-induced channel fading together.

  9. Efficient Load Forecasting Optimized by Fuzzy Programming and OFDM Transmission

    Directory of Open Access Journals (Sweden)

    Sandeep Sachdeva

    2011-01-01

    reduce the error of load forecasting, fuzzy method has been used with Artificial Neural Network (ANN and OFDM transmission is used to get data from outer world and send outputs to outer world accurately and quickly. The error has been reduced to a considerable level in the range of 2-3%. For further reducing the error, Orthogonal Frequency Division Multiplexing (OFDM can be used with Reed-Solomon (RS encoding. Further studies are going on with Fuzzy Regression methods to reduce the error more.

  10. Quality factor of a transmission line coupled coplanar waveguide resonator

    Energy Technology Data Exchange (ETDEWEB)

    Besedin, Ilya [National University for Science and Technology (MISiS), Moscow (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation); Menushenkov, Alexey P. [National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow (Russian Federation)

    2018-12-15

    We investigate analytically the coupling of a coplanar waveguide resonator to a coplanar waveguide feedline. Using a conformal mapping technique we obtain an expression for the characteristic mode impedances and coupling coefficients of an asymmetric multi-conductor transmission line. Leading order terms for the external quality factor and frequency shift are calculated. The obtained analytical results are relevant for designing circuit-QED quantum systems and frequency division multiplexing of superconducting bolometers, detectors and similar microwave-range multi-pixel devices. (orig.)

  11. Uganda's National Transmission Backbone Infrastructure Project: Technical Challenges and the Way Forward

    Science.gov (United States)

    Bulega, T.; Kyeyune, A.; Onek, P.; Sseguya, R.; Mbabazi, D.; Katwiremu, E.

    2011-10-01

    Several publications have identified technical challenges facing Uganda's National Transmission Backbone Infrastructure project. This research addresses the technical limitations of the National Transmission Backbone Infrastructure project, evaluates the goals of the project, and compares the results against the technical capability of the backbone. The findings of the study indicate a bandwidth deficit, which will be addressed by using dense wave division multiplexing repeaters, leasing bandwidth from private companies. Microwave links for redundancy, a Network Operation Center for operation and maintenance, and deployment of wireless interoperability for microwave access as a last-mile solution are also suggested.

  12. 1.114-gb/s time/space division switch system

    Science.gov (United States)

    Pawelski, Robert L.; Nordin, Ronald A.; Huisman, R. F.; Kelly, S.; Payne, William A.; Veach, R. S.

    1990-10-01

    Advanced digital communication services11 such as Broadband ISDN High Definition Television (HDTV) and enhanced data networking are expected to require high bandwidth and fast reconfiguration time switching centers available in the 1990''s. Digital GaAs IC''s can allow the implementation of these switching centers providing these services efficiently and at a low cost. The low cost arises from the reduction in hardware power maintenance etc. when the switch is designed to operate at the incoming data rate instead of at a lower rate. In order to utilize the capacity of a high bandwidth data link time division multiplexing is employed. This is a technique where multiple digital signals are interleaved (bit byte or block) on one data link. Clearly it is advantageous to have a switch that not only has a large bandwidth but can reconfigure at the data rate so as to provide bit byte or block switching functions thus being compatible with many different transmission formats. We present an experimental Time/Space Division Switch System capable of operating at over 1 Gb/s. Both custom and commercial Gallium Arsenide (GaAs) devices are used in the design of the various system functional blocks. These functional blocks include a Time Slot Interchanger (TSI) Time Multiplexed Switch (TMS) TMS Controller Multiplexer and Demultiplexers. In addition to the system overview we discuss such issues as printed circuit board microwave interconnections and CAD tools for high speed

  13. 1:N Space Division Switches for Optical Routing, Reconfigurable Interconnections, and Time and Wavelength-Division Switching Applications

    National Research Council Canada - National Science Library

    Shire, D

    1998-01-01

    ... of time-division multiplexing and demultiplexing operations. Hysteresis in the input-output transfer characteristics of the coupled in-plane lasers and VCSELs also leads to bistable operation over a range of bias conditions...

  14. Experimental demonstration of subcarrier multiplexed quantum key distribution system.

    Science.gov (United States)

    Mora, José; Ruiz-Alba, Antonio; Amaya, Waldimar; Martínez, Alfonso; García-Muñoz, Víctor; Calvo, David; Capmany, José

    2012-06-01

    We provide, to our knowledge, the first experimental demonstration of the feasibility of sending several parallel keys by exploiting the technique of subcarrier multiplexing (SCM) widely employed in microwave photonics. This approach brings several advantages such as high spectral efficiency compatible with the actual secure key rates, the sharing of the optical fainted pulse by all the quantum multiplexed channels reducing the system complexity, and the possibility of upgrading with wavelength division multiplexing in a two-tier scheme, to increase the number of parallel keys. Two independent quantum SCM channels featuring a sifted key rate of 10 Kb/s/channel over a link with quantum bit error rate <2% is reported.

  15. Experimental Demonstration of an Electro-Absorption Modulated Laser for High-Speed Transmissions at 1.55-μm Window Using Digital Signal Processing

    Directory of Open Access Journals (Sweden)

    Fotini Karinou

    2017-02-01

    Full Text Available We experimentally investigate the transmission performance of 56 Gb/s four-level pulse amplitude modulation (PAM-4 over 30-km standard single mode fiber (SMF using a C-band EML for low-cost metro and short-reach wavelength division multiplexing (WDM applications. Bit error rate (BER performance below the HD-FEC threshold is achieved for up to 30-km maximum reported distance without employing dispersion compensation fiber (DCF in the link.

  16. High-speed real-time OFDM transmission based on FPGA

    Science.gov (United States)

    Xiao, Xin; Li, Fan; Yu, Jianjun

    2016-02-01

    In this paper, we review our recent research progresses on real-time orthogonal frequency division multiplexing (OFDM) transmission based on FPGA. We successfully demonstrated four-channel wavelength-division multiplexing (WDM) 256.51Gb/s 16-ary quadrature amplitude modulation (16QAM)-OFDM signal transmission system for short-reach optical amplifier free inter-connection with real-time reception. Four optical carriers are modulated by four different 16QAM-OFDM signals via 10G-class direct modulation lasers (DMLs). We achieved highest capacity real-time reception optical OFDM signal transmission over 2.4-km SMF with the bit-error ratio (BER) under soft-decision forward error correction (SD-FEC) limitation of 2.4×10-2. In order to achieve higher spectrum efficiency (SE), we demonstrate 4-channel high level QAM-OFDM transmission over 20-km SMF-28 with real-time reception. 58.72-Gb/s 256QAM-OFDM and 56.4-Gb/s 128QAM-OFDM signal transmission within 25-GHz grid is achieved with the BER under 2.4×10-2 and real-time reception.

  17. Dynamic Optically Multiplexed Imaging

    Science.gov (United States)

    2015-07-29

    Dynamic Optically Multiplexed Imaging Yaron Rachlin, Vinay Shah, R. Hamilton Shepard, and Tina Shih Lincoln Laboratory, Massachusetts Institute of...V. Shah, and T. Shih “Design Architectures for Optically Multiplexed Imaging,” in submission 9 R. Gupta , P. Indyk, E. Price, and Y. Rachlin

  18. Social contagions on correlated multiplex networks

    Science.gov (United States)

    Wang, Wei; Cai, Meng; Zheng, Muhua

    2018-06-01

    The existence of interlayer degree correlations has been disclosed by abundant multiplex network analysis. However, how they impose on the dynamics of social contagions are remain largely unknown. In this paper, we propose a non-Markovian social contagion model in multiplex networks with inter-layer degree correlations to delineate the behavior spreading, and develop an edge-based compartmental (EBC) theory to describe the model. We find that multiplex networks promote the final behavior adoption size. Remarkably, it can be observed that the growth pattern of the final behavior adoption size, versus the behavioral information transmission probability, changes from discontinuous to continuous once decreasing the behavior adoption threshold in one layer. We finally unravel that the inter-layer degree correlations play a role on the final behavior adoption size but have no effects on the growth pattern, which is coincidence with our prediction by using the suggested theory.

  19. Multiplex PageRank.

    Science.gov (United States)

    Halu, Arda; Mondragón, Raúl J; Panzarasa, Pietro; Bianconi, Ginestra

    2013-01-01

    Many complex systems can be described as multiplex networks in which the same nodes can interact with one another in different layers, thus forming a set of interacting and co-evolving networks. Examples of such multiplex systems are social networks where people are involved in different types of relationships and interact through various forms of communication media. The ranking of nodes in multiplex networks is one of the most pressing and challenging tasks that research on complex networks is currently facing. When pairs of nodes can be connected through multiple links and in multiple layers, the ranking of nodes should necessarily reflect the importance of nodes in one layer as well as their importance in other interdependent layers. In this paper, we draw on the idea of biased random walks to define the Multiplex PageRank centrality measure in which the effects of the interplay between networks on the centrality of nodes are directly taken into account. In particular, depending on the intensity of the interaction between layers, we define the Additive, Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show how each version reflects the extent to which the importance of a node in one layer affects the importance the node can gain in another layer. We discuss these measures and apply them to an online multiplex social network. Findings indicate that taking the multiplex nature of the network into account helps uncover the emergence of rankings of nodes that differ from the rankings obtained from one single layer. Results provide support in favor of the salience of multiplex centrality measures, like Multiplex PageRank, for assessing the prominence of nodes embedded in multiple interacting networks, and for shedding a new light on structural properties that would otherwise remain undetected if each of the interacting networks were analyzed in isolation.

  20. Multiplex PageRank.

    Directory of Open Access Journals (Sweden)

    Arda Halu

    Full Text Available Many complex systems can be described as multiplex networks in which the same nodes can interact with one another in different layers, thus forming a set of interacting and co-evolving networks. Examples of such multiplex systems are social networks where people are involved in different types of relationships and interact through various forms of communication media. The ranking of nodes in multiplex networks is one of the most pressing and challenging tasks that research on complex networks is currently facing. When pairs of nodes can be connected through multiple links and in multiple layers, the ranking of nodes should necessarily reflect the importance of nodes in one layer as well as their importance in other interdependent layers. In this paper, we draw on the idea of biased random walks to define the Multiplex PageRank centrality measure in which the effects of the interplay between networks on the centrality of nodes are directly taken into account. In particular, depending on the intensity of the interaction between layers, we define the Additive, Multiplicative, Combined, and Neutral versions of Multiplex PageRank, and show how each version reflects the extent to which the importance of a node in one layer affects the importance the node can gain in another layer. We discuss these measures and apply them to an online multiplex social network. Findings indicate that taking the multiplex nature of the network into account helps uncover the emergence of rankings of nodes that differ from the rankings obtained from one single layer. Results provide support in favor of the salience of multiplex centrality measures, like Multiplex PageRank, for assessing the prominence of nodes embedded in multiple interacting networks, and for shedding a new light on structural properties that would otherwise remain undetected if each of the interacting networks were analyzed in isolation.

  1. Prototype data terminal-multiplexer/demultiplexer

    Science.gov (United States)

    Leck, D. E.; Goodwin, J. E.

    1972-01-01

    The design and operation of a quad redundant data terminal and a multiplexer/demultiplexer (MDU) is described. The most unique feature is the design of the quad redundant data terminal. This is one of the few designs where the unit is fail/op, fail/op, fail/safe. Laboratory tests confirm that the unit will operate satisfactorily with the failure of three out of four channels. Although the design utilizes state-of-the-art technology, the waveform error checks, the voting techniques, and the parity bit checks are believed to be used in unique configurations. Correct word selection routines are also novel. The MDU design, while not redundant, utilizes, the latest state-of-the-art advantages of light coupler and interested amplifiers. Much of the technology employed was an evolution of prior NASA contracts related to the Addressable Time Division Data System. A good example of the earlier technology development was the development of a low level analog multiplexer, a high level analog multiplexer, and a digital multiplexer. A list of all drawings is included for reference and all schematic, block and timing diagrams are incorporated.

  2. Impulse Response of a 36-Core Few-Mode Photonic Lantern Hybrid Spatial-Multiplexer

    DEFF Research Database (Denmark)

    Rommel, Simon; Mendinueta, José Manuel Delgado; Klaus, Werner

    2017-01-01

    multiple-input multiple-output (MIMO) equalization, provided mode-dependent loss (MDL) is small [3]. Furthermore, mode scrambling at the transmitter improves tolerance to MDL and maximizes system capacity if all supported modes are used to transmit information [3]. Thus, the MDL and mode mixing properties...... significant mode mixing to take place at the multicore few-mode fiber splice. Furthermore, insertion loss and MDL of the system are further analyzed.......Space division multiplexing (SDM) using fibers with multiple cores and/or supporting multiple modes has become an essential technology to support Pbit/s transmissions in a single fiber [1,2]. Despite significant mode-mixing in few-mode fibers (FMF), the original signals can be recovered through...

  3. Multiplex gas chromatography

    Science.gov (United States)

    Valentin, Jose R.

    1990-01-01

    The principles of the multiplex gas chromatography (GC) technique, which is a possible candidate for chemical analysis of planetary atmospheres, are discussed. Particular attention is given to the chemical modulators developed by present investigators for multiplex GC, namely, the thermal-desorption, thermal-decomposition, and catalytic modulators, as well as to mechanical modulators. The basic technique of multiplex GC using chemical modulators and a mechanical modulator is demonstrated. It is shown that, with the chemical modulators, only one gas stream consisting of the carrier in combination with the components is being analyzed, resulting in a simplified instrument that requires relatively few consumables. The mechanical modulator demonstrated a direct application of multiplex GC for the analysis of gases in atmosphere of Titan at very low pressures.

  4. Multiplexed Engineering in Biology.

    Science.gov (United States)

    Rogers, Jameson K; Church, George M

    2016-03-01

    Biotechnology is the manufacturing technology of the future. However, engineering biology is complex, and many possible genetic designs must be evaluated to find cells that produce high levels of a desired drug or chemical. Recent advances have enabled the design and construction of billions of genetic variants per day, but evaluation capacity remains limited to thousands of variants per day. Here we evaluate biological engineering through the lens of the design–build–test cycle framework and highlight the role that multiplexing has had in transforming the design and build steps. We describe a multiplexed solution to the ‘test’ step that is enabled by new research. Achieving a multiplexed test step will permit a fully multiplexed engineering cycle and boost the throughput of biobased product development by up to a millionfold.

  5. Bilevel alarm monitoring multiplexer

    International Nuclear Information System (INIS)

    Johnson, C.S.

    1977-06-01

    This report describes the operation of the Bilevel Alarm Monitoring Multiplexer used in the Adaptive Intrusion Data System (AIDS) to transfer and control alarm signals being sent to the Nova 2 computer, the Memory Controlled Data Processor, and its own integral Display Panel. The multiplexer can handle 48 alarm channels and format the alarms into binary formats compatible with the destination of the alarm data

  6. Flexible Transmission Scheme for 4G Wireless Systems with Multiple Antennas

    Directory of Open Access Journals (Sweden)

    Horlin François

    2005-01-01

    Full Text Available New air interfaces are currently being developed to meet the high requirements of the emerging wireless communication systems. In this context, the combinations of the multicarrier (MC and spread-spectrum (SS technologies are promising candidates. In this paper, we propose a generic transmission scheme that allows to instantiate all the combinations of orthogonal frequency-division multiplexing (OFDM and cyclic-prefixed single-carrier (SC modulations with direct-sequence code-division multiple access (DS-CDMA. The generic transmission scheme is extended to integrate the space-division multiplexing (SDM and the orthogonal space-time block coding (STBC. Based on a generalized matrix model, the linear frequency-domain minimum mean square error (MMSE joint detector is derived. A mode selection strategy for up- and downlink is advised that efficiently trades off the cost of the mobile terminal and the achieved performance of a high-mobility cellular system. It is demonstrated that an adaptive transceiver that supports the proposed communication modes is necessary to track the changing communication conditions.

  7. Preliminary Assessment of Microwave Readout Multiplexing Factor

    Energy Technology Data Exchange (ETDEWEB)

    Croce, Mark Philip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Koehler, Katrina Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rabin, Michael W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Bennett, D. A. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Mates, J. A. B. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Gard, J. D. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Becker, D. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Schmidt, D. R. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Ullom, J. N. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States)

    2017-01-23

    Ultra-high resolution microcalorimeter gamma spectroscopy is a new non-destructive assay technology for measurement of plutonium isotopic composition, with the potential to reduce total measurement uncertainty to a level competitive with destructive analysis methods [1-4]. Achieving this level of performance in practical applications requires not only the energy resolution now routinely achieved with transition-edge sensor microcalorimeter arrays (an order of magnitude better than for germanium detectors) but also high throughput. Microcalorimeter gamma spectrometers have not yet achieved detection efficiency and count rate capability that is comparable to germanium detectors, largely because of limits from existing readout technology. Microcalorimeter detectors must be operated at low temperature to achieve their exceptional energy resolution. Although the typical 100 mK operating temperatures can be achieved with reliable, cryogen-free systems, the cryogenic complexity and heat load from individual readout channels for large sensor arrays is prohibitive. Multiplexing is required for practical systems. The most mature multiplexing technology at present is time-division multiplexing (TDM) [3, 5-6]. In TDM, the sensor outputs are switched by applying bias current to one SQUID amplifier at a time. Transition-edge sensor (TES) microcalorimeter arrays as large as 256 pixels have been developed for X-ray and gamma-ray spectroscopy using TDM technology. Due to bandwidth limits and noise scaling, TDM is limited to a maximum multiplexing factor of approximately 32-40 sensors on one readout line [8]. Increasing the size of microcalorimeter arrays above the kilopixel scale, required to match the throughput of germanium detectors, requires the development of a new readout technology with a much higher multiplexing factor.

  8. W-Band Real-Time Transmission Utilizing a Reconfigurable RAU for NG-PON Networks

    DEFF Research Database (Denmark)

    Chorchos, Łukasz; Turkiewicz, Jarosław P.; Rommel, Simon

    2016-01-01

    In this article, we propose and test a reconfigurable Remote Access Unit (RAU) to interface optical and W-band wireless communication links (75–110 GHz), utilizing optical heterodyne signal upconversion. The RAU is composed of a tunable local oscillator, narrow optical filter and a control unit....... The RAU can be software-reconfigured to select a specific dense wavelength division multiplexed (DWDM) channel. Real-time tests with 100 GHz spaced DWDM signals have been performed. Real-time 2.5 Gbit/s error free radio transmission in the 75 GHz to 95 GHz range of the W-band was achieved after 15 km...

  9. Performance Analysis of Diversity-Controlled Multi-User Superposition Transmission for 5G Wireless Networks.

    Science.gov (United States)

    Yeom, Jeong Seon; Chu, Eunmi; Jung, Bang Chul; Jin, Hu

    2018-02-10

    In this paper, we propose a novel low-complexity multi-user superposition transmission (MUST) technique for 5G downlink networks, which allows multiple cell-edge users to be multiplexed with a single cell-center user. We call the proposed technique diversity-controlled MUST technique since the cell-center user enjoys the frequency diversity effect via signal repetition over multiple orthogonal frequency division multiplexing (OFDM) sub-carriers. We assume that a base station is equipped with a single antenna but users are equipped with multiple antennas. In addition, we assume that the quadrature phase shift keying (QPSK) modulation is used for users. We mathematically analyze the bit error rate (BER) of both cell-edge users and cell-center users, which is the first theoretical result in the literature to the best of our knowledge. The mathematical analysis is validated through extensive link-level simulations.

  10. 80-Channel Multiplexer-Demultiplexer Module for DWDM Communications using Hybrid AWG -- Interleaver Technology

    Science.gov (United States)

    Rablau, Corneliu; Bredthauer, Lance

    2007-10-01

    Aside from the more traditional data, voice and e-mail communications, new bandwidth intensive applications in the larger consumer markets, such as music, digital pictures and movies, have led to an explosive increase in the demand for transmission capacity for optical communications networks. This has resulted in a widespread deployment of Dense Wavelength Division Multiplexing (DWDM) as a means of increasing the communications capacity by multiplexing and transmitting signals of different wavelengths (establishing multiple communication channels) through a single strand of fiber. We report on the design, assembly and characterization of a 50-GHz, 80-channel Mux-Demux module for DWDM systems. The module has been assembled from two commercially available 100 GHz, 40-channel Array Waveguide Grating (AWG) modules and a 50-GHz to 100-GHz interleaver. Relevant performance parameters such as insertion loss, channel uniformity, next-channel isolation (crosstalk) and integrated cross-talk are presented and discussed in contrast with the performance of other competing technologies such as Thin-Film-Filter-based Mux-Demux devices.

  11. 61.3-Gbps hybrid fiber-wireless in-home network enabled by optical heterodyne and polarization multiplexing

    NARCIS (Netherlands)

    Cao, Z.; Li, F.; Liu, Y.; Yu, J.; Wang, Q.; Oh, C.W.; Jiao, Y.; Tran, N.C.; Boom, van den H.P.A.; Tangdiongga, E.; Koonen, A.M.J.

    2014-01-01

    A hybrid fiber-wireless in-home network is proposed to support high-speed multiple input and multiple output (MIMO) orthogonal frequency division multiplexing systems operating at millimeter wave (mm-wave) band by employing optical heterodyne (OH) and polarization multiplexing (PolMux). OH enables

  12. On the capacity of MIMO-OFDM based diversity and spatial multiplexing in Radio-over-Fiber system

    Science.gov (United States)

    El Yahyaoui, Moussa; El Moussati, Ali; El Zein, Ghaïs

    2017-11-01

    This paper proposes a realistic and global simulation to predict the behavior of a Radio over Fiber (RoF) system before its realization. In this work we consider a 2 × 2 Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) RoF system at 60 GHz. This system is based on Spatial Diversity (SD) which increases reliability (decreases probability of error) and Spatial Multiplexing (SMX) which increases data rate, but not necessarily reliability. The 60 GHz MIMO channel model employed in this work based on a lot of measured data and statistical analysis named Triple-S and Valenzuela (TSV) model. To the authors best knowledge; it is the first time that this type of TSV channel model has been employed for 60 GHz MIMO-RoF system. We have evaluated and compared the performance of this system according to the diversity technique, modulation schemes, and channel coding rate for Line-Of-Sight (LOS) desktop environment. The SMX coded is proposed as an intermediate system to improve the Signal to Noise Ratio (SNR) and the data rate. The resulting 2 × 2 MIMO-OFDM SMX system achieves a higher data rate up to 70 Gb/s with 64QAM and Forward Error Correction (FEC) limit of 10-3 over 25-km fiber transmission followed by 3-m wireless transmission using 7 GHz bandwidth of millimeter wave band.

  13. 100-Gb/s 80-km transmission of PIM-SSB-OFDM at C-band using a single-end photodetector

    Science.gov (United States)

    Huo, Jiahao; Zhou, Xian; Zhong, Kangping; Gui, Tao; Tan, Fengze; Tu, Jiajing; Yuan, Jinhui; Zhang, Hongyu; Long, Keping; Yu, Changyuan; Lau, Alan Pak Tao; Lu, Chao

    2017-10-01

    Polarization-interleave-multiplexed (PIM) with single-sideband orthogonal frequency-division multiplexing (SSB-OFDM) based on direct detection is proposed for short-reach applications transmitted up to 80 km in which the guard band can be shared for the two SSB signals with interleave electrical center frequencies. Based on two dual-drive Mach-Zehnder modulators with one single-end photodetector (PD), 100-Gb/s PIM-SSB-OFDM transmission over a 80-km standard single-mode fiber is successfully demonstrated. After 80-km transmission, the optical signal-to-noise ratio requirement is 29.1 dB with respect to the bit error rate threshold of 7% hard decision-forward error correction overhead.

  14. Microprocessorized message multiplexer

    International Nuclear Information System (INIS)

    Ejzman, S.; Guglielmi, L.; Jaeger, J.J.

    1980-07-01

    The 'Microprocessorized Message Multiplexer' is an elementary development tool used to create and debug the software of a target microprocessor (User Module: UM). It connects together four devices: a terminal, a cassette recorder, the target microprocessor and a host computer where macro and editor for the M 6800 microprocessor are resident [fr

  15. Multiplex editing system

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a multiplex editing system. The system allows multiple editing of nucleic acid sequences such as genomic sequences, such as knockins of genes of interest in a genome, knockouts of genomic sequences and/or allele replacement. Also provided herein are a method...... for editing nucleic acids and a cell comprising a stably integrated endonuclease....

  16. ECRH transmission system

    International Nuclear Information System (INIS)

    Tancredi, J.

    1983-01-01

    Hughes, Electron Dynamics Division is developing gyrotrons for ECRH requirements. In the development program, techniques have been evolved for transmission system components. These techniques include over-moded waveguide tapers, high average power windows, and rf water loads for testing

  17. Chaos-based CAZAC scheme for secure transmission in OFDM-PON

    Science.gov (United States)

    Fu, Xiaosong; Bi, Meihua; Zhou, Xuefang; Yang, Guowei; Lu, Yang; Hu, Miao

    2018-01-01

    To effectively resist malicious eavesdropping and performance deterioration, a novel chaos-based secure transmission scheme is proposed to enhance the physical layer security and reduce peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing passive optical network (OFDM-PON). By the randomly extracting operation of common CAZAC values, the specially-designed constant amplitude zero autocorrelation (CAZAC) is created for system encryption and PAPR reduction enhancing the transmission security. This method is verified in {10-Gb/s encrypted OFDM-PON with 20-km fiber transmission. Results show that, compared to common OFDM-PON, our scheme achieves {3-dB PAPR reduction and {1-dB receiver sensitivity improvement.

  18. Extracting information from multiplex networks

    Science.gov (United States)

    Iacovacci, Jacopo; Bianconi, Ginestra

    2016-06-01

    Multiplex networks are generalized network structures that are able to describe networks in which the same set of nodes are connected by links that have different connotations. Multiplex networks are ubiquitous since they describe social, financial, engineering, and biological networks as well. Extending our ability to analyze complex networks to multiplex network structures increases greatly the level of information that is possible to extract from big data. For these reasons, characterizing the centrality of nodes in multiplex networks and finding new ways to solve challenging inference problems defined on multiplex networks are fundamental questions of network science. In this paper, we discuss the relevance of the Multiplex PageRank algorithm for measuring the centrality of nodes in multilayer networks and we characterize the utility of the recently introduced indicator function Θ ˜ S for describing their mesoscale organization and community structure. As working examples for studying these measures, we consider three multiplex network datasets coming for social science.

  19. Power Efficiency Improvement in CE-OFDM System With 0 dB IBO for Transmission over PLC Network

    OpenAIRE

    El Ghzaoui Mohammed, Belkadid Jamal, Benbassou Ali & EL Bekkali Moulhim

    2011-01-01

    Orthogonal frequency division multiplexing (OFDM) OFDM has been adopted for high speeddata transmission of multimedia traffic such as HomePlug A/V and Mobile WiMax. However,OFDM also has a drawback of a high PAPR (peak-to-average-power-ratio). Due to this highPAPR amplifier usually does not act in dynamic range. One potential solution for reducing thepeak-to-average power ratio (PAPR) in an OFDM system is to utilize a constant envelopeOFDM (CE-OFDM) system. Furthermore, by utilizing continuou...

  20. Topology Optimized Components for Mode- and Wavelength Division Multiplexing

    DEFF Research Database (Denmark)

    Frellsen, Louise Floor

    to remake the new designs and then increase complexity without much impact on the footprint. The benefit of inverse design tools, like topology optimization, is that they lead to structures without geometrical constraints and which are independent of the designer. This project has however shown...

  1. Functional Multiplex PageRank

    Science.gov (United States)

    Iacovacci, Jacopo; Rahmede, Christoph; Arenas, Alex; Bianconi, Ginestra

    2016-10-01

    Recently it has been recognized that many complex social, technological and biological networks have a multilayer nature and can be described by multiplex networks. Multiplex networks are formed by a set of nodes connected by links having different connotations forming the different layers of the multiplex. Characterizing the centrality of the nodes in a multiplex network is a challenging task since the centrality of the node naturally depends on the importance associated to links of a certain type. Here we propose to assign to each node of a multiplex network a centrality called Functional Multiplex PageRank that is a function of the weights given to every different pattern of connections (multilinks) existent in the multiplex network between any two nodes. Since multilinks distinguish all the possible ways in which the links in different layers can overlap, the Functional Multiplex PageRank can describe important non-linear effects when large relevance or small relevance is assigned to multilinks with overlap. Here we apply the Functional Page Rank to the multiplex airport networks, to the neuronal network of the nematode C. elegans, and to social collaboration and citation networks between scientists. This analysis reveals important differences existing between the most central nodes of these networks, and the correlations between their so-called pattern to success.

  2. Multiplex measuring systems in physics

    International Nuclear Information System (INIS)

    Soroko, L.M.

    1980-01-01

    The principles of operation of multiplex devices used in different spheres of physics are discussed. The ''multiplex'' notion means that the data output of the device is an integral image of the functional dependence under investigation, but not its readings as in usual instruments. The analysis of the present state of developments of the multiplex systems in optics, nuclear magnetic resonance spectroscopy, in time-of-flight spectrometers for slow and fast neutrons, as well as elementary particle detectors, is given. The construction algorithms for the digital codes are presented, the history of development of the multiplex measuring principle is given [ru

  3. 40-Gb/s PDM-QPSK signal transmission over 160-m wireless distance at W-band.

    Science.gov (United States)

    Xiao, Jiangnan; Yu, Jianjun; Li, Xinying; Xu, Yuming; Zhang, Ziran; Chen, Long

    2015-03-15

    We experimentally demonstrate a W-band optical-wireless transmission system over 160-m wireless distance with a bit rate up to 40 Gb/s. The optical-wireless transmission system adopts optical polarization-division-multiplexing (PDM), multiple-input multiple-output (MIMO) reception and antenna polarization diversity. Using this system, we experimentally demonstrate the 2×2 MIMO wireless delivery of 20- and 40-Gb/s PDM quadrature-phase-shift-keying (PDM-QPSK) signals over 640- and 160-m wireless links, respectively. The bit-error ratios (BERs) of these transmission systems are both less than the forward-error-correction (FEC) threshold of 3.8×10-3.

  4. All-Optical Regenerative OTDM Add-Drop Multiplexing at 40 Gb/s using Monolithic InP Mach-Zehnder Interferometer

    DEFF Research Database (Denmark)

    Fischer, St.; Dülk, M.; Gamper, E.

    2000-01-01

    We present a novel method for all-optical add-drop multiplexing having regenerative capability for 40-Gb/s optical time-division multiplexed (OTDM) data using a semiconductor optical amplifier (SOA) based, monolithic Mach-Zehnder interferometer (MZI). Simultaneous dropping of one 10-Gb/s channel ...

  5. Multiplex Recurrence Networks

    Science.gov (United States)

    Eroglu, Deniz; Marwan, Norbert

    2017-04-01

    The complex nature of a variety of phenomena in physical, biological, or earth sciences is driven by a large number of degrees of freedom which are strongly interconnected. Although the evolution of such systems is described by multivariate time series (MTS), so far research mostly focuses on analyzing these components one by one. Recurrence based analyses are powerful methods to understand the underlying dynamics of a dynamical system and have been used for many successful applications including examples from earth science, economics, or chemical reactions. The backbone of these techniques is creating the phase space of the system. However, increasing the dimension of a system requires increasing the length of the time series in order get significant and reliable results. This requirement is one of the challenges in many disciplines, in particular in palaeoclimate, thus, it is not easy to create a phase space from measured MTS due to the limited number of available obervations (samples). To overcome this problem, we suggest to create recurrence networks from each component of the system and combine them into a multiplex network structure, the multiplex recurrence network (MRN). We test the MRN by using prototypical mathematical models and demonstrate its use by studying high-dimensional palaeoclimate dynamics derived from pollen data from the Bear Lake (Utah, US). By using the MRN, we can distinguish typical climate transition events, e.g., such between Marine Isotope Stages.

  6. Multi-carrier transmission for hybrid radio frequency with optical wireless communications

    Science.gov (United States)

    Wang, Gang; Chen, Genshe; Shen, Dan; Pham, Khanh; Blasch, Erik; Nguyen, Tien M.

    2015-05-01

    Radio frequency (RF) wireless communication is reaching its capacity to support large data rate transmissions due to hardware constraints (e.g., silicon processes), software strategies (e.g., information theory), and consumer desire for timely large file exchanges (e.g., big data and mobile cloud computing). A high transmission rate performance must keep pace with the generated huge volumes of data for real-time processing. Integrated RF and optical wireless communications (RF/OWC) could be the next generation transmission technology to satisfy both the increased data rate exchange and the communications constraints. However, with the promising benefits of RF/OWC, challenges remain to fully develop hybrid RF with wireless optical communications such as uniform waveform design for information transmission and detection. In this paper, an orthogonal frequency division multiplexing (OFDM) transmission scheme, which widely employed in RF communications, is developed for optical communications. The traditional high peak-to-average power ratio (PAPR) in OFDM is reduced to improve system performance. The proposed multi-carrier waveform is evaluated with a frequency-selective fading channel. The results demonstrate that bit error rate (BER) performance of our proposed optical OFDM transmission technique outperforms the traditional OWC on-off keying (OOK) transmission scheme.

  7. Effects of optical layer impairments on 2.5 Gb/s optical CDMA transmission.

    Science.gov (United States)

    Feng, H; Mendez, A; Heritage, J; Lennon, W

    2000-07-03

    We conducted a computer simulation study to assess the effects of optical layer impairments on optical CDMA (O-CDMA) transmission of 8 asynchronous users at 2.5 Gb/s each user over a 214-km link. It was found that with group velocity dispersion compensation, two other residual effects, namely, the nonzero chromatic dispersion slope of the single mode fiber (which causes skew) and the non-uniform EDFA gain (which causes interference power level to exceed signal power level of some codes) degrade the signal to multi-access interference (MAI) ratio. In contrast, four wave mixing and modulation due to the Kerr and Raman contributions to the fiber nonlinear refractive index are less important. Current wavelength-division multiplexing (WDM) technologies, including dispersion management, EDFA gain flattening, and 3 rd order dispersion compensation, are sufficient to overcome the impairments to the O-CDMA transmission system that we considered.

  8. Orbital Angular Momentum Multiplexing over Visible Light Communication Systems

    Science.gov (United States)

    Tripathi, Hardik Rameshchandra

    This thesis proposes and explores the possibility of using Orbital Angular Momentum multiplexing in Visible Light Communication system. Orbital Angular Momentum is mainly applied for laser and optical fiber transmissions, while Visible Light Communication is a technology using the light as a carrier for wireless communication. In this research, the study of the state of art and experiments showing some results on multiplexing based on Orbital Angular Momentum over Visible Light Communication system were done. After completion of the initial stage; research work and simulations were performed on spatial multiplexing over Li-Fi channel modeling. Simulation scenarios which allowed to evaluate the Signal-to-Noise Ratio, Received Power Distribution, Intensity and Illuminance were defined and developed.

  9. Seamless integration of 57.2-Gb/s signal wireline transmission and 100-GHz wireless delivery.

    Science.gov (United States)

    Li, Xinying; Yu, Jianjun; Dong, Ze; Cao, Zizheng; Chi, Nan; Zhang, Junwen; Shao, Yufeng; Tao, Li

    2012-10-22

    We experimentally demonstrated the seamless integration of 57.2-Gb/s signal wireline transmission and 100-GHz wireless delivery adopting polarization-division-multiplexing quadrature-phase-shift-keying (PDM-QPSK) modulation with 400-km single-mode fiber-28 (SMF-28) transmission and 1-m wireless delivery. The X- and Y-polarization components of optical PDM-QPSK baseband signal are simultaneously up-converted to 100 GHz by optical polarization-diversity heterodyne beating, and then independently transmitted and received by two pairs of transmitter and receiver antennas, which make up a 2x2 multiple-input multiple-output (MIMO) wireless link based on microwave polarization multiplexing. At the wireless receiver, a two-stage down conversion is firstly done in analog domain based on balanced mixer and sinusoidal radio frequency (RF) signal, and then in digital domain based on digital signal processing (DSP). Polarization de-multiplexing is realized by constant modulus algorithm (CMA) based on DSP in heterodyne coherent detection. Our experimental results show that more taps are required for CMA when the X- and Y-polarization antennas have different wireless distance.

  10. Generation of Flattened Multicarrier Signals from a Single Laser Source for 330 Gbps WDM-PON Transmission over 25 km SSMF

    Science.gov (United States)

    Ullah, Sibghat; Liu, Bo; Ullah, Rahat; Ahmad, Muhammad; Wang, Fu; Zhang, Lijia; Xin, Xiangjun; Memon, Kamran Ali; Khalid, Hafiz Ahmad

    2017-12-01

    A novel technique is proposed for optical frequency comb generation with a budget friendly system. A Mach-Zehnder modulator is used in connectivity with continuous wave optical signal which is filtered by rectangle optical filter and the signal is then amplified by erbium-doped fiber amplifier. With a frequency spacing of 10 GHz 33 useable OFC lines were generated with good tone to noise ratio which is quite impressive for such a cost effective setup. Each generated carrier carries differential phase shift keying based data of 10 Gbps. A total of 330 Gbps multiplexed data is successfully transmitted through a standard single mode fiber length of 25-km. During the downlink transmission the power penalties are observed to be negligible. The resulted eye diagrams are wide and promises to be a good system for wavelength division multiplexed-passive optical network.

  11. Multiplexed Neurochemical Signaling by Neurons of the Ventral Tegmental Area

    Science.gov (United States)

    Barker, David J.; Root, David H.; Zhang, Shiliang; Morales, Marisela

    2016-01-01

    The ventral tegmental area (VTA) is an evolutionarily conserved structure that has roles in reward-seeking, safety-seeking, learning, motivation, and neuropsychiatric disorders such as addiction and depression. The involvement of the VTA in these various behaviors and disorders is paralleled by its diverse signaling mechanisms. Here we review recent advances in our understanding of neuronal diversity in the VTA with a focus on cell phenotypes that participate in ‘multiplexed’ neurotransmission involving distinct signaling mechanisms. First, we describe the cellular diversity within the VTA, including neurons capable of transmitting dopamine, glutamate or GABA as well as neurons capable of multiplexing combinations of these neurotransmitters. Next, we describe the complex synaptic architecture used by VTA neurons in order to accommodate the transmission of multiple transmitters. We specifically cover recent findings showing that VTA multiplexed neurotransmission may be mediated by either the segregation of dopamine and glutamate into distinct microdomains within a single axon or by the integration of glutamate and GABA into a single axon terminal. In addition, we discuss our current understanding of the functional role that these multiplexed signaling pathways have in the lateral habenula and the nucleus accumbens. Finally, we consider the putative roles of VTA multiplexed neurotransmission in synaptic plasticity and discuss how changes in VTA multiplexed neurons may relate to various psychopathologies including drug addiction and depression. PMID:26763116

  12. Multiplex families with epilepsy

    Science.gov (United States)

    Afawi, Zaid; Oliver, Karen L.; Kivity, Sara; Mazarib, Aziz; Blatt, Ilan; Neufeld, Miriam Y.; Helbig, Katherine L.; Goldberg-Stern, Hadassa; Misk, Adel J.; Straussberg, Rachel; Walid, Simri; Mahajnah, Muhammad; Lerman-Sagie, Tally; Ben-Zeev, Bruria; Kahana, Esther; Masalha, Rafik; Kramer, Uri; Ekstein, Dana; Shorer, Zamir; Wallace, Robyn H.; Mangelsdorf, Marie; MacPherson, James N.; Carvill, Gemma L.; Mefford, Heather C.; Jackson, Graeme D.; Scheffer, Ingrid E.; Bahlo, Melanie; Gecz, Jozef; Heron, Sarah E.; Corbett, Mark; Mulley, John C.; Dibbens, Leanne M.; Korczyn, Amos D.

    2016-01-01

    Objective: To analyze the clinical syndromes and inheritance patterns of multiplex families with epilepsy toward the ultimate aim of uncovering the underlying molecular genetic basis. Methods: Following the referral of families with 2 or more relatives with epilepsy, individuals were classified into epilepsy syndromes. Families were classified into syndromes where at least 2 family members had a specific diagnosis. Pedigrees were analyzed and molecular genetic studies were performed as appropriate. Results: A total of 211 families were ascertained over an 11-year period in Israel. A total of 169 were classified into broad familial epilepsy syndrome groups: 61 generalized, 22 focal, 24 febrile seizure syndromes, 33 special syndromes, and 29 mixed. A total of 42 families remained unclassified. Pathogenic variants were identified in 49/211 families (23%). The majority were found in established epilepsy genes (e.g., SCN1A, KCNQ2, CSTB), but in 11 families, this cohort contributed to the initial discovery (e.g., KCNT1, PCDH19, TBC1D24). We expand the phenotypic spectrum of established epilepsy genes by reporting a familial LAMC3 homozygous variant, where the predominant phenotype was epilepsy with myoclonic-atonic seizures, and a pathogenic SCN1A variant in a family where in 5 siblings the phenotype was broadly consistent with Dravet syndrome, a disorder that usually occurs sporadically. Conclusion: A total of 80% of families were successfully classified, with pathogenic variants identified in 23%. The successful characterization of familial electroclinical and inheritance patterns has highlighted the value of studying multiplex families and their contribution towards uncovering the genetic basis of the epilepsies. PMID:26802095

  13. Signal multiplexing scheme for LINAC

    International Nuclear Information System (INIS)

    Sujo, C.I.; Mohan, Shyam; Joshi, Gopal; Singh, S.K.; Karande, Jitendra

    2004-01-01

    For the proper operation of the LINAC some signals, RF (radio frequency) as well as LF (low frequency) have to be available at the Master Control Station (MCS). These signals are needed to control, calibrate and characterize the RF fields in the resonators. This can be achieved by proper multiplexing of various signals locally and then routing the selected signals to the MCS. A multiplexing scheme has been designed and implemented, which will allow the signals from the selected cavity to the MCS. High isolation between channels and low insertion loss for a given signal are important issues while selecting the multiplexing scheme. (author)

  14. 78 FR 16513 - Application of Advances in Nucleic Acid and Protein Based Detection Methods to Multiplex...

    Science.gov (United States)

    2013-03-15

    ... Methods to Multiplex Detection of Transfusion- Transmissible Agents and Blood Cell Antigens in Blood... Transfusion-Transmissible Agents and Blood Cell Antigens in Blood Donations; Public Workshop AGENCY: Food and... technological advances in gene based and protein based pathogen and blood cell antigen detection methods and to...

  15. Error-free 320 Gb/s simultaneous add-drop multiplexing

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Oxenløwe, Leif Katsuo; Clausen, Anders

    2007-01-01

    We report on the first demonstration of error-free time-division add-drop multiplexing at 320 Gb/s. The add- and drop-operations are performed simultaneously in a non-linear optical loop mirror with only 100 m of highly non-linear fibre....

  16. Ontario Hydro Research Division, 1980

    International Nuclear Information System (INIS)

    The work of the Research Division of Ontario Hydro provides technical and scientific support for the engineering and operation of a power system that includes hydraulic, fossil-fired, and nuclear generation. It also relates to the transmission and distribution of electricity and to the need to help customers use electricity with safety and economy. Among the examples of projects given are qualification of CANDU heat transport system components, pressure tube replacement, steam generator integrity, testing for earthquake resistance, and radioactive waste disposal

  17. Division of solid state physics

    International Nuclear Information System (INIS)

    Beckman, O.

    1983-09-01

    This report gives a survey of the present research projects at the division of solid state physics, Inst. of Technology, Uppsala University. The projects fall within the fields of magnetism, i.e. spin glasses, ordered magnetic structures and itinerant electron magnetism, and optics, i.e. properties of crystalline and amorphous materials for selective transmission and absorption in connection with energy-related research. (author)

  18. Percolation in real multiplex networks

    Science.gov (United States)

    Bianconi, Ginestra; Radicchi, Filippo

    2016-12-01

    We present an exact mathematical framework able to describe site-percolation transitions in real multiplex networks. Specifically, we consider the average percolation diagram valid over an infinite number of random configurations where nodes are present in the system with given probability. The approach relies on the locally treelike ansatz, so that it is expected to accurately reproduce the true percolation diagram of sparse multiplex networks with negligible number of short loops. The performance of our theory is tested in social, biological, and transportation multiplex graphs. When compared against previously introduced methods, we observe improvements in the prediction of the percolation diagrams in all networks analyzed. Results from our method confirm previous claims about the robustness of real multiplex networks, in the sense that the average connectedness of the system does not exhibit any significant abrupt change as its individual components are randomly destroyed.

  19. On the Performance Evaluation of a MIMO-WCDMA Transmission Architecture for Building Management Systems.

    Science.gov (United States)

    Tsampasis, Eleftherios; Gkonis, Panagiotis K; Trakadas, Panagiotis; Zahariadis, Theodοre

    2018-01-08

    The goal of this study was to investigate the performance of a realistic wireless sensor nodes deployment in order to support modern building management systems (BMSs). A three-floor building orientation is taken into account, where each node is equipped with a multi-antenna system while a central base station (BS) collects and processes all received information. The BS is also equipped with multiple antennas; hence, a multiple input-multiple output (MIMO) system is formulated. Due to the multiple reflections during transmission in the inner of the building, a wideband code division multiple access (WCDMA) physical layer protocol has been considered, which has already been adopted for third-generation (3G) mobile networks. Results are presented for various MIMO orientations, where the mean transmission power per node is considered as an output metric for a specific signal-to-noise ratio (SNR) requirement and number of resolvable multipath components. In the first set of presented results, the effects of multiple access interference on overall transmission power are highlighted. As the number of mobile nodes per floor or the requested transmission rate increases, MIMO systems of a higher order should be deployed in order to maintain transmission power at adequate levels. In the second set of results, a comparison is performed among transmission in diversity combining and spatial multiplexing mode, which clearly indicate that the first case is the most appropriate solution for indoor communications.

  20. A Time-Multiplexed Track-Trigger architecture for CMS

    CERN Document Server

    Hall, Geoffrey; Pesaresi, Mark Franco; Rose, A

    2014-01-01

    The CMS Tracker under development for the High Luminosity LHC includes an outer tracker based on ``PT-modules'' which will provide track stubs based on coincident clusters in two closely spaced sensor layers, aiming to reject low transverse momentum track hits before data transmission to the Level-1 trigger. The tracker data will be used to reconstruct track segments in dedicated processors before onward transmission to other trigger processors which will combine tracker information with data originating from the calorimeter and muon detectors, to make the final L1 trigger decision. The architecture for processing the tracker data is still an open question. One attractive option is to explore a Time Multiplexed design similar to one which is currently being implemented in the CMS calorimeter trigger as part of the Phase I trigger upgrade. The Time Multiplexed Trigger concept is explained, the potential benefits of applying it for processing future tracker data are described and a possible design based on cur...

  1. Eliminating Perinatal HIV Transmission

    Centers for Disease Control (CDC) Podcasts

    2012-11-26

    In this podcast, CDC’s Dr. Steve Nesheim discusses perinatal HIV transmission, including the importance of preventing HIV among women, preconception care, and timely HIV testing of the mother. Dr. Nesheim also introduces the revised curriculum Eliminating Perinatal HIV Transmission intended for faculty of OB/GYN and pediatric residents and nurse midwifery students.  Created: 11/26/2012 by Division of HIV/AIDS Prevention.   Date Released: 11/26/2012.

  2. Design and performance investigation of LDPC-coded upstream transmission systems in IM/DD OFDM-PONs

    Science.gov (United States)

    Gong, Xiaoxue; Guo, Lei; Wu, Jingjing; Ning, Zhaolong

    2016-12-01

    In Intensity-Modulation Direct-Detection (IM/DD) Orthogonal Frequency Division Multiplexing Passive Optical Networks (OFDM-PONs), aside from Subcarrier-to-Subcarrier Intermixing Interferences (SSII) induced by square-law detection, the same laser frequency for data sending from Optical Network Units (ONUs) results in ONU-to-ONU Beating Interferences (OOBI) at the receiver. To mitigate those interferences, we design a Low-Density Parity Check (LDPC)-coded and spectrum-efficient upstream transmission system. A theoretical channel model is also derived, in order to analyze the detrimental factors influencing system performances. Simulation results demonstrate that the receiver sensitivity is improved 3.4 dB and 2.5 dB under QPSK and 8QAM, respectively, after 100 km Standard Single-Mode Fiber (SSMF) transmission. Furthermore, the spectrum efficiency can be improved by about 50%.

  3. Experimental demonstration of the transmission performance for LDPC-coded multiband OFDM ultra-wideband over fiber system

    Science.gov (United States)

    He, Jing; Wen, Xuejie; Chen, Ming; Chen, Lin; Su, Jinshu

    2015-01-01

    To improve the transmission performance of multiband orthogonal frequency division multiplexing (MB-OFDM) ultra-wideband (UWB) over optical fiber, a pre-coding scheme based on low-density parity-check (LDPC) is adopted and experimentally demonstrated in the intensity-modulation and direct-detection MB-OFDM UWB over fiber system. Meanwhile, a symbol synchronization and pilot-aided channel estimation scheme is implemented on the receiver of the MB-OFDM UWB over fiber system. The experimental results show that the LDPC pre-coding scheme can work effectively in the MB-OFDM UWB over fiber system. After 70 km standard single-mode fiber (SSMF) transmission, at the bit error rate of 1 × 10-3, the receiver sensitivities are improved about 4 dB when the LDPC code rate is 75%.

  4. EAM-based high-speed 100-km OFDM transmission featuring tolerant modulator operation enabled using SSII cancellation.

    Science.gov (United States)

    Chen, Hsing-Yu; Wei, Chia-Chien; Lu, I-Cheng; Chen, Yu-Chao; Chu, Hsuan-Hao; Chen, Jyehong

    2014-06-16

    In this study, a technique was developed to compensate for nonlinear distortion through cancelling subcarrier-to-subcarrier intermixing interference (SSII) in an electroabsorption modulator (EAM)-based orthogonal frequency-division multiplexing (OFDM) transmission system. The nonlinear distortion to be compensated for is induced by both EAM nonlinearity and fiber dispersion. Because an OFDM signal features an inherently high peak-to-average power ratio, a trade-off exists between the optical modulation index (OMI) and modulator nonlinearity. Therefore, the nonlinear distortion limits the operational tolerance of the bias voltage and the driving power to a small region. After applying the proposed SSII cancellation, the OMI of an OFDM signal was increased yielding only a small increment of nonlinear distortion, and the tolerance region of the operational conditions was also increased. By employing the proposed scheme, this study successfully demonstrates 50-Gbps OFDM transmission over 100-km dispersion-uncompensated single-mode fiber based on a single 10-GHz EAM.

  5. Demostration of 520 Gb/s/λ pre-equalized DFT-spread PDM-16QAM-OFDM signal transmission.

    Science.gov (United States)

    Li, Fan; Yu, Jianjun; Cao, Zizheng; Chen, Ming; Zhang, Junwen; Li, Xinying

    2016-02-08

    In this paper, we successfully transmit 8 × 520 Gb/s pre-equalized DFT-spread PDM-16QAM orthogonal frequency-division multiplexing (OFDM) signal over 840 km SMF with BER under 2.4 × 10(-2). We discuss how to obtain accurate tranceivers' response during pre-equalization for DFT-spread OFDM with coherent detection and we find conventional OFDM symbols training sequences (TSs) outperform DFT-spread OFDM symbols TSs in obtaining channel response for pre-equalization and equalization. Additionally, the optimal IFFT/FFT size is explored for the pre-equalized DFT-spread PDM-16QAM-OFDM transmission systems. It is the first time to realize 400 Gb/s/λ net rate OFDM signal transmission.

  6. 400-GHz wireless transmission of 60-Gb/s nyquist-QPSK signals using UTC-PD and heterodyne mixer

    DEFF Research Database (Denmark)

    Yu, Xianbin; Asif, Rameez; Piels, Molly

    2016-01-01

    We experimentally demonstrate an optical network compatible high-speed optoelectronics THz wireless transmission system operating at 400-GHz band. In the experiment, optical Nyquist quadrature phase-shift keying signals in a 12.5-GHz ultradense wavelength-division multiplexing grid is converted...... to the THz wireless radiation by photomixing in an antenna integrated unitravelling photodiode. The photomixing is transparent to optical modulation formats. We also demonstrate in the experiment the scalability of our system by applying single to four channels, as well as mixed three channels. Wireless...... transmission of a capacity of 60 Gb/s for four channels (15 Gb/s per channel) at 400-GHz band is successfully achieved, which pushes the data rates enabled by optoelectronics approach beyond the envelope in the frequency range above 300 GHz. Besides those, this study also validates the potential of bridging...

  7. Thermally multiplexed polymerase chain reaction.

    Science.gov (United States)

    Phaneuf, Christopher R; Pak, Nikita; Saunders, D Curtis; Holst, Gregory L; Birjiniuk, Joav; Nagpal, Nikita; Culpepper, Stephen; Popler, Emily; Shane, Andi L; Jerris, Robert; Forest, Craig R

    2015-07-01

    Amplification of multiple unique genetic targets using the polymerase chain reaction (PCR) is commonly required in molecular biology laboratories. Such reactions are typically performed either serially or by multiplex PCR. Serial reactions are time consuming, and multiplex PCR, while powerful and widely used, can be prone to amplification bias, PCR drift, and primer-primer interactions. We present a new thermocycling method, termed thermal multiplexing, in which a single heat source is uniformly distributed and selectively modulated for independent temperature control of an array of PCR reactions. Thermal multiplexing allows amplification of multiple targets simultaneously-each reaction segregated and performed at optimal conditions. We demonstrate the method using a microfluidic system consisting of an infrared laser thermocycler, a polymer microchip featuring 1 μl, oil-encapsulated reactions, and closed-loop pulse-width modulation control. Heat transfer modeling is used to characterize thermal performance limitations of the system. We validate the model and perform two reactions simultaneously with widely varying annealing temperatures (48 °C and 68 °C), demonstrating excellent amplification. In addition, to demonstrate microfluidic infrared PCR using clinical specimens, we successfully amplified and detected both influenza A and B from human nasopharyngeal swabs. Thermal multiplexing is scalable and applicable to challenges such as pathogen detection where patients presenting non-specific symptoms need to be efficiently screened across a viral or bacterial panel.

  8. Transmission Characteristics of an OFDM signal for Power Line Communication System with High Bit Rate

    Science.gov (United States)

    Mori, Akira; Watanabe, Yosuke; Tokuda, Masamitsu; Kawamoto, Koji

    In this paper, we measured what influence the sinusoidal transmission characteristics of the electric power line with various forms gave to the transmission characteristic of OFDM (Orthogonal Frequency Division Multiplexing) signal through PLC (power line communication system) modem. We classified the electric power line transmission line with various forms in a real environment into two basic elements, which are an outlet type branch and a switch type branch. Next, PHY rate (Physical rate) is measured for each basic element connected with the PLC modem. At this time, the transmission characteristics of the electric power line are simulated from measured data. OFDM sending and receiving systems are composed on the computer, and the PHY rate is simulated. By comparing with measured and calculated values, it is revealed that PHY rate of PLC modem is most affected in the case of the power line transmission characteristics having broad band and high level attenuation and group delay variation, and is not affected in the case of that having narrow band attenuation and group delay variation.

  9. Experimental demonstration of novel source-free ONUs in bidirectional RF up-converted optical OFDM-PON utilizing polarization multiplexing.

    Science.gov (United States)

    Zhang, Chongfu; Chen, Chen; Feng, Yuan; Qiu, Kun

    2012-03-12

    We propose and experimentally demonstrate a novel cost-effective optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system, wherein all optical network units (ONUs) are source-free not only in the optical domain but also in the electric domain, by utilizing polarization multiplexing (PolMUX) in the downlink transmission. Two pure optical bands with a frequency interval of 10 GHz and downlink up-converted 10 GHz OFDM signal are carried in two orthogonal states of polarization (SOPs), respectively. 10 GHz radio frequency (RF) source can be generated by a heterodyne of two pure optical bands after polarization beam splitting in each ONU, therefore it can be used to down-convert the downlink OFDM signal and up-convert the uplink OFDM signal. In the whole bidirectional up-converted OFDM-PON system, only one single RF source is employed in the optical line terminal (OLT). Experimental results successfully verify the feasibility of our proposed cost-effective optical OFDM-PON system.

  10. Helicity multiplexed broadband metasurface holograms.

    Science.gov (United States)

    Wen, Dandan; Yue, Fuyong; Li, Guixin; Zheng, Guoxing; Chan, Kinlong; Chen, Shumei; Chen, Ming; Li, King Fai; Wong, Polis Wing Han; Cheah, Kok Wai; Pun, Edwin Yue Bun; Zhang, Shuang; Chen, Xianzhong

    2015-09-10

    Metasurfaces are engineered interfaces that contain a thin layer of plasmonic or dielectric nanostructures capable of manipulating light in a desirable manner. Advances in metasurfaces have led to various practical applications ranging from lensing to holography. Metasurface holograms that can be switched by the polarization state of incident light have been demonstrated for achieving polarization multiplexed functionalities. However, practical application of these devices has been limited by their capability for achieving high efficiency and high image quality. Here we experimentally demonstrate a helicity multiplexed metasurface hologram with high efficiency and good image fidelity over a broad range of frequencies. The metasurface hologram features the combination of two sets of hologram patterns operating with opposite incident helicities. Two symmetrically distributed off-axis images are interchangeable by controlling the helicity of the input light. The demonstrated helicity multiplexed metasurface hologram with its high performance opens avenues for future applications with functionality switchable optical devices.

  11. Laguerre Gaussian beam multiplexing through turbulence

    CSIR Research Space (South Africa)

    Trichili, A

    2014-08-17

    Full Text Available We analyze the effect of atmospheric turbulence on the propagation of multiplexed Laguerre Gaussian modes. We present a method to multiplex Laguerre Gaussian modes using digital holograms and decompose the resulting field after encountering a...

  12. Spatial analysis of various multiplex cinema types

    Directory of Open Access Journals (Sweden)

    Young-Seo Park

    2016-03-01

    Full Text Available This study identifies the spatial characteristics and relationships of each used space according to the multiplex type. In this study, multiplexes are classified according to screen rooms and circulation systems, and each used space is quantitatively analyzed. The multiplex type based on screen rooms and moving line systems influences the relationship and characteristics of each used space in various ways. In particular, the structure of the used space of multiplexes has a significant effect on profit generation and audience convenience.

  13. Turbulence mitigation scheme based on spatial diversity in orbital-angular-momentum multiplexed system

    Science.gov (United States)

    Zou, Li; Wang, Le; Zhao, Shengmei

    2017-10-01

    Atmospheric turbulence (AT) induced crosstalk can significantly impair the performance of free-space optical (FSO) communication link using orbital angular momentum (OAM) multiplexing. In this paper, we propose a spatial diversity (SD) turbulence mitigation scheme in an OAM-multiplexed FSO communication link. First, we present a SD mitigation model for the OAM-multiplexed FSO communication link under AT. Then we present a SD combining technique based on equal gain to enhance AT tolerance of the OAM-multiplexed FSO communication link. The numerical results show that performance of the OAM-multiplexed communication link has greatly improved by the proposed scheme. When the turbulence strength Cn2 is 5 × 10-15m - 2 / 3, the transmission distance is 1000 m and the channel signal-to-noise ratio (SNR) is 20 dB, the bit-error-rate (BER) performance of four spatial multiplexed OAM modes lm = + 1 , + 2 , + 3 , + 4 are 3 fold increase in comparison with those results without the proposed scheme. The proposed scheme is a promising direction for compensating the interference caused by AT in the OAM-multiplexed FSO communication link.

  14. Performance Analysis of Long-Reach Coherent Detection OFDM-PON Downstream Transmission Using m-QAM-Mapped OFDM Signal

    Science.gov (United States)

    Pandey, Gaurav; Goel, Aditya

    2017-12-01

    In this paper, orthogonal frequency division multiplexing (OFDM)-passive optical network (PON) downstream transmission is demonstrated over different lengths of fiber at remote node (RN) for different m-QAM (quadrature amplitude modulation)-mapped OFDM signal (m=4, 16, 32 and 64) transmission from the central office (CO) for different data rates (10, 20 30 and 40 Gbps) using coherent detection at the user end or optical network unit (ONU). Investigation is performed with different number of subcarriers (32, 64, 128, 512 and 1,024), back-to-back optical signal-to-noise ratio (OSNR) along with transmitted and received constellation diagrams for m-QAM-mapped coherent OFDM downstream transmission at different speeds over different transmission distances. Received optical power is calculated for different bit error rates (BERs) at different speeds using m-QAM-mapped coherent detection OFDM downstream transmission. No dispersion compensation is utilized in between the fiber span. Simulation results suggest the different lengths and data rates that can be used for different m-QAM-mapped coherent detection OFDM downstream transmission, and the proposed system may be implemented in next-generation high-speed PONs (NG-PONs).

  15. Cell Division Synchronization

    Science.gov (United States)

    The report summarizes the progress in the design and construction of automatic equipment for synchronizing cell division in culture by periodic...Concurrent experiments in hypothermic synchronization of algal cell division are reported.

  16. Data transmission with twisted light through a free-space to fiber optical communication link

    International Nuclear Information System (INIS)

    Brüning, Robert; Duparré, Michael; Ndagano, Bienvenu; McLaren, Melanie; Forbes, Andrew; Schröter, Siegmund; Kobelke, Jens

    2016-01-01

    Mode division multiplexing (MDM), where information is transmitted in the spatial modes of light, is mooted as a future technology with which to transmit large bits of information. However, one of the key issues in optical communication lies in connecting free-space to optical fiber networks, otherwise known as the ‘last mile’ problem. This is particularly problematic for MDM as the eigenmodes of free-space and fibers are in general not the same. Here we demonstrate a data transmission scheme across a free-space and fiber link using twisted light in the form of Laguerre–Gaussian (LG) azimuthal modes. As a proof-of-principle we design and implement a custom fiber where the supported LG modes can be grouped into five non-degenerate sets, and successfully transmit a gray-scale image across the composite link using one mode from each group, thereby ensuring minimal crosstalk. (letter)

  17. Division of Finance Homepage

    Science.gov (United States)

    Top Department of Administration logo Alaska Department of Administration Division of Finance Search Search the Division of Finance site DOF State of Alaska Finance Home Content Area Accounting Charge Cards You are here Administration / Finance Division of Finance Updates IRIS Expenditure Object Codes

  18. Argonne Physics Division Colloquium

    Science.gov (United States)

    [Argonne Logo] [DOE Logo] Physics Division Home News Division Information Contact PHY Org Chart Physics Division Colloquium Auditorium, Building 203, Argonne National Laboratory Fridays at 11:00 AM 2017 : Sereres Johnston 15 Sep 2017 Joint Physics and Materials Science Colloquium J. C. Séamus Davis, Cornell

  19. SP-100 Position Multiplexer and Analog Input Processor

    International Nuclear Information System (INIS)

    Syed, A.; Gilliland, K.; Shukla, J.N.

    1992-01-01

    This paper describes the design, implementation, and performance test results of an engineering model of the Position Multiplexer (MUX)-Analog Input Processor (AIP) System for the transmission and continuous measurements of Reflector Control Drive position in SP-100. This paper describes the work performed to determine the practical circuit limitations, investigate the circuit/component degradation of the multiplexer due to radiation, develop an interference cancellation technique, and evaluate the measurement accuracy as a function of resolver angle, temperature, radiation, and interference. The system developed performs a complex cross-correlation between the resolver excitation and the resolver sine cosine outputs, from which the precise resolver amplitude and phase can be determined while simultaneously eliminating virtually all uncorrelated interference

  20. Ploidy-Dependent Unreductional Meiotic Cell Division in Polyploid Wheat

    Science.gov (United States)

    Meiosis includes one round of DNA replication and two successive nuclear divisions, i.e. meiosis I (reductional) and meiosis II (equational). This specialized cell division reduces chromosomes in half and generates haploid gametes in sexual reproduction of eukaryotes. It ensures faithful transmiss...

  1. METHODS OF POLYMODAL INFORMATION TRANSMISSION

    Directory of Open Access Journals (Sweden)

    O. O. Basov

    2015-03-01

    Full Text Available The research results upon the application of the existing information transmission methods in polymodal info communication systems are presented herein. The analysis of the existing commutation ways and multiplexing schemes has revealed that modern means of telecommunication are capable of providing polymodal information delivery with the required quality to the customer correspondent terminal. Under these conditions substantial capacity resource consumption in the data transmission networks with a simultaneous static time multiplexing is required, however, it is easier to achieve the modality synchronization within that kind of an infrastructure. The data networks with a static time multiplexing demand employing more sophisticated supporting algorithms of the guaranteed data blocks delivery quality. However, due to the stochastic data blocks delays modality synchronizing during the off-line processing is more difficult to provide. Nowadays there are objective preconditions for a data networking realization which is invariable to the applied transmission technology. This capability is defined by a wide (person-to-person application of the optical technologies in the transport infrastructure of the polymodal info communication systems. In case of the availability of the customer terminal and networking functioning matching mode it becomes possible to organize channels in the latter which can adaptively select the most effective networking technology according to the current volume allocation and modality types in the messages.

  2. Centrality in earthquake multiplex networks

    Science.gov (United States)

    Lotfi, Nastaran; Darooneh, Amir Hossein; Rodrigues, Francisco A.

    2018-06-01

    Seismic time series has been mapped as a complex network, where a geographical region is divided into square cells that represent the nodes and connections are defined according to the sequence of earthquakes. In this paper, we map a seismic time series to a temporal network, described by a multiplex network, and characterize the evolution of the network structure in terms of the eigenvector centrality measure. We generalize previous works that considered the single layer representation of earthquake networks. Our results suggest that the multiplex representation captures better earthquake activity than methods based on single layer networks. We also verify that the regions with highest seismological activities in Iran and California can be identified from the network centrality analysis. The temporal modeling of seismic data provided here may open new possibilities for a better comprehension of the physics of earthquakes.

  3. 47 CFR 73.669 - TV stereophonic aural and multiplex subcarrier operation.

    Science.gov (United States)

    2010-10-01

    ... multiplex subcarrier operation. (a) A TV broadcast station may without specific authority from the FCC... commencement of multichannel broadcasting, the equipment shall be measured in accordance with § 73.1690(e). (b... the FCC. Transmissions must be conducted in accordance with the technical standards given in § 73.682...

  4. On infinitely divisible semimartingales

    DEFF Research Database (Denmark)

    Basse-O'Connor, Andreas; Rosiński, Jan

    2015-01-01

    to non Gaussian infinitely divisible processes. First we show that the class of infinitely divisible semimartingales is so large that the natural analog of Stricker's theorem fails to hold. Then, as the main result, we prove that an infinitely divisible semimartingale relative to the filtration generated...... by a random measure admits a unique decomposition into an independent increment process and an infinitely divisible process of finite variation. Consequently, the natural analog of Stricker's theorem holds for all strictly representable processes (as defined in this paper). Since Gaussian processes...... are strictly representable due to Hida's multiplicity theorem, the classical Stricker's theorem follows from our result. Another consequence is that the question when an infinitely divisible process is a semimartingale can often be reduced to a path property, when a certain associated infinitely divisible...

  5. Implementation of multiplexing in a subcarrier-wave quantum cryptography system

    International Nuclear Information System (INIS)

    Chistyakov, V V; Gleim, A V; Egorov, V I; Nazarov, Yu V

    2014-01-01

    Quantum cryptography allows distributing secure keys in a way that any eavesdropping in the channel is inevitably detected. This work is dedicated to introducing wavelength division multiplexing in a subcarrier-wave quantum cryptography system. Compared to other existing schemes, the resulting device is able to achieve higher bitrates (up to 2.26 Mbit/s at 20 km), is robust against external conditions and compatible with standard telecommunication fibres in multi-user environment

  6. The LHCb VELO analogue transmission line

    International Nuclear Information System (INIS)

    Bay, A.; Borel, J.; Buytaert, J.; De Laere, S.; Frei, R.; Haefeli, G.; Koppenburg, P.; Locatelli, L.; Schneider, O.; Zehr, F.

    2010-01-01

    The Vertex Locator is one of the most important sub-detectors of the LHCb experiment, which is devoted to B physics. The signals from the silicon strip sensors are multiplexed at 40 MHz and transported by 60 m copper lines to the counting stations placed in a radiation safe area. This paper describes the development of this long transmission line and its performance.

  7. Free-space coherent optical communication with orbital angular, momentum multiplexing/demultiplexing using a hybrid 3D photonic integrated circuit.

    Science.gov (United States)

    Guan, Binbin; Scott, Ryan P; Qin, Chuan; Fontaine, Nicolas K; Su, Tiehui; Ferrari, Carlo; Cappuzzo, Mark; Klemens, Fred; Keller, Bob; Earnshaw, Mark; Yoo, S J B

    2014-01-13

    We demonstrate free-space space-division-multiplexing (SDM) with 15 orbital angular momentum (OAM) states using a three-dimensional (3D) photonic integrated circuit (PIC). The hybrid device consists of a silica planar lightwave circuit (PLC) coupled to a 3D waveguide circuit to multiplex/demultiplex OAM states. The low excess loss hybrid device is used in individual and two simultaneous OAM states multiplexing and demultiplexing link experiments with a 20 Gb/s, 1.67 b/s/Hz quadrature phase shift keyed (QPSK) signal, which shows error-free performance for 379,960 tested bits for all OAM states.

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

    DEFF Research Database (Denmark)

    Limal, Emmanuel; Stubkjær, Kristian Elmholdt

    1999-01-01

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

  9. Division of atomic physics

    International Nuclear Information System (INIS)

    Kroell, S.

    1994-01-01

    The Division of Atomic Physics, Lund Institute of Technology (LTH), is responsible for the basic physics teaching in all subjects at LTH and for specialized teaching in Optics, Atomic Physics, Atomic and Molecular Spectroscopy and Laser Physics. The Division has research activities in basic and applied optical spectroscopy, to a large extent based on lasers. It is also part of the Physics Department, Lund University, where it forms one of eight divisions. Since the beginning of 1980 the research activities of our division have been centred around the use of lasers. The activities during the period 1991-1992 is described in this progress reports

  10. Evaluation of HOPG mounting possibilities for multiplexing spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Groitl, Felix, E-mail: felix.groitl@psi.ch [Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland); Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Bartkowiak, Marek [Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, 5232 Villigen (Switzerland); Bergmann, Ryan M. [Division Large Research Facilities, Paul Scherrer Institut, 5232 Villigen (Switzerland); Birk, Jonas Okkels [Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Department of Physics, Technical University of Denmark (DTU), 2800 Kgs. Lyngby (Denmark); Markó, Márton [Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Wigner Research Centre for Physics, Neutron Spectroscopy Department, 1525 Budapest (Hungary); Bollhalder, Alex; Graf, Dieter [Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, 5232 Villigen (Switzerland); Niedermayer, Christof [Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Rüegg, Christian [Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen (Switzerland); Department of Quantum Matter Physics, University of Geneva, 1211 Geneva (Switzerland); Rønnow, Henrik M. [Laboratory for Quantum Magnetism, École Polytechnique Fédérale de Lausanne, 1015 Lausanne (Switzerland); Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark)

    2017-06-21

    Four different methods for mounting HOPG analyzer crystals on Si holders have been evaluated in the design process of the new multiplexing spectrometer CAMEA. Contrary to neutron optics used in standard spectrometers, the new instrument concept employs a series of analyzer segments behind each other where the neutrons have to pass through the bonding compound of the different analyzer crystals. The different methods, namely screws, shellac, indium soldering and clips, have been evaluated with regards to background, transmission, cooling, activation and handling. The results presented here will give valuable input for future CAMEA-type spectrometers currently planned and designed at various neutron sources.

  11. Evaluation of HOPG mounting possibilities for multiplexing spectrometers

    International Nuclear Information System (INIS)

    Groitl, Felix; Bartkowiak, Marek; Bergmann, Ryan M.; Birk, Jonas Okkels; Markó, Márton; Bollhalder, Alex; Graf, Dieter; Niedermayer, Christof; Rüegg, Christian; Rønnow, Henrik M.

    2017-01-01

    Four different methods for mounting HOPG analyzer crystals on Si holders have been evaluated in the design process of the new multiplexing spectrometer CAMEA. Contrary to neutron optics used in standard spectrometers, the new instrument concept employs a series of analyzer segments behind each other where the neutrons have to pass through the bonding compound of the different analyzer crystals. The different methods, namely screws, shellac, indium soldering and clips, have been evaluated with regards to background, transmission, cooling, activation and handling. The results presented here will give valuable input for future CAMEA-type spectrometers currently planned and designed at various neutron sources.

  12. Frequency multiplexing for readout of spin qubits

    Energy Technology Data Exchange (ETDEWEB)

    Hornibrook, J. M.; Colless, J. I.; Mahoney, A. C.; Croot, X. G.; Blanvillain, S.; Reilly, D. J., E-mail: david.reilly@sydney.edu.au [ARC Centre of Excellence for Engineered Quantum Systems, School of Physics, University of Sydney, Sydney, NSW 2006 (Australia); Lu, H.; Gossard, A. C. [Materials Department, University of California, Santa Barbara, California 93106 (United States)

    2014-03-10

    We demonstrate a low loss, chip-level frequency multiplexing scheme for readout of scaled-up spin qubit devices. By integrating separate bias tees and resonator circuits on-chip for each readout channel, we realise dispersive gate-sensing in combination with charge detection based on two radio frequency quantum point contacts. We apply this approach to perform multiplexed readout of a double quantum dot in the few-electron regime and further demonstrate operation of a 10-channel multiplexing device. Limitations for scaling spin qubit readout to large numbers of multiplexed channels are discussed.

  13. Quantum internet using code division multiple access

    Science.gov (United States)

    Zhang, Jing; Liu, Yu-xi; Özdemir, Şahin Kaya; Wu, Re-Bing; Gao, Feifei; Wang, Xiang-Bin; Yang, Lan; Nori, Franco

    2013-01-01

    A crucial open problem inS large-scale quantum networks is how to efficiently transmit quantum data among many pairs of users via a common data-transmission medium. We propose a solution by developing a quantum code division multiple access (q-CDMA) approach in which quantum information is chaotically encoded to spread its spectral content, and then decoded via chaos synchronization to separate different sender-receiver pairs. In comparison to other existing approaches, such as frequency division multiple access (FDMA), the proposed q-CDMA can greatly increase the information rates per channel used, especially for very noisy quantum channels. PMID:23860488

  14. Rate-Optimized Power Allocation for DF-Relayed OFDM Transmission under Sum and Individual Power Constraints

    Directory of Open Access Journals (Sweden)

    Vandendorpe Luc

    2009-01-01

    Full Text Available We consider an OFDM (orthogonal frequency division multiplexing point-to-point transmission scheme which is enhanced by means of a relay. Symbols sent by the source during a first time slot may be (but are not necessarily retransmitted by the relay during a second time slot. The relay is assumed to be of the DF (decode-and-forward type. For each relayed carrier, the destination implements maximum ratio combining. Two protocols are considered. Assuming perfect CSI (channel state information, the paper investigates the power allocation problem so as to maximize the rate offered by the scheme for two types of power constraints. Both cases of sum power constraint and individual power constraints at the source and at the relay are addressed. The theoretical analysis is illustrated through numerical results for the two protocols and both types of constraints.

  15. Chemical and Laser Sciences Division: Annual report, 1987

    International Nuclear Information System (INIS)

    1988-01-01

    As the Chemical and Laser Sciences Division concludes its first year, the Division personnel can be proud of their many scientific and technical accomplishments. Among the important milestones which the Division achieved were significant demonstrations of the process performance in the Special Isotope Separation program, of beam sensing techniques for the NPB program, and of optical angular multiplexing and energy extraction from the ICF KrF laser. In addition, the Los Alamos FTS was brought to operational status and the Bright Source attained intensities on the order of 10 17 W/cm 2 . A few highlights of these and other research and development activities are presented in the following sections of this report

  16. Steatocystoma multiplex hos 39-årig kvinde

    DEFF Research Database (Denmark)

    Duffy, Jonas Raymond; Siersen, Hans Erik; Bonde, Christian T

    2011-01-01

    -coloured cystic lesions on the chest, abdomen, axillae and back. The patient's clinical presentations and history were compatible with steatocystoma multiplex. Various treatment options for steatocystoma multiplex and steatocystoma multiplex suppurativum have been published and include oral antibiotics...

  17. Transmission/reception of a partial sc-fdm symbol

    DEFF Research Database (Denmark)

    2017-01-01

    A method is disclosed for signal processing in a radio system. The method comprises generating (801), in an apparatus (602), a single carrier frequency division multiplexing SC-FDM signal having a shorter duration than a time symbol duration defined by a radio standard applied in the radio system...

  18. Division: The Sleeping Dragon

    Science.gov (United States)

    Watson, Anne

    2012-01-01

    Of the four mathematical operators, division seems to not sit easily for many learners. Division is often described as "the odd one out". Pupils develop coping strategies that enable them to "get away with it". So, problems, misunderstandings, and misconceptions go unresolved perhaps for a lifetime. Why is this? Is it a case of "out of sight out…

  19. Computational Fair Division

    DEFF Research Database (Denmark)

    Branzei, Simina

    Fair division is a fundamental problem in economic theory and one of the oldest questions faced through the history of human society. The high level scenario is that of several participants having to divide a collection of resources such that everyone is satisfied with their allocation -- e.g. two...... heirs dividing a car, house, and piece of land inherited. The literature on fair division was developed in the 20th century in mathematics and economics, but computational work on fair division is still sparse. This thesis can be seen as an excursion in computational fair division divided in two parts....... The first part tackles the cake cutting problem, where the cake is a metaphor for a heterogeneous divisible resource such as land, time, mineral deposits, and computer memory. We study the equilibria of classical protocols and design an algorithmic framework for reasoning about their game theoretic...

  20. Golay sequences coded coherent optical OFDM for long-haul transmission

    Science.gov (United States)

    Qin, Cui; Ma, Xiangrong; Hua, Tao; Zhao, Jing; Yu, Huilong; Zhang, Jian

    2017-09-01

    We propose to use binary Golay sequences in coherent optical orthogonal frequency division multiplexing (CO-OFDM) to improve the long-haul transmission performance. The Golay sequences are generated by binary Reed-Muller codes, which have low peak-to-average power ratio and certain error correction capability. A low-complexity decoding algorithm for the Golay sequences is then proposed to recover the signal. Under same spectral efficiency, the QPSK modulated OFDM with binary Golay sequences coding with and without discrete Fourier transform (DFT) spreading (DFTS-QPSK-GOFDM and QPSK-GOFDM) are compared with the normal BPSK modulated OFDM with and without DFT spreading (DFTS-BPSK-OFDM and BPSK-OFDM) after long-haul transmission. At a 7% forward error correction code threshold (Q2 factor of 8.5 dB), it is shown that DFTS-QPSK-GOFDM outperforms DFTS-BPSK-OFDM by extending the transmission distance by 29% and 18%, in non-dispersion managed and dispersion managed links, respectively.

  1. 128 Gb/s TWDM PON system using dispersion-supported transmission method

    Science.gov (United States)

    Bindhaiq, Salem; Zulkifli, Nadiatulhuda; Supa'at, Abusahmah M.; Idrus, Sevia M.; Salleh, M. S.

    2017-11-01

    Time and wavelength division multiplexed passive optical network (TWDM-PON) trend is considered as the most extraordinary trend of the next generation solution to accommodate exponential traffic growth for converged new services. In this paper, we briefly review recent progress on TWDM-PON system through the use of low cost directly modulated lasers (DMLs) transmission for various line rate transmissions to date. Furthermore, through simulation, we propose and evaluate a cost effective way to upgrade TWDM-PON up to a symmetric capacity of 128 Gb/s using fiber Bragg gratings (FBGs) in optical line terminal (OLT) as a paramount dispersion manager in high speed light-wave systems in both upstream and downstream directions. A low cost and potential chirpless directed modulated grating laser (DMGL) is employed for downstream link and DML with a single delay-interferometer (DI) is employed for upstream link. After illustrating the demonstrated system architecture and configuration, we present the results and analysis to prove the system feasibility. The results show that a successful transmission is achieved over 40 km single mode fiber with a power budget of 33.7 dB, which could support 1:256 splitting ratio.

  2. Layered ACO-OFDM for intensity-modulated direct-detection optical wireless transmission.

    Science.gov (United States)

    Wang, Qi; Qian, Chen; Guo, Xuhan; Wang, Zhaocheng; Cunningham, David G; White, Ian H

    2015-05-04

    Layered asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) with high spectral efficiency is proposed in this paper for optical wireless transmission employing intensity modulation with direct detection. In contrast to the conventional ACO-OFDM, which only utilizes odd subcarriers for modulation, leading to an obvious spectral efficiency loss, in layered ACO-OFDM, the subcarriers are divided into different layers and modulated by different kinds of ACO-OFDM, which are combined for simultaneous transmission. In this way, more subcarriers are used for data transmission and the spectral efficiency is improved. An iterative receiver is also proposed for layered ACO-OFDM, where the negative clipping distortion of each layer is subtracted once it is detected so that the signals from different layers can be recovered. Theoretical analysis shows that the proposed scheme can improve the spectral efficiency by up to 2 times compared with conventional ACO-OFDM approaches with the same modulation order. Meanwhile, simulation results confirm a considerable signal-to-noise ratio gain over ACO-OFDM at the same spectral efficiency.

  3. Towards development of a fiber optic-based transmission monitoring system

    Science.gov (United States)

    Baldwin, Chris S.; Kiddy, Jason S.; Samuel, Paul D.

    2011-06-01

    There is interest in the rotorcraft community to develop health monitoring technologies. Among these technologies is the ability to monitor the transmission planetary gear system. The gearbox environment does not lend itself to traditional sensing technologies due to the harsh environment and crowed space. Traditional vibration-based diagnostics are based on the output from externally mounted sensors, usually accelerometers fixed to the gearbox exterior. This type of system relies on the ability of the vibration signal to travel from the gears through the gearbox housing. These sensors are also susceptible to other interference including electrical magnetic interference (EMI). For these reasons, the development of a fiber optic-based transmission monitoring system represents an appealing alternative to the accelerometer due to their resistance to EMI and other signal corrupting influences. Aither Engineering has been working on integrating the fiber optic sensors into the gearbox environment to measure strain on the ring gear of the planetary gear system. This application utilizes a serial array of wavelength division multiplexed fiber Bragg grating (FBG) sensors. Work in this area has been conducted at both the University of Maryland, College Park and more recently at the NASA Glenn Research Center (NGRC) OH-58 transmission test rig facility. This paper discusses some of the testing results collected from the fiber optic ring gear sensor array. Based on these results, recommendations for system requirements are addressed in terms of the capabilities of the FBG instrumentation.

  4. Interference Robust Transmission for the Downlink of an OFDM-Based Mobile Communications System

    Directory of Open Access Journals (Sweden)

    Markus Konrad

    2008-01-01

    Full Text Available Radio networks for future mobile communications systems, for example, 3GPP Long-Term Evolution (LTE, are likely to use an orthogonal frequency division multiplexing- (OFDM- based air interface in the downlink with a frequency reuse factor of one to avoid frequency planning. Therefore, system capacity is limited by interference, which is particularly crucial for mobile terminals with a single receive antenna. Nevertheless, next generation mobile communications systems aim at increasing downlink throughput. In this paper, a single antenna interference cancellation (SAIC algorithm is introduced for amplitude-shift keying (ASK modulation schemes in combination with bit-interleaved coded OFDM. By using such a transmission strategy, high gains in comparison to a conventional OFDM transmission with quadrature amplitude modulation (QAM can be achieved. The superior performance of the novel scheme is confirmed by an analytical bit-error probability (BEP analysis of the SAIC receiver for a single interferer, Rayleigh fading, and uncoded transmission. For the practically more relevant multiple interferer case we present an adaptive least-mean-square (LMS and an adaptive recursive least-squares (RLS SAIC algorithm. We show that in particular the RLS approach enables a good tradeoff between performance and complexity and is robust even to multiple interferers.

  5. Dual-polarization multi-band optical OFDM transmission and transceiver limitations for up to 500 Gb/s uncompensated long-haul links.

    Science.gov (United States)

    Giacoumidis, E; Jarajreh, M A; Sygletos, S; Le, S T; Farjady, F; Tsokanos, A; Hamié, A; Pincemin, E; Jaouën, Y; Ellis, A D; Doran, N J

    2014-05-05

    A number of critical issues for dual-polarization single- and multi-band optical orthogonal-frequency division multiplexing (DP-SB/MB-OFDM) signals are analyzed in dispersion compensation fiber (DCF)-free long-haul links. For the first time, different DP crosstalk removal techniques are compared, the maximum transmission-reach is investigated, and the impact of subcarrier number and high-level modulation formats are explored thoroughly. It is shown, for a bit-error-rate (BER) of 10(-3), 2000 km of quaternary phase-shift keying (QPSK) DP-MB-OFDM transmission is feasible. At high launched optical powers (LOP), maximum-likelihood decoding can extend the LOP of 40 Gb/s QPSK DP-SB-OFDM at 2000 km by 1.5 dB compared to zero-forcing. For a 100 Gb/s DP-MB-OFDM system, a high number of subcarriers contribute to improved BER but at the cost of digital signal processing computational complexity, whilst by adapting the cyclic prefix length the BER can be improved for a low number of subcarriers. In addition, when 16-quadrature amplitude modulation (16QAM) is employed the digital-to-analogue/analogue-to-digital converter (DAC/ADC) bandwidth is relaxed with a degraded BER; while the 'circular' 8QAM is slightly superior to its 'rectangular' form. Finally, the transmission of wavelength-division multiplexing DP-MB-OFDM and single-carrier DP-QPSK is experimentally compared for up to 500 Gb/s showing great potential and similar performance at 1000 km DCF-free G.652 line.

  6. An alarm multiplexer communication system

    International Nuclear Information System (INIS)

    Herrera, G.V.

    1986-01-01

    A low cost Alarm Multiplexer Communication System (AMCS) has been developed to perform the security sensor monitoring and control functions and to provide remote relay control capability for integrated security systems. AMCS has a distributed multiplexer/repeater architecture with up to four dual communication loops and dual control computers that guarantee total system operation under any single point failure condition. Each AMCS can control up to 4096 sensors and 2048 remote relays. AMCS reports alarm status information to and is controlled by either one or two Host computers. This allows for independent operation of primary and backup security command centers. AMCS communicates with the Host computers over an asynchronous serial communication link and has a message protocol which allows AMCS to fully recover from lost messages or large blocks of data communication errors. This paper describes the AMCS theory of operation, AMCS fault modes, and AMCS system design methodology. Also, cost and timing information is presented. AMCS is being used and considered for several DOE and DOD facilities

  7. Experimental multiplexing of quantum key distribution with classical optical communication

    International Nuclear Information System (INIS)

    Wang, Liu-Jun; Chen, Luo-Kan; Ju, Lei; Xu, Mu-Lan; Zhao, Yong; Chen, Kai; Chen, Zeng-Bing; Chen, Teng-Yun; Pan, Jian-Wei

    2015-01-01

    We demonstrate the realization of quantum key distribution (QKD) when combined with classical optical communication, and synchronous signals within a single optical fiber. In the experiment, the classical communication sources use Fabry-Pérot (FP) lasers, which are implemented extensively in optical access networks. To perform QKD, multistage band-stop filtering techniques are developed, and a wavelength-division multiplexing scheme is designed for the multi-longitudinal-mode FP lasers. We have managed to maintain sufficient isolation among the quantum channel, the synchronous channel and the classical channels to guarantee good QKD performance. Finally, the quantum bit error rate remains below a level of 2% across the entire practical application range. The proposed multiplexing scheme can ensure low classical light loss, and enables QKD over fiber lengths of up to 45 km simultaneously when the fibers are populated with bidirectional FP laser communications. Our demonstration paves the way for application of QKD to current optical access networks, where FP lasers are widely used by the end users

  8. Divisible ℤ-modules

    Directory of Open Access Journals (Sweden)

    Futa Yuichi

    2016-03-01

    Full Text Available In this article, we formalize the definition of divisible ℤ-module and its properties in the Mizar system [3]. We formally prove that any non-trivial divisible ℤ-modules are not finitely-generated.We introduce a divisible ℤ-module, equivalent to a vector space of a torsion-free ℤ-module with a coefficient ring ℚ. ℤ-modules are important for lattice problems, LLL (Lenstra, Lenstra and Lovász base reduction algorithm [15], cryptographic systems with lattices [16] and coding theory [8].

  9. DSP-based CSO cancellation technique for RoF transmission system implemented by using directly modulated laser.

    Science.gov (United States)

    Kim, Byung Gon; Bae, Sung Hyun; Kim, Hoon; Chung, Yun C

    2017-05-29

    We propose and demonstrate a simple composite second-order (CSO) cancellation technique based on the digital signal processing (DSP) for the radio-over-fiber (RoF) transmission system implemented by using directly modulated lasers (DMLs). When the RoF transmission system is implemented by using DMLs, its performance could be limited by the CSO distortions caused by the interplay between the DML's chirp and fiber's chromatic dispersion. We present the theoretical analysis of these nonlinear distortions and show that they can be suppressed at the receiver by using a simple DSP. To verify the effectiveness of the proposed technique, we demonstrate the transmission of twenty-four 100-MHz filtered orthogonal frequency-division multiplexing (f-OFDM) signals in 64 quadrature amplitude modulation (QAM) format over 20 km of the standard single-mode fiber (SSMF). The results show that, by using the proposed technique, we can suppress the CSO distortion components by >10 dB and achieve the error-vector magnitude performance better than 6% even after the 20-km long SSMF transmission.

  10. Long-range high-speed visible light communication system over 100-m outdoor transmission utilizing receiver diversity technology

    Science.gov (United States)

    Wang, Yiguang; Huang, Xingxing; Shi, Jianyang; Wang, Yuan-quan; Chi, Nan

    2016-05-01

    Visible light communication (VLC) has no doubt become a promising candidate for future wireless communications due to the increasing trends in the usage of light-emitting diodes (LEDs). In addition to indoor high-speed wireless access and positioning applications, VLC usage in outdoor scenarios, such as vehicle networks and intelligent transportation systems, are also attracting significant interest. However, the complex outdoor environment and ambient noise are the key challenges for long-range high-speed VLC outdoor applications. To improve system performance and transmission distance, we propose to use receiver diversity technology in an outdoor VLC system. Maximal ratio combining-based receiver diversity technology is utilized in two receivers to achieve the maximal signal-to-noise ratio. A 400-Mb/s VLC transmission using a phosphor-based white LED and a 1-Gb/s wavelength division multiplexing VLC transmission using a red-green-blue LED are both successfully achieved over a 100-m outdoor distance with the bit error rate below the 7% forward error correction limit of 3.8×10-3. To the best of our knowledge, this is the highest data rate at 100-m outdoor VLC transmission ever achieved. The experimental results clearly prove the benefit and feasibility of receiver diversity technology for long-range high-speed outdoor VLC systems.

  11. Mathematical Verification for Transmission Performance of Centralized Lightwave WDM-RoF-PON with Quintuple Services Integrated in Each Wavelength Channel

    Directory of Open Access Journals (Sweden)

    Shuai Chen

    2015-01-01

    Full Text Available Wavelength-division-multiplexing passive-optical-network (WDM-PON has been recognized as a promising solution of the “last mile” access as well as multibroadband data services access for end users, and WDM-RoF-PON, which employs radio-over-fiber (RoF technique in WDM-PON, is even a more attractive approach for future broadband fiber and wireless access for its strong availability of centralized multiservices transmission operation and its transparency for bandwidth and signal modulation formats. As for multiservices development in WDM-RoF-PON, various system designs have been reported and verified via simulation or experiment till now, and the scheme with multiservices transmitted in each single wavelength channel is believed as the one that has the highest bandwidth efficiency; however, the corresponding mathematical verification is still hard to be found in state-of-the-art literature. In this paper, system design and data transmission performance of a quintuple services integrated WDM-RoF-PON which jointly employs carrier multiplexing and orthogonal modulation techniques, have been theoretically analyzed and verified in detail; moreover, the system design has been duplicated and verified experimentally and the theory system of such WDM-RoF-PON scheme has thus been formed.

  12. Theoretical physics division

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Research activities of the theoretical physics division for 1979 are described. Short summaries are given of specific research work in the following fields: nuclear structure, nuclear reactions, intermediate energy physics, elementary particles [fr

  13. Bidirectional and simultaneous FTTX/Ethernet services using RSOA based remodulation and polarization multiplexing technique

    Science.gov (United States)

    Das, Anindya S.; Patra, Ardhendu S.

    2015-08-01

    A bidirectional and simultaneous transmission of Ethernet, FTTX services through single optical carrier wavelength employing polarization multiplexing technique in the transmitter end and the user end. 10 Gbps and 2.5 Gbps datarates are transmitted over 50 km single mode fiber employing POLMUX technique at OLT and ONU to provide Ethernet and FTTX services concurrently to the user. Reflective semiconductor optical amplifier is used to reuse and remodulate the downlink signal to uplink transmission. The upstream and the downstream transmission performances are observed by the bit error rate values and the eye diagrams obtained by the BER analyzer.

  14. Algebraic Number Precoded OFDM Transmission for Asynchronous Cooperative Multirelay Networks

    Directory of Open Access Journals (Sweden)

    Hua Jiang

    2014-01-01

    Full Text Available This paper proposes a space-time block coding (STBC transmission scheme for asynchronous cooperative systems. By combination of rotated complex constellations and Hadamard transform, these constructed codes are capable of achieving full cooperative diversity with the analysis of the pairwise error probability (PEP. Due to the asynchronous characteristic of cooperative systems, orthogonal frequency division multiplexing (OFDM technique with cyclic prefix (CP is adopted for combating timing delays from relay nodes. The total transmit power across the entire network is fixed and appropriate power allocation can be implemented to optimize the network performance. The relay nodes do not require decoding and demodulation operation, resulting in a low complexity. Besides, there is no delay for forwarding the OFDM symbols to the destination node. At the destination node the received signals have the corresponding STBC structure on each subcarrier. In order to reduce the decoding complexity, the sphere decoder is implemented for fast data decoding. Bit error rate (BER performance demonstrates the effectiveness of the proposed scheme.

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

    Science.gov (United States)

    Wang, Zhenxing

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

  16. Angular multiplexing holograms of four images recorded on photopolymer films with recording-film-thickness-dependent holographic characteristics

    Science.gov (United States)

    Osabe, Keiichi; Kawai, Kotaro

    2017-03-01

    In this study, angular multiplexing hologram recording photopolymer films were studied experimentally. The films contained acrylamide as a monomer, eosin Y as a sensitizer, and triethanolamine as a promoter in a polyvinyl alcohol matrix. In order to determine the appropriate thickness of the photopolymer films for angular multiplexing, photopolymer films with thicknesses of 29-503 μm were exposed to two intersecting beams of a YVO laser at a wavelength of 532 nm to form a holographic grating with a spatial frequency of 653 line/mm. The diffraction efficiencies as a function of the incident angle of reconstruction were measured. A narrow angular bandwidth and high diffraction efficiency are required for angular multiplexing; hence, we define the Q value, which is the diffraction efficiency divided by half the bandwidth. The Q value of the films depended on the thickness of the films, and was calculated based on the measured diffraction efficiencies. The Q value of a 297-μm-thick film was the highest of the all films. Therefore, the angular multiplexing experiments were conducted using 300-μm-thick films. In the angular multiplexing experiments, the object beam transmitted by a square aperture was focused by a Fourier transform lens and interfered with a reference beam. The maximum order of angular multiplexing was four. The signal intensity that corresponds to the squared-aperture transmission and the noise intensity that corresponds to transmission without the square aperture were measured. The signal intensities decreased as the order of angular multiplexing increased, and the noise intensities were not dependent on the order of angular multiplexing.

  17. A two layer chaotic encryption scheme of secure image transmission for DCT precoded OFDM-VLC transmission

    Science.gov (United States)

    Wang, Zhongpeng; Chen, Fangni; Qiu, Weiwei; Chen, Shoufa; Ren, Dongxiao

    2018-03-01

    In this paper, a two-layer image encryption scheme for a discrete cosine transform (DCT) precoded orthogonal frequency division multiplexing (OFDM) visible light communication (VLC) system is proposed. Firstly, in the proposed scheme the transmitted image is first encrypted by a chaos scrambling sequence,which is generated from the hybrid 4-D hyper- and Arnold map in the upper-layer. After that, the encrypted image is converted into digital QAM modulation signal, which is re-encrypted by chaos scrambling sequence based on Arnold map in physical layer to further enhance the security of the transmitted image. Moreover, DCT precoding is employed to improve BER performance of the proposed system and reduce the PAPR of OFDM signal. The BER and PAPR performances of the proposed system are evaluated by simulation experiments. The experiment results show that the proposed two-layer chaos scrambling schemes achieve image secure transmission for image-based OFDM VLC. Furthermore, DCT precoding can reduce the PAPR and improve the BER performance of OFDM-based VLC.

  18. Cooperative epidemics on multiplex networks

    Science.gov (United States)

    Azimi-Tafreshi, N.

    2016-04-01

    The spread of one disease, in some cases, can stimulate the spreading of another infectious disease. Here, we treat analytically a symmetric coinfection model for spreading of two diseases on a two-layer multiplex network. We allow layer overlapping, but we assume that each layer is random and locally loopless. Infection with one of the diseases increases the probability of getting infected with the other. Using the generating function method, we calculate exactly the fraction of individuals infected with both diseases (so-called coinfected clusters) in the stationary state, as well as the epidemic spreading thresholds and the phase diagram of the model. With increasing cooperation, we observe a tricritical point and the type of transition changes from continuous to hybrid. Finally, we compare the coinfected clusters in the case of cooperating diseases with the so-called "viable" clusters in networks with dependencies.

  19. Spectrally efficient polarization multiplexed direct-detection OFDM system without frequency gap.

    Science.gov (United States)

    Wei, Chia-Chien; Zeng, Wei-Siang; Lin, Chun-Ting

    2016-01-25

    We experimentally demonstrate a spectrally efficient direct-detection orthogonal frequency-division multiplexing (DD-OFDM) system. In addition to polarization-division multiplexing, removing the frequency gap further improves the spectral efficiency of the OFDM system. The frequency gap between a reference carrier and OFDM subcarriers avoids subcarrier-to-subcarrier beating interference (SSBI) in traditional DD-OFDM systems. Without dynamic polarization control, the resulting interference after square-law direct detection in the proposed gap-less system is polarization-dependent and composed of linear inter-carrier interference (ICI) and nonlinear SSBI. Thus, this work proposes an iterative multiple-input multiple-output detection scheme to remove the mixed polarization-dependent interference. Compared to the previous scheme, which only removes ICI, the proposed scheme can further eliminate SSBI to achieve the improvement of ∼ 7 dB in signal-to-noise ratio. Without the need for polarization control, we successfully utilize 7-GHz bandwidth to transmit a 39.5-Gbps polarization multiplexed OFDM signal over 100 km.

  20. SQUID multiplexing using baseband feedback for space application of transition-edge sensor microcalorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Takei, Y; Yamasaki, N Y; Hirakoso, W; Kimura, S; Mitsuda, K, E-mail: takei@astro.isas.jaxa.j [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, 229-8510 (Japan)

    2009-11-15

    A microcalorimeter array based on a transition-edge sensor (TES) thermometer is a promising imaging spectrometer for use in future x-ray astronomy missions. A TES microcalorimeter achieves {approx}<5 eV energy resolution and an array of >100 pixels also provides a moderate imaging capability. For a large format array, signal multiplexing at the low temperature stage is mandatory in order to reduce heat loads from cold stage preamplifiers and through wirings. We are developing frequency division multiplexing (FDM). In FDM, each TES is ac-biased with a different carrier frequency. Signals from several pixels are summed and then read out by one dc SQUID (superconducting quantum interference device). The maximum number of multiplexed pixels is limited by the bandwidth of a SQUID in a flux-locked loop. Assuming 1 m cable length between the room temperature and the cold stage, the bandwidth is only <1 MHz with a standard flux-locked loop, due to the delay and phase shift of wirings. We report our development of baseband feedback, a new feedback scheme that overcomes the bandwidth limitation. In baseband feedback, the signal ({approx}<10 kHz) from the TES is sent back to the SQUID after the phase of carrier frequency ({approx}1 MHz) has been adjusted. We demonstrated open-loop gain of 8 for 10 kHz signal at 5 MHz carrier frequency, which indicates the possibility of {approx}40-pixel multiplexing of the TES signal.

  1. Large area double p-i-n heterostructure for signal multiplexing and demultiplexing in the visible range

    International Nuclear Information System (INIS)

    Vieira, M.; Louro, P.; Fernandes, M.; Vieira, M.A.; Fantoni, A.; Barata, M.

    2009-01-01

    Results on the use of a double a-SiC:H p-i-n heterostructure for signal multiplexing and demultiplexing applications in the visible range, are presented. Modulated monochromatic beams together (multiplexing mode), or a single polychromatic beam (demultiplexing mode) impinge in the device and are absorbed, accordingly to their wavelength, giving rise to a time and wavelength dependent electrical field modulation. Red, green and blue pulsed input channels are transmitted together, each one with a specific transmission rate. The combined optical signal is analyzed by reading out, under different applied voltages, the generated photocurrent. Results show that in the multiplexing mode the output signal is balanced by the wavelength and transmission rate of each input channel, keeping the memory of the incoming optical carriers. In the demultiplexing mode the photocurrent is controlled by the applied voltage allowing regaining the transmitted information. An electrical model gives insight into the device operation.

  2. Two-mode multiplexing at 2 × 10.7 Gbps over a 7-cell hollow-core photonic bandgap fiber

    DEFF Research Database (Denmark)

    Xu, Jing; Peucheret, Christophe; Lyngsø, Jens Kristian

    2012-01-01

    mode division multiplexing (MDM). In this work, we demonstrate MDM over a HC-PBGF for the first time. Two 10.7 Gbps channels are simultaneously transmitted over two modes of a 30-m long 7-cell HC-PBGF. Bit error ratio (BER) performances below the FEC threshold limit (3.3 × 10−3) are shown for both data...

  3. 6.4 Tb/s (32 × 200 Gb/s) WDM direct-detection transmission with twin-SSB modulation and Kramers-Kronig receiver

    Science.gov (United States)

    Zhu, Yixiao; Jiang, Mingxuan; Ruan, Xiaoke; Chen, Zeyu; Li, Chenjia; Zhang, Fan

    2018-05-01

    We experimentally demonstrate 6.4 Tb/s wavelength division multiplexed (WDM) direct-detection transmission based on Nyquist twin-SSB modulation over 25 km SSMF with bit error rates (BERs) below the 20% hard-decision forward error correction (HD-FEC) threshold of 1.5 × 10-2. The two sidebands of each channel are separately detected using Kramers-Kronig receiver without MIMO equalization. We also carry out numerical simulations to evaluate the system robustness against I/Q amplitude imbalance, I/Q phase deviation and the extinction ratio of modulator, respectively. Furthermore, we show in simulation that the requirement of steep edge optical filter can be relaxed if multi-input-multi-output (MIMO) equalization between the two sidebands is used.

  4. 4-Gbit/s visible light communication link based on 16-QAM OFDM transmission over remote phosphor-film converted white light by using blue laser diode

    KAUST Repository

    Duran Retamal, Jose Ramon

    2015-12-21

    Visible Light Communication (VLC) as a new technology for ultrahigh-speed communication is still limited when using slow modulation light-emitting diode (LED). Alternatively, we present a 4-Gbit/s VLC system using coherent blue-laser diode (LD) via 16-quadrature amplitude modulation orthogonal frequency division multiplexing. By changing the composition and the optical-configuration of a remote phosphor-film the generated white light is tuned from cool day to neutral, and the bit error rate is optimized from 1.9 × 10-2 to 2.8 × 10-5 in a blue filter-free link due to enhanced blue light transmission in forward direction. Briefly, blue-LD is an alternative to LED for generating white light and boosting the data rate of VLC. © 2015 Optical Society of America.

  5. 4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication

    KAUST Repository

    Oubei, Hassan M.; Duran, Jose R.; Janjua, Bilal; Wang, Huai-Yung; Tsai, Cheng-Ting; Chi, Yu-Cheih; Ng, Tien Khee; Kuo, Hao-Chung; He, Jr-Hau; Alouini, Mohamed-Slim; Lin, Gong-Ru; Ooi, Boon S.

    2015-01-01

    We experimentally demonstrate an underwater wireless optical communications (UWOC) employing 450-nm TO-9 packaged and fiberpigtailed laser diode (LD) directly encoded with an orthogonal frequency division multiplexed quadrature amplitude modulation (QAM-OFDM) data. A record data rate of up to 4.8 Gbit/s over 5.4-m transmission distance is achieved. By encoding the full 1.2-GHz bandwidth of the 450-nm LD with a 16-QAM-OFDM data, an error vector magnitude (EVM) of 16.5%, a signal-to-noise ratio (SNR) of 15.63 dB and a bit error rate (BER) of 2.6 × 10-3, well pass the forward error correction (FEC) criterion, were obtained. © 2015 Optical Society of America.

  6. 4.8 Gbit/s 16-QAM-OFDM transmission based on compact 450-nm laser for underwater wireless optical communication

    KAUST Repository

    Oubei, Hassan M.

    2015-08-26

    We experimentally demonstrate an underwater wireless optical communications (UWOC) employing 450-nm TO-9 packaged and fiberpigtailed laser diode (LD) directly encoded with an orthogonal frequency division multiplexed quadrature amplitude modulation (QAM-OFDM) data. A record data rate of up to 4.8 Gbit/s over 5.4-m transmission distance is achieved. By encoding the full 1.2-GHz bandwidth of the 450-nm LD with a 16-QAM-OFDM data, an error vector magnitude (EVM) of 16.5%, a signal-to-noise ratio (SNR) of 15.63 dB and a bit error rate (BER) of 2.6 × 10-3, well pass the forward error correction (FEC) criterion, were obtained. © 2015 Optical Society of America.

  7. 4-Gbit/s visible light communication link based on 16-QAM OFDM transmission over remote phosphor-film converted white light by using blue laser diode

    KAUST Repository

    Duran Retamal, Jose Ramon; Oubei, Hassan M.; Janjua, Bilal; Chi, Yu-Chieh; Wang, Huai-Yung; Tsai, Cheng-Ting; Ng, Tien Khee; Hsieh, Dan-Hua; Kuo, Hao-Chung; Alouini, Mohamed-Slim; He, Jr-Hau; Lin, Gong-Ru; Ooi, Boon S.

    2015-01-01

    Visible Light Communication (VLC) as a new technology for ultrahigh-speed communication is still limited when using slow modulation light-emitting diode (LED). Alternatively, we present a 4-Gbit/s VLC system using coherent blue-laser diode (LD) via 16-quadrature amplitude modulation orthogonal frequency division multiplexing. By changing the composition and the optical-configuration of a remote phosphor-film the generated white light is tuned from cool day to neutral, and the bit error rate is optimized from 1.9 × 10-2 to 2.8 × 10-5 in a blue filter-free link due to enhanced blue light transmission in forward direction. Briefly, blue-LD is an alternative to LED for generating white light and boosting the data rate of VLC. © 2015 Optical Society of America.

  8. Immunization of Epidemics in Multiplex Networks

    Science.gov (United States)

    Zhao, Dawei; Wang, Lianhai; Li, Shudong; Wang, Zhen; Wang, Lin; Gao, Bo

    2014-01-01

    Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted) immunization and layer node-based random (targeted) immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER) random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF) networks. PMID:25401755

  9. 16-channel analog store and multiplexer unit

    Energy Technology Data Exchange (ETDEWEB)

    Brossard, M; Kulka, Z [Clermont-Ferrand-2 Univ., 63 - Aubiere (France). Lab. de Physique Corpusculaire

    1979-03-15

    A 16-channel analog store and multiplexer unit is described. The unit enables storing and selection of analog information which is then digitally encoded by single ADC. This solution becomes economically attractive particularly in multidetector pulse height analysis systems.

  10. Packaged mode multiplexer based on silicon photonics

    NARCIS (Netherlands)

    Chen, H.; Koonen, A.M.J.; Snyder, B.; Raz, O.; Boom, van den H.P.A.; Chen, X.

    2012-01-01

    A silicon photonics based mode multiplexer is proposed. Four chirped grating couplers structure can support all 6 channels in a two-mode fiber and realize LP01 and LP11 mode selective exciting. The packaged device is tested.

  11. Immunization of epidemics in multiplex networks.

    Science.gov (United States)

    Zhao, Dawei; Wang, Lianhai; Li, Shudong; Wang, Zhen; Wang, Lin; Gao, Bo

    2014-01-01

    Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted) immunization and layer node-based random (targeted) immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER) random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF) networks.

  12. Immunization of epidemics in multiplex networks.

    Directory of Open Access Journals (Sweden)

    Dawei Zhao

    Full Text Available Up to now, immunization of disease propagation has attracted great attention in both theoretical and experimental researches. However, vast majority of existing achievements are limited to the simple assumption of single layer networked population, which seems obviously inconsistent with recent development of complex network theory: each node could possess multiple roles in different topology connections. Inspired by this fact, we here propose the immunization strategies on multiplex networks, including multiplex node-based random (targeted immunization and layer node-based random (targeted immunization. With the theory of generating function, theoretical analysis is developed to calculate the immunization threshold, which is regarded as the most critical index for the effectiveness of addressed immunization strategies. Interestingly, both types of random immunization strategies show more efficiency in controlling disease spreading on multiplex Erdös-Rényi (ER random networks; while targeted immunization strategies provide better protection on multiplex scale-free (SF networks.

  13. Theoretical Division progress report

    International Nuclear Information System (INIS)

    Cooper, N.G.

    1979-04-01

    This report presents highlights of activities in the Theoretical (T) Division from October 1976-January 1979. The report is divided into three parts. Part I presents an overview of the Division: its unique function at the Los Alamos Scientific Laboratory (LASL) and within the scientific community as a whole; the organization of personnel; the main areas of research; and a survey of recent T-Division initiatives. This overview is followed by a survey of the 13 groups within the Division, their main responsibilities, interests, and expertise, consulting activities, and recent scientific accomplisments. The remainder of the report, Parts II and III, is devoted to articles on selected research activities. Recent efforts on topics of immediate interest to energy and weapons programs at LASL and elsewhere are described in Part II, Major National Programs. Separate articles present T-Divison contributions to weapons research, reactor safety and reactor physics research, fusion research, laser isotope separation, and other energy research. Each article is a compilation of independent projects within T Division, all related to but addressing different aspects of the major program. Part III is organized by subject discipline, and describes recent scientific advances of fundamental interest. An introduction, defining the scope and general nature of T-Division efforts within a given discipline, is followed by articles on the research topics selected. The reporting is done by the scientists involved in the research, and an attempt is made to communicate to a general audience. Some data are given incidentally; more technical presentations of the research accomplished may be found among the 47 pages of references. 110 figures, 5 tables

  14. Neuroglial Transmission

    DEFF Research Database (Denmark)

    Gundersen, Vidar; Storm-Mathisen, Jon; Bergersen, Linda Hildegard

    2015-01-01

    as a signaling substance recently shown to act on specific lactate receptors in the brain. Complementing neurotransmission at a synapse, neuroglial transmission often implies diffusion of the transmitter over a longer distance and concurs with the concept of volume transmission. Transmission from glia modulates...... synaptic neurotransmission based on energetic and other local conditions in a volume of tissue surrounding the individual synapse. Neuroglial transmission appears to contribute significantly to brain functions such as memory, as well as to prevalent neuropathologies....

  15. Power Dissipation in Division

    DEFF Research Database (Denmark)

    Liu, Wei; Nannarelli, Alberto

    2008-01-01

    A few classes of algorithms to implement division in hardware have been used over the years: division by digit-recurrence, by reciprocal approximation by iterative methods and by polynomial approximation. Due to the differences in the algorithms, a comparison among their implementation in terms o...... of performance and precision is sometimes hard to make. In this work, we use power dissipation and energy consumption as metrics to compare among those different classes of algorithms. There are no previous works in the literature presenting such a comparison....

  16. Digital Arithmetic: Division Algorithms

    DEFF Research Database (Denmark)

    Montuschi, Paolo; Nannarelli, Alberto

    2017-01-01

    Division is one of the basic arithmetic operations supported by every computer system. The operation can be performed and implemented by either hardware or software, or by a combination of the two. Although division is not as frequent as addition and multiplication, nowadays, most processors impl...... significant hardware resources and is more suitable for software implementation on the existing multiply units. The purpose of this entry is to provide an introductory survey using a presentation style suitable for the interested non-specialist readers as well....

  17. A Time-Multiplexed Track-Trigger for the CMS HL-LHC upgrade

    CERN Document Server

    Hall, Geoffrey

    2016-01-01

    A new CMS Tracker is under development for operation at the High Luminosity LHC from 2025. It includes an outer tracker based on special modules of two different types which will construct track stubs using spatially coincident clusters in two closely spaced sensor layers, to reject low transverse momentum track hits and reduce the data volume before data transmission to the Level-1 trigger. The tracker data will be used to reconstruct track segments in dedicated processors before onward transmission to other trigger processors which will combine tracker information with data originating from the calorimeter and muon detectors, to make the final L1 trigger decision. The architecture for processing the tracker data outside the detector is under study, using several alternative approaches. One attractive possibility is to exploit a Time Multiplexed design similar to the one which is currently being implemented in the CMS calorimeter trigger as part of the Phase I trigger upgrade. The novel Time Multiplexed Trig...

  18. Cascaded multiplexed optical link on a telecommunication network for frequency dissemination.

    Science.gov (United States)

    Lopez, Olivier; Haboucha, Adil; Kéfélian, Fabien; Jiang, Haifeng; Chanteau, Bruno; Roncin, Vincent; Chardonnet, Christian; Amy-Klein, Anne; Santarelli, Giorgio

    2010-08-02

    We demonstrate a cascaded optical link for ultrastable frequency dissemination comprised of two compensated links of 150 km and a repeater station. Each link includes 114 km of Internet fiber simultaneously carrying data traffic through a dense wavelength division multiplexing technology, and passes through two routing centers of the telecommunication network. The optical reference signal is inserted in and extracted from the communication network using bidirectional optical add-drop multiplexers. The repeater station operates autonomously ensuring noise compensation on the two links and the ultra-stable signal optical regeneration. The compensated link shows a fractional frequency instability of 3 x 10(-15) at one second measurement time and 5 x 10(-20) at 20 hours. This work paves the way to a wide dissemination of ultra-stable optical clock signals between distant laboratories via the Internet network.

  19. Demonstration of DFT-spread 256QAM-OFDM signal transmission with cost-effective directly modulated laser.

    Science.gov (United States)

    Li, Fan; Yu, Jianjun; Fang, Yuan; Dong, Ze; Li, Xinying; Chen, Lin

    2014-04-07

    We experimentally demonstrated a 256-ary quadrature amplitude modulation (256QAM) direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) transmission system utilizing a cost-effective directly modulated laser (DML). Intra-symbol frequency-domain averaging (ISFA) is applied to suppress in-band noise while the channel response estimation and Discrete Fourier Transform-spread (DFT-spread) is used to reduce the peak-to-average power ratio (PAPR) of the transmitted OFDM signal. The bit-error ratio (BER) of 15-Gbit/s 256QAM-OFDM signal has been measured after 20-km SSMF transmission that is less than 7% forward-error-correction (FEC) threshold of 3.8 × 10(-3) as the launch power into fiber is set at 6dBm. For 11.85-Gbit/s 256QAM-OFDM signal, with the aid of ISFA-based channel estimation and PAPR reduction enabled by DFT-spread, the BER after 20-km SSMF transmission can be improved from 6.4 × 10(-3) to 6.8 × 10(-4) when the received optical power is -6dBm.

  20. Division of Agriculture

    Science.gov (United States)

    Department of Natural Resources logo, color scheme Department of Natural Resources Division of Agriculture Search Search DNR's site DNR State of Alaska Toggle main menu visibility Agriculture Home Programs Asset Disposals Alaska Caps Progam Board of Agriculture & Conservation Farm To School Program Grants

  1. Solid State Division

    International Nuclear Information System (INIS)

    Green, P.H.; Watson, D.M.

    1989-08-01

    This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces

  2. Solid State Division

    Energy Technology Data Exchange (ETDEWEB)

    Green, P.H.; Watson, D.M. (eds.)

    1989-08-01

    This report contains brief discussions on work done in the Solid State Division of Oak Ridge National Laboratory. The topics covered are: Theoretical Solid State Physics; Neutron scattering; Physical properties of materials; The synthesis and characterization of materials; Ion beam and laser processing; and Structure of solids and surfaces. (LSP)

  3. Order Division Automated System.

    Science.gov (United States)

    Kniemeyer, Justin M.; And Others

    This publication was prepared by the Order Division Automation Project staff to fulfill the Library of Congress' requirement to document all automation efforts. The report was originally intended for internal use only and not for distribution outside the Library. It is now felt that the library community at-large may have an interest in the…

  4. Theoretical Physics Division

    International Nuclear Information System (INIS)

    This report is a survey of the studies done in the Theoretical Physics Division of the Nuclear Physics Institute; the subjects studied in theoretical nuclear physics were the few-nucleon problem, nuclear structure, nuclear reactions, weak interactions, intermediate energy and high energy physics. In this last field, the subjects studied were field theory, group theory, symmetry and strong interactions [fr

  5. Combining spatial domain multiplexing and orbital angular momentum of photon-based multiplexing to increase the bandwidth of optical fiber communication systems

    Science.gov (United States)

    Murshid, Syed; Alanzi, Saud; Hridoy, Arnob; Lovell, Gregory L.; Parhar, Gurinder; Chakravarty, Abhijit; Chowdhury, Bilas

    2016-06-01

    Spatial domain multiplexing/space division multiplexing (SDM) can increase the bandwidth of existing and futuristic optical fibers by an order of magnitude or more. In the SDM technique, we launch multiple single-mode pigtail laser sources of the same wavelength into a carrier multimode fiber at different angles. The launching angles decide the output of the carrier fiber by allocating separate spatial locations for each channel. Each channel follows a helical trajectory while traversing the length of the carrier fiber, thereby allowing spatial reuse of optical frequencies. We launch light from five different single-mode pigtail laser sources (of same wavelength) at different angles (with respect to the axis of the carrier fiber) into the carrier fiber. Owing to helical propagation, five distinct concentric donut-shaped rings with negligible crosstalk at the output end of the fiber were obtained. These SDM channels also exhibit orbital angular momentum (OAM), thereby adding an extradegree of photon freedom. We present the experimental data of five spatially multiplexed channels and compare them with simulated results to show that this technique can potentially improve the data capacity of optical fibers by an order of magnitude: A factor of five using SDM and another factor of two using OAM.

  6. Reducing LTE Uplink Transmission Energy by Allocating Resources

    DEFF Research Database (Denmark)

    Lauridsen, Mads; Jensen, Anders Riis; Mogensen, Preben

    2011-01-01

    The effect of physical resource block (PRB) allocation on an LTE modem's transmit power and total modem energy consumption is examined. In this paper the uplink resource blocks are scheduled in either a Frequency Division Multiple Access (FDMA) or Time Division Multiple Access (TDMA) manner......, to determine if low transmission power & long transmission time or high transmission power & short transmission time is most energy efficient. It is important to minimize the LTE modem's energy consumption caused by uplink transmission because it affects phone battery time, and because researchers rarely focus...

  7. Super-multiplex vibrational imaging

    Science.gov (United States)

    Wei, Lu; Chen, Zhixing; Shi, Lixue; Long, Rong; Anzalone, Andrew V.; Zhang, Luyuan; Hu, Fanghao; Yuste, Rafael; Cornish, Virginia W.; Min, Wei

    2017-04-01

    potential of this 24-colour (super-multiplex) optical imaging approach for elucidating intricate interactions in complex biological systems.

  8. Rapid spectro-polarimetry to probe molecular symmetry in multiplex coherent anti-Stokes Raman scattering.

    Science.gov (United States)

    Würthwein, Thomas; Brinkmann, Maximilian; Hellwig, Tim; Fallnich, Carsten

    2017-11-21

    We present the simultaneous detection of the spectrum and the complete polarization state of a multiplex coherent anti-Stokes Raman scattering signal with a fast division-of-amplitude spectro-polarimeter. The spectro-polarimeter is based on a commercial imaging spectrograph, a birefringent wedge prism, and a segmented polarizer. Compared to the standard rotating-retarder fixed-analyzer spectro-polarimeter, only a single measurement is required and an up to 21-fold reduced acquisition time is shown. The measured Stokes parameters allow us to differentiate between vibrational symmetries and to determine the depolarization ratio ρ by data post-processing.

  9. Podcast: The Electronic Crimes Division

    Science.gov (United States)

    Sept 26, 2016. Chris Lukas, the Special Agent in Charge of the Electronic Crimes Division within the OIG's Office of Investigations talks about computer forensics, cybercrime in the EPA and his division's role in criminal investigations.

  10. Division of Integrity and Materials

    International Nuclear Information System (INIS)

    Zdarek, J.

    1995-01-01

    The organization structure is described of the Division of Integrity and Materials, Institute of Nuclear Research plc, Rez, and the main fields of their activities given. Listed are the major research projects of the Division in 1994. (Z.S.)

  11. 2016 T Division Lightning Talks

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Marilyn Leann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Adams, Luke Clyde [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Ferre, Gregoire Robing [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Grantcharov, Vesselin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Iaroshenko, Oleksandr [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Krishnapriyan, Aditi [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Kurtakoti, Prajvala Kishore [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Le Thien, Minh Quan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Lim, Jonathan Ng [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Low, Thaddeus Song En [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Lystrom, Levi Aaron [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Ma, Xiaoyu [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Nguyen, Hong T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Pogue, Sabine Silvia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Orandle, Zoe Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Reisner, Andrew Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Revard, Benjamin Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Roy, Julien [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Sandor, Csanad [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Slavkova, Kalina Polet [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Weichman, Kathleen Joy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Wu, Fei [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Yang, Yang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division

    2016-11-29

    These are the slides for all of the 2016 T Division lightning talks. There are 350 pages worth of slides from different presentations, all of which cover different topics within the theoretical division at Los Alamos National Laboratory (LANL).

  12. 2017 T Division Lightning Talks

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Marilyn Leann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Abeywardhana, Jayalath AMM [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Adams, Colin Mackenzie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Adams, Luke Clyde [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carter, Austin Lewis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ducru, Pablo Philippe [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Duignan, Thomas John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gifford, Brendan Joel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hills, Benjamin Hale [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hoffman, Kentaro Jack [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Khair, Adnan Ibne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kochanski, Kelly Anne Pribble [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ledwith, Patrick John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Leveillee, Joshua Anthony [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lewis, Sina Genevieve [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ma, Xiaoyu [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Merians, Hugh Drake [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moore, Bryan Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nijjar, Parmeet Kaur [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Oles, Vladyslav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Olszewski, Maciej W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Philipbar, Brad Montgomery [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reisner, Andrew Ray [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Roberts, David Benjamin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rufa, Dominic Antonio [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sifain, Andrew E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Smith, Justin Steven [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Smith, Lauren Taylor Wisbey [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Svolos, Lampros [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Thibault, Joshua Ryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ushijima-Mwesigwa, Hayato Montezuma [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weaver, Claire Marie [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Witzen, Wyatt Andrew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zentgraf, Sabine Silvia [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alred, John Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-06

    All members of the T Division Community, students, staff members, group leaders, division management, and other interested individuals are invited to come and support the following student(s) as they present their Lightning Talks.

  13. Transmission issues

    International Nuclear Information System (INIS)

    Bradford, J.; Wilson, L.; Thon, S.; Millar, N.

    2005-01-01

    This session on transmission issues focused on the role that transmission plays in electricity markets and the importance of getting the market structure right in terms of generation divestiture with buy back contracts, demand side responsive programs, transmission upgrades and long term contracts. The difficulties of distinguishing between market power and scarcity were examined along with some of the complications that ensue if transmission experiences congestion, as exemplified by the August 2003 blackout in eastern North America. The presentations described the best ways to handle transmission issues, and debated whether transmission should be deregulated or follow market forces. Issues of interconnections and reliability of connections were also debated along with the attempt to integrate renewables into the grid. Some presentations identified what new transmission must be built and what must be done to ensure that transmission gets built. The challenges and business opportunities for transmission in Alberta were discussed with reference to plans to invest in new infrastructure, where it is going outside of the province and how it works with other jurisdictions. Manitoba's Conawapa Hydro Project and its 2000 MW tie line to Ontario was also discussed. Some examples of non-optimal use of interconnections in Europe were also discussed in an effort to learn from these mistakes and avoid them in Canada. tabs., figs

  14. Division of Labor

    KAUST Repository

    Oke, Muse; Zaher, Manal S.; Hamdan, Samir

    2014-01-01

    The first assignment of DNA polymerases at the eukaryotic replication fork was possible after the in vitro reconstitution of the simian virus 40 (SV40) replication system. In this system, DNA polymerase α (Pol α) provides both leading and lagging strands with RNA-DNA primers that are extended by DNA polymerase δ (Pol δ). Extrapolating the architecture of the replication fork from the SV40 model system to an actual eukaryotic cell has been challenged by the discovery of a third DNA polymerase in Saccharomyces cerevisiae, DNA polymerase ε (Pol ε). A division of labor has been proposed for the eukaryotic replication fork whereby Pol ε replicates the leading strand and Pol δ replicates the lagging strand. However, an alternative model of unequal division of labor in which Pol δ can still participate in leading-strand synthesis is plausible.

  15. Division of Labor

    KAUST Repository

    Oke, Muse

    2014-09-12

    The first assignment of DNA polymerases at the eukaryotic replication fork was possible after the in vitro reconstitution of the simian virus 40 (SV40) replication system. In this system, DNA polymerase α (Pol α) provides both leading and lagging strands with RNA-DNA primers that are extended by DNA polymerase δ (Pol δ). Extrapolating the architecture of the replication fork from the SV40 model system to an actual eukaryotic cell has been challenged by the discovery of a third DNA polymerase in Saccharomyces cerevisiae, DNA polymerase ε (Pol ε). A division of labor has been proposed for the eukaryotic replication fork whereby Pol ε replicates the leading strand and Pol δ replicates the lagging strand. However, an alternative model of unequal division of labor in which Pol δ can still participate in leading-strand synthesis is plausible.

  16. Spatial optic multiplexer/diplexer

    International Nuclear Information System (INIS)

    Tremblay, P.L.

    1991-01-01

    An apparatus is described for simultaneous transmission of optic signals having different wavelengths over a single optic fiber. Multiple light signals are transmitted through optic fibers that are formed into a circumference surrounding a central core fiber. The multiple light signals are directed by a lens into a single receiving fiber where the light combines and is then focused into the central core fiber which transmits the light to a wavelength discriminating receiver assembly

  17. 3. Theoretical Physics Division

    International Nuclear Information System (INIS)

    For the period September 1980 - Aug 1981, the studies in theoretical physics divisions have been compiled under the following headings: in nuclear physics, nuclear structure, nuclear reactions and intermediate energies; in particle physics, NN and NantiN interactions, dual topological unitarization, quark model and quantum chromodynamics, classical and quantum field theories, non linear integrable equations and topological preons and Grand unified theories. A list of publications, lectures and meetings is included [fr

  18. A 1550-nm all-optical VCSEL-to-VCSEL wavelength conversion of a 8.5-Gb/s data signal and transmission over a 24.7-km fibre

    Science.gov (United States)

    Boiyo, D. Kiboi; Isoe, G. M.; Gamatham, R. R. G.; Leitch, A. W. R.; Gibbon, T. B.

    2016-02-01

    For the first time, we demonstrate, VCSEL-to-VCSEL wavelength conversion within the low attenuation 1550 nm window, including transmission over fibre and bit error rate (BER) performance characterization. We experimentally demonstrate a low injection power optical wavelength conversion by injecting an optical beam from a signal carrier master vertical cavity surface-emitting laser (VCSEL) into the side-mode of the slave VCSEL. This technique solves the challenge of wavelength collisions and also provides wavelength re-use in typical wavelength division multiplexed (WDM) systems. This paper, for the first time, uses two 1550 nm VCSELs with tunability range of 3 nm for a 5-9.8 mA bias current. The master VCSEL is modulated with a non-return-to-zero (NRZ) pseudo-random binary sequence (PRBS_27-1) 8.5 Gb/s data. A data conversion penalty of 1.1 dB is realized when a 15 dBm injection beam is used. The transmission performance of the converted wavelength from the slave VCSEL is evaluated using BER measurement at a 10-9 threshold. A 0.5 dB transmission penalty of the converted wavelength data is realized in an 8.5 Gb/s transmission over 24.7 km. This work is vital for optical fibre systems that may require wavelength switching for transmission of data signals.

  19. Division Quilts: A Measurement Model

    Science.gov (United States)

    Pratt, Sarah S.; Lupton, Tina M.; Richardson, Kerri

    2015-01-01

    As teachers seek activities to assist students in understanding division as more than just the algorithm, they find many examples of division as fair sharing. However, teachers have few activities to engage students in a quotative (measurement) model of division. Efraim Fischbein and his colleagues (1985) defined two types of whole-number…

  20. Mapping Urban Social Divisions

    Directory of Open Access Journals (Sweden)

    Susan Ball

    2010-05-01

    Full Text Available Against the background of increased levels of interest in space and images beyond the field of geography, this article (re- introduces earlier work on the semiotics of maps undertaken by geographers in the 1960s. The data limitations, purpose and cultural context in which a user interprets a map's codes and conventions are highlighted in this work, which remains relevant to the interpretation of maps—new and old—forty years later. By means of drawing on geography's contribution to the semiotics of maps, the article goes on to examine the concept of urban social divisions as represented in map images. Using a small number of map images, including two of the most widely known maps of urban social division in Europe and North America, the roles of context, data and purpose in the production and interpretation of maps are discussed. By presenting the examples chronologically the article shows that although advances in data collection and manipulation have allowed researchers to combine different social variables in maps of social division, and to interact with map images, work by geographers on the semiotics of maps is no less relevant today than when it was first proposed forty years ago. URN: urn:nbn:de:0114-fqs1002372

  1. Reduced-Rank Chip-Level MMSE Equalization for the 3G CDMA Forward Link with Code-Multiplexed Pilot

    Directory of Open Access Journals (Sweden)

    Goldstein J Scott

    2002-01-01

    Full Text Available This paper deals with synchronous direct-sequence code-division multiple access (CDMA transmission using orthogonal channel codes in frequency selective multipath, motivated by the forward link in 3G CDMA systems. The chip-level minimum mean square error (MMSE estimate of the (multiuser synchronous sum signal transmitted by the base, followed by a correlate and sum, has been shown to perform very well in saturated systems compared to a Rake receiver. In this paper, we present the reduced-rank, chip-level MMSE estimation based on the multistage nested Wiener filter (MSNWF. We show that, for the case of a known channel, only a small number of stages of the MSNWF is needed to achieve near full-rank MSE performance over a practical single-to-noise ratio (SNR range. This holds true even for an edge-of-cell scenario, where two base stations are contributing near equal-power signals, as well as for the single base station case. We then utilize the code-multiplexed pilot channel to train the MSNWF coefficients and show that adaptive MSNWF operating in a very low rank subspace performs slightly better than full-rank recursive least square (RLS and significantly better than least mean square (LMS. An important advantage of the MSNWF is that it can be implemented in a lattice structure, which involves significantly less computation than RLS. We also present structured MMSE equalizers that exploit the estimate of the multipath arrival times and the underlying channel structure to project the data vector onto a much lower dimensional subspace. Specifically, due to the sparseness of high-speed CDMA multipath channels, the channel vector lies in the subspace spanned by a small number of columns of the pulse shaping filter convolution matrix. We demonstrate that the performance of these structured low-rank equalizers is much superior to unstructured equalizers in terms of convergence speed and error rates.

  2. Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

    Science.gov (United States)

    Prele, D.

    2015-08-01

    As we have seen for digital camera market and a sensor resolution increasing to "megapixels", all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, "simple" and "efficient" techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described.

  3. Front-end multiplexing—applied to SQUID multiplexing: Athena X-IFU and QUBIC experiments

    International Nuclear Information System (INIS)

    Prele, D.

    2015-01-01

    As we have seen for digital camera market and a sensor resolution increasing to 'megapixels', all the scientific and high-tech imagers (whatever the wave length - from radio to X-ray range) tends also to always increases the pixels number. So the constraints on front-end signals transmission increase too. An almost unavoidable solution to simplify integration of large arrays of pixels is front-end multiplexing. Moreover, 'simple' and 'efficient' techniques allow integration of read-out multiplexers in the focal plane itself. For instance, CCD (Charge Coupled Device) technology has boost number of pixels in digital camera. Indeed, this is exactly a planar technology which integrates both the sensors and a front-end multiplexed readout. In this context, front-end multiplexing techniques will be discussed for a better understanding of their advantages and their limits. Finally, the cases of astronomical instruments in the millimeter and in the X-ray ranges using SQUID (Superconducting QUantum Interference Device) will be described

  4. Transmission Quality Measurements in DAB+ Broadcast System

    Directory of Open Access Journals (Sweden)

    Gilski Przemysław

    2017-12-01

    Full Text Available In the age of digital media, delivering broadcast content to customers at an acceptable level of quality is one of the most challenging tasks. The most important factor is the efficient use of available resources, including bandwidth. An appropriate way of managing the digital multiplex is essential for both the economic and technical issues. In this paper we describe transmission quality measurements in the DAB+ broadcast system. We provide a methodology for analysing parameters and factors related with the efficiency and reliability of a digital radio link. We describe a laboratory stand that can be used for transmission quality assessment on a regional and national level.

  5. General Time-Division AltBOC Modulation Technique for GNSS Signals

    Directory of Open Access Journals (Sweden)

    Z. Zhou

    2018-04-01

    Full Text Available In this paper, a general time-division alternate binary offset carrier (GTD-AltBOC modulation method is proposed, which is an extension of TD-AltBOC and time-multiplexed offset-carrier quadrature phase shift keying (TMOC-QPSK with high design flexibility. In this method, binary complex subcarriers and a time-division technique with flexible time slot assignment are used to achieve constant envelope modulation of the signal components with a variable power allocation ratio (PAR. The underlying principle of GTD-AltBOC and the constraints related to the PAR are investigated. For the generation of GTD-AltBOC signals, a lookup table (LUT-based scheme is presented; the minimum required clock rate is half or less of that for existing non-time-division methods. The receiver processing complexities are analyzed for three typical receiving modes, and the power spectral densities (PSDs, cross-correlation functions, multiplexing efficiencies and code-tracking performance are simulated; the results show that GTD-AltBOC enables a significant decrease in receiving complexity compared with existing methods while maintaining high performance in terms of multiplexing efficiency and code tracking.

  6. Transmission eigenvalues

    Science.gov (United States)

    Cakoni, Fioralba; Haddar, Houssem

    2013-10-01

    In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission

  7. Multiplexed image storage by electromagnetically induced transparency in a solid

    Science.gov (United States)

    Heinze, G.; Rentzsch, N.; Halfmann, T.

    2012-11-01

    We report on frequency- and angle-multiplexed image storage by electromagnetically induced transparency (EIT) in a Pr3+:Y2SiO5 crystal. Frequency multiplexing by EIT relies on simultaneous storage of light pulses in atomic coherences, driven in different frequency ensembles of the inhomogeneously broadened solid medium. Angular multiplexing by EIT relies on phase matching of the driving laser beams, which permits simultaneous storage of light pulses propagating under different angles into the crystal. We apply the multiplexing techniques to increase the storage capacity of the EIT-driven optical memory, in particular to implement multiplexed storage of larger two-dimensional amounts of data (images). We demonstrate selective storage and readout of images by frequency-multiplexed EIT and angular-multiplexed EIT, as well as the potential to combine both multiplexing approaches towards further enhanced storage capacities.

  8. Performance modeling, loss networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi

    2009-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of understanding the phenomenon of statistical multiplexing. The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the important ideas of Palm distributions associated with traffic models and their role in performance measures. Also presented are recent ideas of large buffer, and many sources asymptotics that play an important role in understanding statistical multiplexing. I

  9. Digital holograms for laser mode multiplexing

    CSIR Research Space (South Africa)

    Mhlanga, T

    2014-10-02

    Full Text Available multiplexing Thandeka Mhlangaa, b, Abderrahmen Trichilic, Angela Dudleya, Darryl Naidooa, b, Mourad Zghalc and Andrew Forbesa, b aCSIR National Laser Centre, P.O. Box 395, Pretoria 0001, South Africa bSchool of Physics, University of KwaZulu-Natal, Private Bag... problems. In this context, we demonstrate a method of multiplexing laser modes using spatial light modulators (SLMs). In our proposed technique, we use Laguerre Gaussian (LG) modes, which form a complete basis set; hence multi-mode masks can be created...

  10. Simple Multiplexing Hand-Held Control Unit

    Science.gov (United States)

    Hannaford, Blake

    1989-01-01

    Multiplexer consists of series of resistors, each shunted by single-pole, single-throw switch. User operates switches by pressing buttons or squeezing triggers. Prototype includes three switches operated successfully in over 200 hours of system operations. Number of switches accommodated determined by signal-to-noise ratio of current source, noise induced in control unit and cable, and number of bits in output of analog-to-digital converter. Because many computer-contolled robots have extra analog-to-digital channels, such multiplexer added at little extra cost.

  11. Cooperative spreading processes in multiplex networks.

    Science.gov (United States)

    Wei, Xiang; Chen, Shihua; Wu, Xiaoqun; Ning, Di; Lu, Jun-An

    2016-06-01

    This study is concerned with the dynamic behaviors of epidemic spreading in multiplex networks. A model composed of two interacting complex networks is proposed to describe cooperative spreading processes, wherein the virus spreading in one layer can penetrate into the other to promote the spreading process. The global epidemic threshold of the model is smaller than the epidemic thresholds of the corresponding isolated networks. Thus, global epidemic onset arises in the interacting networks even though an epidemic onset does not arise in each isolated network. Simulations verify the analysis results and indicate that cooperative spreading processes in multiplex networks enhance the final infection fraction.

  12. Optical phase-modulated radio-over-fiber links with k-means algorithm for digital demodulation of 8PSK subcarrier multiplexed signals

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Yu, Xianbin

    2010-01-01

    A k-means algorithm for phase recovery of three, 50 Mbaud, 8PSK subcarrier multiplexed signals at 5 GHz for optical phase-modulated radio-over-fiber is proposed and experimentally demonstrated after 40 km of single mode fiber transmission......A k-means algorithm for phase recovery of three, 50 Mbaud, 8PSK subcarrier multiplexed signals at 5 GHz for optical phase-modulated radio-over-fiber is proposed and experimentally demonstrated after 40 km of single mode fiber transmission...

  13. Advanced combinational microfluidic multiplexer for fuel cell reactors

    International Nuclear Information System (INIS)

    Lee, D W; Kim, Y; Cho, Y-H; Doh, I

    2013-01-01

    An advanced combinational microfluidic multiplexer capable to address multiple fluidic channels for fuel cell reactors is proposed. Using only 4 control lines and two different levels of control pressures, the proposed multiplexer addresses up to 19 fluidic channels, at least two times larger than the previous microfluidic multiplexers. The present multiplexer providing high control efficiency and simple structure for channel addressing would be used in the application areas of the integrated microfluidic systems such as fuel cell reactors and dynamic pressure generators

  14. A Code Division Technique for Multiple Element Synthetic Aperture Transmission

    DEFF Research Database (Denmark)

    Gran, Fredrik; Jensen, Jørgen Arendt; Jakobsson, Andreas

    2004-01-01

    a method in which all transmitting centers can be excited at the same time and separated at the receiver. Hereby the benefits from traditional STA can be utilized and a high fframe rate can be maintained and the images are not influenced by motion artifacts. The different centers are excited using mutually...

  15. Quantifying Transmission.

    Science.gov (United States)

    Woolhouse, Mark

    2017-07-01

    Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

  16. BNFL Springfields Fuel Division

    International Nuclear Information System (INIS)

    Tarkiainen, S.; Plit, H.

    1998-01-01

    The Fuel Division of British Nuclear Fuels Ltd (BNFL) manufactures nuclear fuel elements for British Magnox and AGR power plants as well as for LWR plants. The new fuel factory - Oxide Fuel Complex (OFC), located in Springfields, is equipped with modern technology and the automation level of the factory is very high. With their quality products, BNFL aims for the new business areas. A recent example of this expansion was shown, when BNFL signed a contract to design and license new VVER-440 fuel for Finnish Loviisa and Hungarian Paks power plants. (author)

  17. Reach Extension and Capacity Enhancement of VCSEL-Based Transmission Over Single-Lane MMF Links

    DEFF Research Database (Denmark)

    Tatarczak, Anna; Motaghiannezam, S. M. Reza; Kocot, Chris

    2017-01-01

    This paper reviews and examines several techniques for expanding the carrying capacity of multimode fiber (MMF) using vertical cavity surface emitting lasers (VCSELs). The first approach utilizes short wavelength division multiplexing in combination with MMF optimized for operation between 850 an...

  18. Transmission enhancement by deployment of interferometric wavelength converters within all-optical cross connects

    DEFF Research Database (Denmark)

    Poulsen, Henrik Nørskov; Mikkelsen, Benny; Stubkjær, Kristian

    1997-01-01

    Wavelength-division multiplexing (WDM) networks are expected to utilize all-optical cross connects (OXCN) for signal routing. Because a signal path is likely to contain a number of OXCNs, their cascadability is essential. Furthermore, because wavelength converters in the OXCNs improve traffic...

  19. Force transmissibility versus displacement transmissibility

    Science.gov (United States)

    Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

    2014-10-01

    It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this

  20. Moving through a multiplex holographic scene

    Science.gov (United States)

    Mrongovius, Martina

    2013-02-01

    This paper explores how movement can be used as a compositional element in installations of multiplex holograms. My holographic images are created from montages of hand-held video and photo-sequences. These spatially dynamic compositions are visually complex but anchored to landmarks and hints of the capturing process - such as the appearance of the photographer's shadow - to establish a sense of connection to the holographic scene. Moving around in front of the hologram, the viewer animates the holographic scene. A perception of motion then results from the viewer's bodily awareness of physical motion and the visual reading of dynamics within the scene or movement of perspective through a virtual suggestion of space. By linking and transforming the physical motion of the viewer with the visual animation, the viewer's bodily awareness - including proprioception, balance and orientation - play into the holographic composition. How multiplex holography can be a tool for exploring coupled, cross-referenced and transformed perceptions of movement is demonstrated with a number of holographic image installations. Through this process I expanded my creative composition practice to consider how dynamic and spatial scenes can be conveyed through the fragmented view of a multiplex hologram. This body of work was developed through an installation art practice and was the basis of my recently completed doctoral thesis: 'The Emergent Holographic Scene — compositions of movement and affect using multiplex holographic images'.

  1. Silicon Photonic Integrated Circuit Mode Multiplexer

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ou, Haiyan; Xu, Jing

    2013-01-01

    We propose and demonstrate a novel silicon photonic integrated circuit enabling multiplexing of orthogonal modes in a few-mode fiber (FMF). By selectively launching light to four vertical grating couplers, all six orthogonal spatial and polarization modes supported by the FMF are successfully...

  2. Multiple routes transmitted epidemics on multiplex networks

    International Nuclear Information System (INIS)

    Zhao, Dawei; Li, Lixiang; Peng, Haipeng; Luo, Qun; Yang, Yixian

    2014-01-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  3. Beyond Multiplexing Gain in Large MIMO Systems

    DEFF Research Database (Denmark)

    Cakmak, Burak; Müller, Ralf R.; Fleury, Bernard Henri

    growth (multiplexing gain). Even when the channel entries are i.i.d. the deviation from the linear growth is significant. We also find an additive property of the deviation for a concatenated MIMO system. Finally, we quantify the deviation of the large SNR capacity from the exact capacity and find...

  4. Multiple routes transmitted epidemics on multiplex networks

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Dawei [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Shandong Provincial Key Laboratory of Computer Network, Shandong Computer Science Center, Jinan 250014 (China); Li, Lixiang [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng, E-mail: penghaipeng@bupt.edu.cn [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Luo, Qun; Yang, Yixian [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2014-02-01

    This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.

  5. Microwave multiplex readout for superconducting sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ferri, E., E-mail: elena.ferri@mib.infn.it [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Becker, D.; Bennett, D. [NIST, Boulder, CO (United States); Faverzani, M. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Fowler, J.; Gard, J. [NIST, Boulder, CO (United States); Giachero, A. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Hays-Wehle, J.; Hilton, G. [NIST, Boulder, CO (United States); Maino, M. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Mates, J. [NIST, Boulder, CO (United States); Puiu, A.; Nucciotti, A. [Università Milano-Bicocca, Milan (Italy); INFN Sez. di Milano-Bicocca, Milan (Italy); Reintsema, C.; Schmidt, D.; Swetz, D.; Ullom, J.; Vale, L. [NIST, Boulder, CO (United States)

    2016-07-11

    The absolute neutrino mass scale is still an outstanding challenge in both particle physics and cosmology. The calorimetric measurement of the energy released in a nuclear beta decay is a powerful tool to determine the effective electron-neutrino mass. In the last years, the progress on low temperature detector technologies has allowed to design large scale experiments aiming at pushing down the sensitivity on the neutrino mass below 1 eV. Even with outstanding performances in both energy (~ eV on keV) and time resolution (~ 1 μs) on the single channel, a large number of detectors working in parallel is required to reach a sub-eV sensitivity. Microwave frequency domain readout is the best available technique to readout large array of low temperature detectors, such as Transition Edge Sensors (TESs) or Microwave Kinetic Inductance Detectors (MKIDs). In this way a multiplex factor of the order of thousands can be reached, limited only by the bandwidth of the available commercial fast digitizers. This microwave multiplexing system will be used to readout the HOLMES detectors, an array of 1000 microcalorimeters based on TES sensors in which the {sup 163}Ho will be implanted. HOLMES is a new experiment for measuring the electron neutrino mass by means of the electron capture (EC) decay of {sup 163}Ho. We present here the microwave frequency multiplex which will be used in the HOLMES experiment and the microwave frequency multiplex used to readout the MKID detectors developed in Milan as well.

  6. Determinants of public cooperation in multiplex networks

    Science.gov (United States)

    Battiston, Federico; Perc, Matjaž; Latora, Vito

    2017-07-01

    Synergies between evolutionary game theory and statistical physics have significantly improved our understanding of public cooperation in structured populations. Multiplex networks, in particular, provide the theoretical framework within network science that allows us to mathematically describe the rich structure of interactions characterizing human societies. While research has shown that multiplex networks may enhance the resilience of cooperation, the interplay between the overlap in the structure of the layers and the control parameters of the corresponding games has not yet been investigated. With this aim, we consider here the public goods game on a multiplex network, and we unveil the role of the number of layers and the overlap of links, as well as the impact of different synergy factors in different layers, on the onset of cooperation. We show that enhanced public cooperation emerges only when a significant edge overlap is combined with at least one layer being able to sustain some cooperation by means of a sufficiently high synergy factor. In the absence of either of these conditions, the evolution of cooperation in multiplex networks is determined by the bounds of traditional network reciprocity with no enhanced resilience. These results caution against overly optimistic predictions that the presence of multiple social domains may in itself promote cooperation, and they help us better understand the complexity behind prosocial behavior in layered social systems.

  7. Data transmission

    National Research Council Canada - National Science Library

    Tugal, Dogan A; Tugal, Osman

    1989-01-01

    This updated second edition provides working answers to today's critical questions about designing and managing all types of data transmission systems and features a new chapter on local area networks (LANs...

  8. Nuclear Power Division

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The 1981-85 research program planned by the Nuclear Power Division of EPRI places major emphasis on the assurance of safety and realiability of light water reactors (LWRs). Of high priority is a better knowledge of LWR-system behavior undeer abnormal conditions and the behavior of structural materials used for pressure vessels, piping, and large nuclear-plant components. Strong emphasis is also placed on achieving the most-effective performance and utilization of nuclear fuels and improving the corrosion resistance of pressurized-water-reactor steam generators. Efforts are underway to reduce radiation exposure and outage duration and to investigate the human factors involved in plant operation and maintenance. Substantial emphasis is placed on short-range goals designed to achieve useful results in the next two to seven years. The Division's mid- and long-range goal is to improve the use of fissionable and fertile materials and aid in the realization of other reactor systems. A series of general goals, categorized into three time frames and planned expenditures shows the trend of work to be undertaken. 53 figures

  9. Wavefront division digital holography

    Science.gov (United States)

    Zhang, Wenhui; Cao, Liangcai; Li, Rujia; Zhang, Hua; Zhang, Hao; Jiang, Qiang; Jin, Guofan

    2018-05-01

    Digital holography (DH), mostly Mach-Zehnder configuration based, belongs to non-common path amplitude splitting interference imaging whose stability and fringe contrast are environmental sensitive. This paper presents a wavefront division DH configuration with both high stability and high-contrast fringes benefitting from quasi common path wavefront-splitting interference. In our proposal, two spherical waves with similar curvature coming from the same wavefront are used, which makes full use of the physical sampling capacity of the detectors. The interference fringe spacing can be adjusted flexibly for both in-line and off-axis mode due to the independent modulation to these two waves. Only a few optical elements, including the mirror-beam splitter interference component, are used without strict alignments, which makes it robust and easy-to-implement. The proposed wavefront division DH promotes interference imaging physics into the practical and miniaturized a step forward. The feasibility of this method is proved by the imaging of a resolution target and a water flea.

  10. Pulse-Shape Analysis of PDM-QPSK Modulation Formats for 100 and 200 Gb/s DWDM transmissions

    OpenAIRE

    Macho Ortiz, Andrés; Rodriguez Horche, Paloma

    2013-01-01

    Advanced optical modulation format polarization-division multiplexed quadrature phase shift keying (PDM-QPSK) has become a key ingredient in the design of 100 and 200-Gb/s dense wavelength-division multiplexed (DWDM) networks. The performance of this format varies according to the shape of the pulses employed by the optical carrier: non-return to zero (NRZ), return to zero (RZ) or carrier-suppressed return to zero (CSRZ). In this paper we analyze the tolerance of PDM-QPSK to linear and nonlin...

  11. Suppressing epidemic spreading in multiplex networks with social-support

    Science.gov (United States)

    Chen, Xiaolong; Wang, Ruijie; Tang, Ming; Cai, Shimin; Stanley, H. Eugene; Braunstein, Lidia A.

    2018-01-01

    Although suppressing the spread of a disease is usually achieved by investing in public resources, in the real world only a small percentage of the population have access to government assistance when there is an outbreak, and most must rely on resources from family or friends. We study the dynamics of disease spreading in social-contact multiplex networks when the recovery of infected nodes depends on resources from healthy neighbors in the social layer. We investigate how degree heterogeneity affects the spreading dynamics. Using theoretical analysis and simulations we find that degree heterogeneity promotes disease spreading. The phase transition of the infected density is hybrid and increases smoothly from zero to a finite small value at the first invasion threshold and then suddenly jumps at the second invasion threshold. We also find a hysteresis loop in the transition of the infected density. We further investigate how an overlap in the edges between two layers affects the spreading dynamics. We find that when the amount of overlap is smaller than a critical value the phase transition is hybrid and there is a hysteresis loop, otherwise the phase transition is continuous and the hysteresis loop vanishes. In addition, the edge overlap allows an epidemic outbreak when the transmission rate is below the first invasion threshold, but suppresses any explosive transition when the transmission rate is above the first invasion threshold.

  12. Multiplexed FBG Monitoring System for Forecasting Coalmine Water Inrush Disaster

    Directory of Open Access Journals (Sweden)

    B. Liu

    2012-01-01

    Full Text Available This paper presents a novel fiber-Bragg-grating- (FBG- based system which can monitor and analyze multiple parameters such as temperature, strain, displacement, and seepage pressure simultaneously for forecasting coalmine water inrush disaster. The sensors have minimum perturbation on the strain field. And the seepage pressure sensors adopt a drawbar structure and employ a corrugated diaphragm to transmit seepage pressure to the axial strain of FBG. The pressure sensitivity is 20.20 pm/KPa, which is 6E3 times higher than that of ordinary bare FBG. The FBG sensors are all preembedded on the roof of mining area in coalmine water inrush model test. Then FBG sensing network is set up applying wavelength-division multiplexing (WDM technology. The experiment is carried out by twelve steps, while the system acquires temperature, strain, displacement, and seepage pressure signals in real time. The results show that strain, displacement, and seepage pressure monitored by the system change significantly before water inrush occurs, and the strain changes firstly. Through signal fusion analyzed it can be concluded that the system provides a novel way to forecast water inrush disaster successfully.

  13. Detection of Lymnaea columella infection by Fasciola hepatica through Multiplex-PCR

    Directory of Open Access Journals (Sweden)

    Kelly Grace Magalhães

    2004-06-01

    Full Text Available From complete mitochondrial DNA sequence of Fasciola hepatica available in Genbank, specific primers were designed for a conserved and repetitive region of this trematode. A pair of primers was used for diagnosis of infected Lymnaea columella by F. hepatica during the pre-patent period simultaneously with another pair of primers which amplified the internal transcribed spacer (ITS region of rDNA from L. columella in a single Multiplex-PCR. The amplification generated a ladder band profile specific for F. hepatica. This profile was observed in positive molluscs at different times of infection, including adult worms from the trematode. The Multiplex-PCR technique showed to be a fast and safe tool for fascioliasis diagnosis, enabling the detection of F. hepatica miracidia in L. columella during the pre-patent period and identification of transmission areas.

  14. A multi-channel low-power system-on-chip for single-unit recording and narrowband wireless transmission of neural signal.

    Science.gov (United States)

    Bonfanti, A; Ceravolo, M; Zambra, G; Gusmeroli, R; Spinelli, A S; Lacaita, A L; Angotzi, G N; Baranauskas, G; Fadiga, L

    2010-01-01

    This paper reports a multi-channel neural recording system-on-chip (SoC) with digital data compression and wireless telemetry. The circuit consists of a 16 amplifiers, an analog time division multiplexer, an 8-bit SAR AD converter, a digital signal processor (DSP) and a wireless narrowband 400-MHz binary FSK transmitter. Even though only 16 amplifiers are present in our current die version, the whole system is designed to work with 64 channels demonstrating the feasibility of a digital processing and narrowband wireless transmission of 64 neural recording channels. A digital data compression, based on the detection of action potentials and storage of correspondent waveforms, allows the use of a 1.25-Mbit/s binary FSK wireless transmission. This moderate bit-rate and a low frequency deviation, Manchester-coded modulation are crucial for exploiting a narrowband wireless link and an efficient embeddable antenna. The chip is realized in a 0.35- εm CMOS process with a power consumption of 105 εW per channel (269 εW per channel with an extended transmission range of 4 m) and an area of 3.1 × 2.7 mm(2). The transmitted signal is captured by a digital TV tuner and demodulated by a wideband phase-locked loop (PLL), and then sent to a PC via an FPGA module. The system has been tested for electrical specifications and its functionality verified in in-vivo neural recording experiments.

  15. Evaluation of PLC Channel Capacity and ABER Performances for OFDM-Based Two-Hop Relaying Transmission

    Directory of Open Access Journals (Sweden)

    Sana Ezzine

    2017-01-01

    Full Text Available Powerline network is recognized as a favorable infrastructure for Smart Grid to transmit information in the network thanks to its broad coverage and low cost deployment. The existing works are trying to improve and adapt transmission techniques to reduce Powerline Communication (PLC channel attenuation and exploit the limited bandwidth to support high data rate over long distances. Two-hop relaying BroadBand PLC (BB-PLC system, in which Orthogonal Frequency Division Multiplexing (OFDM is used, is considered in this paper. We derive and compare the PLC channel capacity and the end-to-end Average BER (ABER for OFDM-based direct link (DL BB-PLC system and for OFDM-based two-hop relaying BB-PLC system for Amplify and Forward (AF and Decode and Forward (DF protocols. We analyze the improvements when we consider the direct link in a cooperative communication when the relay node only transmits the correctly decoded signal. Maximum ratio combining is employed at the destination node to detect the transmitted signal. In addition, in this paper, we highlight the impact of the relay location on the channel capacity and ABER for AF and DF transmission protocols. Moreover, an efficient use of the direct link was also investigated in this paper.

  16. Two orthogonal carriers assisted 101-Gb/s dual-band DDO-OFDM transmission over 320-km SSMF.

    Science.gov (United States)

    Chen, Yiqin; Hu, Rong; Yang, Qi; Luo, Ming; Yu, Shaohua; Li, Wei

    2015-05-04

    We propose a novel fading-free direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) scheme for 100-Gb/s medium-reach transmission. In the proposed scheme, we adopts two bands spaced at 100-GHz to accommodate the same complex-valued OFDM signal. However, the signals are coupled with a pair of orthogonal optical carriers. By doing so, real and imaginary parts of the complex-valued OFDM signal can be recovered from the two bands, respectively. We also propose a cost-effective scheme to generate such DDO-OFDM signal using an optical 90-degree hybrid and an optical I/Q modulator. The advantage of the proposed method is that it is fading-free, and the electrical spectral efficiency (SE) is doubled compared to traditional direct-detection method. Finally, we experimentally demonstrated a 101-Gb/s dual-band transmission over 320-km SSMF within only 30-GHz electrical bandwidth, which is highly competitive in both capacity and cost.

  17. A novel IPTV program multiplex access system to EPON

    Science.gov (United States)

    Xu, Xian; Liu, Deming; He, Wei; Lu, Xi

    2007-11-01

    With the rapid development of high speed networks, such as Ethernet Passive Optical Network (EPON), traffic patterns in access networks have evolved from traditional text-oriented service to the mixed text-, voice- and video- based services, leading to so called "Triple Play". For supporting IPTV service in EPON access network infrastructure, in this article we propose a novel IPTV program multiplex access system to EPON, which enables multiple IPTV program source servers to seamlessly access to IPTV service access port of optical line terminal (OLT) in EPON. There are two multiplex schemes, namely static multiplex scheme and dynamic multiplex scheme, in implementing the program multiplexing. Static multiplex scheme is to multiplex all the IPTV programs and forward them to the OLT, regardless of the need of end-users. While dynamic multiplex scheme can dynamically multiplex and forward IPTV programs according to what the end-users actually demand and those watched by no end-user would not be multiplexed. By comparing these two schemes, a reduced traffic of EPON can be achieved by using dynamic multiplex scheme, especially when most end-users are watching the same few IPTV programs. Both schemes are implemented in our system, with their hardware and software designs described.

  18. a phenomenon for achieving time-division-multiplexed multi-port

    Indian Academy of Sciences (India)

    Olive Ray

    MS received 8 December 2015; revised 21 September 2016; accepted 28 January 2017. Abstract. Multi-port .... Converters based upon this principle operate using lower number of ..... Smart DC power management system based on software-.

  19. Mode division multiplexing technology for single-fiber optical trapping axial-position adjustment.

    Science.gov (United States)

    Liu, Zhihai; Wang, Lei; Liang, Peibo; Zhang, Yu; Yang, Jun; Yuan, Libo

    2013-07-15

    We demonstrate trapped yeast cell axial-position adjustment without moving the optical fiber in a single-fiber optical trapping system. The dynamic axial-position adjustment is realized by controlling the power ratio of the fundamental mode beam (LP01) and the low-order mode beam (LP11) generated in a normal single-core fiber. In order to separate the trapping positions produced by the two mode beams, we fabricate a special fiber tapered tip with a selective two-step method. A yeast cell of 6 μm diameter is moved along the optical axis direction for a distance of ~3 μm. To the best of our knowledge, this is the first demonstration of the trapping position adjustment without moving the fiber for single-fiber optical tweezers. The excitation and utilization of multimode beams in a single fiber constitutes a new development for single-fiber optical trapping and makes possible more practical applications in biomedical research fields.

  20. Performance of Spatial Division Multiplexing MIMO with Frequency Domain Packet Scheduling

    DEFF Research Database (Denmark)

    Wei, Na; Pokhariyal, Akhilesh; Sørensen, Troels Bundgaard

    2008-01-01

    the performance bounds of SDM-FDPS. To facilitate the analysis, a unified SINR concept is utilized to make a fair comparison of MIMO schemes with different number of spatial streams. The effect of packet scheduling is included in the post-scheduling SINR distribution using an analytical model. Based on that...

  1. Novel equalization techniques for space division multiplexing based on stokes space update rule

    DEFF Research Database (Denmark)

    Caballero, Francisco Javier Vaquero; Pittalà, Fabio; Goeger, Gernot

    2017-01-01

    with higher frequency offsets and linewidths than LMS, being suitable for optical communications with higher phase noise. SSA does not need pre-compensation of frequency offset, which can be compensated after equalization without penalties. On the other hand, due to reduced convergence speed, SSA requires...... longer training sequences than LMS....

  2. Quantum-noise randomized data encryption for wavelength-division-multiplexed fiber-optic networks

    International Nuclear Information System (INIS)

    Corndorf, Eric; Liang Chuang; Kanter, Gregory S.; Kumar, Prem; Yuen, Horace P.

    2005-01-01

    We demonstrate high-rate randomized data-encryption through optical fibers using the inherent quantum-measurement noise of coherent states of light. Specifically, we demonstrate 650 Mbit/s data encryption through a 10 Gbit/s data-bearing, in-line amplified 200-km-long line. In our protocol, legitimate users (who share a short secret key) communicate using an M-ry signal set while an attacker (who does not share the secret key) is forced to contend with the fundamental and irreducible quantum-measurement noise of coherent states. Implementations of our protocol using both polarization-encoded signal sets as well as polarization-insensitive phase-keyed signal sets are experimentally and theoretically evaluated. Different from the performance criteria for the cryptographic objective of key generation (quantum key-generation), one possible set of performance criteria for the cryptographic objective of data encryption is established and carefully considered

  3. Decoy-state BB84 protocol using space division multiplexing in silicon photonics

    DEFF Research Database (Denmark)

    Bacco, Davide; Ding, Yunhong; Dalgaard, Kjeld

    2017-01-01

    Quantum key distribution (QKD), a technique based on quantum physics, provides unconditional secure quantum keys to be shared between two or more clients (Alice and Bob) [1]. Most QKD systems are implemented in a point-to-point link using bulky and expensive devices. Consequently a large scale...... experiments have already demonstrated conventional binary QKD systems, using polarization and phase reference degrees of freedom [2, 3]. In this paper, we show the first silicon chip-to-chip decoy-state BB84 protocol based on spatial degrees of freedom (the cores of a multi-core fiber-MCF-). By tuning...... the superposition of the quantum state between cores, combined with a positive/negative phase relation. A train of weak coherent pulses (5 kHz repetition and 10 ns wide) are injected into the transmitter chip (Alice), where multiple variable optical attenuators (VOAs) are used to decrease the number of photons per...

  4. Next generation passive optical networks based on orthogonal frequency division multiplexing techniques

    OpenAIRE

    Escayola Elias, Francesc Xavier

    2015-01-01

    In recent decades, the industry of communications has acquired huge significance, and nowadays constitutes an essential tool for the society information. Thus, the exponential growth in demand of broadband services and the increasing amount of information to be transmitted have spurred the evolution of the access network infrastructure to effectively meet the user needs in an effective way in terms of costs of both installation and maintenance. Passive optical networks (PON) are current...

  5. Design of Multi-core Fiber Patch Panel for Space Division Multiplexing Implementations

    DEFF Research Database (Denmark)

    Gonzalez, Luz E.; Morales, Alvaro; Rommel, Simon

    2018-01-01

    A multi-core fiber (MCF) patch panel was designed, allowing easy coupling of individual signals to and from a 7-core MCF. The device was characterized, measuring insertion loss and cross talk, finding highest insertion loss and lowest crosstalk at 1300 nm with values of 9.7 dB and -36.5 d...

  6. Design of Multi-core Fiber Patch Panel for Space Division Multiplexing Implementations

    Science.gov (United States)

    González, Luz E.; Morales, Alvaro; Rommel, Simon; Jørgensen, Bo F.; Porras-Montenegro, N.; Tafur Monroy, Idelfonso

    2018-03-01

    A multi-core fiber (MCF) patch panel was designed, allowing easy coupling of individual signals to and from a 7-core MCF. The device was characterized, measuring insertion loss and cross talk, finding highest insertion loss and lowest crosstalk at 1300 nm with values of 9.7 dB and -36.5 dB respectively, while at 1600 nm insertion loss drops to 4.8 dB and crosstalk increases to -24.1 dB. Two MCF splices between the fan-in module, the MCF, and the fan-out module are included in the characterization, and splicing parameters are discussed.

  7. Design of multi-core fiber patch panel for space division multiplexing implementations

    NARCIS (Netherlands)

    González, Luz E.; Morales, Alvaro; Rommel, Simon; Jørgensen, Bo F.; Porras-Montenegro, N.; Tafur Monroy, Idelfonso

    2018-01-01

    A multi-core fiber (MCF) patch panel was designed, allowing easy coupling of individual signals to and from a 7-core MCF. The device was characterized, measuring insertion loss and cross talk, finding highest insertion loss and lowest crosstalk at 1300 nm with values of 9.7 dB and -36.5 dB

  8. Integrated optical devices for wavelength division multiplexing using PECVD and direct UV writing techniques

    DEFF Research Database (Denmark)

    Zauner, Dan; Leistiko, Otto

    1999-01-01

    channel waveguides are presented: a conventional method and direct UV writing. It is shown that an optimized three layer glass structure yields directly UV written waveguides with low insertion losses. Integrated optical structures have been designed and fabricated. The impact of process variations...

  9. Performance Evaluation of Clock Recovery for Coherent Mode Division Multiplexed Systems

    DEFF Research Database (Denmark)

    Medeiros Diniz, Júlio César; Piels, Molly; Zibar, Darko

    2017-01-01

    The impact of mode mixing and group delay spread on clock tone quality of a 6-mode 32 GBd NRZ-QPSK MDM system is investigated. Even for low group delay spread, strong coupling causes clock tone disappearance....

  10. The SPICA-SAFARI Detector System : TES Detector Arrays With Frequency-Division Multiplexed SQUID Readout

    NARCIS (Netherlands)

    Jackson, B. D.; de Korte, P. A. J.; van der Kuur, J.; Mauskopf, P. D.; Beyer, J.; Bruijn, M. P.; Cros, A.; Gao, J. -R.; Griffin, D.; den Hartog, R.; Kiviranta, M.; de Lange, G.; van Leeuwen, B. -J.; Macculi, C.; Ravera, L.; Trappe, N.; van Weers, H.; Withington, S.

    The SAFARI instrument is a far-infrared imaging Fourier transform spectrometer for JAXA's SPICA mission. Taking advantage of the low emission of SPICA's 5 K telescope, SAFARI will provide sky background-limited, Nyquist-sampled spectroscopic imaging of a 2' x 2' field-of-view over 34-210 mu m,

  11. Fiber-distributed feedback lasers for high-speed wavelength-division multiplexed networks

    DEFF Research Database (Denmark)

    Sejka, Milan; Hübner, Jörg; Varming, Poul

    1996-01-01

    Summary form only given. In conclusion, we have demonstrated that fiber DFB lasers constitute an excellent alternative to commercially available semiconductor DFB lasers. We have also shown that two fiber DFB lasers can be spliced together without any BER power penalty. Therefore, we suggest...... the possibility of using a single pump source for pumping a WDM laser array consisting of a number of fiber lasers spliced in series....

  12. A Metaheuristic Scheduler for Time Division Multiplexed Network-on-Chip

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Bo; Sparsø, Jens; Pedersen, Mark Ruvald

    2014-01-01

    significant practical implications, is the minimization of the TDM schedule period by over-provisioning bandwidth to connections with the smallest bandwidth requirements. Our results show that this is possible with only negligible impact on the schedule period. We evaluate the scheduler with seven different...... applications from the MCSL NOC benchmark suite. In the special case of all-to-all communication with equal bandwidths on all communication channels, we obtain schedules with a shorter period than reported in previous work....

  13. A Metaheuristic Scheduler for Time Division Multiplexed Network-on-Chip

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Bo; Sparsø, Jens; Pedersen, Mark Ruvald

    that this is possible with only negligible impact on the schedule period. We evaluate the scheduler with seven different applications from the MCSL NOC benchmark suite. We observe that the metaheuristics perform better than the greedy solution. In the special case of all-to-all communication with equal bandwidths...

  14. Illumination sensing in LED lighting systems based on frequency-division multiplexing

    NARCIS (Netherlands)

    Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.

    2009-01-01

    Recently, light emitting diode (LED) based illumination systems have attracted considerable research interest. Such systems normally consist of a large number of LEDs. In order to facilitate the control of such high-complexity system, a novel signal processing application, namely illumination

  15. A filter bank approach for LED illumintaion sensing based on frequency division multiplexing

    NARCIS (Netherlands)

    Yang, Hongming; Bergmans, J.W.M.; Schenk, T.C.W.

    2009-01-01

    In this work, we consider illumination sensing in a light emitting diode (LED) based illumination system that normally consists of a large number of LEDs. Illumination sensing is used in order to facilitate the control of such system whose complexity, due to the large number of LEDs, can be quite

  16. High-performance parallel processors based on star-coupled wavelength division multiplexing optical interconnects

    Science.gov (United States)

    Deri, Robert J.; DeGroot, Anthony J.; Haigh, Ronald E.

    2002-01-01

    As the performance of individual elements within parallel processing systems increases, increased communication capability between distributed processor and memory elements is required. There is great interest in using fiber optics to improve interconnect communication beyond that attainable using electronic technology. Several groups have considered WDM, star-coupled optical interconnects. The invention uses a fiber optic transceiver to provide low latency, high bandwidth channels for such interconnects using a robust multimode fiber technology. Instruction-level simulation is used to quantify the bandwidth, latency, and concurrency required for such interconnects to scale to 256 nodes, each operating at 1 GFLOPS performance. Performance scales have been shown to .apprxeq.100 GFLOPS for scientific application kernels using a small number of wavelengths (8 to 32), only one wavelength received per node, and achievable optoelectronic bandwidth and latency.

  17. High-spatial-multiplicity multi-core fibres for future dense space-division-multiplexing system

    DEFF Research Database (Denmark)

    Matsuo, Shoichiro; Takenaga, Katsuhiro; Saitoh, Kunimasa

    2015-01-01

    Design and fabrication results of high-spatial-multiplicity multi-core fibres are presented. A 30-core single-mode multi-core fibre and a 36-spatial-channels multi-core fibre with low differential mode delay have been realized with low-crosstalk characteristics through optimisation of core struct...

  18. Security and Emergency Management Division

    Data.gov (United States)

    Federal Laboratory Consortium — Volpe's Security and Emergency Management Division identifies vulnerabilities, risks, and opportunities to improve the security of transportation systems, critical...

  19. Situational Awareness and Logistics Division

    Data.gov (United States)

    Federal Laboratory Consortium — Volpe's Situational Awareness and Logistics Division researches, develops, implements, and analyzes advanced systems to protect, enhance, and ensure resilienceof the...

  20. Systems Safety and Engineering Division

    Data.gov (United States)

    Federal Laboratory Consortium — Volpe's Systems Safety and Engineering Division conducts engineering, research, and analysis to improve transportation safety, capacity, and resiliency. We provide...

  1. Infrastructure Engineering and Deployment Division

    Data.gov (United States)

    Federal Laboratory Consortium — Volpe's Infrastructure Engineering and Deployment Division advances transportation innovation by being leaders in infrastructure technology, including vehicles and...

  2. Electrical transmission

    Energy Technology Data Exchange (ETDEWEB)

    Sayers, D P

    1960-05-01

    After briefly tracing the history of electricity transmission, trends in high voltage transmission and experiments being conducted on 650 kV are discussed. 5000 miles of the U.K. grid are operated at 132 kV and 1000 at 275 kV, ultimately to provide a super grid at 380 kV. Problems are insulation, radio interference and the cost of underground lines (16 times that of overhead lines). Also considered are the economics of the grid as a means of transporting energy and as a means of spreading the peak load over the power stations in the most efficient manner. Finally, the question of amenities is discussed.

  3. Ecological multiplex interactions determine the role of species for parasite spread amplification.

    Science.gov (United States)

    Stella, Massimo; Selakovic, Sanja; Antonioni, Alberto; Andreazzi, Cecilia

    2018-04-23

    Despite their potential interplay, multiple routes of many disease transmissions are often investigated separately. As an unifying framework for understanding parasite spread through interdependent transmission paths, we present the 'ecomultiplex' model, where the multiple transmission paths among a diverse community of interacting hosts are represented as a spatially explicit multiplex network. We adopt this framework for designing and testing potential control strategies for T. cruzi spread in two empirical host communities. We show that the ecomultiplex model is an efficient and low data-demanding method to identify which species enhances parasite spread and should thus be a target for control strategies. We also find that the interplay between predator-prey and host-parasite interactions leads to a phenomenon of parasite amplification, in which top predators facilitate T. cruzi spread, offering a mechanistic interpretation of previous empirical findings. Our approach can provide novel insights in understanding and controlling parasite spreading in real-world complex systems. © 2018, Stella et al.

  4. Channel-aware multi-user uplink transmission scheme for SIMO-OFDM systems

    Institute of Scientific and Technical Information of China (English)

    PAN ChengKang; CAI YueMing; XU YouYun

    2009-01-01

    The problem of medium access control (MAC) in wireless single-Input multiple-output-orthogonal frequency division multiplexing (SIMO-OFOM) systems is addressed.Traditional random access protocols have low overheads and inferior performance.Centralized methods have superior performance and high overheads.To achieve the tradeoff between overhead and performance,we propose a channelaware uplink transmission (CaUT) scheme for SIMO-OFDM systems.In CaUT,users transmit requestto-send (RTS) at some subcarriers whose channel gains are above a predetermined threshold.Using the channel state information provided by RTS,access point performs user selection with receive beamforming to decide which users can access and then broadcasts the selection results via clear-to-send (CTS) to users.We present a distributed power control scheme by using a simple fixed modulation mode.We optimize the modulation order and channel gain thresholds to maximize the separable packets subject to the bit-error-rate (BER) and temporal fairness requirements and the Individual average transmit power constraints.The performance of CaUT scheme is analyzed analytically and evaluated by simulations.Simulation results show that CaUT can achieve more significant throughput performance than traditional random access protocols.

  5. A pulsated weak-resonant-cavity laser diode with transient wavelength scanning and tracking for injection-locked RZ transmission.

    Science.gov (United States)

    Lin, Gong-Ru; Chi, Yu-Chieh; Liao, Yu-Sheng; Kuo, Hao-Chung; Liao, Zhi-Wang; Wang, Hai-Lin; Lin, Gong-Cheng

    2012-06-18

    By spectrally slicing a single longitudinal-mode from a master weak-resonant-cavity Fabry-Perot laser diode with transient wavelength scanning and tracking functions, the broadened self-injection-locking of a slave weak-resonant-cavity Fabry-Perot laser diode is demonstrated to achieve bi-directional transmission in a 200-GHz array-waveguide-grating channelized dense-wavelength-division-multiplexing passive optical network system. Both the down- and up-stream slave weak-resonant-cavity Fabry-Perot laser diodes are non-return-to-zero modulated below threshold and coherently injection-locked to deliver the pulsed carrier for 25-km bi-directional 2.5 Gbits/s return-to-zero transmission. The master weak-resonant-cavity Fabry-Perot laser diode is gain-switched at near threshold condition and delivers an optical coherent pulse-train with its mode linewidth broadened from 0.2 to 0.8 nm by transient wavelength scanning, which facilitates the broadband injection-locking of the slave weak-resonant-cavity Fabry-Perot laser diodes with a threshold current reducing by 10 mA. Such a transient wavelength scanning induced spectral broadening greatly releases the limitation on wavelength injection-locking range required for the slave weak-resonant-cavity Fabry-Perot laser diode. The theoretical modeling and numerical simulation on the wavelength scanning and tracking effects of the master and slave weak-resonant-cavity Fabry-Perot laser diodes are performed. The receiving power sensitivity for back-to-back transmission at bit-error-rate transmission is less than 2 dB for all 16 channels.

  6. Division of Analytical Chemistry, 1998

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    1999-01-01

    The article recounts the 1998 activities of the Division of Analytical Chemistry (DAC- formerly the Working Party on Analytical Chemistry, WPAC), which body is a division of the Federation of European Chemical Societies (FECS). Elo Harald Hansen is the Danish delegate, representing The Danish...... Chemical Society/The Society for Analytical Chemistry....

  7. Lightning Talks 2015: Theoretical Division

    Energy Technology Data Exchange (ETDEWEB)

    Shlachter, Jack S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-25

    This document is a compilation of slides from a number of student presentations given to LANL Theoretical Division members. The subjects cover the range of activities of the Division, including plasma physics, environmental issues, materials research, bacterial resistance to antibiotics, and computational methods.

  8. Important projects of the Division

    International Nuclear Information System (INIS)

    2008-01-01

    In this chapter important projects of the Division for Radiation Safety, NPP Decommissioning and Radwaste Management of the VUJE, a. s. are presented. Division for Radiation Safety, NPP Decommissioning and Radwaste Management has successfully carried out variety of significant projects. The most significant projects that were realised, are implemented and possible future projects are introduced in the following part of presentation.

  9. E-Division activities report

    International Nuclear Information System (INIS)

    Barschall, H.H.

    1979-07-01

    This report describes some of the activities in E (Experimental Physics) Division during the past year. E-Division carries out research and development in areas related to the missions of the Laboratory. Many of the activities are in pure and applied atomic and nuclear physics. In addition, this report describes work on accelerators, radiation damage, microwaves, and plasma diagnostics

  10. Developmental control of cell division

    NARCIS (Netherlands)

    Boxem, M. (Mike)

    2002-01-01

    During development of multicellular organisms, cell divisions need to be coordinated with the developmental program of the entire organism. Although the mechanisms that drive cells through the division cycle are well understood, very little is known about the pathways that link extracellular signals

  11. Spin and wavelength multiplexed nonlinear metasurface holography

    Science.gov (United States)

    Ye, Weimin; Zeuner, Franziska; Li, Xin; Reineke, Bernhard; He, Shan; Qiu, Cheng-Wei; Liu, Juan; Wang, Yongtian; Zhang, Shuang; Zentgraf, Thomas

    2016-06-01

    Metasurfaces, as the ultrathin version of metamaterials, have caught growing attention due to their superior capability in controlling the phase, amplitude and polarization states of light. Among various types of metasurfaces, geometric metasurface that encodes a geometric or Pancharatnam-Berry phase into the orientation angle of the constituent meta-atoms has shown great potential in controlling light in both linear and nonlinear optical regimes. The robust and dispersionless nature of the geometric phase simplifies the wave manipulation tremendously. Benefitting from the continuous phase control, metasurface holography has exhibited advantages over conventional depth controlled holography with discretized phase levels. Here we report on spin and wavelength multiplexed nonlinear metasurface holography, which allows construction of multiple target holographic images carried independently by the fundamental and harmonic generation waves of different spins. The nonlinear holograms provide independent, nondispersive and crosstalk-free post-selective channels for holographic multiplexing and multidimensional optical data storages, anti-counterfeiting, and optical encryption.

  12. Multiplexing Short Primers for Viral Family PCR

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, S N; Hiddessen, A L; Hara, C A; Williams, P L; Wagner, M; Colston, B W

    2008-06-26

    We describe a Multiplex Primer Prediction (MPP) algorithm to build multiplex compatible primer sets for large, diverse, and unalignable sets of target sequences. The MPP algorithm is scalable to larger target sets than other available software, and it does not require a multiple sequence alignment. We applied it to questions in viral detection, and demonstrated that there are no universally conserved priming sequences among viruses and that it could require an unfeasibly large number of primers ({approx}3700 18-mers or {approx}2000 10-mers) to generate amplicons from all sequenced viruses. We then designed primer sets separately for each viral family, and for several diverse species such as foot-and-mouth disease virus, hemagglutinin and neuraminidase segments of influenza A virus, Norwalk virus, and HIV-1.

  13. 1.25 Gbit/s bidirectional link in an access network employing a reconfigurable optical add/drop multiplexer and a reflective semiconductor optical amplifier

    NARCIS (Netherlands)

    Urban, P.J.; de Laat, M.M.; Klein, E.J.; Koonen, A.M.J.; Khoe, G.D.; de Waardt, H.; Marciniak, M.; Jaworski, M.; Zdabiwicz, M.

    2008-01-01

    In this paper, we demonstrate symmetrical bidirectional transmission of 1.25 Gbit/s wavelength channels in an access network link employing centralized light generation, colourless optical network unit (ONU) and a reconfigurable optical add/drop multiplexer (ROADM). The architecture of ONU is based

  14. Wireless Multiplexed Surface Acoustic Wave Sensors Project

    Science.gov (United States)

    Youngquist, Robert C.

    2014-01-01

    Wireless Surface Acoustic Wave (SAW) Sensor is a new technology for obtaining multiple, real-time measurements under extreme environmental conditions. This project plans to develop a wireless multiplexed sensor system that uses SAW sensors, with no batteries or semiconductors, that are passive and rugged, can operate down to cryogenic temperatures and up to hundreds of degrees C, and can be used to sense a wide variety of parameters over reasonable distances (meters).

  15. Multiplex congruence network of natural numbers.

    Science.gov (United States)

    Yan, Xiao-Yong; Wang, Wen-Xu; Chen, Guan-Rong; Shi, Ding-Hua

    2016-03-31

    Congruence theory has many applications in physical, social, biological and technological systems. Congruence arithmetic has been a fundamental tool for data security and computer algebra. However, much less attention was devoted to the topological features of congruence relations among natural numbers. Here, we explore the congruence relations in the setting of a multiplex network and unveil some unique and outstanding properties of the multiplex congruence network. Analytical results show that every layer therein is a sparse and heterogeneous subnetwork with a scale-free topology. Counterintuitively, every layer has an extremely strong controllability in spite of its scale-free structure that is usually difficult to control. Another amazing feature is that the controllability is robust against targeted attacks to critical nodes but vulnerable to random failures, which also differs from ordinary scale-free networks. The multi-chain structure with a small number of chain roots arising from each layer accounts for the strong controllability and the abnormal feature. The multiplex congruence network offers a graphical solution to the simultaneous congruences problem, which may have implication in cryptography based on simultaneous congruences. Our work also gains insight into the design of networks integrating advantages of both heterogeneous and homogeneous networks without inheriting their limitations.

  16. Epidemics in partially overlapped multiplex networks.

    Directory of Open Access Journals (Sweden)

    Camila Buono

    Full Text Available Many real networks exhibit a layered structure in which links in each layer reflect the function of nodes on different environments. These multiple types of links are usually represented by a multiplex network in which each layer has a different topology. In real-world networks, however, not all nodes are present on every layer. To generate a more realistic scenario, we use a generalized multiplex network and assume that only a fraction [Formula: see text] of the nodes are shared by the layers. We develop a theoretical framework for a branching process to describe the spread of an epidemic on these partially overlapped multiplex networks. This allows us to obtain the fraction of infected individuals as a function of the effective probability that the disease will be transmitted [Formula: see text]. We also theoretically determine the dependence of the epidemic threshold on the fraction [Formula: see text] of shared nodes in a system composed of two layers. We find that in the limit of [Formula: see text] the threshold is dominated by the layer with the smaller isolated threshold. Although a system of two completely isolated networks is nearly indistinguishable from a system of two networks that share just a few nodes, we find that the presence of these few shared nodes causes the epidemic threshold of the isolated network with the lower propagating capacity to change discontinuously and to acquire the threshold of the other network.

  17. Scientific Equipment Division - Overview

    International Nuclear Information System (INIS)

    Halik, J.

    2001-01-01

    Full text: The Scientific Equipment Division consists of the Design Group and the Mechanical Workshop. The activity of the Division includes the following: - designing of devices and equipment for experiments in physics, their mechanical construction and assembly. In particular, there are vacuum chambers and installations for HV and UHV; - maintenance and upgrading of the existing installations and equipment in our Institute; - participation of our engineers and technicians in design works, equipment assembly and maintenance for experiments in foreign laboratories. The Design Group is equipped with PC-computers and AutoCAD graphic software (release 2000 and Mechanical Desktop 4.0) and a AO plotter, what allows us to make drawings and 2- and 3-dimensional mechanical documentation to the world standards. The Mechanical Workshop can offer a wide range of machining and treatment methods with satisfactory tolerances and surface quality. It offers the following possibilities: - turning - cylindrical elements of a length up to 2000 mm and a diameter up to 400 mm, and also disc-type elements of a diameter up to 600 mm and a length not exceeding 300 mm; - milling - elements of length up to 1000 mm and gear wheels of diameter up to 300 mm; - grinding - flat surfaces of dimensions up to 300 mm x 1000 mm and cylindrical elements of a diameter up to 200 mm and a length up to 800 mm; - drilling - holes of a diameter up to 50 mm; - welding - electrical and gas welding, including TIG vacuum-tight welding; - soft and hard soldering; - mechanical works including precision engineering; - plastics treatment - machining and polishing using diamond milling, modelling, lamination of various shapes and materials, including plexiglas, scintillators and light-guides; - painting - paint spraying with possibility of using furnace-fred drier of internal dimensions of 800 mm x 800 mm x 800 mm. Our workshop posses CNC milling machine which can be used for machining of work-pieces up to 500 kg

  18. 77 FR 40586 - Coastal Programs Division

    Science.gov (United States)

    2012-07-10

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Coastal Programs Division AGENCY: Coastal Programs Division, Office of Ocean and Coastal Resource Management, National Ocean.... FOR FURTHER INFORMATION CONTACT: Kerry Kehoe, Coastal Programs Division (NORM/3), Office of Ocean and...

  19. Physics division annual report 2006.

    Energy Technology Data Exchange (ETDEWEB)

    Glover, J.; Physics

    2008-02-28

    This report highlights the activities of the Physics Division of Argonne National Laboratory in 2006. The Division's programs include the operation as a national user facility of ATLAS, the Argonne Tandem Linear Accelerator System, research in nuclear structure and reactions, nuclear astrophysics, nuclear theory, investigations in medium-energy nuclear physics as well as research and development in accelerator technology. The mission of nuclear physics is to understand the origin, evolution and structure of baryonic matter in the universe--the core of matter, the fuel of stars, and the basic constituent of life itself. The Division's research focuses on innovative new ways to address this mission.

  20. Comparison of multiplex reverse transcription-PCR-enzyme ...

    African Journals Online (AJOL)

    Comparison of multiplex reverse transcription-PCR-enzyme hybridization assay with immunofluorescence techniques for the detection of four viral respiratory pathogens in pediatric community acquired pneumonia.

  1. Gigabit Access Passive Optical Network Using Wavelength Division Multiplexing—GigaWaM

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Suhr, Lau; Prince, Kamau

    2014-01-01

    passive optical network (WDM-PON) architecture that can deliver symmetric 1 Gb/s to 64 users over 20 km standard single mode fiber using the L and C bands for down and upstream, respectively. During the course of the project, a number of key enabling technologies were developed including tunable......This paper summarizes the research and technical achievements done under the EU project GigaWaM. The goal of this project was to develop a cost-effective solution that can meet the increasing bandwidth demands in access networks. The approach was to use a novel wavelength division multiplexing...... transceivers, athermal 50 GHz spaced arrayed waveguide grating multiplexer devices, novel hybridization technologies for integration of passive and active electro-optic devices, and system-level algorithms that ensure the quality of service. The outcome of the project proved a reliable, cost...

  2. Enabling 4-Lane Based 400 G Client-Side Transmission Links with MultiCAP Modulation

    DEFF Research Database (Denmark)

    Tatarczak, Anna; Iglesias Olmedo, Miguel; Zuo, Tianjian

    2015-01-01

    We propose a uniform solution for a future client-side 400 G Ethernet standard based on MultiCAP advanced modulation format, intensity modulation, and direct detection. It employs 4 local area networks-wavelength division multiplexing (LAN-WDM) lanes in 1300 nm wavelength band and parallel optics...

  3. Generalized BICM-T transceivers: Constellation and multiplexer design

    KAUST Repository

    Malik, Muhammad Talha

    2013-09-01

    Recently, it has been shown that the performance of bit-interleaved coded modulation (BICM) using convolutional codes in nonfading channels can be significantly improved if the coded bits are not interleaved at all. This particular BICM design is referred to as BICM trivial (BICM-T) and is shown to be asymptotically as good as Ungerboeck\\'s one dimensional (1D) trellis coded modulation (TCM). This BICM-T design and analysis considered a simple case of rate 1/2 channel encoder with equally spaced 16-ary quadrature amplitude modulation (QAM) constellation where the code rate matches with the modulation order as required in TCM transmission. In this paper, we consider and analyze a new BICM-T design that uses a non equally spaced signal constellation in conjunction with a bit level multiplexer. With this design and analysis, one can not only exploit the full benefit of BICM-T design by jointly optimizing different transceiver\\'s modules but also enjoys the same design flexibility as the traditional BICM to independently choose the code rate and the modulation order. The presented numerical results for 64-ary QAM with rate 1/3 code shows that the considered design can offer gains up to 2.5 dB over the traditional optimal BICM design for a target bit error rate (BER) of 10-6. © 2013 IEEE.

  4. Annual report 1983/1984. Division of Solid State Physics

    International Nuclear Information System (INIS)

    1984-10-01

    This report gives a survey of the present research projects at the division of solid state physics, Inst. of Technology, Uppsala University. The projects fall within the fields of magnetism, i.e. spin glasses, ordered magnetic structures and itinerant electron magnetism, as well as optics, i.e. properties of crystalline and amorphous materials for selective transmission and absorption in connection with energy-related research. (author)

  5. Frequency-multiplexed bias and readout of a 16-pixel superconducting nanowire single-photon detector array

    Science.gov (United States)

    Doerner, S.; Kuzmin, A.; Wuensch, S.; Charaev, I.; Boes, F.; Zwick, T.; Siegel, M.

    2017-07-01

    We demonstrate a 16-pixel array of microwave-current driven superconducting nanowire single-photon detectors with an integrated and scalable frequency-division multiplexing architecture, which reduces the required number of bias and readout lines to a single microwave feed line. The electrical behavior of the photon-sensitive nanowires, embedded in a resonant circuit, as well as the optical performance and timing jitter of the single detectors is discussed. Besides the single pixel measurements, we also demonstrate the operation of a 16-pixel array with a temporal, spatial, and photon-number resolution.

  6. 76 FR 71982 - Advancing Regulatory Science for Highly Multiplexed Microbiology/Medical Countermeasure Devices...

    Science.gov (United States)

    2011-11-21

    ... Multiplexed Microbiology Devices: Their clinical application and public health/clinical needs; inclusion of...] Advancing Regulatory Science for Highly Multiplexed Microbiology/ Medical Countermeasure Devices; Public... Multiplexed Microbiology/ Medical Countermeasure Devices'' that published in the Federal Register of August 8...

  7. Computers in Nuclear Physics Division

    International Nuclear Information System (INIS)

    Kowalczyk, M.; Tarasiuk, J.; Srebrny, J.

    1997-01-01

    Improving of the computer equipment in Nuclear Physics Division is described. It include: new computer equipment and hardware upgrading, software developing, new programs for computer booting and modernization of data acquisition systems

  8. Division 1137 property control system

    Energy Technology Data Exchange (ETDEWEB)

    Pastor, D.J.

    1982-01-01

    An automated data processing property control system was developed by Mobile and Remote Range Division 1137. This report describes the operation of the system and examines ways of using it in operational planning and control.

  9. E-Division activities report

    International Nuclear Information System (INIS)

    Barschall, H.H.

    1984-07-01

    E (Experimental Physics) Division carries out basic and applied research in atomic and nuclear physics, in materials science, and in other areas related to the missions of the Laboratory. Some of the activities are cooperative efforts with other divisions of the Laboratory, and, in a few cases, with other laboratories. Many of the experiments are directly applicable to problems in weapons and energy, some have only potential applied uses, and others are in pure physics. This report presents abstracts of papers published by E (Experimental Physics) Division staff members between July 1983 and June 1984. In addition, it lists the members of the scientific staff of the division, including visitors and students, and some of the assignments of staff members on scientific committees. A brief summary of the budget is included

  10. Enhanced speed in fluorescence imaging using beat frequency multiplexing

    Science.gov (United States)

    Mikami, Hideharu; Kobayashi, Hirofumi; Wang, Yisen; Hamad, Syed; Ozeki, Yasuyuki; Goda, Keisuke

    2016-03-01

    Fluorescence imaging using radiofrequency-tagged emission (FIRE) is an emerging technique that enables higher imaging speed (namely, temporal resolution) in fluorescence microscopy compared to conventional fluorescence imaging techniques such as confocal microscopy and wide-field microscopy. It works based on the principle that it uses multiple intensity-modulated fields in an interferometric setup as excitation fields and applies frequency-division multiplexing to fluorescence signals. Unfortunately, despite its high potential, FIRE has limited imaging speed due to two practical limitations: signal bandwidth and signal detection efficiency. The signal bandwidth is limited by that of an acousto-optic deflector (AOD) employed in the setup, which is typically 100-200 MHz for the spectral range of fluorescence excitation (400-600 nm). The signal detection efficiency is limited by poor spatial mode-matching between two interfering fields to produce a modulated excitation field. Here we present a method to overcome these limitations and thus to achieve higher imaging speed than the prior version of FIRE. Our method achieves an increase in signal bandwidth by a factor of two and nearly optimal mode matching, which enables the imaging speed limited by the lifetime of the target fluorophore rather than the imaging system itself. The higher bandwidth and better signal detection efficiency work synergistically because higher bandwidth requires higher signal levels to avoid the contribution of shot noise and amplifier noise to the fluorescence signal. Due to its unprecedentedly high-speed performance, our method has a wide variety of applications in cancer detection, drug discovery, and regenerative medicine.

  11. E-Division activities report

    International Nuclear Information System (INIS)

    Barschall, H.H.

    1981-07-01

    This report describes some of the activities in E (Experimental Physics) Division during the past year. E-Division carries out research and development in areas related to the missions of the Laboratory. Many of the activities are in pure and applied atomic and nuclear physics and in material science. In addition this report describes work on accelerators, microwaves, plasma diagnostics, determination of atmospheric oxygen and of nitrogen in tissue

  12. Multiplexed Western Blotting Using Microchip Electrophoresis.

    Science.gov (United States)

    Jin, Shi; Furtaw, Michael D; Chen, Huaxian; Lamb, Don T; Ferguson, Stephen A; Arvin, Natalie E; Dawod, Mohamed; Kennedy, Robert T

    2016-07-05

    Western blotting is a commonly used protein assay that combines the selectivity of electrophoretic separation and immunoassay. The technique is limited by long time, manual operation with mediocre reproducibility, and large sample consumption, typically 10-20 μg per assay. Western blots are also usually used to measure only one protein per assay with an additional housekeeping protein for normalization. Measurement of multiple proteins is possible; however, it requires stripping membranes of antibody and then reprobing with a second antibody. Miniaturized alternatives to Western blot based on microfluidic or capillary electrophoresis have been developed that enable higher-throughput, automation, and greater mass sensitivity. In one approach, proteins are separated by electrophoresis on a microchip that is dragged along a polyvinylidene fluoride membrane so that as proteins exit the chip they are captured on the membrane for immunoassay. In this work, we improve this method to allow multiplexed protein detection. Multiple injections made from the same sample can be deposited in separate tracks so that each is probed with a different antibody. To further enhance multiplexing capability, the electrophoresis channel dimensions were optimized for resolution while keeping separation and blotting times to less than 8 min. Using a 15 μm deep × 50 μm wide × 8.6 cm long channel, it is possible to achieve baseline resolution of proteins that differ by 5% in molecular weight, e.g., ERK1 (44 kDa) from ERK2 (42 kDa). This resolution allows similar proteins detected by cross-reactive antibodies in a single track. We demonstrate detection of 11 proteins from 9 injections from a single Jurkat cell lysate sample consisting of 400 ng of total protein using this procedure. Thus, multiplexed Western blots are possible without cumbersome stripping and reprobing steps.

  13. Multiplex serology of paraneoplastic antineuronal antibodies.

    Science.gov (United States)

    Maat, Peter; Brouwer, Eric; Hulsenboom, Esther; VanDuijn, Martijn; Schreurs, Marco W J; Hooijkaas, Herbert; Smitt, Peter A E Sillevis

    2013-05-31

    Paraneoplastic neurological syndromes (PNS) are devastating neurological disorders secondary to cancer, associated with onconeural autoantibodies. Such antibodies are directed against neuronal antigens aberrantly expressed by the tumor. The detection of onconeural antibodies in a patient is extremely important in diagnosing a neurological syndrome as paraneoplastic (70% is not yet known to have cancer) and in directing the search for the underlying neoplasm. At present six onconeural antibodies are considered 'well characterized' and recognize the antigens HuD, CDR62 (Yo), amphiphysin, CRMP-5 (CV2), NOVA-1 (Ri), and Ma2. The gold standard of detection is the characteristic immunohistochemical staining pattern on brain tissue sections combined with confirmation by immunoblotting using recombinant purified proteins. Since all six onconeural antibodies are usually analyzed simultaneously and objective cut-off values for these analyses are warranted, we developed a multiplex assay based on Luminex technology. Reaction of serial dilutions of six onconeural standard sera with microsphere-bound antigens showed lower limits of detection than with Western blotting. Using the six standard sera at a dilution of 1:200, the average within-run coefficient of variation (CV) was 4% (range 1.9-7.3%). The average between-run within-day CV was 5.1% (range 2.9-6.7%) while the average between-day CV was 8.1% (range 2.8-11.6%). The shelf-life of the antigen coupled microspheres was at least two months. The sensitivity of the multiplex assay ranged from 83% (Ri) to 100% (Yo, amphiphysin, CV2) and the specificity from 96% (CV2) to 100% (Ri). In conclusion, Luminex-based multiplex serology is highly reproducible with high sensitivity and specificity for the detection of onconeural antibodies. Conventional immunoblotting for diagnosis of onconeural antibodies in the setting of a routine laboratory may be replaced by this novel, robust technology. Copyright © 2013 Elsevier B.V. All rights

  14. Turbulence mitigation scheme based on multiple-user detection in an orbital-angular-momentum multiplexed system

    Science.gov (United States)

    Zou, Li; Wang, Le; Zhao, Sheng-Mei; Chen, Han-Wu

    2016-11-01

    Atmospheric turbulence (AT) induced crosstalk can significantly impair the performance of a free-space optical (FSO) communication link using orbital angular momentum (OAM) multiplexing. In this paper, we propose a multiple-user detection (MUD) turbulence mitigation scheme in an OAM-multiplexed FSO communication link. First, we present a MUD equivalent communication model for an OAM-multiplexed FSO communication link under AT. In the equivalent model, each input bit stream represents one user’s information. The deformed OAM spatial modes caused by AT, instead of the pure OAM spatial modes, are used as information carriers, and the overlapping between the deformed OAM spatial modes are computed as the correlation coefficients between the users. Then, we present a turbulence mitigation scheme based on MUD idea to enhance AT tolerance of the OAM-multiplexed FSO communication link. In the proposed scheme, the crosstalk caused by AT is used as a useful component to deduce users’ information. The numerical results show that the performance of the OAM-multiplexed communication link has greatly improved by the proposed scheme. When the turbulence strength is 1 × 10-15 m-2/3, the transmission distance is 1000 m and the channel signal-to-noise ratio (SNR) is 26 dB, the bit-error-rate (BER) performance of four spatial multiplexed OAM modes lm = +1,+2,+3,+4 are all close to 10-5, and there is a 2-3 fold increase in the BER performance in comparison with those results without the proposed scheme. In addition, the proposed scheme is more effective for an OAM-multiplexed FSO communication link with a larger OAM mode topological charge interval. The proposed scheme is a promising direction for compensating the interference caused by AT in the OAM-multiplexed FSO communication link. Project supported by the National Natural Science Foundation of China (Grant Nos. 61271238 and 61475075), the Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network

  15. Performance modeling, stochastic networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi R

    2013-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of introducing an appropriate mathematical framework for modeling and analysis as well as understanding the phenomenon of statistical multiplexing. The models, techniques, and results presented form the core of traffic engineering methods used to design, control and allocate resources in communication networks.The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the importan

  16. Subcarrier multiplexing optical quantum key distribution

    International Nuclear Information System (INIS)

    Ortigosa-Blanch, A.; Capmany, J.

    2006-01-01

    We present the physical principles of a quantum key distribution system that opens the possibility of parallel quantum key distribution and, therefore, of a substantial improvement in the bit rate of such systems. Quantum mechanics allows for multiple measurements at different frequencies and thus we exploit this concept by extending the concept of frequency coding to the case where more than one radio-frequency subcarrier is used for independently encoding the bits onto an optical carrier. Taking advantage of subcarrier multiplexing techniques we demonstrate that the bit rate can be greatly improved as parallel key distribution is enabled

  17. Entamoeba spp. diagnosis in patients with inflmmatory diarrhea by staining, copro-antigen ELISA and multiplex PCR methods

    Directory of Open Access Journals (Sweden)

    Zahra Gharibi

    2017-10-01

    Full Text Available Objective: To evaluate Entamoeba spp. diagnosis in patients with inflammatory diarrhea by staining, copro-antigen ELISA and multiplex PCR methods. Methods: In this descriptive cross-sectional survey, 200 stool samples were randomly collected during 2015–2016. The stool samples were evaluated microscopically for the presence of the parasite using direct and formalin-ether concentration and trichrome staining methods. Then, the stool samples were examined by copro-antigen ELISA (Biomerica Company and multiplex PCR methods. Results: Of 200 samples, 17, 29 and 23 cases were positive for Entamoeba species by the staining, copro-antigen ELISA and multiplex PCR methods, respectively. Of 23 positive samples in multiplex PCR test, 13 and 10 samples were positive for Entamoeba dispar (E. dispar and Entamoeba histolytica (E. histolytica, respectively. Conclusions: Our finding indicated a relatively high prevalence of Entamoeba species in patients with inflammatory diarrhea in Ahvaz city. Due to the complications of E. histolytica/ dispar infection, the health authorities of the city must pay more attention to control and prevent the transmission of E. histolytica/dispar to individuals.

  18. Double random phase spread spectrum spread space technique for secure parallel optical multiplexing with individual encryption key

    Science.gov (United States)

    Hennelly, B. M.; Javidi, B.; Sheridan, J. T.

    2005-09-01

    A number of methods have been recently proposed in the literature for the encryption of 2-D information using linear optical systems. In particular the double random phase encoding system has received widespread attention. This system uses two Random Phase Keys (RPK) positioned in the input spatial domain and the spatial frequency domain and if these random phases are described by statistically independent white noises then the encrypted image can be shown to be a white noise. Decryption only requires knowledge of the RPK in the frequency domain. The RPK may be implemented using a Spatial Light Modulators (SLM). In this paper we propose and investigate the use of SLMs for secure optical multiplexing. We show that in this case it is possible to encrypt multiple images in parallel and multiplex them for transmission or storage. The signal energy is effectively spread in the spatial frequency domain. As expected the number of images that can be multiplexed together and recovered without loss is proportional to the ratio of the input image and the SLM resolution. Many more images may be multiplexed with some loss in recovery. Furthermore each individual encryption is more robust than traditional double random phase encoding since decryption requires knowledge of both RPK and a lowpass filter in order to despread the spectrum and decrypt the image. Numerical simulations are presented and discussed.

  19. Suppressing the relaxation oscillation noise of injection-locked WRC-FPLD for directly modulated OFDM transmission.

    Science.gov (United States)

    Cheng, Min-Chi; Chi, Yu-Chieh; Li, Yi-Cheng; Tsai, Cheng-Ting; Lin, Gong-Ru

    2014-06-30

    By up-shifting the relaxation oscillation peak and suppressing its relative intensity noise in a weak-resonant-cavity Fabry-Perot laser diode (WRC-FPLD) under intense injection-locking, the directly modulated transmission of optical 16 quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) data-stream is demonstrated. The total bit rate of up to 20 Gbit/s within 5-GHz bandwidth is achieved by using the OFDM subcarrier pre-leveling technique. With increasing the injection-locking power from -12 to -3 dBm, the effective reduction on threshold current of the WRC-FPLD significantly shifts its relaxation oscillation frequency from 5 to 7.5 GHz. This concurrently induces an up-shift of the peak relative intensity noise (RIN) of the WRC-FPLD, and effectively suppresses the background RIN level to -104 dBc/Hz within the OFDM band between 3 and 6 GHz. The enhanced signal-to-noise ratio from 16 to 20 dB leads to a significant reduction of bit-error-rate (BER) of the back-to-back transmitted 16-QAM-OFDM data from 1.3 × 10(-3) to 5 × 10(-5), which slightly degrades to 1.1 × 10(-4) after 25-km single-mode fiber (SMF) transmission. However, the enlarged injection-locking power from -12 to -3 dBm inevitably declines the modulation throughput and increases its negative throughput slope from -0.8 to -1.9 dBm/GHz. After pre-leveling the peak amplitude of the OFDM subcarriers to compensate the throughput degradation of the directly modulated WRC-FPLD, the BER under 25-km SMF transmission can be further improved to 3 × 10(-5) under a receiving power of -3 dBm.

  20. Preliminary study of visual effect of multiplex hologram

    Science.gov (United States)

    Fu, Huaiping; Xiong, Bingheng; Yang, Hong; Zhang, Xueguo

    2004-06-01

    The process of any movement of real object can be recorded and displayed by a multiplex holographic stereogram. An embossing multiplex holographic stereogram and a multiplex rainbow holographic stereogram have been made by us, the multiplex rainbow holographic stereogram reconstructs the dynamic 2D line drawing of speech organs, the embossing multiplex holographic stereogram reconstructs the process of an old man drinking water. In this paper, we studied the visual result of an embossing multiplex holographic stereogram made with 80 films of 2-D pictures. Forty-eight persons of aged from 13 to 67 were asked to see the hologram and then to answer some questions about the feeling of viewing. The results indicate that this kind of holograms could be accepted by human visual sense organ without any problem. This paper also discusses visual effect of the multiplex holography stereograms base on visual perceptual psychology. It is open out that the planar multiplex holograms can be recorded and present the movement of real animal and object. Not only have the human visual perceptual constancy for shape, just as that size, color, etc... but also have visual perceptual constancy for binocular parallax.

  1. Topology-optimized silicon photonic wire mode (de)multiplexer

    DEFF Research Database (Denmark)

    Frellsen, Louise Floor; Frandsen, Lars Hagedorn; Ding, Yunhong

    2015-01-01

    We have designed and for the first time experimentally verified a topology optimized mode (de)multiplexer, which demultiplexes the fundamental and the first order mode of a double mode photonic wire to two separate single mode waveguides (and multiplexes vice versa). The device has a footprint...

  2. Computerized multiplexing and processing of in-core signals

    International Nuclear Information System (INIS)

    Meyer, J.

    1982-09-01

    After a presentation of the in-core instrumentation the main objectives of electric connection multiplexing are given. The conclusion of a study led to choose the multiplexing solution for the reactor building/electric building connections and to associate an information order management system based on the utilization of microprocessors. Finally, the control system (processors, organization, communication, language) is presented [fr

  3. Multiplexing and data processing of in-core signals

    International Nuclear Information System (INIS)

    Meyer, M.

    1983-01-01

    The application of multiplexing and signal processing techniques used for reactor operation and utilisation of data from the in-core instrumentation system is described. After a brief recall about in-core instrumentation, the aims, the advantages of multiplexing are presented. One of the aims of this realization is to show the compatibity between the technologies used with a PWR environment [fr

  4. Explaining HIV Risk Multiplexity: A Social Network Analysis.

    Science.gov (United States)

    Felsher, Marisa; Koku, Emmanuel

    2018-04-21

    Risk multiplexity (i.e., overlap in drug-use, needle exchange and sexual relations) is a known risk factor for HIV. However, little is known about predictors of multiplexity. This study uses egocentric data from the Colorado Springs study to examine how individual, behavioral and social network factors influence engagement in multiplex risk behavior. Analyses revealed that compared to Whites, Hispanics were significantly more likely to engage in risk multiplexity and Blacks less so. Respondents who were similar to each other (e.g., in terms of race) had significantly higher odds of being in risk multiplex relationships, and respondents' risk perceptions and network size were significantly associated with engaging in multiplex risk behaviors. Findings from interaction analysis showed the effect of knowing someone with HIV on the odds of multiplexity depends partly on whether respondents' know their HIV status. Findings suggest that demographics, HIV behaviors and network factors impact engagement in multiplex risk behaviors, highlighting the need for multi-level interventions aimed at reducing HIV risk behavior.

  5. SiDIVS: Simple Detection of Inductive Vehicle Signatures with a Multiplex Resonant Sensor

    Directory of Open Access Journals (Sweden)

    José J. Lamas-Seco

    2016-08-01

    Full Text Available This work provides a system capable of obtaining simultaneous inductive signatures of vehicles traveling on a roadway with minimal cost. Based on Time-Division Multiplexing (TDM with multiple oscillators, one for each inductive loop, the proposed system detects the presence of vehicles by means of a shift in the oscillation period of the selected loop and registers the signature of the detected vehicles by measuring the duration of a fixed number of oscillator pulses. In order to test the system in an actual environment, we implement a prototype that we denote as SiDIVS (Simple Detection of Inductive Vehicle Signatures and acquire different vehicle inductive signatures under real scenarios. We also test the robustness of the detector by simulating the effect of noise on the signature acquisition.

  6. Data multiplexing in radio interferometric calibration

    Science.gov (United States)

    Yatawatta, Sarod; Diblen, Faruk; Spreeuw, Hanno; Koopmans, L. V. E.

    2018-03-01

    New and upcoming radio interferometers will produce unprecedented amount of data that demand extremely powerful computers for processing. This is a limiting factor due to the large computational power and energy costs involved. Such limitations restrict several key data processing steps in radio interferometry. One such step is calibration where systematic errors in the data are determined and corrected. Accurate calibration is an essential component in reaching many scientific goals in radio astronomy and the use of consensus optimization that exploits the continuity of systematic errors across frequency significantly improves calibration accuracy. In order to reach full consensus, data at all frequencies need to be calibrated simultaneously. In the SKA regime, this can become intractable if the available compute agents do not have the resources to process data from all frequency channels simultaneously. In this paper, we propose a multiplexing scheme that is based on the alternating direction method of multipliers with cyclic updates. With this scheme, it is possible to simultaneously calibrate the full data set using far fewer compute agents than the number of frequencies at which data are available. We give simulation results to show the feasibility of the proposed multiplexing scheme in simultaneously calibrating a full data set when a limited number of compute agents are available.

  7. Multiplexed microsatellite recovery using massively parallel sequencing

    Science.gov (United States)

    Jennings, T.N.; Knaus, B.J.; Mullins, T.D.; Haig, S.M.; Cronn, R.C.

    2011-01-01

    Conservation and management of natural populations requires accurate and inexpensive genotyping methods. Traditional microsatellite, or simple sequence repeat (SSR), marker analysis remains a popular genotyping method because of the comparatively low cost of marker development, ease of analysis and high power of genotype discrimination. With the availability of massively parallel sequencing (MPS), it is now possible to sequence microsatellite-enriched genomic libraries in multiplex pools. To test this approach, we prepared seven microsatellite-enriched, barcoded genomic libraries from diverse taxa (two conifer trees, five birds) and sequenced these on one lane of the Illumina Genome Analyzer using paired-end 80-bp reads. In this experiment, we screened 6.1 million sequences and identified 356958 unique microreads that contained di- or trinucleotide microsatellites. Examination of four species shows that our conversion rate from raw sequences to polymorphic markers compares favourably to Sanger- and 454-based methods. The advantage of multiplexed MPS is that the staggering capacity of modern microread sequencing is spread across many libraries; this reduces sample preparation and sequencing costs to less than $400 (USD) per species. This price is sufficiently low that microsatellite libraries could be prepared and sequenced for all 1373 organisms listed as 'threatened' and 'endangered' in the United States for under $0.5M (USD).

  8. Multiplexed electrospray scaling for liquid fuel injection

    International Nuclear Information System (INIS)

    Waits, C Mike; Hanrahan, Brendan; Lee, Ivan

    2010-01-01

    Evaporation and space-charge requirements are evaluated to understand the effect of device scaling and fuel preheating for a liquid fuel injector using a multiplexed electrospray (MES) configuration in compact combustion applications. This work reveals the influence of the droplet diameter, droplet velocity and droplet surface temperature as well as the surrounding gas temperature on the size and performance of microfabricated MES. Measurements from MES devices are used in the model to accurately account for the droplet diameter versus flow rate relationship, the minimum droplet diameter and the relevant droplet velocities. A maximum extractor electrode to ground electrode distance of 3.1 mm required to overcome space-charge forces is found to be independent of voltage or droplet velocity for large levels of multiplexing. This maximum distance also becomes the required evaporation length scale which imposes minimum fuel pre-heating requirements for large flow densities. Required fuel preheating is therefore evaluated for both ethanol and 1-butanol with combustor parameters relevant to fuel reformation, thermoelectric conversion, thermophotovoltaic conversion and thermionic conversion

  9. Non-identical multiplexing promotes chimera states

    Science.gov (United States)

    Ghosh, Saptarshi; Zakharova, Anna; Jalan, Sarika

    2018-01-01

    We present the emergence of chimeras, a state referring to coexistence of partly coherent, partly incoherent dynamics in networks of identical oscillators, in a multiplex network consisting of two non-identical layers which are interconnected. We demonstrate that the parameter range displaying the chimera state in the homogeneous first layer of the multiplex networks can be tuned by changing the link density or connection architecture of the same nodes in the second layer. We focus on the impact of the interconnected second layer on the enlargement or shrinking of the coupling regime for which chimeras are displayed in the homogeneous first layer. We find that a denser homogeneous second layer promotes chimera in a sparse first layer, where chimeras do not occur in isolation. Furthermore, while a dense connection density is required for the second layer if it is homogeneous, this is not true if the second layer is inhomogeneous. We demonstrate that a sparse inhomogeneous second layer which is common in real-world complex systems can promote chimera states in a sparse homogeneous first layer.

  10. Multiplexed Colorimetric Solid-Phase Extraction

    Science.gov (United States)

    Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.

    2009-01-01

    Multiplexed colorimetric solid-phase extraction (MC-SPE) is an extension of colorimetric solid-phase extraction (C-SPE) an analytical platform that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water. In CSPE, analytes are extracted and complexed on the surface of an extraction membrane impregnated with a colorimetric reagent. The analytes are then quantified directly on the membrane surface using a handheld diffuse reflectance spectrophotometer. Importantly, the use of solid-phase extraction membranes as the matrix for impregnation of the colorimetric reagents creates a concentration factor that enables the detection of low concentrations of analytes in small sample volumes. In extending C-SPE to a multiplexed format, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple sample syringes have been designed, enabling the simultaneous determination of multiple analytes. Separate, single analyte membranes, placed in a readout cartridge create unique, analyte-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. In a demonstration, MC-SPE was used to measure the pH of a sample and quantitate Ag(I) and Ni(II).

  11. Link prediction in multiplex online social networks

    Science.gov (United States)

    Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

    2017-02-01

    Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

  12. A micro-controlled universal message multiplexer

    International Nuclear Information System (INIS)

    Fontaine, G.; Guglielmi, L.; Jaeger, J.J.; Szafran, S.

    1981-01-01

    Based on the Motorola 6800, this multiplexer is designed to provide a microprocessor development tool in the specific environment of a high energy physics laboratory. The basic philosophy of this device is to allow communication of a target (prototype) processor with a host computer under control of a human operator. The host can be an experimental on-line computer or any remote machine with a time-sharing network. It is thus possible to speed up design and debugging of a physics application program by taking advantage of the sophisticated resources usually available in a computer centre (powerful editor, large disk space, source management via ''Patchy'' etc...). In addition to the classical cross-macroassembler, a loader is available on the host for down-line loading binary code, via the multiplexer, into the prototype memory. Such a scheme is easiextended to the communication of any host interactive processing program with a data acquisition microprocessor, and provides the latter with a convenient and easily portable extension of its computing power. A typical application of this mode is described in a separate paper

  13. A time-multiplexed track-trigger for the CMS HL-LHC upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Hall, G., E-mail: g.hall@imperial.ac.uk

    2016-07-11

    A new CMS Tracker is under development for operation at the High Luminosity LHC from 2025. It includes an outer tracker based on special modules of two different types which will construct track stubs using spatially coincident clusters in two closely spaced sensor layers, to reject low transverse momentum track hits and reduce the data volume before data transmission to the Level-1 trigger. The tracker data will be used to reconstruct track segments in dedicated processors before onward transmission to other trigger processors which will combine tracker information with data originating from the calorimeter and muon detectors, to make the final L1 trigger decision. The architecture for processing the tracker data outside the detector is under study, using several alternative approaches. One attractive possibility is to exploit a Time Multiplexed design similar to the one which is currently being implemented in the CMS calorimeter trigger as part of the Phase I trigger upgrade. The novel Time Multiplexed Trigger concept is explained, the potential benefits for processing future tracker data are described and a feasible design based on currently existing hardware is outlined.

  14. Multiplex PCR identification of Taenia spp. in rodents and carnivores.

    Science.gov (United States)

    Al-Sabi, Mohammad N S; Kapel, Christian M O

    2011-11-01

    The genus Taenia includes several species of veterinary and public health importance, but diagnosis of the etiological agent in definitive and intermediate hosts often relies on labor intensive and few specific morphometric criteria, especially in immature worms and underdeveloped metacestodes. In the present study, a multiplex PCR, based on five primers targeting the 18S rDNA and ITS2 sequences, produced a species-specific banding patterns for a range of Taenia spp. Species typing by the multiplex PCR was compared to morphological identification and sequencing of cox1 and/or 12S rDNA genes. As compared to sequencing, the multiplex PCR identified 31 of 32 Taenia metacestodes from rodents, whereas only 14 cysts were specifically identified by morphology. Likewise, the multiplex PCR identified 108 of 130 adult worms, while only 57 were identified to species by morphology. The tested multiplex PCR system may potentially be used for studies of Taenia spp. transmitted between rodents and carnivores.

  15. Electronics for a Next-Generation SQUID-Based Time-Domain Multiplexing System

    International Nuclear Information System (INIS)

    Reintsema, C. D.; Doriese, W. R.; Hilton, G. C.; Irwin, K. D.; Krinsky, J. W.; Adams, J. S.; Baker, R.; Bandler, S. R.; Kelly, R. L.; Kilbourne, C. A.; Porter, F. S.; Figueroa-Feliciano, E.; Wikus, P.

    2009-01-01

    A decade has elapsed since the design, development and realization of a SQUID-based time-division multiplexer at NIST. During this time the system has been used extensively for low-temperature-detector-array measurements. Concurrently, there have been substantial advancements both in detector array and commercial electronic component technology. The relevance and applicability of the technology has blossomed as well, often accompanied by more demanding measurement requirements. These factors have motivated a complete redesign of the NIST room-temperature read-out electronics. The redesign has leveraged advancements in component technology to achieve new capabilities better suited to the SQUID multiplexers and detector arrays being realized today. As examples of specific performance enhancements, the overall system bandwidth has been increased by a factor of four (a row switching rate of 6.24 MHz), the compactness has been increased by over a factor of two (a higher number of detector columns and rows per circuit board), and there are two high speed outputs per column (allowing fast switching of SQUID offsets in addition to digital feedback). The system architecture, design implementations, and performance advantages of the new system will be discussed. As an application example, the science chain flight electronics for the Micro-X High Resolution Microcalorimeter X-ray Imaging Rocket will be described as both a motivation for, and a direct implementation of the new system.

  16. On-chip single photon filtering and multiplexing in hybrid quantum photonic circuits.

    Science.gov (United States)

    Elshaari, Ali W; Zadeh, Iman Esmaeil; Fognini, Andreas; Reimer, Michael E; Dalacu, Dan; Poole, Philip J; Zwiller, Val; Jöns, Klaus D

    2017-08-30

    Quantum light plays a pivotal role in modern science and future photonic applications. Since the advent of integrated quantum nanophotonics different material platforms based on III-V nanostructures-, colour centers-, and nonlinear waveguides as on-chip light sources have been investigated. Each platform has unique advantages and limitations; however, all implementations face major challenges with filtering of individual quantum states, scalable integration, deterministic multiplexing of selected quantum emitters, and on-chip excitation suppression. Here we overcome all of these challenges with a hybrid and scalable approach, where single III-V quantum emitters are positioned and deterministically integrated in a complementary metal-oxide-semiconductor-compatible photonic circuit. We demonstrate reconfigurable on-chip single-photon filtering and wavelength division multiplexing with a foot print one million times smaller than similar table-top approaches, while offering excitation suppression of more than 95 dB and efficient routing of single photons over a bandwidth of 40 nm. Our work marks an important step to harvest quantum optical technologies' full potential.Combining different integration platforms on the same chip is currently one of the main challenges for quantum technologies. Here, Elshaari et al. show III-V Quantum Dots embedded in nanowires operating in a CMOS compatible circuit, with controlled on-chip filtering and tunable routing.

  17. A robust and scalable neuromorphic communication system by combining synaptic time multiplexing and MIMO-OFDM.

    Science.gov (United States)

    Srinivasa, Narayan; Zhang, Deying; Grigorian, Beayna

    2014-03-01

    This paper describes a novel architecture for enabling robust and efficient neuromorphic communication. The architecture combines two concepts: 1) synaptic time multiplexing (STM) that trades space for speed of processing to create an intragroup communication approach that is firing rate independent and offers more flexibility in connectivity than cross-bar architectures and 2) a wired multiple input multiple output (MIMO) communication with orthogonal frequency division multiplexing (OFDM) techniques to enable a robust and efficient intergroup communication for neuromorphic systems. The MIMO-OFDM concept for the proposed architecture was analyzed by simulating large-scale spiking neural network architecture. Analysis shows that the neuromorphic system with MIMO-OFDM exhibits robust and efficient communication while operating in real time with a high bit rate. Through combining STM with MIMO-OFDM techniques, the resulting system offers a flexible and scalable connectivity as well as a power and area efficient solution for the implementation of very large-scale spiking neural architectures in hardware.

  18. Transcending Transmission

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Trittin, Hannah

    2013-01-01

    Purpose – Extant research on corporate social responsibility (CSR) communication primarily relies on a transmission model of communication that treats organizations and communication as distinct phenomena. This approach has been criticized for neglecting the formative role of communication...... in the emergence of organizations. This paper seeks to propose to reconceptualize CSR communication by drawing on the “communication constitutes organizations” (CCO) perspective. Design/methodology/approach – This is a conceptual paper that explores the implications of switching from an instrumental...... to a constitutive notion of communication. Findings – The study brings forth four main findings: from the CCO view, organizations are constituted by several, partly dissonant, and potentially contradictory communicative practices. From that viewpoint, the potential impact of CSR communication becomes a matter...

  19. Inclusive bit error rate analysis for coherent optical code-division multiple-access system

    Science.gov (United States)

    Katz, Gilad; Sadot, Dan

    2002-06-01

    Inclusive noise and bit error rate (BER) analysis for optical code-division multiplexing (OCDM) using coherence techniques is presented. The analysis contains crosstalk calculation of the mutual field variance for different number of users. It is shown that the crosstalk noise depends deeply on the receiver integration time, the laser coherence time, and the number of users. In addition, analytical results of the power fluctuation at the received channel due to the data modulation at the rejected channels are presented. The analysis also includes amplified spontaneous emission (ASE)-related noise effects of in-line amplifiers in a long-distance communication link.

  20. Technical activities, 1990: Surface Science Division

    International Nuclear Information System (INIS)

    Powell, C.J.

    1991-05-01

    The report summarizes technical activities and accomplishments of the NIST Surface Science Division during Fiscal Year 1990. Overviews are presented of the Division and of its three constituent groups: Surface Dynamical Processes, Thin Films and Interfaces, and Surface Spectroscopies and Standards. These overviews are followed by reports of selected technical accomplishments during the year. A summary is given of Division outputs and interactions that includes lists of publications, talks, committee assignments, seminars (including both Division seminars and Interface Science seminars arranged through the Division), conferences organized, and a standard reference material certified. Finally, lists are given of Division staff and of guest scientists who have worked in the Division during the past year