WorldWideScience

Sample records for wdm phase-modulated radio-over-fiber

  1. Quality Analysis in Phase Modulated Radio over Fiber in WDM/DWDM Network

    Science.gov (United States)

    Sahoo, S.; Kiran, K. V.; Kumar, V.; Yadav, D.; Barpanda, N. K.; Das, Santos Kumar

    2017-05-01

    There has been increasing demand for connection setup with a higher quality of service (QoS) in WDM/DWDM networks, especially in fields like radio over fiber, where phase modulation affects the link quality. Hence to meet guaranteed QoS in a phase modulated link, the effects of phase modulation on link quality are very much needed. The link quality is termed as quality factor (Q-factor). The primary objective is to use effectively the connections available to optimize the computed number of connections and reduce the blocked connections but at the same time guaranteeing QoS as per client's need. The analysis has been done by taking care of routing and wavelength assignment (RWA) techniques. The performance analysis is presented in terms of blocking probability.

  2. Experimental 2.5-Gb/s QPSK WDM phase-modulated radio-over-fiber link with digital demodulation by a K-means algorithm

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Caballero Jambrina, Antonio

    2010-01-01

    Highest reported bit rate of 2.5 Gb/s for optically phase modulated radio-over-fiber (RoF) link, employing digital coherent detection, is demonstrated. Demodulation of 3$,times,$ 2.5 Gb/s quadrature phase-shift keying modulated wavelength-division-multiplexed RoF channels is achieved after 79 km...... of transmission through deployed fiber. Error-free performance (bit-error rate corresponding to $10^{{-}4}$) is achieved using a digital coherent receiver in combination with a $K$-means algorithm for radio-frequency phase recovery....

  3. Bidirectional hybrid CATV/radio-over-fiber WDM transport system.

    Science.gov (United States)

    Lu, Hai-Han; Peng, Hsiang-Chun; Tsai, Wen-Shing; Lin, Chun-Cheng; Tzeng, Shah-Jye; Lin, Yi-Zsai

    2010-02-01

    A bidirectional hybrid cable antenna television (CATV)/radio-over-fiber (ROF) wavelength-division-multiplexing (WDM) transport system using injection locking technique to suppress the rf power degradation, tunable optical bandpass filter to generate optical single-sideband format for the CATV signal or only one optical sideband format for the ROF one, and photonic crystal fiber to reduce the net dispersion is proposed and demonstrated. Impressive performances of the carrier-to-noise ratio, the composite second-order, the composite triple beat, and the bit error rate were obtained in our proposed systems.

  4. DSP based coherent receiver for phase-modulated radio-over-fiber optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Tafur Monroy, Idelfonso; Peucheret, Christophe

    2008-01-01

    A novel DSP based coherent receiver for phase modulated radio-over-fiber optical links is reported. Using the proposed digital receiver, signal demodulation of 1.25 Gb/s ASK-modulated 10 GHz RF carrier is experimentally demonstrated.......A novel DSP based coherent receiver for phase modulated radio-over-fiber optical links is reported. Using the proposed digital receiver, signal demodulation of 1.25 Gb/s ASK-modulated 10 GHz RF carrier is experimentally demonstrated....

  5. Compact Wireless Access Nodes for WDM Bidirectional Radio-over-Fiber System Based on RSOA

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2009-01-01

    We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact.......We demonstrate a RSOA based WDM radio-over-fiber, bidirectional system for wireless access networks. The multi-functionalities of a RSOA, such as colorless operation, re-modulation and envelope detection, make wireless access nodes more compact....

  6. Performance Evaluation of Digital Coherent Receivers for Phase-Modulated Radio-Over-Fiber Links

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Zibar, Darko; Tafur Monroy, Idelfonso

    2011-01-01

    The performance of optical phase-modulated (PM) radio-over-fiber (RoF) links assisted with coherent detection and digital signal processing (PM-Coh) is analyzed and experimentally demonstrated for next-generation wireless-over-fiber systems. PM-Coh offers high linearity for transparent transport......-bandwidth electronics. Analytical assessment and simulations are used to determine the ultimate performance with respect to laser linewidth, modulation index, and receiver sensitivity. Then, two different scenarios are studied and experimentally demonstrated as an application of PM-Coh links: a high...

  7. Study of converged 60 GHz radio over fiber with WDM-PON access networks

    OpenAIRE

    Shao, Tong

    2012-01-01

    Recently, convergence of 60 GHz radio over fiber (RoF) technique with wavelength division multiplexing (WDM) passive optical networks (PON) has raised great interests because it provides the possibility for simultaneous broadband 60 GHz signal generation and multi-gigabit per second wireline transmission. The objective of the thesis is to study the solutions for converged 60 GHz RoF and WDM-PON technique.In this thesis, we have made the following achievements for RoF technology and the integr...

  8. Photonic downconversion for coherent phase-modulated radio-over-fiber links using free-running local oscillator

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Zibar, Darko; Schäffer, Christian G.

    2011-01-01

    A digital coherent receiver employing photonic downconversion is presented and experimentally demonstrated for phase-modulated radio-over-fiber optical links. Photonic downconversion adds additional advantages to optical phase modulated links by allowing demodulation of signals with RF carrier...... frequencies exceeding the bandwidth of electrical analog-to-digital converter. High spurious-free dynamic range is observed for RF carriers at 5GHz photonically downconverted to 1GHz....

  9. Directly-Modulated VCSELs for 2x2 MIMO-OFDM Radio over Fiber in WDM-PON

    DEFF Research Database (Denmark)

    Binti Othman, Maisara; Deng, Lei; Pang, Xiaodan

    2011-01-01

    We demonstrate directly- modulated VCSELs supporting 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20-km WDM-PON. Error-free signal demodulation of 64-subcarrier 4-QAM signals modulated at 198.5-Mb/s is achieved after fiber and 2-m indoor wireless transmission.......We demonstrate directly- modulated VCSELs supporting 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20-km WDM-PON. Error-free signal demodulation of 64-subcarrier 4-QAM signals modulated at 198.5-Mb/s is achieved after fiber and 2-m indoor wireless transmission....

  10. WDM Phase-Modulated Millimeter-Wave Fiber Systems

    DEFF Research Database (Denmark)

    Yu, Xianbin; Prince, Kamau; Gibbon, Timothy Braidwood

    2012-01-01

    This chapter presents a computer simulation case study of two typical WDM phase-modulated millimeter-wave systems. The phase-modulated 60 GHz fiber multi-channel transmission systems employ single sideband (SSB) and double sideband subcarrier modulation (DSB-SC) schemes and present one...... of the latest research efforts in the rapidly emerging Radio-over-Fiber (RoF) application space for in-house access networks....

  11. Cognitive digital receiver for burst mode phase modulated radio over fiber links

    DEFF Research Database (Denmark)

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

    2010-01-01

    A novel cognitive receiver for modulation format recognition with reconfigurable carrier recovery scheme is proposed and experimentally demonstrated for phase modulated radio-over-fibre links. Demodulation of burst-mode mixed modulation formats (PSK and QAM) is demonstrated after 40km of transmis......A novel cognitive receiver for modulation format recognition with reconfigurable carrier recovery scheme is proposed and experimentally demonstrated for phase modulated radio-over-fibre links. Demodulation of burst-mode mixed modulation formats (PSK and QAM) is demonstrated after 40km...

  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...

  13. Bandpass sampling based digital coherent receiver with free-running local oscillator laser for phase-modulated radio-over-fiber links.

    Science.gov (United States)

    Cao, Minghua; Li, Jianqiang; Dai, Yitang; Yin, Feifei; Xu, Kun

    2014-11-03

    A bandpass sampling based digital coherent receiver is presented for phase modulated radio-over-fiber links with coherent detection. In the scheme, the bandpass sampling technique is introduced in RoF systems to overcome the high sampling rate requirement and front-end hardware dependency of conventional digtal coherent receivers. In particular, the selection rule of bandpass sampling rate was defined by taking into account the frequency offset induced by free-running optical local oscillator. Analytical assessment and simulations are used to determine the ultimate performance in terms of tolerances to ADC bit resolution and laser linewidth. Thereafter, a 40Mbps QPSK modulated data signal at 2.4GHz RF carrier frequency is experimentally demonstrated over the proposed 50.6-km radio-over-fiber link employing bandpass sampling.

  14. Bidirectional Radio-Over-Fiber System With Phase-Modulation Downlink and RF Oscillator-Free Uplink Using a Reflective SOA

    DEFF Research Database (Denmark)

    Yu, Xianbin; Gibbon, Timothy Braidwood; Tafur Monroy, Idelfonso

    2008-01-01

    We propose and demonstrate a bidirectional radio-over-fiber (RoF) system based on a reflective semiconductor optical amplifier (RSOA). In this system, phase-modulated 5.25-GHz radio frequency (RF) carrying 850 Mb/s is used for the downstream signal. Optical envelope detection of 10-GHz RF carryin......-effective. The experimental results indicate that after simultaneous transmission of downstream and upstream signals over 25-km fiber, the receiver sensitivities are -22 and -14.5 dBm, respectively....

  15. Reconfigurable Radio-Over-Fiber Networks [Invited

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2015-01-01

    This paper discusses reconfigurable Radio-over-Fiber networks, including activities in coherent remote access units, silicon photonics for microwave photonics and optical switching.......This paper discusses reconfigurable Radio-over-Fiber networks, including activities in coherent remote access units, silicon photonics for microwave photonics and optical switching....

  16. Reconfigurable Radio-Over-Fiber Networks

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2015-01-01

    This paper discusses reconfigurable Radio-over-Fiber networks, including activities in coherent remote access units, silicon photonics for microwave photonics and optical switching.......This paper discusses reconfigurable Radio-over-Fiber networks, including activities in coherent remote access units, silicon photonics for microwave photonics and optical switching....

  17. A robust optical phase modulated 60 GHz RoF WDM system

    DEFF Research Database (Denmark)

    Yu, Xianbin; Kozuch, Wojciech; Turkiewicz, Jaroslaw

    2010-01-01

    robust 4-channel WDM optical phase modulated 60GHz wireless fiber system is proposed and simulated. In this system, a Fabry-Perot (FP) frequency interleaver is designed to suppress optical carriers for 60GHz signal generation. The simulated results show that this phase modulated WDM system is not...

  18. Upgradable radio-over-fiber transport system

    Science.gov (United States)

    Chang, Ching-Hung; Tu, Liang-Shuo; Huang, Yi-Syuan; Li, Chung-Yi

    2017-10-01

    An upgradable radio-over-fiber (RoF) transport system is proposed based on a vertical-cavity surface-emitting laser (VCSEL)-composed wavelength selector. The passband window of the wavelength selector can be electrically adjusted to select a specific lightwave from multiple injected optical carriers and attenuate the others. By adding the VCSEL-composed wavelength selector installed inside each base station (BS), the proposed transport system can remain as the original tree topology, but its overall network capacity can be flexibly extended (reduced) by adding (removing) an additional optical carrier into (out of) the optical network. Each BS can dynamically receive data from one of the multiple injected optical carriers. This method is useful because the bandwidth requirement of each BS, which is serviced by an RoF transport system, may significantly change with the visitor flow rate. Experimental results prove that the BSs in the proposed upgradable RoF transport system can be reallocated to multiple logical RoF links and can be dynamically switched to receive data from any one of the logical RoF signals without modifying the original network structure. The transmission performances of these optical carriers are ensured by low bit error rate, clear eye, and optical/electrical spectra diagrams.

  19. Digital coherent receiver for phase modulated radio-over-fibre optical links

    DEFF Research Database (Denmark)

    Zibar, Darko; Yu, Xianbin; Peucheret, Christophe

    2009-01-01

    A novel digital signal processing-based coherent receiver for phase-modulated radio-over-fiber (RoF) optical links is presented and demonstrated experimentally. Error-free demodulation of 50-Mbaud binary phase-shift keying (BPSK) and quadrature phase-shift keying data signal modulated on a 5-GHz...... radio-frequency (RF) carrier is experimentally demonstrated using the proposed digital coherent receiver. Additionally, a wavelength-division-multiplexing (WDM) phase-modulated RoF optical link is experimentally demonstrated. A 3 x50 Mb/s WDM transmission of a BPSK modulated 5-GHz RF carrier is achieved...

  20. High Capacity Radio over Fiber Transmission Links

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio

    confirmed that this configuration provides high linear end-to-end transmission links and is capable of transparent transport of high spectral efficient modulation formats. Furthermore, this thesis introduces a novel approach for the generation and detection of high speed wireless signals in mm-wave......This thesis expands the state-of-the-art on the detection of high speed wireless signals using optics. Signal detection at speeds over 1 Gbps at carrier Radio Frequency (RF) ranging from 5 GHz to 100 GHz have been achieved by applying novel concepts on optical digital coherent receivers....... This achievement has satisfied the requirements on transmission robustness and high capacity of next generation hybrid optical fibre-wireless networks. One important contribution of this thesis is the novel concept of photonic downconversion with free-running pulsed laser source for phase modulated Radio...

  1. Next generation wireless communications using radio over fiber

    CERN Document Server

    Gomes, Nathan J; Gameiro, Atilio

    2012-01-01

    Taking a coherent and logical approach, this book describes the potential use of co-ordinated multipoint systems supported by radio over fiber. It covers an impressive breadth of topics, ranging from components, subsystem and system architecture, to network management and business perspectives. The authors show the importance of radio over fiber in eliminating or mitigating against the current, perceived barriers to the use of co-ordinated multipoint, and the drivers for standardisation activities in future mobile/wireless systems over the next few years. The book brings together the

  2. Radio-over-Fiber Transmission Using Vortex Modes

    DEFF Research Database (Denmark)

    Tatarczak, Anna; Lu, Xiaofeng; Rommel, Simon

    2015-01-01

    This paper demonstrates experimentally the distribution of radio-over-fiber (RoF) signals using orbital angular momentum (OAM) of light over standard OM4 multimode fiber (MMF) at 850 nm wavelength. Five independent OAM modes are used to convey RoF signals in the microwave regime showing robust...

  3. Carrierless amplitude phase modulation of VCSEL with 4 bit/s/Hz spectral efficiency for use in WDM-PON

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Wieckowski, Marcin; Pham, Tien Thang

    2011-01-01

    We experimentally demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs. © 2011 Optical Society of America....

  4. Carrierless amplitude phase modulation of VCSEL with 4 bit/s/Hz spectral efficiency for use in WDM-PON.

    Science.gov (United States)

    Rodes, Roberto; Wieckowski, Marcin; Pham, Thang Tien; Jensen, Jesper Bevensee; Turkiewicz, Jarek; Siuzdak, Jerzy; Monroy, Idelfonso Tafur

    2011-12-19

    We experimentally demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs.

  5. On Radio over Fiber for Heterogeneous Wireless Networks

    DEFF Research Database (Denmark)

    Riaz, M. Tahir; Nielsen, Rasmus Hjorth; Pedersen, Jens Myrup

    2009-01-01

    The paper provides an overview of the radio over fiber (RoF) technology and its potential use in heterogeneous wireless networks. Wireless communications have seen a huge growth in the last decade. It has been estimated that five in every six people in the entire world will have a mobile phone...... provisioning - FUTON) based on RoF technology has been introduced. The project adopts centralized processing of radio signals for number of wireless base stations can enhance the network performance in terms of bandwidth, and QoS parameters. The simplified remote access units (RAU) are expected to not only...

  6. Linearization Technologies for Broadband Radio-Over-Fiber Transmission Systems

    Directory of Open Access Journals (Sweden)

    Xiupu Zhang

    2014-11-01

    Full Text Available Linearization technologies that can be used for linearizing RoF transmission are reviewed. Three main linearization methods, i.e. electrical analog linearization, optical linearization, and electrical digital linearization are presented and compared. Analog linearization can be achieved using analog predistortion circuits, and can be used for suppression of odd order nonlinear distortion components, such as third and fifth order. Optical linearization includes mixed-polarization, dual-wavelength, optical channelization and the others, implemented in optical domain, to suppress both even and odd order nonlinear distortion components, such as second and third order. Digital predistortion has been a widely used linearization method for RF power amplifiers. However, digital linearization that requires analog to digital converter is severely limited to hundreds of MHz bandwidth. Instead, analog and optical linearization provide broadband linearization with up to tens of GHz. Therefore, for broadband radio over fiber transmission that can be used for future broadband cloud radio access networks, analog and optical linearization are more appropriate than digital linearization. Generally speaking, both analog and optical linearization are able to improve spur-free dynamic range greater than 10 dB over tens of GHz. In order for current digital linearization to be used for broadband radio over fiber transmission, the reduced linearization complexity and increased linearization bandwidth are required. Moreover, some digital linearization methods in which the complexity can be reduced, such as Hammerstein type, may be more promising and require further investigation.

  7. Heterogeneous radio-over-fiber passive access network architecture to mitigate Rayleigh backscattering interferometric beat noise.

    Science.gov (United States)

    Yeh, C H; Chow, C W

    2011-03-28

    We propose and experimentally demonstrate a hybrid radio-over-fiber (ROF) wavelength division multiplexed and time division multiplexed passive optical network (WDM-TDM PON) architecture to mitigate Rayleigh backscattering (RB) interferometric beat noises. Here, only a single wavelength is needed at the central office (CO) to generate the downstream baseband data for optical wired application and optical millimeter-wave (mm-wave) signal for wireless application. The upstream signal is produced by remodulating the downstream signal. No optical filter is required at the optical network unit/remote antenna unit (ONU/RAU) to separate the optical wired and optical mm-wave signals. In the proposed network, 10 Gb/s differential phase shift keying (DPSK) signal is used for the downstream optical wired application and 2.5 Gb/s on-off keying (OOK) signal on 20 GHz carrier is used for the optical mm-wave signal. In each ONU, a reflective optical semiconductor amplifier (RSOA) is used to remodulate and produce a 2.5 Gb/s OOK format for upstream traffic. As the back-refection produced by the downstream DPSK signal and the upstream OOK signal is traveling in different fiber path, RB noise at the CO can be completely mitigated.

  8. 64-GHz millimeter-wave photonic generation with a feasible radio over fiber system

    Science.gov (United States)

    Al-Dabbagh, Rasha K.; Al-Raweshidy, Hamed S.

    2017-02-01

    A full-duplex radio over fiber (RoF) link with the generation of a 64-GHz millimeter wave (mm-wave) is investigated. This system is proposed as a solution to cope with the demands of a multi-Gb/s data transmission in the fifth generation (5G) and beyond for small cell networks. Cost reduction and performance improvement are achieved by simplifying the mm-wave generation method with an RoF technique. High-frequency radio signals are considered challenging in the electrical generation domain; therefore, our photonic generation method is introduced and examined. RoF design is proposed for mm-wave generation using both phase modulation and the effect of stimulated Brillouin scattering in the optical fiber for the first time. RoF system with transmission rates of 5 Gb/s is successfully achieved. In our scheme, one laser source is utilized and a fiber Bragg grating is used for wavelength reuse for the uplink connection. Stable mm-wave RoF link is successfully achieved in up to a 100-km fiber link length with high quality carrier. Simulation results show a reduction in fiber nonlinearity effects and the mm-wave signal has low noise equal to -75 dBm. This study ensures a practical mm-wave RoF link, and it could be appropriate for small cell 5G networks by reducing the installation cost.

  9. Experimental 2.5 Gbit/s QPSK WDM coherent phase modulated radio-over-fibre link with digital demodulation by a K-means algorithm

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Caballero Jambrina, Antonio; Amaya Fernández, Ferney Orlando

    2009-01-01

    Highest reported bit rate of 2.5 Gbit/s for optically phase modulated radio-over-fibre link employing coherent detection is demonstrated. Demodulation of 3·2.5 Gbit/s QPSK modulated WDM channels, is achieved after 79km of transmission through deployed fiber.......Highest reported bit rate of 2.5 Gbit/s for optically phase modulated radio-over-fibre link employing coherent detection is demonstrated. Demodulation of 3·2.5 Gbit/s QPSK modulated WDM channels, is achieved after 79km of transmission through deployed fiber....

  10. Investigation of Cross-Phase Modulation in WDM Systems with NRZ and RZ Modulation Formats

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2000-01-01

    Our experimental and numerical results show that there is no large difference of XPM-induced intensity interferences between NRZ and RZ format with a duty cycle larger than a certain value in WDM systems of multi-span SMF or TW fibers.......Our experimental and numerical results show that there is no large difference of XPM-induced intensity interferences between NRZ and RZ format with a duty cycle larger than a certain value in WDM systems of multi-span SMF or TW fibers....

  11. 225m Outdoor W-Band Radio-over-Fiber Link Using an Optical SFP+ Module

    DEFF Research Database (Denmark)

    Rommel, Simon; Rodríguez Páez, Juan Sebastián; Chorchos, Łukasz

    2016-01-01

    A W-band radio-over-fiber link based on a commercial SFP+ module is demonstrated, allowing easy integration into existing PON solutions. Without active laser control good RF frequency stability and 225m wireless distance are achieved...

  12. A flexible millimeter-wave radio-over-fiber system for various transmission bit rate

    Science.gov (United States)

    Yang, Tao; Gao, Mingyi; Qian, Jiaqin; Zhang, Junfeng; Chen, Wei

    2017-11-01

    In this paper, we propose a flexible scheme to generate millimeter-waves (MMWs) for millimeter-wave radio-over-fiber (MMW-RoF) system. The proposed scheme has two configurations to adapt to various transmission bit rate by slightly rearranging the allocation of the system. The main structure of the system is cascaded LiNbO3 Mach-Zehnder modulators (LiNbO3-MZMs). The first configuration is cost effective method, where we utilize a wavelength division multiplexing de-multiplexer (WDM Demux) and an optical splitter (OS) to generate two unmodulated optical signals and a modulated optical signal. Each unmodulated optical signal and the modulated signal will form an optical single sideband (OSSB) modulation and therefore we simultaneously achieve a Q-band (45 GHz) and a V-band (60 GHz) MMWs in the receiver. The bit-error-ratio (BER) curves show that the power penalties of 45 GHz and 60 GHz are 0.6 dB and 1.1 dB at a BER of 1 × 10-9 with 2.5 Gb/s transmission data rate and 50 km fiber transmission distances. The second configuration can accommodate high bit rate, where few optical devices is rearranged to only generate a 60 GHz MMW with 40 Gb/s 4 quadrature amplitude modulation orthogonal frequency division multiplexing (4-QAM OFDM) signals. The power penalty is 1.1 dB at a BER of 1 × 10-9 with 50 km fiber transmission distances. Therefore, the proposed scheme can flexibly generate either two Q&V-band MMWs (45 GHz and 60 GHz) for the applications of the low data-rate transmission systems or one V-band MMW (60 GHz) for the applications of the high data-rate transmission systems.

  13. Enabling uncompressed video transmission in double-sideband 60 GHz radio-over-fiber links

    DEFF Research Database (Denmark)

    Lebedev, Alexander; Vegas Olmos, Juan José; Iglesias Olmedo, Miguel

    2012-01-01

    We experimentally investigate the 60 GHz double-sideband radio-over-fiber link. We present the bit error rate performance of the system for HD video transmission in the access architecture and the phase noise measurements for metro-access scenarios.......We experimentally investigate the 60 GHz double-sideband radio-over-fiber link. We present the bit error rate performance of the system for HD video transmission in the access architecture and the phase noise measurements for metro-access scenarios....

  14. Performance Evaluation for DFB and VCSEL-based 60 GHz Radio-over-Fiber System

    DEFF Research Database (Denmark)

    Pang, Xiaodan; Lebedev, Alexander; Vegas Olmos, Juan José

    2013-01-01

    In this paper, we report on a detailed analysis and performance comparison work between 60 GHz radio-over-fiber systems based on a DFB laser and a C-band VCSEL. Coherent photonic up-conversion method is applied for the 60 GHz millimeter-wave signal generation. The generated signals are evaluated...

  15. 15Gbit/s Duobinary Transmission Over a W-Band Radio-over-Fiber Link

    DEFF Research Database (Denmark)

    Rommel, Simon; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2016-01-01

    In this paper the transmission of a 15Gbit/s duobinary signal over a W-band hybrid photonic wireless link is demonstrated experimentally. The radio-over-fiber link consists of 10km SMF and a wireless distance of 50m, utilizing RF carriers at 83–87GHz. Transmission of a 15Gbit/s duobinary signal...

  16. Reconfigurable remote access unit for W-band Radio-over-Fiber transmission

    DEFF Research Database (Denmark)

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

    2016-01-01

    There is a growing demand for cost-effective radio over fibre transmission techniques. In this paper, we propose and realize the reconfigurable remote access unit for radio-over-fiber transmission. The reconfigurable unit is build from the tunable filter and laser as well as remote controller. Su...

  17. Triple-Play and 60-GHz Radio-over-Fiber Techniques for Next-Generation Optical Access Networks

    DEFF Research Database (Denmark)

    Llorente, R.; Walker, S.; Tafur Monroy, Idelfonso

    2011-01-01

    Radio-over-fiber techniques apply to fiber-to-thehome distributions to reach the customer premises with the services to be received with full-standard low-cost equipment. Bi-directional coarse wavelength division multiplexing (CWDM) radio-over-fiber transmission of triple-format full-standard ort...

  18. 15Gbit/s Duobinary Transmission Over a W-Band Radio-over-Fiber Link

    DEFF Research Database (Denmark)

    Rommel, Simon; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

    2016-01-01

    In this paper the transmission of a 15Gbit/s duobinary signal over a W-band hybrid photonic wireless link is demonstrated experimentally. The radio-over-fiber link consists of 10km SMF and a wireless distance of 50m, utilizing RF carriers at 83–87GHz. Transmission of a 15Gbit/s duobinary signal i...... is achieved with a BER of 2.9×10-3, i.e. below the limit for a 7% overhead FEC.......In this paper the transmission of a 15Gbit/s duobinary signal over a W-band hybrid photonic wireless link is demonstrated experimentally. The radio-over-fiber link consists of 10km SMF and a wireless distance of 50m, utilizing RF carriers at 83–87GHz. Transmission of a 15Gbit/s duobinary signal...

  19. Architectures for radio over fiber transmission of high-quality video and data signals

    DEFF Research Database (Denmark)

    Lebedev, Alexander

    In this Ph.D. project, design and performance evaluation of mm-wave radio over fiber links for diverse applications including video transmission are conducted. Major objective of this Thesis is to study performance of video and data signals transmitted in radio over fiber (RoF) setups...... frequency (RF) power fading in a simple intensity modulation-direct detection mm-wave RoF link through introduction of a degree of frequency tunability at the RoF transmitter. We study advanced RoF infrastructures to better suit video transmission. To enable efficient dynamic multicast/broadcast of video...... to designated BSs is evaluated for diverse lightwave generation and data modulation techniques. Mm-wave RoF links employing various lightwave generation techniques are experimentally demonstrated for diversified fiber infractructure including standard single mode fiber, multimode fiber and dispersion shifted...

  20. Mitigation of signal fading in radio over fiber transmission using fiber nonlinearity.

    Science.gov (United States)

    Maeda, Joji; Kusama, Kazutoyo; Fukuchi, Yutaka

    2009-03-16

    Radio over fiber systems in a microwave/millimeter wave band experience a severe signal fading due to fiber dispersion. However, parametric amplification in transmission fibers, known as modulation instability, can compensate for the signal fading. In this paper, we experimentally demonstrate radio over fiber transmission of 111.689 Mbps BPSK signal with a carrier frequency of 10.804 GHz, and measure bit error rates varying the optical transmission power. For the fiber launched power of 0 dBm, we observe a power penalty of 5.8 dB in the transmission over a 25 km fiber, though by increasing the fiber launched power up to +10 dBm, we successfully reduce the power penalty by 1.1 dB. (c) 2009 Optical Society of America

  1. Performance improvement on a MIMO radio-over-fiber system by probabilistic shaping

    Science.gov (United States)

    Kong, Miao; Yu, Jianjun

    2018-01-01

    As we know, probabilistic shaping (PS), as a typical one of modulation format optimization technologies, becomes a promising technology and attracts more and more attention, because of its higher transmission capacity and lower computation complexity. In this paper, we experimentally demonstrated a reliable 8 Gbaud-rate delivery of polarization multiplexed PS 16-QAM single carrier signal in a MIMO radio-over-fiber system with 20-km SMF-28 wire link and 2.5-m wireless link at 60 GHz. The BER performance of PS 16-QAM signals at different baud rate was also evaluated. What is more, PS 16-QAM was also experimentally compared with uniform 16-QAM, and it can be concluded that PS 16-QAM brings a better compromise between effectiveness and reliability performance and a higher capacity than uniform 16-QAM for the radio-over-fiber system.

  2. Effective Design for Optical CDMA Based on Radio over Fiber (RoF Technique

    Directory of Open Access Journals (Sweden)

    Rashidi C. B. M.

    2017-01-01

    Full Text Available In this paper, the performance of OCDMA coding systems utilizing the radio over fiber (RoF technique is presented. It has been done by means of conventional OptiSystem simulation tools, where the propagation of radio signals up to 50 km using standard single mode fiber (SMF was investigated. The analysis was made based on the performance of eye diagram, bit rate, bit error rate and optical received power.

  3. Coverage Range and Cost Comparison of Remote Antenna Unit Designs for Inbuilding Radio over Fiber Technology

    Directory of Open Access Journals (Sweden)

    Razali Ngah

    2013-09-01

    Full Text Available Future communication needs to be ubiquitous, broadband, convergent, and seamless. Radio over fiber (RoF technology is one of the most important enabler in access network for the technologies. Adoption of RoF faces bottleneck in optoelectronics, that they are still expensive, high power consumption, and limited in bandwidth. To solve the problem, transceiver in remote antenna unit (RAU is developed, i.e. electroabsorption transceiver (EAT and asymmetric FabryPerot modulator (AFPM. This paper compares their coverage range and cost in providing WCDMA and WLAN services. Needed gain of RF amplifier for supporting picocell is also discussed.

  4. Radio over fiber for wireless communications from fundamentals to advanced topics

    CERN Document Server

    Fernando, Xavier N

    2014-01-01

    A comprehensive evaluation of Fi-Wi,  enabling readers to design links using channel estimation and equalization algorithms  This book provides a detailed study of radio over fiber (ROF) based wireless communication systems, otherwise called fiber wireless (Fi-Wi) systems. This is an emerging hot topic where the abundant bandwidth of optical fiber is directly combined with the flexibility and mobility of wireless networks to provide broadband connectivity.  Its application is increasing because of the growing demand for broadband wireless services. In such a system the transmission of the ra

  5. Radio-over-fiber technology and devices for 5G: an overview

    Science.gov (United States)

    Iezekiel, Stavros

    2016-02-01

    Radio-over-fiber has received renewed impetus due to various worldwide research initiatives in 5G. Here we will highlight recent developments at the device and integration level that are driving development of systems at various mmwave and sub-THz carriers, such as 30 GHz, 60 GHz and 120 GHz. Various device and circuit technologies will be reviewed in the framework of recent European projects. In addition, we will examine the outlook for monolithic and hybrid integration as a means of meeting size and power consumption requirements in picocell and femtocell applications.

  6. Reconfigurable radio-over-fiber system based on optical switch and tunable filter

    Science.gov (United States)

    Li, Xiao; Yin, Rui; Ji, Wei; Sun, Kai; Zhang, Shicheng

    2017-09-01

    As the best candidate for wireless-access networks, radio-over-fiber (RoF) technology can carry a variety of business. It is necessary to provide differentiated services for different users, so the network needs to produce signals with different modulation formats and different frequencies. A reconfigurable RoF system based on a switch and tunable optical filter that can realize modulation format conversion and multiple frequency signal switching functions is designed. It has a good performance in terms of bit error rate and an eye diagram. The design can help to use radio frequency resources efficiently and make dynamic bandwidth resources controllable.

  7. Experimental demonstration of 24-Gb/s CAP-64QAM radio-over-fiber system over 40-GHz mm-wave fiber-wireless transmission.

    Science.gov (United States)

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

    2013-11-04

    We propose and demonstrate a novel CAP-ROF system based on multi-level carrier-less amplitude and phase modulation (CAP) 64QAM with high spectrum efficiency for mm-wave fiber-wireless transmission. The performance of novel CAP modulation with high order QAM, for the first time, is investigated in the mm-wave fiber-wireless transmission system. One I/Q modulator is used for mm-wave generation and base-band signal modulation based on optical carrier suppression (OCS) and intensity modulation. Finally, we demonstrated a 24-Gb/s CAP-64QAM radio-over-fiber (ROF) system over 40-km stand single-mode-fiber (SMMF) and 1.5-m 38-GHz wireless transmission. The system operation factors are also experimentally investigated.

  8. INFLUENCE OF POLARIZATION MODE DISPERSION ON THE EFFECT OF CROSS-PHASE MODULATION IN INTENSITY MODULATION-DIRECT DETECTION WDM TRANSMISSION SYSTEM

    Directory of Open Access Journals (Sweden)

    M S Islam

    2010-03-01

    Full Text Available Cross-phase modulation (XPM changes the state-of-polarization (SOP of the channels through nonlinear polarization rotation and induces nonlinear time dependent phase shift for polarization components that leads to amplitude modulation of the propagating waves in a wavelength division multiplexing (WDM system. Due to the presence of birefringence, the angle between the SOP changes randomly and as a result polarization mode dispersion (PMD causes XPM modulation amplitude fluctuation random in the perturbed channel. In this paper we analytically determine the probability density function of the random angle between the SOP of pump and probe, and evaluate the impact of polarization mode dispersion on XPM in terms of bit error rate, channel spacing etc for a two channel intensity modulation-direct detection WDM system at 10 Gb/s. It is found that the XPM induced crosstalk is polarization independent for channel spacing greater than 3 nm or PMD coefficient larger than 2 ps/√km. We also investigate the dependence of SOP variance on PMD coefficient and channel spacing.

  9. Radio over fiber link with adaptive order n‐QAM optical phase modulated OFDM and digital coherent detection

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Borkowski, Robert; Guerrero Gonzalez, Neil

    2011-01-01

    Successful digital coherent demodulation of asynchronous optical phase‐modulated adaptive order QAM (4, 16, and 64) orthogonal frequency division multiplexing signals is achieved by a single reconfigurable digital receiver after 78 km of optical deployed fiber transmission.......Successful digital coherent demodulation of asynchronous optical phase‐modulated adaptive order QAM (4, 16, and 64) orthogonal frequency division multiplexing signals is achieved by a single reconfigurable digital receiver after 78 km of optical deployed fiber transmission....

  10. A Review on Radio-Over-Fiber Technology-Based Integrated (Optical/Wireless) Networks

    Science.gov (United States)

    Rajpal, Shivika; Goyal, Rakesh

    2017-06-01

    In the present paper, radio-over-fiber (RoF) technology has been proposed, which is the integration of the optical and radio networks. With a high transmission capacity, comparatively low cost and low attenuation, optical fiber provides an ideal solution for accomplishing the interconnections. In addition, a radio system enables the significant mobility, flexibility and easy access. Therefore, the system integration can meet the increasing demands of subscribers for voice, data and multimedia services that require the access network to support high data rates at any time and any place inexpensively. RoF has the potentiality to the backbone of the wireless access network and it has gained significant momentum in the last decade as a potential last-mile access scheme. This paper gives the comprehensive review of RoF technology used in the communication system. Concept, applications, advantages and limitations of RoF technology are also discussed in this paper.

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

    Directory of Open Access Journals (Sweden)

    Hsu-Chih Cheng

    2013-01-01

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

  12. Direct CATV modulation and phase remodulated radio-over-fiber transport system.

    Science.gov (United States)

    Lin, Wen-Yi; Chang, Ching-Hung; Peng, Peng-Chun; Lu, Hai-Han; Huang, Ching-Hsiu

    2010-05-10

    A novel transport system, with directly modulating community antenna television (CATV) signal downstream and phase-remodulating radio-over-fiber (ROF) signal upstream, is proposed and experimentally demonstrated. By modulating multi-carriers CATV signal in amplitude domain and ROF signal in phase domain, a single optical wavelength is able to serve these two applications simultaneous. To be the first system of communicating CATV signal downstream and phase remodulating radio signal upstream, the performances of transmitting CATV and radio signals over 20 km single-mode fiber (SMF) were experimentally verified. Good performances of carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple beat (CTB) were obtained for CATV applications as well as high extinction ration (ER) and low bit error rate (BER) values were measured for ROF transmission. (c) 2010 Optical Society of America.

  13. Simplified radio-over-fiber transport systems with a low-cost multiband light source.

    Science.gov (United States)

    Chang, Ching-Hung; Peng, Peng-Chun; Lu, Hai-Han; Shih, Chine-Liang; Chen, Hwan-Wen

    2010-12-01

    In this Letter, low-cost radio-over-fiber (ROF) transport systems are proposed and experimentally demonstrated. By utilizing a laser diode (LD) and a local oscillator (LO) to generate coherent multiband optical carriers, as well as a self-composed wavelength selector to separate every two carriers for different ROF transport systems, no any other dedicated LD or electrical frequency upconverting circuit/process is needed in the central station (CS). Compared with current ROF systems, the required numbers of LDs, LOs, and mixers in a CS are significantly reduced. Reducing the number of components not only can simplify the network structure but can also reduce the volume and complexity of the relative logistics. To demonstrate the practice of the proposed ROF transport systems, clear eye diagrams and error-free transmission performance are experimentally presented.

  14. 2 × 2 MIMO radio-over-fiber system at 60 GHz employing frequency domain equalization.

    Science.gov (United States)

    Lin, Chun-Ting; Ng'oma, Anthony; Lee, Wei-Yuan; Wei, Chia-Chien; Wang, Chih-Yun; Lu, Tsung-Hung; Chen, Jyehong; Jiang, Wen-Jr; Ho, Chun-Hung

    2012-01-02

    This work experimentally demonstrates the efficacy of the 2 × 2 multiple-input multiple-output (MIMO) technique for capacity improvement of a 60-GHz radio-over-fiber (RoF) system employing single-carrier modulation format. We employ frequency domain equalization (FDE) to estimate the channel response, including frequency response of the 60 GHz RoF system and the MIMO wireless channel. Using FDE and MIMO techniques, we experimentally demonstrate the doubling the of wireless data capacity of a 60 GHz RoF system to 27.15 Gb/s using 16-QAM modulation format, with transmission over 25 km of standard single-mode fiber and 3 m wireless distance.

  15. Radio-over-fiber linearization with optimized genetic algorithm CPWL model.

    Science.gov (United States)

    Mateo, Carlos; Carro, Pedro L; García-Dúcar, Paloma; De Mingo, Jesús; Salinas, Íñigo

    2017-02-20

    This article proposes an optimized version of a canonical piece-wise-linear (CPWL) digital predistorter in order to enhance the linearity of a radio-over-fiber (RoF) LTE mobile fronthaul. In this work, we propose a threshold allocation optimization process carried out by a genetic algorithm (GA) in order to optimize the CPWL model (GA-CPWL). Firstly, experiments show how the CPWL model outperforms the classical memory polynomial DPD in an intensity modulation/direct detection (IM/DD) RoF link. Then, the GA-CPWL predistorter is compared with the CPWL model in several scenarios, in order to verify that the proposed DPD offers better performance in different optical transmission conditions. Experimental results reveal that with a proper threshold allocation, the GA-CPWL predistorter offers very promising outcomes.

  16. Millimeter-wave and Terahertz Reconfigurable Radio-over-Fiber Systems

    DEFF Research Database (Denmark)

    Vegas Olmos, Juan José

    on photonic technologies enable to generate, transport and radiate in a straight forward manner microwave and millimeter wave signals. Although electronic technologies are able to sustain an increase in frequency from a technology point of view, with current developments hitting the Terahertz regime...... when deploying fiber is not an option. Radio-over-Fiber (RoF) technologies have evolved from a blue sky academic topic in the 90s to a main driver within the current quest for the 5th generation mobile systems (5G). A twist in RoF technologies is that it has found along the way niches in areas non...... purely related to communication technologies (ICT) applications: distribution of highly pure clock signals for radio telescopes, photonic-based coherent radar and fiber optic sensing. It is however in the communication arena where RoF seems to be able to provide a technological edge; RoF techniques based...

  17. Double-locked semiconductor laser for radio-over-fiber uplink transmission.

    Science.gov (United States)

    Cui, Cuicui; Fu, Xuelei; Chan, Sze-Chun

    2009-12-15

    The nonlinear dynamics of an optically injected semiconductor laser are explored for radio-over-fiber uplink transmission. Under optical injection locking, the laser at the base station is operated in the period-one oscillation state, where its intensity oscillates at a tunable microwave frequency. When the oscillation is tuned to the subcarrier frequency, it is further locked by the uplink microwave signal. By simply using an ordinary 2.5-Gbps-grade semiconductor laser, uplink transmission of the phase-shift keying (PSK) signal at a subcarrier of 16 GHz with bit-error rate of less than 10(-11) is demonstrated experimentally. Microwave PSK to optical PSK is achieved at the double-locked laser, which allows all-optical demodulation without any high-speed microwave electronics.

  18. Digital coherent detection of multi-gigabit 40 GHz carrier frequency radio-over-fiber signals using photonic downconversion

    DEFF Research Database (Denmark)

    Caballero Jambrina, Antonio; Zibar, Darko; Tafur Monroy, Idelfonso

    Detection of high speed radio signals is a challenge for next generation radio-over-fiber links, requiring high bandwidth and linearity in the receiver. By using photonic downconversion in a coherent receiver, it is possible to detect signals exceeding the electrical bandwidth of the receiver...

  19. Multi-band radio over fiber system with all-optical halfwave rectification, transmission and frequency down-conversion

    DEFF Research Database (Denmark)

    Prince, Kamau; Tafur Monroy, Idelfonso

    2011-01-01

    We introduce a novel application of all-optical half-wave rectification in the transportation and delivery of multi-frequency radio-over fiber signals. System evaluation was performed of transmission over various optical fiber types and all-optical envelope detection was implemented to achieve...

  20. Tunable microwave photonic duplexer for full-duplex radio-over-fiber access.

    Science.gov (United States)

    Li, Peixuan; Pan, Wei; Zou, Xihua; Yan, Lianshan; Luo, Bin; Lu, Bing

    2017-02-20

    A tunable microwave photonic duplexer (MPD) for full-duplex radio-over-fiber access is proposed and experimentally demonstrated. The proposed MPD is implemented by two single-bandpass microwave photonic filters (MPFs) to separate the transmit (Tx) and receive (Rx) channels. More specifically, a broadband optical source (BOS) is spectrally sliced by a differential-group-delay interferometer (DGDI) and a Mach-Zehnder interferometer (MZI) to form two tunable single-bandpass MPFs with different central frequencies. The two MPFs are used for the Tx and Rx channels, respectively. By adjusting the free spectral ranges (FSRs) of the DGDI and MZI, the central frequencies of the Tx and Rx channels can be tuned independently in a wide frequency range. In the experiments, tunable ranges from 0 to 6.1 GHz for the Tx channel and from 0 to 17 GHz for the Rx channel are achieved. Meanwhile, a high isolation up to 44 dB between the Tx and Rx channels is also obtained. Based on the proposed MPD, the duplex transmission of a 10-MBaud 16-quadrature-amplitude-modulation (QAM) signal at 2.45 GHz and 2.82 GHz is demonstrated.

  1. An experimental study on digital predistortion for radio-over-fiber links

    Science.gov (United States)

    Vieira, Luis C.; Gomes, Nathan J.; Nkansah, Anthony

    2010-12-01

    Radio-over-fiber (RoF) has been proposed as an enabling technology for broadband networks, such as WiMAX and WiFi. Besides the inherent high bandwidth and reliability of RoF systems, they also allow the reduction of installation and maintenance cost of the remote antenna units (RAUs) and improvement in the coverage area of the base station/access point. However, the nonlinear distortion of the optical link, which stems mainly from the laser diode, may impose serious limitations on the system performance, especially when high PAPR, wideband signals are used. Thus, distortion compensation is a key issue in order to facilitate the application of the RoF technology for broadband networks. In this work, digital predistortion for directly modulated RoF links is experimentally investigated. A memory-polynomial- based predistorter model is identified from measurements of the baseband OFDM input-output signals and through the use of an indirect learning architecture. Then, a predistorted signal is generated and fed to the RoF link for comparing its output with that of the non-predistorted one. As a result of this compensation technique, an improvement of the static link linearity and the output constellation diagram has been found, with an EVM reduction of 1.73 %.

  2. Blind post processed nonlinearity mitigation in multiband OFDM radio over fiber optical transmission

    Science.gov (United States)

    Park, Hyoung-Joon; Jung, Sun-Young; Han, Sang-Kook

    2016-02-01

    We propose a blind adaptive post-processing method to reduce nonlinear distortion in multiband radio over fiber (RoF) transmission. Mitigating nonlinear distortion has been a critical challenge to enhance signal quality in RoF system due to analog optical transmission. To keep up with explosive increase in number of mobiles and their data capacity demands, remote antenna unit (RAU) has to be widely and densely distributed with RoF system. Consequently, RAU should be simple and compensation should be fully processed in central office (CO). In optical uplink transmission of RoF system, post-processing of distortion mitigation will be effective. In this paper, we propose post compensation structure constructed by means of Hammerstein equalizer without inserting preamble. Specifically, Hammerstein equalizer, which is separated into linear and nonlinear parts, was used to compensate both linear and nonlinear distortion of RoF system. The filter coefficients were updated adaptively by using LMS algorithm to adjust variable channel environments. In our experiment, multiband OFDM signal, which is LTE standard according to 3GPP, was optically transmitted through RoF channel. Experimental demonstration for the improvement of EVM performance with proposed post-processing was verified.

  3. Chaotic communication in radio-over-fiber transmission based on optoelectronic feedback semiconductor lasers.

    Science.gov (United States)

    Lin, Fan-Yi; Tsai, Meng-Chiao

    2007-01-22

    Performance of chaotic communication in radio-over-fiber (ROF) transmission based on optoelectronic feedback semiconductor lasers is studied numerically. The chaotic carrier is generated by optoelectronic feedback semiconductor lasers, where chaotic communication is realized by synchronizing a receiver laser with a transmitter laser. Transmission quality of different message encoding schemes, including additive chaos modulation (ACM) and on-off shift keying (OOSK), are investigated and compared. In this study, the dispersion and nonlinearity effects in the fiber transmission module and the amplified spontaneous emission noise from the optical amplifiers are considered. In the wireless channel, effects of additive white Gaussian noise, multipath, and path loss are included. To quantitatively study the performance of this chaotic communication system in the ROF transmission, bit-error-rates (BER) of different transmission lengths, message bit-rates, and signal-to-noise ratios are studied. The optimal launched power and message strength that minimize the BER while assuring effective communication security are discussed. While the ACM scheme is shown to perform better in a fiber only configuration, the OOSK scheme shows better immunity to the random effects and waveform distortions presented in the wireless channel.

  4. Next Generation Radio over Fiber Network Management for a Distributed Antenna System

    DEFF Research Database (Denmark)

    Santiago, Carlos; Gangopadhyay, Bodhisattwa; arsenio, Artur

    2009-01-01

    Dette dokument beskriver funktioner og procedurer i futon Radio Over Fiber Manager til at operere med det øvre (net) og nederste (fysiske) lag, der anvendes til transport af trådløse signaler mellem en central enhed (CU) og Remote Antenna Units. Også, det giver nogle mekanismer og procedurer, der...... skal anvendes i tilfælde af fejl, samtidig med at end-to-end service problemløsning og service kvalitetsstyring af Futon Middleware. En oversigt over aktuelle ROF Management-løsninger er i første omgang præsenteres. Det papir, så på nogle af de udfordringer, der i [1], nemlig specifikationen af Radio......-over-Fibre (ROF) leder virksomheden funktioner, der kontrollerer futon optisk infrastruktur definition af interoperabilitet med futon Middleware og Radio Resource Management, og definitionen af ROF Management funktioner, som er tæt korreleret og integreret med radio-og optiske interface, fysiske lag algoritmer på...

  5. Practical demonstration of spectrally efficient FDM millimeter-wave radio over fiber systems for 5G cellular networking

    Science.gov (United States)

    Mikroulis, Spiros; Xu, Tongyang; Darwazeh, Izzat

    2016-02-01

    This work reports the first demonstration of spectrally efficient frequency division multiplexed (SEFDM) signal transmission based on mm-wave radio over fiber (RoF) technology. Such systems aim to satisfy the beyond 4G (5G) demands of low cost, low energy, millimeter-wave carrier frequencies and high spectral efficiency. The proposed radio over fiber topology, using passive optical network (PON) infrastructure and low-cost multimode fiber (MMF), is analyzed and a proof-of-concept SEFDM radio over 250m OM-1 MMF transmission with a 3m 60GHz wireless link is successfully demonstrated. Different systems are demonstrated, at raw data rates up to 3.7 Gb/s, showing SEFDM spectrum saving up to 40% relative to OFDM.

  6. A novel radio over fiber system with DWDM mm-wave generation and wavelength reuse for upstream data connection.

    Science.gov (United States)

    Chen, Lin; Lei, Xiaoyan; Wen, Shuangchun; Yu, Jianguo

    2007-04-30

    We proposed and experimentally demonstrated a novel radio-over-fiber architecture using an electrical mixer and an optical intensity modulator based on double side-band modulation scheme to generate dense wavelength-division multiplexing (DWDM) optical millimeter for carrying downstream data and centralized lightwave for carrying upstream data. Since the remaining optical carriers with high power have been reused, the optical power is effectively utilized; therefore the system cost can be reduced.

  7. SDN based millimetre wave radio over fiber (RoF) network

    Science.gov (United States)

    Amate, Ahmed; Milosavljevic, Milos; Kourtessis, Pandelis; Robinson, Matthew; Senior, John M.

    2015-01-01

    This paper introduces software-defined, millimeter Wave (mm-Wave) networks with Radio over Fiber (RoF) for the delivery of gigabit connectivity required to develop fifth generation (5G) mobile. This network will enable an effective open access system allowing providers to manage and lease the infrastructure to service providers through unbundling new business models. Exploiting the inherited benefits of RoF, complete base station functionalities are centralized at the edges of the metro and aggregation network, leaving remote radio heads (RRHs) with only tunable filtering and amplification. A Software Defined Network (SDN) Central Controller (SCC) is responsible for managing the resource across several mm-Wave Radio Access Networks (RANs) providing a global view of the several network segments. This ensures flexible resource allocation for reduced overall latency and increased throughput. The SDN based mm-Wave RAN also allows for inter edge node communication. Therefore, certain packets can be routed between different RANs supported by the same edge node, reducing latency. System level simulations of the complete network have shown significant improvement of the overall throughput and SINR for wireless users by providing effective resource allocation and coordination among interfering cells. A new Coordinated Multipoint (CoMP) algorithm exploiting the benefits of the SCC global network view for reduced delay in control message exchange is presented, accounting for a minimum packet delay and limited Channel State Information (CSI) in a Long Term Evolution-Advanced (LTE-A), Cloud RAN (CRAN) configuration. The algorithm does not require detailed CSI feedback from UEs but it rather considers UE location (determined by the eNB) as the required parameter. UE throughput in the target sector is represented using a Cumulative Distributive Function (CDF). The drawn characteristics suggest that there is a significant 60% improvement in UE cell edge throughput following the

  8. Differential Service in a Bidirectional Radio-over-Fiber System over a Spectral-Amplitude-Coding OCDMA Network

    Directory of Open Access Journals (Sweden)

    Chao-Chin Yang

    2016-10-01

    Full Text Available A new scheme of radio-over-fiber (RoF network based on spectral-amplitude-coding (SAC optical code division multiple access (OCDMA is herein proposed. Differential service is provided by a power control scheme that classifies users into several classes and assigns each of them with a specific power level. Additionally, the wavelength reuse technique is adapted to support bidirectional transmission and reduce base station (BS cost. Both simulation and numerical results show that significantly differential quality-of-service (QoS in bit-error rate (BER is achieved in both downlink and uplink transmissions.

  9. Integrated Coherent Radio-over-Fiber Units for Millimeter-Wave Wireless Access

    DEFF Research Database (Denmark)

    Stöhr, A.; Babiel, S.; Chuenchom, M.

    2015-01-01

    to provide wireless services within the E-band (60-90 GHz). In detail, GaAs-based single-sideband millimeter-wave Mach-Zehnder modulators, InP-based millimeter-wave photodiodes featuring rectangular waveguide outputs and monolithically integrated low-linewidth tunable laser diodes as well as Si......Ge-based millimeter-wave RF amplifier technology will be reported. In addition, a new coherent optical heterodyne radio-over–fiber scheme is proposed for seamless integration of next generation millimeter-wave wireless access systems into a next generation passive optical network employing dense or even ultra......-dense WDM. We propose and demonstrate novel radio access units (RAU) using coherent optical heterodyne detection for the generation of the millimeter-wave radio signals in the RAUs. The proposed CRoF concept supports the provision of multiple services over a single optical distribution network including...

  10. Cross stratum resources protection in fog-computing-based radio over fiber networks for 5G services

    Science.gov (United States)

    Guo, Shaoyong; Shao, Sujie; Wang, Yao; Yang, Hui

    2017-09-01

    In order to meet the requirement of internet of things (IoT) and 5G, the cloud radio access network is a paradigm which converges all base stations computational resources into a cloud baseband unit (BBU) pool, while the distributed radio frequency signals are collected by remote radio head (RRH). A precondition for centralized processing in the BBU pool is an interconnection fronthaul network with high capacity and low delay. However, it has become more complex and frequent in the interaction between RRH and BBU and resource scheduling among BBUs in cloud. Cloud radio over fiber network has been proposed in our previous work already. In order to overcome the complexity and latency, in this paper, we first present a novel cross stratum resources protection (CSRP) architecture in fog-computing-based radio over fiber networks (F-RoFN) for 5G services. Additionally, a cross stratum protection (CSP) scheme considering the network survivability is introduced in the proposed architecture. The CSRP with CSP scheme can effectively pull the remote processing resource locally to implement the cooperative radio resource management, enhance the responsiveness and resilience to the dynamic end-to-end 5G service demands, and globally optimize optical network, wireless and fog resources. The feasibility and efficiency of the proposed architecture with CSP scheme are verified on our software defined networking testbed in terms of service latency, transmission success rate, resource occupation rate and blocking probability.

  11. 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.

  12. Digital radio-over-fiber system with multi-pulse Manchester encoding-assisted delta-sigma modulation.

    Science.gov (United States)

    Jang, Seunghyun; Park, Bonghyuk; Hong, Songcheol

    2017-04-03

    Two ∆Σ-modulated digital radio-over-fiber (DRoF) transmission systems that employ a multi-pulse Manchester encoder are proposed and experimentally evaluated. With a two-step modulation process comprised of ∆Σ modulation and multi-pulse Manchester encoding, a high frequency replica or image of a ∆Σ-digitized analog communication signal can be transmitted without significant power loss. This is achieved by exploiting the spectral characteristics of the modified Manchester code. For comparative analysis, a conventional ∆Σ-modulation-based DRoF system is also evaluated. Based on the evaluation results, the proposed DRoF systems more significantly improve the reliability and flexibility of the RoF system by providing higher power margins or by making the DRoF system implementation more cost-effective and easier to perform on account of the low-frequency requirement for electronics and optical transceivers.

  13. MIMO-OFDM WDM PON with DM-VCSEL for femtocells application

    DEFF Research Database (Denmark)

    Binti Othman, Maisara; Deng, Lei; Pang, Xiaodan

    2011-01-01

    We report on experimental demonstration of 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20 km WDM-PON with directly modulated (DM) VCSELs for femtocells application. MIMO-OFDM algorithms effectively compensate for impairments in the wireless link. Error-free signal demodulation of 64...

  14. Optically Generated Single Side-Band Radio-over-Fiber Transmission of 60Gbit/s over 50m at W-Band

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Vegas Olmos, Juan José

    2017-01-01

    60 Gbit/s single side-band multi-band CAP radio-over-fiber transmission at W-band is demonstrated. A spectral efficiency of 3.8 bit/s/Hz and bit error rates below 3.8×10-3 are achieved after 50 m wireless transmission.......60 Gbit/s single side-band multi-band CAP radio-over-fiber transmission at W-band is demonstrated. A spectral efficiency of 3.8 bit/s/Hz and bit error rates below 3.8×10-3 are achieved after 50 m wireless transmission....

  15. Performance evaluation of a real time OFDM radio over fiber system at 2.5 GHz using software defined radio SDR

    DEFF Research Database (Denmark)

    David Cepeda, Juan; Rodriguez, Santiago Isaac; Rico-Martinez, Monica

    2017-01-01

    This paper presents the implementation of an OFDM radio over fiber (RoF) system at 2.5 GHz using software defined radio (SDR). In this work, first we present an introduction of the main concepts about radio over fiber and an orthogonal frequency-division multiplexing (OFDM) system at 2.5 GHz......, then we present a comparison of an OFDM RoF system in three scenarios, modifying the wireless distances and the optical fiber distance in order to evaluate the performance of the system taking into account the symbol error rate (SER) vs signal to noise ratio (SNR) curves....

  16. Experimental demonstration of a digital maximum likelihood based feedforward carrier recovery scheme for phase-modulated radio-over-fibre links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Yu, Xianbin

    2008-01-01

    Maximum likelihood based feedforward RF carrier synchronization scheme is proposed for a coherently detected phase-modulated radio-over-fiber link. Error-free demodulation of 100 Mbit/s QPSK modulated signal is experimentally demonstrated after 25 km of fiber transmission.......Maximum likelihood based feedforward RF carrier synchronization scheme is proposed for a coherently detected phase-modulated radio-over-fiber link. Error-free demodulation of 100 Mbit/s QPSK modulated signal is experimentally demonstrated after 25 km of fiber transmission....

  17. 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.

  18. Multi-dimensional crest factor reduction and digital predistortion for multi-band radio-over-fiber links.

    Science.gov (United States)

    Chen, Hao; Li, Jianqiang; Yin, Chunjing; Xu, Kun; Dai, Yitang; Yin, Feifei

    2014-08-25

    A multi-dimensional crest factor reduction (MD-CFR) technique is proposed to improve the performance and efficiency of multi-band radio-over-fiber (RoF) links. Cooperating with multi-dimensional digital predistortion (MD-DPD), MD-CFR increases the performance of both directly-modulated and externally-modulated RoF links, in terms of error vector magnitude (EVM) and adjacent channel power ratio (ACPR). For directly-modulated RoF link, more than 5 dB output ACPR reduction is obtained, output EVMs are reduced from 11.83% and 12.47% to 7.51% and 7.26% for two bands respectively, while only a slight improvement to 11.58% and 10.78% is obtained solely using MD-DPD. Similar results are achieved in externally-modulated RoF link. Given a threshold in EVM or ACPR, the RF power transmit efficiency is also further enhanced.

  19. Experimental demonstration of multi-dimensional resources integration for service provisioning in cloud radio over fiber network

    Science.gov (United States)

    Yang, Hui; Zhang, Jie; Ji, Yuefeng; He, Yongqi; Lee, Young

    2016-07-01

    Cloud radio access network (C-RAN) becomes a promising scenario to accommodate high-performance services with ubiquitous user coverage and real-time cloud computing in 5G area. However, the radio network, optical network and processing unit cloud have been decoupled from each other, so that their resources are controlled independently. Traditional architecture cannot implement the resource optimization and scheduling for the high-level service guarantee due to the communication obstacle among them with the growing number of mobile internet users. In this paper, we report a study on multi-dimensional resources integration (MDRI) for service provisioning in cloud radio over fiber network (C-RoFN). A resources integrated provisioning (RIP) scheme using an auxiliary graph is introduced based on the proposed architecture. The MDRI can enhance the responsiveness to dynamic end-to-end user demands and globally optimize radio frequency, optical network and processing resources effectively to maximize radio coverage. The feasibility of the proposed architecture is experimentally verified on OpenFlow-based enhanced SDN testbed. The performance of RIP scheme under heavy traffic load scenario is also quantitatively evaluated to demonstrate the efficiency of the proposal based on MDRI architecture in terms of resource utilization, path blocking probability, network cost and path provisioning latency, compared with other provisioning schemes.

  20. Performance analysis for IEEE 802.11 distributed coordination function in radio-over-fiber-based distributed antenna systems.

    Science.gov (United States)

    Fan, Yuting; Li, Jianqiang; Xu, Kun; Chen, Hao; Lu, Xun; Dai, Yitang; Yin, Feifei; Ji, Yuefeng; Lin, Jintong

    2013-09-09

    In this paper, we analyze the performance of IEEE 802.11 distributed coordination function in simulcast radio-over-fiber-based distributed antenna systems (RoF-DASs) where multiple remote antenna units (RAUs) are connected to one wireless local-area network (WLAN) access point (AP) with different-length fiber links. We also present an analytical model to evaluate the throughput of the systems in the presence of both the inter-RAU hidden-node problem and fiber-length difference effect. In the model, the unequal delay induced by different fiber length is involved both in the backoff stage and in the calculation of Ts and Tc, which are the period of time when the channel is sensed busy due to a successful transmission or a collision. The throughput performances of WLAN-RoF-DAS in both basic access and request to send/clear to send (RTS/CTS) exchange modes are evaluated with the help of the derived model.

  1. High-throughput and low-latency 60GHz small-cell network architectures over radio-over-fiber technologies

    Science.gov (United States)

    Pleros, N.; Kalfas, G.; Mitsolidou, C.; Vagionas, C.; Tsiokos, D.; Miliou, A.

    2017-01-01

    Future broadband access networks in the 5G framework will need to be bilateral, exploiting both optical and wireless technologies. This paper deals with new approaches and synergies on radio-over-fiber (RoF) technologies and how those can be leveraged to seamlessly converge wireless technology for agility and mobility with passive optical networks (PON)-based backhauling. The proposed convergence paradigm is based upon a holistic network architecture mixing mm-wave wireless access with photonic integration, dynamic capacity allocation and network coding schemes to enable high bandwidth and low-latency fixed and 60GHz wireless personal area communications for gigabit rate per user, proposing and deploying on top a Medium-Transparent MAC (MT-MAC) protocol as a low-latency bandwidth allocation mechanism. We have evaluated alternative network topologies between the central office (CO) and the access point module (APM) for data rates up to 2.5 Gb/s and SC frequencies up to 60 GHz. Optical network coding is demonstrated for SCM-based signaling to enhance bandwidth utilization and facilitate optical-wireless convergence in 5G applications, reporting medium-transparent network coding directly at the physical layer between end-users communicating over a RoF infrastructure. Towards equipping the physical layer with the appropriate agility to support MT-MAC protocols, a monolithic InP-based Remote Antenna Unit optoelectronic PIC interface is shown that ensures control over the optical resource allocation assisting at the same time broadband wireless service. Finally, the MT-MAC protocol is analysed and simulation and analytical theoretical results are presented that are found to be in good agreement confirming latency values lower than 1msec for small- to mid-load conditions.

  2. Enabling technologies for millimeter-wave radio-over-fiber systems in next generation heterogeneous mobile access networks

    Science.gov (United States)

    Zhang, Junwen; Yu, Jianjun; Wang, Jing; Xu, Mu; Cheng, Lin; Lu, Feng; Shen, Shuyi; Yan, Yan; Cho, Hyunwoo; Guidotti, Daniel; Chang, Gee-kung

    2017-01-01

    Fifth-generation (5G) wireless access network promises to support higher access data rate with more than 1,000 times capacity with respect to current long-term evolution (LTE) systems. New radio-access-technologies (RATs) based on higher carrier frequencies to millimeter-wave (MMW) radio-over-fiber, and carrier-aggregation (CA) using multi-band resources are intensively studied to support the high data rate access and effectively use of frequency resources in heterogeneous mobile network (Het-Net). In this paper, we investigate several enabling technologies for MMW RoF systems in 5G Het-Net. Efficient mobile fronthaul (MFH) solutions for 5G centralized radio access network (C-RAN) and beyond are proposed, analyzed and experimentally demonstrated based on the analog scheme. Digital predistortion based on memory polynomial for analog MFH linearization are presented with improved EVM performances and receiver sensitivity. We also propose and experimentally demonstrate a novel inter-/intra- RAT CA scheme for 5G Het- Net. The real-time standard 4G-LTE signal is carrier-aggregated with three broadband 60GHz MMW signals based on proposed optical-domain band-mapping method. RATs based on new waveforms have also been studied here to achieve higher spectral-efficiency (SE) in asynchronous environments. Full-duplex asynchronous quasi-gapless carrier aggregation scheme for MMW ROF inter-/intra-RAT based on the FBMC is also presented with 4G-LTE signals. Compared with OFDM-based signals with large guard-bands, FBMC achieves higher spectral-efficiency with better EVM performance at less received power and smaller guard-bands.

  3. Cost-Efficient DWDM-PON / Mm-Wave Wireless Integration using Coherent Radio-over-Fiber (CRoF)

    DEFF Research Database (Denmark)

    Thakur, Manoj P.; Mikroulis, S.; Renaud, C. C.

    2015-01-01

    This work aims to investigate the performance of millimetre wave (mm-wave) broadband wireless access for seamless integration with the (ultra-dense) WDM infrastructure. By using two uncorrelated lasers, this system concept allows simple implementation that can additionally be improved, if thermal...

  4. 40 Gb/s W-band (75-110 GHz) 16-QAM radio-over-fiber signal generation and its wireless transmission.

    Science.gov (United States)

    Kanno, Atsushi; Inagaki, Keizo; Morohashi, Isao; Sakamoto, Takahide; Kuri, Toshiaki; Hosako, Iwao; Kawanishi, Tetsuya; Yoshida, Yuki; Kitayama, Ken-ichi

    2011-12-12

    The generation of a 40-Gb/s 16-QAM radio-over-fiber (RoF) signal and its demodulation of the wireless signal transmitted over free space of 30 mm in W-band (75-110 GHz) is demonstrated. The 16-QAM signal is generated by a coherent polarization synthesis method using a dual-polarization QPSK modulator. A combination of the simple RoF generation and the versatile digital receiver technique is suitable for the proposed coherent optical/wireless seamless network. © 2011 Optical Society of America

  5. Coding for stable transmission of W-band radio-over-fiber system using direct-beating of two independent lasers.

    Science.gov (United States)

    Yang, L G; Sung, J Y; Chow, C W; Yeh, C H; Cheng, K T; Shi, J W; Pan, C L

    2014-10-20

    We demonstrate experimentally Manchester (MC) coding based W-band (75 - 110 GHz) radio-over-fiber (ROF) system to reduce the low-frequency-components (LFCs) signal distortion generated by two independent low-cost lasers using spectral shaping. Hence, a low-cost and higher performance W-band ROF system is achieved. In this system, direct-beating of two independent low-cost CW lasers without frequency tracking circuit (FTC) is used to generate the millimeter-wave. Approaches, such as delayed self-heterodyne interferometer and heterodyne beating are performed to characterize the optical-beating-interference sub-terahertz signal (OBIS). Furthermore, W-band ROF systems using MC coding and NRZ-OOK are compared and discussed.

  6. Performance Evaluation of Wavelet-Coded OFDM on a 4.9 Gbps W-Band Radio-over-Fiber Link

    DEFF Research Database (Denmark)

    Cavalcante, Lucas Costa Pereira; Rommel, Simon; Dinis, Rui

    2017-01-01

    Future generation mobile communications running on mm-wave frequencies will require great robustness against frequency selective channels. In this work we evaluate the transmission performance of 4.9 Gbps Wavelet-Coded OFDM signals on a 10 km fiber plus 58 m wireless Radio-over-Fiber link using...... a mm-wave radio frequency carrier. The results show that a 2×128 Wavelet-Coded OFDM system achieves a bit-error rate of 1e-4 with nearly 2.5 dB less signal-to-noise ratio than a convolutional coded OFDM system with equivalent spectral efficiency for 8 GHz-wide signals with 512 sub-carriers on a carrier...

  7. Gigabit radio-over-fiber link for converged baseband and millimeter-wave band signal transmission using cascaded injection-locked Fabry-Pérot laser diodes.

    Science.gov (United States)

    Hong, Moon-Ki; Won, Yong-Yuk; Han, Sang-Kook

    2009-05-11

    A novel scheme, for both baseband and millimeter-wave band gigabit data transmission in radio-over-fiber system, is proposed and experimentally demonstrated by using cascaded injection-locked Fabry- Pérot laser diodes. It was able to improve suppression ratio of carrier suppressed signal using the cascaded injection-locking. The suppression ratio improvement of the optical carrier suppressed signal of 20 dB was verified. Applying this mechanism, 60-GHz millimeter-wave carrier of enhanced signal quality could be accomplished. Its peak power and phase noise were obtained as -40 dBm and -103.5 dBm/Hz respectively, which was suitable for 60-GHz data transmission. In addition, a successful bidirectional transmission of 1.25-Gbps wired and wireless data was achieved by adopting remodulation technique using a gain-saturated reflective semiconductor optical amplifier for uplink.

  8. Laser-phase-fluctuation-insensitive offset-frequency-spaced two-tone optical coherent detection scheme and its transmission for radio-over-fiber systems.

    Science.gov (United States)

    Kuri, Toshiaki; Sakamoto, Takahide; Kawanishi, Tetsuya

    2015-09-21

    We propose a new optical coherent detection scheme with a "two-tone" local light, which is also in principle insensitive to the laser phase fluctuation and is assisted by the digital signal processing technique for radio-over-fiber (RoF) systems. The main feature of our proposal is that the frequency separation of the two-tone local light is different from that of the RoF signal, which is called "offset-frequency-spaced" in this paper. First, we explain the principle of our new proposal and experimentally demonstrate the data recovery. Then, the influence of the frequency detuning between photo-detected modulated and unmodulated signals is discussed. Moreover, the transmission performance with an error vector magnitude (EVM) is evaluated for the optical coherent detection of a 10-Gbaud quadrature-phase-shift-keying RoF signal after a 20-km-long standard single-mode fiber transmission.

  9. Converged wireline and wireless access over a 78-km deployed fiber long-reach WDM PON

    DEFF Research Database (Denmark)

    Prince, Kamau; Jensen, Jesper Bevensee; Caballero Jambrina, Antonio

    2009-01-01

    In this letter, we demonstrate a 78.8-km wavelength-division-multiplexing passive optical network supporting converged transport of 21.4-Gb/s nonreturn-to-zero differential quadrature phase-shift keying, optical phase-modulated 5-GHz radio-over-fiber, fiber and air transmission of 3.125-Gb/s pulse...... ultrawideband, and 256-quadratic-amplitude modulation wireless interoperability for microwave access....

  10. Evaluation of selective control information detection scheme in orthogonal frequency division multiplexing-based radio-over-fiber and visible light communication links

    Science.gov (United States)

    Dalarmelina, Carlos A.; Adegbite, Saheed A.; Pereira, Esequiel da V.; Nunes, Reginaldo B.; Rocha, Helder R. O.; Segatto, Marcelo E. V.; Silva, Jair A. L.

    2017-05-01

    Block-level detection is required to decode what may be classified as selective control information (SCI) such as control format indicator in 4G-long-term evolution systems. Using optical orthogonal frequency division multiplexing over radio-over-fiber (RoF) links, we report the experimental evaluation of an SCI detection scheme based on a time-domain correlation (TDC) technique in comparison with the conventional maximum likelihood (ML) approach. When compared with the ML method, it is shown that the TDC method improves detection performance over both 20 and 40 km of standard single mode fiber (SSMF) links. We also report a performance analysis of the TDC scheme in noisy visible light communication channel models after propagation through 40 km of SSMF. Experimental and simulation results confirm that the TDC method is attractive for practical orthogonal frequency division multiplexing-based RoF and fiber-wireless systems. Unlike the ML method, another key benefit of the TDC is that it requires no channel estimation.

  11. Performance of a 60-GHz DCM-OFDM and BPSK-Impulse Ultra-Wideband System with Radio-Over-Fiber and Wireless Transmission Employing a Directly-Modulated VCSEL

    DEFF Research Database (Denmark)

    Beltrán, Marta; Jensen, Jesper Bevensee; Yu, Xianbin

    2011-01-01

    The performance of radio-over-fiber optical transmission employing vertical-cavity surface-emitting lasers (VCSELs), and further wireless transmission, of the two major ultra-wideband (UWB) implementations is reported when operating in the 60-GHz radio band. Performance is evaluated at 1.44 Gbit...... good tolerance to chromatic dispersion due to the chirp characteristics of electro-optical conversion when a directly-modulated VCSEL is employed. The performance comparison indicates that BPSK-IR UWB exhibits better tolerance to optical transmission impairments requiring lower received optical power...

  12. Non-Orthogonal Multiple Access and Carrierless Amplitude Phase Modulation for Flexible Multi-User Provisioning in 5G Mobile Networks

    DEFF Research Database (Denmark)

    Rommel, Simon; Altabas, Jose Antonio; Puerta Ramírez, Rafael

    2017-01-01

    In this paper, a combined non-orthogonal multiple access (NOMA) and multiband carrierless amplitude phase modulation (multiCAP) scheme is proposed for capacity enhancement of and flexible resource provisioning in 5G mobile networks. The proposed scheme is experimentally evaluated over a W......-band millimeter wave radio-over fiber system. The evaluated NOMACAP system consists of six 1.25 GHz multiCAP bands and two NOMA levels with quadrature phase shift keying and can provide an aggregated transmission rate of 30 Gbit/s. The proposed system can dynamically adapt to different user densities and data...

  13. WDM up-conversion employing frequency quadrupling in optical modulator.

    Science.gov (United States)

    Shih, Po-Tsung; Lin, Chun-Ting; Jiang, Wen-Jr; Chen, Jason Jyehong; Huang, Han-Sheng; Chen, Yu-Hung; Peng, Peng-Chun; Chi, Sien

    2009-02-02

    This work presents an optical up-conversion system with frequency quadrupling for wavelength-division-multiplexing (WDM) communication systems using a dual-parallel Mach-Zehnder modulator without optical filtering. Four-channel 1.25-Gb/s wired fiber-to-the-x (FTTx) and wireless radio-over-fiber (RoF) signals are generated and transmitted simultaneously. Moreover, the decline in receiver sensitivities due to Mach-Zehnder modulator bias drifts is also investigated. Receiver power penalties of the 20-GHz up-converted WDM signals and baseband (BB) FTTx signals are less than 1 dB when bias deviation voltage is less the 20% of the half-wave voltage. After transmission over a 50-km SSMF, the receiver power penalties of both the BB and 20-GHz RF OOK signals are less than 1 dB. Notably, 60-GHz optical up-conversion can be achieved using 15-GHz radio frequency (RF) components and equipment.

  14. Generation and transmission of 3 × 3 W-Band multi-input multi-output orthogonal frequency division multiplexing-radio-over-fiber signals using micro-ring resonators.

    Science.gov (United States)

    Alavi, S E; Amiri, I S; Ahmad, H; Supa'at, A S M; Fisal, N

    2014-12-01

    Using the micro-ring resonator (MRR) system, the single and multi-carriers at frequencies of f(1)=192.898, f(2)=192.990, f(3)=193.1, f(4)=193.315, and f(5)=193.537  THz with a free spectral range (FSR) of 92, 110, 215, and 222 GHz, respectively, are generated to be suitable for a radio-over-fiber (RoF) system based on multi-input multi-output (MIMO) with orthogonal frequency division multiplexing (OFDM). Demonstrated are the concepts of all-optical MIMO signal generation and its transmission over a 50 km single mode fiber (SMF) optical link and an up to 3 m wireless link. Sixty-four multi-carriers are used in the all-optical generation of three MIMO W-Band RF signals, where the single carriers (f(3)-f(5)) transport the signals over the RoF link. The bit error rate (BER) of the overall system performance is discussed; thus, the transmission of MIMO signals is feasible for up to an SMF path 50 km long and a wireless distance of 3 m.

  15. 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.

  16. MIMO-OFDM WDM PON with DM-VCSEL for femtocells application.

    Science.gov (United States)

    Othman, M B; Deng, Lei; Pang, Xiaodan; Caminos, J; Kozuch, W; Prince, K; Yu, Xianbin; Jensen, Jesper Bevensee; Monroy, I Tafur

    2011-12-12

    We report on experimental demonstration of 2x2 MIMO-OFDM 5.6-GHz radio over fiber signaling over 20 km WDM-PON with directly modulated (DM) VCSELs for femtocells application. MIMO-OFDM algorithms effectively compensate for impairments in the wireless link. Error-free signal demodulation of 64 subcarrier 4-QAM signals modulated at 198.5 Mb/s net data rate is achieved after fiber and 2 m indoor wireless transmission. We report BER of 7x10(-3) at the receiver for 16-QAM signals modulated at 397 Mb/s after 1 m of wireless transmission. Performance dependence on different wireless transmission path lengths, antenna separation, and number of subcarriers have been investigated. © 2011 Optical Society of America

  17. Investigation of SPM in WDM System with EDFA

    Directory of Open Access Journals (Sweden)

    Tomáš Ivaniga

    2016-12-01

    Full Text Available The article describes a nonlinear phenomenon SPM (Self Phase Modulation, which occurs in the all-optical communications systems. In the 21st century, the WDM (Wavelength Division Multiplex system cannot be created without the software that simulates the system under real conditions. The most important WDM components include the EDFA (Erbium Doped Fiber Amplifier, in which amplification occurs at all wavelengths. The 10 Gbps optical line DWDM (Dense Wavelength Division Multiplex system is created according to the ITU-T.G.694.1, in which the SPM phenomenon is observed.

  18. VCSEL-Based DWDM PON With 4 BIT/S/HZ Spectral Efficiency Using Carrierless Amplitude Phase Modulation

    DEFF Research Database (Denmark)

    Rodes Lopez, Roberto; Wieckowski, Marcin; Pham, Tien Thang

    2011-01-01

    We experimental demonstrate successful performance of VCSEL-based WDM link supporting advanced 16-level carrierless amplitude/phase modulation up to 1.25 Gbps, over 26 km SSMF with spectral efficiency of 4 bit/s/Hz for application in high capacity PONs....

  19. Simultaneous generation of independent wired and 60-GHz wireless signals in an integrated WDM-PON-RoF system based on frequency-sextupling and OCS-DPSK modulation.

    Science.gov (United States)

    Zhang, Liang; Hu, Xiaofeng; Cao, Pan; Chang, Qingjiang; Su, Yikai

    2012-06-18

    We propose a simple and cost-effective scheme to integrate a wavelength division multiplexed-passive optical network (WDM-PON) with a 60-GHz radio-over-fiber (RoF) system. In optical line terminal/central station (OLT/CS), 10-GHz electronic devices and single-drive Mach-Zehnder modulators (MZMs) are used to generate 60-GHz wireless signals based on frequency-sextupling and optical carrier suppression-differential phase shift keying (OCS-DPSK) modulation. By designing a new architecture, only N + 1 single-drive MZMs are required for an N-channel WDM-PON-RoF converged system. The proposed scheme is experimentally demonstrated with 1.25-Gb/s independent wired, wireless and upstream data. Error-free performances are achieved for all these signals after transmission of 25-km single mode fiber (SMF).

  20. An OTDM-To-WDM Converter Using Optical Fourier Transformation

    Directory of Open Access Journals (Sweden)

    Khin Su Myat Min

    2015-08-01

    Full Text Available We demonstrate serial-to-parallel conversion of 40 Gbps optical time division multiplexed OTDM signal to 4x10 Gbps wavelength division-multiplexed WDM individual channels by using Optical Fourier Transformation OFT method. OFT is also called time lens technique and it is implemented by the combination of dispersive fiber and phase modulation. In this research electro-optic phase modulator EOM is used as time lens. As our investigations simulation results and bit error rate BER measurements are expressed.

  1. Influence of Self-Phase Modulation on 8 and 16-Channel DWDM System with NRZ and Miller Coding

    Directory of Open Access Journals (Sweden)

    Tomáš Ivaniga

    2015-06-01

    Full Text Available This article is focused SPM (Self-Phase Modulation, whic affects the signal transmision in fully optical communication systems. With the advent of WDM (Wavelength Division Multiplexing the optical power in optical fiber. For WDM are used weak lasers with 16 or 32 channels. A power of these channels are summed and then we work with the power in fiber about 0.5W which is dangerous for eyes. Therefore for design of the optical network over 10Gbit/s per 1 channel WDM, it is obligation to solve this nonlinear phenomenon. In program package OptSim was created topology 8 and 16- channel DWDM (Dense Wavelenght Division Multiplexing system according to standard ITU-T (International Telecommunication Union-Telecommunication G.694.1 with channel spacing of 25GHz, transmission power of 1 and 15 dBm, with transmision speed of 10Gbit/s and two coding types to see the SPM.

  2. The emerging WDM EPON

    CERN Document Server

    Radivojević, Mirjana

    2017-01-01

    This book proposes dynamic wavelength and bandwidth allocation (DWBA), a hybrid of time-division multiplexing (TDM) and wavelength-division multiplexing (WDM), which offers a solution for service providers faced with multiservice networks. It discusses different models, architectures and implementations and evaluates their performance.

  3. Parametric Amplification, Wavelength Conversion, and Phase Conjugation of a 2.048-Tbit/s WDM PDM 16-QAM Signal

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Gnauck, A. H.

    2015-01-01

    We demonstrate polarization-independent parametric amplification of a 2.048-Tbit/s 8-WDM PDM 16-QAM signal and simultaneous wavelength conversion and phase conjugation in a highly nonlinear fiber. Two high-power continuous-wave pumps with orthogonal polarizations and counter-phase modulation...

  4. Mitigation of nonlinear interference noise introduced by cross-phase modulation in the dual-polarization 16 QAM wavelength-division multiplexing coherent optical system

    Science.gov (United States)

    Zhang, Bo; Liu, Bo; Zhang, Lijia; Xin, Xiangjun; Zhang, Ru; Zhang, Qi; Tian, Feng; Wang, Yongjun; Tian, Qinghua; Rao, Lan; Guo, Yuhan

    2017-05-01

    A complex adaptive equalizer using a least-mean-square (LMS) algorithm is proposed to mitigate the effect of nonlinear interference induced by cross-phase modulation in wavelength-division multiplexing (WDM) coherent optical systems. We show the effect of nonlinear interference is equivalent to slow time-varying intersymbol interference. Simulations of dual-polarization 16 quadrature amplitude modulation (QAM) WDM systems are conducted to test the effectiveness of our proposed compensation method. The consequences show that significant improvement in system performance can be achieved by using the adaptive LMS equalization method.

  5. Dispersion management of holographic grating filter for WDM applications

    Science.gov (United States)

    Han, Seunghoon; Kim, Taesu; Chung, Seunghwan; Lee, Byoungho

    2004-10-01

    We propose a model of a holographic grating (HG) filter for WDM applications and provide a method to control the chromatic dispersion of WDM demultiplexer as one of its specific applications. The general filter characteristics can be described as a correlation between the scattered mode from the HG and the out-coupling optic mode. We note that the HG phase distribution and lens aberration of out-coupling optics provide effective phase modulation for the chromatic dispersion of the filtered output. Also the amplitude distributions of the two modes perform a kind of weighting function (i.e., apodization), which controls the overall filter spectrum. This filter scheme can exploit wavelength dependent diffraction angle transition (i.e., spatial dispersion) and can be used for multi-channel demultiplexer in WDM system. In this case, lens aberrations of the out-coupling optics cause chromatic dispersion problems in each separated channel and among the channels. The problems can be managed by controlling the HG phase distribution so that the overall chromatic dispersion of the demultiplexer can be reduced and managed over the demultiplexed channels. We characterize the chromatic dispersion properties according to the third order lens aberrations and propose methods to control them by using HG phase distribution.

  6. Non-Orthogonal Multiple Access and Carrierless Amplitude Phase Modulation for 5G Mobile Networks

    DEFF Research Database (Denmark)

    Altabas, Jose A.; Rommel, Simon; Puerta Ramírez, Rafael

    2017-01-01

    A combined NOMA and multiCAP scheme is proposed for capacity enhancement of 5G mobile networks and experimentally tested over a W-band millimeter-wave radio-over-fiber system. The evaluated NOMA-CAP system provides an aggregated transmission rate of 30Gbps.......A combined NOMA and multiCAP scheme is proposed for capacity enhancement of 5G mobile networks and experimentally tested over a W-band millimeter-wave radio-over-fiber system. The evaluated NOMA-CAP system provides an aggregated transmission rate of 30Gbps....

  7. Linearization Technologies for Broadband Radio-Over-Fiber Transmission Systems

    OpenAIRE

    Xiupu Zhang; Ran Zhu; Dongyan Shen; Taijun Liu

    2014-01-01

    Linearization technologies that can be used for linearizing RoF transmission are reviewed. Three main linearization methods, i.e. electrical analog linearization, optical linearization, and electrical digital linearization are presented and compared. Analog linearization can be achieved using analog predistortion circuits, and can be used for suppression of odd order nonlinear distortion components, such as third and fifth order. Optical linearization includes mixed-polarization, dual-wavelen...

  8. Handoff Management in Radio over Fiber 60 GHz Indoor Networks

    NARCIS (Netherlands)

    Bien, V.Q.

    2014-01-01

    Because of high data rate multimedia applications such as HD and UHDTV, online games, etc., the future home networks are expected to support short-range gigabit transmission. With the worldwide availability of 5 GHz spectrum at the 60 GHz band, it creates the opportunity for a promising air

  9. Optimizing power efficiency in radio-over-fiber systems

    DEFF Research Database (Denmark)

    Koonen, A. M. J.; Popov, M.; Wessing, Henrik

    2013-01-01

    Fiber-fed radio pico-cells topologies can reduce the overall power consumption of wireless communication networks. Joint optimization of fiber and radio network parts yields an optimum number of pico-cells which minimizes power consumption....

  10. Symmetry, phase modulation and nonlinear waves

    CERN Document Server

    Bridges, Thomas J

    2017-01-01

    Nonlinear waves are pervasive in nature, but are often elusive when they are modelled and analysed. This book develops a natural approach to the problem based on phase modulation. It is both an elaboration of the use of phase modulation for the study of nonlinear waves and a compendium of background results in mathematics, such as Hamiltonian systems, symplectic geometry, conservation laws, Noether theory, Lagrangian field theory and analysis, all of which combine to generate the new theory of phase modulation. While the build-up of theory can be intensive, the resulting emergent partial differential equations are relatively simple. A key outcome of the theory is that the coefficients in the emergent modulation equations are universal and easy to calculate. This book gives several examples of the implications in the theory of fluid mechanics and points to a wide range of new applications.

  11. WDM PONs based on colorless technology

    Science.gov (United States)

    Saliou, Fabienne; Simon, Gael; Chanclou, Philippe; Pizzinat, Anna; Lin, Huafeng; Zhou, Enyu; Xu, Zhiguang

    2015-12-01

    Wavelength Division Multiplexing (WDM) Passive Optical Network (PON) is foreseen to be part of the Next Generation Passive Optical Networks. Business and mobile fronthaul networks already express the need to develop WDM PONs in the access segment. Fixed wavelength transceivers based on Coarse WDM are already available to respond to today's market needs but Dense WDM technologies will be needed and colorless technologies are essential to provide simple and cost-effective WDM PON systems. We propose in this paper to demonstrate the capabilities of a DWDM PON system prototype based on self-seeded RSOAs and designed to transmit CPRI over 60 km of fiber at 2.5 Gbit/s.

  12. Optimization of spectral band utilization in gridless WDM optical network

    Science.gov (United States)

    Martins, Indayara B.; Aldaya, Ivan; Perez-Sanchez, G.; Gallion, Philippe

    2014-02-01

    In this paper, the effects of gridless spectrum allocation in Wavelength Division Multiplexed (WDM) optical networks are examined. The advanced modulation formats and multi-rate transmissions of the signals, which are key parameters in the optical system project, are taken into account. The consumed spectrum, as well as the impact of linear and nonlinear impairments on the signal transmission, are compared to WDM network adopting standard grid and gridless ITU. To analyze the influence of these physical effects, some key network design parameters are monitored and evaluated, such as the guard band size, the signal occupied bandwidth, the laser power and the quality of channels. The applied signal modulation formats were On/Off Keying (OOK), Quadrature Phase Shift keying (QPSK), and Dual Polarization State Phase Modulation (DP-QPSK), whereas the transmission rate per wavelength was varied from 10 Gb/s to 100Ghz. The guard band, signal band, and laser power were swept and the resulted Bit Error Rate (BER) was estimated from the eye-diagram. Analytical calculations and simulations are conducted in order to evaluate the impact of the gridless spectrum allocation on both the spectral consumption and the signal quality of transmission (QoT). Results reveal that a gridless transmission system reduces the spectral consumption while offering an acceptable QoT. This work was carried out with both analytical modeling and numerical calculation using the Optisystem as well as Matlab.

  13. Phase-Modulation Laser Interference Microscopy

    DEFF Research Database (Denmark)

    Brazhe, Alexey; Brazhe, Nadezda; Maximov, G. V.

    2008-01-01

    We describe how phase-modulation laser interference microscopy and wavelet analysis can be applied to noninvasive nonstained visualization and study of the structural and dynamical properties of living cells. We show how phase images of erythrocytes can reveal the difference between various...... erythrocyte forms and stages of hemolysis and how phase images of neurons reveal their complex intracellular structure. Temporal variations of the refractive index are analyzed to detect cellular rhythmic activity on different time scales as well as to uncover interactions between the cellular processes....

  14. Directly Phase-Modulated Light Source

    Science.gov (United States)

    Yuan, Z. L.; Fröhlich, B.; Lucamarini, M.; Roberts, G. L.; Dynes, J. F.; Shields, A. J.

    2016-07-01

    The art of imparting information onto a light wave by optical signal modulation is fundamental to all forms of optical communication. Among many schemes, direct modulation of laser diodes stands out as a simple, robust, and cost-effective method. However, the simultaneous changes in intensity, frequency, and phase have prevented its application in the field of secure quantum communication. Here, we propose and experimentally demonstrate a directly phase-modulated light source which overcomes the main disadvantages associated with direct modulation and is suitable for diverse applications such as coherent communications and quantum cryptography. The source separates the tasks of phase preparation and pulse generation between a pair of semiconductor lasers leading to very pure phase states. Moreover, the cavity-enhanced electro-optic effect enables the first example of subvolt half-wave phase modulation at high signal rates. The source is compact, stable, and versatile, and we show its potential to become the standard transmitter for future quantum communication networks based on attenuated laser pulses.

  15. Directly Phase-Modulated Light Source

    Directory of Open Access Journals (Sweden)

    Z. L. Yuan

    2016-09-01

    Full Text Available The art of imparting information onto a light wave by optical signal modulation is fundamental to all forms of optical communication. Among many schemes, direct modulation of laser diodes stands out as a simple, robust, and cost-effective method. However, the simultaneous changes in intensity, frequency, and phase have prevented its application in the field of secure quantum communication. Here, we propose and experimentally demonstrate a directly phase-modulated light source which overcomes the main disadvantages associated with direct modulation and is suitable for diverse applications such as coherent communications and quantum cryptography. The source separates the tasks of phase preparation and pulse generation between a pair of semiconductor lasers leading to very pure phase states. Moreover, the cavity-enhanced electro-optic effect enables the first example of subvolt half-wave phase modulation at high signal rates. The source is compact, stable, and versatile, and we show its potential to become the standard transmitter for future quantum communication networks based on attenuated laser pulses.

  16. Ultrafast Hierarchical OTDM/WDM Network

    Directory of Open Access Journals (Sweden)

    Hideyuki Sotobayashi

    2003-12-01

    Full Text Available Ultrafast hierarchical OTDM/WDM network is proposed for the future core-network. We review its enabling technologies: C- and L-wavelength-band generation, OTDM-WDM mutual multiplexing format conversions, and ultrafast OTDM wavelengthband conversions.

  17. Institutional Assessment for Effective WDM Implementation ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    In MENA, much work has been advanced on the technical side and through public awareness. Yet,. WDM, though .... Recognition of this rural‐urban distinction is a vitally important conclusion, but not one that can be ..... In many MENA nations, it will not be possible to create a brand new agency with responsibility for. WDM.

  18. Active plasmonics in WDM traffic switching applications

    National Research Council Canada - National Science Library

    Papaioannou, Sotirios; Kalavrouziotis, Dimitrios; Vyrsokinos, Konstantinos; Weeber, Jean-Claude; Hassan, Karim; Markey, Laurent; Dereux, Alain; Kumar, Ashwani; Bozhevolnyi, Sergey I; Baus, Matthias; Tekin, Tolga; Apostolopoulos, Dimitrios; Avramopoulos, Hercules; Pleros, Nikos

    2012-01-01

    .... In this article, we introduce active plasmonics into Wavelength Division Multiplexed (WDM) switching applications, using the smallest TO DLSPP-based Mach-Zehnder interferometric switch reported so far and showing its successful performance in 4×10...

  19. WDM network and multicasting protocol strategies.

    Science.gov (United States)

    Kirci, Pinar; Zaim, Abdul Halim

    2014-01-01

    Optical technology gains extensive attention and ever increasing improvement because of the huge amount of network traffic caused by the growing number of internet users and their rising demands. However, with wavelength division multiplexing (WDM), it is easier to take the advantage of optical networks and optical burst switching (OBS) and to construct WDM networks with low delay rates and better data transparency these technologies are the best choices. Furthermore, multicasting in WDM is an urgent solution for bandwidth-intensive applications. In the paper, a new multicasting protocol with OBS is proposed. The protocol depends on a leaf initiated structure. The network is composed of source, ingress switches, intermediate switches, edge switches, and client nodes. The performance of the protocol is examined with Just Enough Time (JET) and Just In Time (JIT) reservation protocols. Also, the paper involves most of the recent advances about WDM multicasting in optical networks. WDM multicasting in optical networks is given as three common subtitles: Broadcast and-select networks, wavelength-routed networks, and OBS networks. Also, in the paper, multicast routing protocols are briefly summarized and optical burst switched WDM networks are investigated with the proposed multicast schemes.

  20. WDM Network and Multicasting Protocol Strategies

    Directory of Open Access Journals (Sweden)

    Pinar Kirci

    2014-01-01

    Full Text Available Optical technology gains extensive attention and ever increasing improvement because of the huge amount of network traffic caused by the growing number of internet users and their rising demands. However, with wavelength division multiplexing (WDM, it is easier to take the advantage of optical networks and optical burst switching (OBS and to construct WDM networks with low delay rates and better data transparency these technologies are the best choices. Furthermore, multicasting in WDM is an urgent solution for bandwidth-intensive applications. In the paper, a new multicasting protocol with OBS is proposed. The protocol depends on a leaf initiated structure. The network is composed of source, ingress switches, intermediate switches, edge switches, and client nodes. The performance of the protocol is examined with Just Enough Time (JET and Just In Time (JIT reservation protocols. Also, the paper involves most of the recent advances about WDM multicasting in optical networks. WDM multicasting in optical networks is given as three common subtitles: Broadcast and-select networks, wavelength-routed networks, and OBS networks. Also, in the paper, multicast routing protocols are briefly summarized and optical burst switched WDM networks are investigated with the proposed multicast schemes.

  1. Recent progress in WDM passive optical networks

    Science.gov (United States)

    Chung, Y. C.

    2005-11-01

    Recently, FTTH has finally emerged from the R&D stage and became a commercial reality. For example, in Japan, it has been reported that the total number of FTTH subscribers exceeded 1.5 million in 2004. In US, there have been numerous announcements of FTTH deployments by both operating companies and municipalities. It appears that this trend is rapidly spreading all over the world. At present, most of the FTTH deployments utilize TDM PON (such as GPON and EPON). However, WDM PON is beginning to attract significant attention, as Korea started a large-scale field traial this year. In fact, WDM PON has long been considered as an ultimate solution for the access networks due to its large capacity, easy management, network security, and upgradeability. In this paper, we review the current issues in WDM PON and report the relevant technical progresses achieved at KAIST. The subjects to be covered include low-cost WDM light sources (such as spectrum-sliced incoherent light sources and ASE-injected Fabry-Perot lasers), techniques for the delivery of broadcast services in WDM PON, wavelength-tracking technique for the wavelength-selective devices placed at the un-powered remote node, survivable WDM PON architectures, and fault monitoring and localization techniques.

  2. Proposta de rede de interconexão WDM com controle TDM Proposal of WDM interconnection network with TDM control

    Directory of Open Access Journals (Sweden)

    João Angelo Martini

    1999-05-01

    Full Text Available Este artigo apresenta uma proposta de rede de interconexão WDM com controle TDM e discute os princípios da tecnologia WDM. O artigo também classifica as redes de interconexão WDM e discute as arquiteturas de redes de interconexão e os protocolos de controle.This article presents a proposal for a WDM interconnection network with TDM control and discusses principles of WDM technology. It also classifies WDM interconnection networks and discusses interconnection network architectures as well as the protocols for control.

  3. Open-Loop Wide-Bandwidth Phase Modulation Techniques

    Directory of Open Access Journals (Sweden)

    Nitin Nidhi

    2011-01-01

    Full Text Available The ever-increasing growth in the bandwidth of wireless communication channels requires the transmitter to be wide-bandwidth and power-efficient. Polar and outphasing transmitter topologies are two promising candidates for such applications, in future. Both these architectures require a wide-bandwidth phase modulator. Open-loop phase modulation presents a viable solution for achieving wide-bandwidth operation. An overview of prior art and recent approaches for phase modulation is presented in this paper. Phase quantization noise cancellation was recently introduced to lower the out-of-band noise in a digital phase modulator. A detailed analysis on the impact of timing and quantization of the cancellation signal is presented. Noise generated by the transmitter in the receive band frequency poses another challenge for wide-bandwidth transmitter design. Addition of a noise transfer function notch, in a digital phase modulator, to reduce the noise in the receive band during phase modulation is described in this paper.

  4. Working Paper 2: WDM, Poverty & Equity | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Despite the growing practical and policy-level engagement with WDM, there has been little analytical or empirical effort devoted to its potential social implications. Establishing a better foundation for understanding the linkages between WDM and poverty is, therefore, very important. This paper shows that WDM can ...

  5. Low-Complexity Tracking of Laser and Nonlinear Phase Noise in WDM Optical Fiber Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Fehenberger, Tobias; Barletta, Luca

    2015-01-01

    In this paper, the wavelength division multiplexed (WDM) fiber optic channel is considered. It is shown that for ideal distributed Raman amplification (IDRA), the Wiener process model is suitable for the non-linear phase noise due to cross phase modulation from neighboring channels. Based...... on this model, a phase noise tracking algorithm is presented. We approximate the distribution of the phase noise at each time instant by a mixture of Tikhonov distributions, and derive a closed form expression for the posterior probabilities of the input symbols. This reduces the complexity dramatically...... compared to previous trellis-based approaches, which require numerical integration. Further, the proposed method performs very well in low-to-moderate signal-to-noise ratio (SNR), where standard decision directed (DD) methods, especially for high-order modulation, fail. The proposed algorithm does not rely...

  6. THEORETICAL EVALUATION OF NONLINEAR EFFECTS ON OPTICAL WDM NETWORKS WITH VARIOUS FIBER TYPES

    Directory of Open Access Journals (Sweden)

    YASIN M. KARFAA

    2010-09-01

    Full Text Available A theoretical study is carried out to evaluate the performance of an opticalwavelength division multiplexing (WDM network transmission system in the presenceof crosstalk due to optical fiber nonlinearities. The most significant nonlinear effects inthe optical fiber which are Cross-Phase Modulation (XPM, Four-Wave Mixing (FWM,and Stimulated Raman Scattering (SRS are investigated. Four types of optical fiber areincluded in the analysis; these are: single-mode fiber (SMF, dispersion compensationfiber (DCF, non-zero dispersion fiber (NZDF, and non-zero dispersion shifted fiber(NZDSF. The results represent the standard deviation of nonlinearity induced crosstalknoise power due to FWM and SRS, XPM power penalty for SMF, DCF, NZDF, andNZDSF types of fiber, besides the Bit Error Rate (BER for the three nonlinear effectsusing standard fiber type (SMF. It is concluded that three significant fiber nonlinearitiesare making huge limitations against increasing the launched power which is desired,otherwise, lower values of launched power limit network expansion including length,distance, covered areas, and number of users accessing the WDM network, unlesssuitable precautions are taken to neutralize the nonlinear effects. Besides, various fibertypes are not behaving similarly towards network parameters.

  7. Institutional Assessment for Effective WDM Implementation ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    nkhaled

    1 Water demand management (WDM) refers to “any measure that aims to improve the efficiency of water used to achieve ..... demand-side management” and that “this bias for 'ribbon cutting' projects is maintained by political .... with lack of institutional capacity, capability and motivation- barriers that arise mainly from.

  8. Water brief-WDM & wastewater reuse

    International Development Research Centre (IDRC) Digital Library (Canada)

    aalfouns

    Water Demand Management (WDM) is a water management approach that aims to promote water- use efficient, equitable and ... freshwater, wastewater supply is cheap, reliable, and available to farmers on demand allowing them to grow crops they ... Tunisia, there exists 98 water treatment plants, around. 190 million m3 ...

  9. WDM in Courses of Communication Technologies

    Directory of Open Access Journals (Sweden)

    Miloslav Filka

    2008-01-01

    Full Text Available This conference paper shows and demonstrates how modern technologies (such as WDM – Wavelength Division Multiplex were introduced to students of Optical Networks lectured at Brno University of Technology, Faculty of Electrical Engineering and Communication, Dept. of Telecommunications.

  10. Discontinuous conduction mode analysis of phase-modulated series ...

    Indian Academy of Sciences (India)

    Utsab Kundu

    Discontinuous conduction mode (DCM); phase modulation; series resonant converter (SRC); time domain analysis; frequency domain ... tank energy is dissipated in MOSFET on resistances and effective series resistance (ESR) of tank ... quency square/quasi-square wave to excite the resonant tank. The tank comprises two ...

  11. Cross-phase modulational instability in an elliptical birefringent fiber ...

    Indian Academy of Sciences (India)

    We obtain conditions for the occurrence of cross-phase modulational instability in the normal dispersion regime for the coupled higher order nonlinear Schrödinger equation with higher order dispersion and nonlinear terms. Author Affiliations. R Ganapathy1 V C Kuriakose1. Department of Physics, Cochin University of ...

  12. The Wavelength Conversion in WDM Networks

    Directory of Open Access Journals (Sweden)

    Miroslav Bahleda

    2004-01-01

    Full Text Available In this article we deal with a problem of wavelength conversion in WDM networks and with the wavelength conversion impact on throughput of network. The throughput of networks is determined in terms of blocking probability. The optical networks can be built without wavelength conversion or with full or limited wavelength conversion. Different traffic models are designed for different types of wavelength conversions, which describe performance of wavelength conversion. I describe some results of these models.

  13. Demonstration of flexible and reconfigurable WDM multicast scheme supporting downstream emergency multicast communication for WDM optical access network

    Science.gov (United States)

    Li, Ze; Zhang, Min; Wang, Danshi; Cui, Yue

    2017-09-01

    We propose a flexible and reconfigurable wavelength-division multiplexing (WDM) multicast scheme supporting downstream emergency multicast communication for WDM optical access network (WDM-OAN) via a multicast module (MM) based on four-wave mixing (FWM) in a semiconductor optical amplifier. It serves as an emergency measure to dispose of the burst, large bandwidth, and real-time multicast service with fast service provisioning and high resource efficiency. It also plays the role of physical backup in cases of big data migration or network disaster caused by invalid lasers or modulator failures. It provides convenient and reliable multicast service and emergency protection for WDM-OAN without modifying WDM-OAN structure. The strategies of an MM setting at the optical line terminal and remote node are discussed to apply this scheme to passive optical networks and active optical networks, respectively. Utilizing the proposed scheme, we demonstrate a proof-of-concept experiment in which one-to-six/eight 10-Gbps nonreturn-to-zero-differential phase-shift keying WDM multicasts in both strategies are successfully transmitted over single-mode fiber of 20.2 km. One-to-many reconfigurable WDM multicasts dealing with higher data rate and other modulation formats of multicast service are possible through the proposed scheme. It can be applied to different WDM access technologies, e.g., time-wavelength-division multiplexing-OAN and coherent WDM-OAN, and upgraded smoothly.

  14. Hybrid Microoptical WDM Receiver for PON Communication

    Directory of Open Access Journals (Sweden)

    Vitezslav Jerabek

    2012-01-01

    Full Text Available The paper presents the design, simulation and construction results of the wavelength division multiplex (WDM optical hybrid receiver module for the passive optical network (PON. The optical WDM receiver was constructed using system of three micromodules in the new circle topology. The optical micromodule contains multimode fiber pigtail 50/125 µm, VHGT filter with collimation lens and two microwave optoelectronics receiver micromodules (OE receiver micromodules. OE receiver micromodules were designed by use small signal equivalent electrical circuit model and noise model, from which the mathematically solved the transmittance function, which was used for calculation and simulation of the optimal frequency characteristics and signal to noise ratio. For determine the limit frequency of OE receiver micromodule, the transcendent equation with transmittance function was numerically solved. OE receiver micromodule was composed of decollimation lenses and microwave optoelectronics receivers with bandwidth 2,5 GHz and alternatively in SMD technology with bandwidth 1,25 GHz, using the thin layer hybrid technology. WDM receiver use radiation 1490 nm for internet and 1550 nm for digital TV signals download information.

  15. Cavity Voltage Phase Modulation MD blocks 3 and 4

    CERN Document Server

    Mastoridis, T; Butterworth, A; Molendijk, J; Tuckmantel, J

    2013-01-01

    The LHC RF/LLRF system is currently setup for extremely stable RF voltage to minimize transient beam loading effects. The present scheme cannot be extended beyond nominal beam current since the demanded power would push the klystrons to saturation. For beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam (transient beam loading) will not be corrected, but the strong RF feedback and One-Turn Delay feedback will still be active for RF loop and beam stability in physics. To achieve this, the voltage set point should be adapted for each bunch. The goal of these MDs was to test thefirmware version of an iterative algorithm that adjusts the voltage set point to achieve the optimal phase modulation for klystron forward power considerations.

  16. Numerical analysis on RSOD-based phase modulation in OCT

    Science.gov (United States)

    Wang, Ling; Ding, Zhihua; Wang, Kai

    2007-05-01

    Optical coherence tomography (OCT) is an emerging technology for high-resolution bio-medical imaging. The rapid scanning optical delay line (RSOD) has developed basically for depth scanning and dispersion compensation. If the pivot center of the galvamirror in RSOD is offset, phase modulation can be realized, providing a high carrier frequency required for heterodyne detection. However, the size of galvamirror should be increased, leading to lower response for its oscillation and hence a low scanning rate. In this paper we propose to apply a sinusoidal waveform (resonant scan) instead of a triangle waveform (linear scan) to the galvamirror. Numerical analysis on phase modulation by RSOD and successive envelop demodulation under different driving waveform is conducted. We demonstrate that it is possible to improve OCT frame rate by resonant scan without compromising the signal-to-noise performance if complete and accurate envelope demodulation and appropriate signal processing are adopted.

  17. A novel wavelength reused bidirectional RoF-WDM-PON architecture to mitigate reflection and Rayleigh backscattered noise in multi-Gb/s m-QAM OFDM SSB upstream and downstream transmission over a single fiber

    Science.gov (United States)

    Patel, Dhananjay; Dalal, U. D.

    2017-05-01

    A novel m-QAM Orthogonal Frequency Division Multiplexing (OFDM) Single Sideband (SSB) architecture is proposed for centralized light source (CLS) bidirectional Radio over Fiber (RoF) - Wavelength Division Multiplexing (WDM) - Passive Optical Network (PON). In bidirectional transmission with carrier reuse over the single fiber, the Rayleigh Backscattering (RB) noise and reflection (RE) interferences from optical components can seriously deteriorate the transmission performance of the fiber optic systems. These interferometric noises can be mitigated by utilizing the optical modulation schemes at the Optical Line Terminal (OLT) and Optical Network Unit (ONU) such that the spectral overlap between the optical data spectrum and the RB and RE noise is minimum. A mathematical model is developed for the proposed architecture to accurately measure the performance of the transmission system and also to analyze the effect of interferometric noise caused by the RB and RE. The model takes into the account the different modulation schemes employed at the OLT and the ONU using a Mach Zehnder Modulator (MZM), the optical launch power and the bit-rates of the downstream and upstream signals, the gain of the amplifiers at the OLT and the ONU, the RB-RE noise, chromatic dispersion of the single mode fiber and optical filter responses. In addition, the model analyzes all the components of the RB-RE noise such as carrier RB, signal RB, carrier RE and signal RE, thus providing the complete representation of all the physical phenomena involved. An optical m-QAM OFDM SSB signal acts as a test signal to validate the model which provides excellent agreement with simulation results. The SSB modulation technique using the MZM at the OLT and the ONU differs in the data transmission technique that takes place through the first-order higher and the lower optical sideband respectively. This spectral gap between the downstream and upstream signals reduces the effect of Rayleigh backscattering and

  18. Working Paper 2: WDM, Poverty & Equity | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-01-23

    Jan 23, 2012 ... Despite the growing practical and policy-level engagement with WDM, there has been little analytical or empirical effort devoted to its potential social implications. Establishing a better foundation for understanding the linkages between WDM and poverty is, therefore, very important. This paper shows that ...

  19. Working Paper 2: WDM, Poverty & Equity | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Despite the growing practical and policy-level engagement with WDM, there has been little analytical or empirical effort devoted to its potential social implications. Establishing a better foundation for understanding the linkages between WDM and poverty is, therefore, very important.

  20. Programme Code for Projecting of WDM Fiber Optic Sensor Systems

    Directory of Open Access Journals (Sweden)

    R. Probstner

    1993-04-01

    Full Text Available Wavelength division multiplex (WDM offers a potentially powerful technique for use within optical fibre sensor systems. The paper deals with short description of methodology and a programme code for WDM fiber optic sensor system projecting with use of CAD.

  1. A Method and an Apparatus for Generating a Phase-Modulated Wave Front of Electromagnetic Radiation

    DEFF Research Database (Denmark)

    2002-01-01

    The present invention provides a method and a system for generating a phase-modulated wave front. According to the present invention, the spatial phase-modulation is not performed on the different parts of the wave front individually as in known POSLMs. Rather, the spatial phase-modulation of the...

  2. Quality of Context Enhancements and Cost Effective Radio over Fiber Network Planning

    DEFF Research Database (Denmark)

    Shawky, Ahmed Sherif Mahmoud

    In Communication networks today there is an endless quest for increased capacity and improved quality. With wireless systems being now popular worldwide for allowing users and devices to communicate and share information with each other irrespective of their location, the development of sustainable...

  3. On the capacity of radio-over-fiber links at the W-band

    DEFF Research Database (Denmark)

    Cavalcante, Lucas Costa Pereira; Rommel, Simon; Rodríguez Páez, Juan Sebastián

    2016-01-01

    provide a set of trade-off maps in terms of crucial resources on the design of W-band RoF links. The proposed framework offers a unified view for answering how fundamental spectrum resources can be optimally utilized, and how far we are from overcoming the challenge of offering seamless convergence...

  4. Optical and millimeter-wave radio seamless MIMO transmission based on a radio over fiber technology.

    Science.gov (United States)

    Kanno, Atsushi; Kuri, Toshiaki; Hosako, Iwao; Kawanishi, Tetsuya; Yoshida, Yuki; Yasumura, Yoshihiro; Kitayama, Ken-ichi

    2012-12-31

    Multi-input multi-output (MIMO) transmission of two millimeter-wave radio signals seamlessly converted from polarization-division-multiplexed quadrature-phase-shift-keying optical signals is successfully demonstrated, where a radio access unit basically consisting of only optical-to-electrical converters and a radio receiver performs total signal equalization of both the optical and the radio paths and demodulation with digital signal processing (DSP). Orthogonally polarized optical components that are directly converted to two-channel radio components can be demultiplexed and demodulated with high-speed DSP as in optical digital coherent detection. 20-Gbaud optical and radio seamless MIMO transmission provides a total capacity of 74.4 Gb/s with a forward error correction overhead of 7%.

  5. 146-GHz millimeter-wave radio-over-fiber photonic wireless transmission system.

    Science.gov (United States)

    Fice, M J; Rouvalis, E; van Dijk, F; Accard, A; Lelarge, F; Renaud, C C; Carpintero, G; Seeds, A J

    2012-01-16

    We report the experimental implementation of a wireless transmission system with a 146-GHz carrier frequency which is generated by optical heterodyning the two modes from a monolithically integrated quantum dash dual-DFB source. The monolithic structure of the device and the inherent low noise characteristics of quantum dash gain material allow us to demonstrate the transmission of a 1 Gbps ON-OFF keyed data signal with the two wavelengths in a free-running state at 146-GHz carrier wave frequency. The tuning range of the device fully covers the W-band (75 - 110 GHz) and the F-band (90 - 140 GHz).

  6. Network Management System for (FUTON-like) Radio-over-Fiber Infrastructure

    DEFF Research Database (Denmark)

    Santiago, Carlos; Gangopadhyay, Bodhisattwa; Ramkumar, Venkata

    2010-01-01

    operational costs. The RoF Network Manager manages the network equipment on the optical front haul between the Central Unit (CU) and all Remote Antenna Units (RAU)s connected by it, as well as the communication links, while enabling end-to-end service problem resolution and service quality management...... by the FUTON Middleware. Although a significant amount of prior research work can be found in the literature related to RoF, there is still significant lack of technologies concerning RoF networks management. RoF Manager and its sub-systems target to fill such gap, proposing a novel concept in the form...... of Channel Forwarding Table (CFT). RoF Manager follows an autonomous and generic network management framework, designed to be scalable in terms of adding new network elements (NEs). It targets multi-technology, multi-service and multi-vendor NEs in the network using Simple Network Management Protocol (SNMP...

  7. Parallel phase modulation scheme for interferometric gravitational-wave detectors

    OpenAIRE

    Hartman, M.T.; Quetschke, V.; Tanner, D. B.; Reitze, D. H.; Mueller, G.

    2014-01-01

    Advanced LIGO (aLIGO) requires multiple frequency sidebands to disentangle all of the main interferometer’s length signals. This paper presents the results of a risk reduction experiment to produce two sets of frequency sidebands in parallel, avoiding mixed ‘sidebands on sidebands’. Two phase modulation frequencies are applied to separate Electro-Optic Modulators (EOMs), with one EOM in each of the two arms of a Mach-Zehnder interferometer. In this system the Mach-Zehnder’s arm lengths are st...

  8. Wavelength-agnostic WDM-PON System

    DEFF Research Database (Denmark)

    Wagner, Christoph; Eiselt, Michael; Zou, S.

    2016-01-01

    Next-generation WDM-PON solutions for metro and access systems will take advantage of remotely controlled wavelength-tunable ONUs to keep system costs as low as possible. For such a purpose, each ONU signal can be labeled by a pilot tone modulated onto the optical data stream. We report...... on the standardization status of this lowcost system in the new ITU-T G.metro draft recommendation, in the context of autonomous tuning. We also discuss some low-effort implementations of the pilot-tone labels and investigate the impact of these labels on the transmission channels....

  9. Parallel phase modulation scheme for interferometric gravitational-wave detectors.

    Science.gov (United States)

    Hartman, M T; Quetschke, V; Tanner, D B; Reitze, D H; Mueller, G

    2014-11-17

    Advanced LIGO (aLIGO) requires multiple frequency sidebands to disentangle all of the main interferometer's length signals. This paper presents the results of a risk reduction experiment to produce two sets of frequency sidebands in parallel, avoiding mixed 'sidebands on sidebands'. Two phase modulation frequencies are applied to separate Electro-Optic Modulators (EOMs), with one EOM in each of the two arms of a Mach-Zehnder interferometer. In this system the Mach-Zehnder's arm lengths are stabilized to reduce relative intensity noise in the recombined carrier beam by feeding a corrective control signal back to the Rubidium Titanyl Phosphate (RTP) EOM crystals to drive the optical path length difference to zero. This setup's use of the RTP crystals as length actuators provides enough bandwidth in the feedback to meet arm length stability requirements for aLIGO.

  10. Nonlinear optical polymeric waveguide electro-optic phase modulator

    Science.gov (United States)

    Swalen, Jerome D.; Bjorklund, Gary C.; Fleming, William W.; Hung, R. Y.; Jurich, Mark C.; Lee, Victor Y.; Miller, Robert D.; Moerner, William E.; Morichere, D. Y.; Skumanich, Andrew; Smith, Barton A.

    1993-02-01

    Three nonlinear optical polymeric systems based on nonlinear optical chromophores attached as side chains to poly(methyl methacrylate) were synthesized and their nonlinear optical properties measured in thin film form by second harmonic generation and by the electro-optic effect. Also, attenuation of light propagation in optical waveguides and photothermal deflection infrared spectra were measured on these films to aid in selecting the best system for device development. Based on these results, a phase modulator was constructed and with sub- carrier multiplexing the signals from five TV channels were placed on an infrared laser beam as sidebands. After a short transmission through space, these signals were then heterodyne detected and displayed on a TV monitor with good signal to noise and with no crosstalk.

  11. Characterisation of random DFB Raman laser amplifier for WDM transmission

    National Research Council Canada - National Science Library

    Rosa, Paweł; Rizzelli, Giuseppe; Tan, Mingming; Harper, Paul; Ania-Castañόn, Juan Diego

    2015-01-01

    We perform a full numerical characterisation of half-open cavity random DFB Raman fibre laser amplifier schemes for WDM transmission in terms of signal power variation, noise and nonlinear impairments...

  12. Gaussian Process Regression for WDM System Performance Prediction

    DEFF Research Database (Denmark)

    Wass, Jesper; Thrane, Jakob; Piels, Molly

    2017-01-01

    Gaussian process regression is numerically and experimentally investigated to predict the bit error rate of a 24 x 28 CiBd QPSK WDM system. The proposed method produces accurate predictions from multi-dimensional and sparse measurement data....

  13. Export policies for multi-domain WDM networks

    DEFF Research Database (Denmark)

    Manolova, Anna Vasileva; Ruepp, Sarah Renée

    2010-01-01

    We analyze the performance of six export policies for a multi-domain routing protocol in WDM networks. We show that providing many AS-disjoint paths for survivability and load-balancing does not necessarily guarantee the lowest connection blocking......We analyze the performance of six export policies for a multi-domain routing protocol in WDM networks. We show that providing many AS-disjoint paths for survivability and load-balancing does not necessarily guarantee the lowest connection blocking...

  14. WDM-PON Architecture for FTTx Networks

    Science.gov (United States)

    Iannone, E.; Franco, P.; Santoni, S.

    Broadband services for residential users in European countries have until now largely relied on xDSL technologies, while FTTx technologies have been mainly exploited in Asia and North America. The increasing bandwidth demand and the growing penetration of new services are pushing the deployment of optical access networks, and major European operators are now announcing FTTx projects. While FTTH is recognized as the target solution to bring broadband services to residential users, the identification of an FTTx evolutionary path able to seamlessly migrate to FTTH is key to enabling a massive deployment, easing the huge investments needed. WDM-PON architecture is an interesting solution that is able to accommodate the strategic need of building a new fiber-based access infrastructure with the possibility of adapting investments to actual demands and evolving to FTTH without requiring further interventions on fiber infrastructures.

  15. Provision of IR-UWB wireless and baseband wired services over a WDM-PON.

    Science.gov (United States)

    Pan, Shilong; Yao, Jianping

    2011-12-12

    A simple scheme to simultaneously generate an on-off keying or bi-phase modulation (BPM) impulse radio ultra wideband (IR-UWB) signal and a baseband wired signal in the optical domain using a dual-drive modulator is proposed and demonstrated. Although the two signals have spectral overlap in the optical spectrum, they are located at different frequency bands when converted to electrical signals at a photodetector (PD), which can be well separated by an electrical filter. An experiment is carried out. Eye diagrams, electrical spectra and BER measurements show that the co-channel interference between the UWB and the wired signals is small for a single-channel 36-km fiber link to provide 1.25-Gb/s UWB wireless and 1.25-Gb/s baseband wired services. The inter-channel interference is also small and negligible when the link is operated together with two other 1.25 Gb/s baseband wired links, which demonstrates that a conventional WDM-PON can be upgraded to provide additional UWB services without affecting the existing services by modifying the modulators in the center office and inserting UWB antennas in the optical network units. © 2011 Optical Society of America

  16. Ultimate DWDM format in fiber-true bit-parallel solitons on WDM beams

    Science.gov (United States)

    Yeh, C.; Bergman, L. A.

    2000-01-01

    Whether true solitons can exist on WDM beams (and in what form) is a question that is generally unknown. This paper will discuss an answer to this question and a demonstration of the bit-parallel WDM transmission.

  17. Modelling and evaluation of optical WDM transport networks

    Science.gov (United States)

    Wauters, Nico

    1997-10-01

    In this PhD thesis optical WDM transport networks are investigated that use novel optical components to transmit simultaneously multiple datasignals using WDM and which route in their nodes incoming datasignals to one of the outlet fibers without converting these signals to the electrical domain. The goal of the thesis is twofold. On the one hand developing new models that lead to a classification of components, nodes, network architectures and network management techniques such as monitoring and signalling. On the other hand to investigate to which extent wavelength convertors are required for an optimal use of the available wavelength channels. At the same time the tuneability of the WDM terminal multiplexers is questioned. Part 1 gives a general introduction to optical transmission and network techniques by an extensive study of the literature and a limited market survey. In part 2 we propose a number of new models to represent WDM networks and their main building blocks. This leads to a black box model and a classification of all the OXC architectures. Secondly we extend the G.803 layer structure with new layers allowing the representation of hybrid WDM and SDH networks. Finally the model is used to classify different signalling and monitoring options that can be followed. In part 3 we investigate the requirement of wavelength convertors and the tuneability of the WDM terminal multiplexers. The main conclusion of this part is that wavelength translation is not a conditio sine qua non to achieve low blocking probabilities. This contrasts to the much larger difference that appeared between WPa and WPb and which allowed us to conclude that tuneability of the WDM terminal multiplexers is thoroughly required. We do not want to disregard other consequences of not using wavelength convertors in the network as e.g., simplified wavelength management in networks with wavelength convertors and the regeneration capabilities of new all- optical wavelength conversion devices.

  18. Polarization states encoded by phase modulation for high bit rate quantum key distribution

    Science.gov (United States)

    Liu, Xiaobao; Tang, Zhilie; Liao, Changjun; Lu, Yiqun; Zhao, Feng; Liu, Songhao

    2006-10-01

    We present implementation of quantum cryptography with polarization code by wave-guide type phase modulator. At four different low input voltages of the phase modulator, coder encodes pulses into four different polarization states, 45°, 135° linearly polarized or right, left circle polarized, while the decoder serves as the complementary polarizers.

  19. Experimental Determination of the Hamiltonian for Synchrotron Motion with RF Phase Modulation

    Energy Technology Data Exchange (ETDEWEB)

    Minty, Michiko

    2003-07-11

    Synchrotron motion with rf phase modulation was studied experimentally. Poincare maps in the resonant processing frame were obtained from the experimental data and compared with the tori of the resonant Hamiltonian. The experimental data revealed island structure in longitudinal phase space. Experimental results for synchrotron motion excited by phase modulation at the third harmonic of the synchrotron frequency are also reported.

  20. Proposta de rede de interconexão WDM com controle TDM

    Directory of Open Access Journals (Sweden)

    João Angelo Martini

    1999-05-01

    Full Text Available Este artigo apresenta uma proposta de rede de interconexão WDM com controle TDM e discute os princípios da tecnologia WDM. O artigo também classifica as redes de interconexão WDM e discute as arquiteturas de redes de interconexão e os protocolos de controle.

  1. An extended differentiated optical services model for WDM optical networks

    Science.gov (United States)

    Ouyang, Yong; Zeng, Qingji; Wei, Wei

    2004-04-01

    The need to provide QoS-guaranteed services in the WDM optical networks is becoming increasingly important because of a variety of candidate client networks (e.g., IP, ATM, SONET/SDH) and the requirement for QoS-delivery within the transport layers. This article addresses the QoS problem and presents a framework of QoS provisioning in the WDM optical network. We first characterize the QoS problem in the WDM optical network by comparing with that in the traditional networks. Then we propose a QoS service model in the optical domain called extended differentiated optical services (E-DoS) model based on a set of optical parameters that captures the quality, the reliability and the priority of an optical connection. Each component of the E-DoS model has been analyzed in detail in this article.

  2. Impact of transmission parameters on Nyquist WDM system

    Science.gov (United States)

    Kowalczyk, Agnieszka; Perlicki, Krzysztof

    2015-09-01

    In this paper the analysis of the transmission quality in Nyquist WDM transport system is presented. Results are presented of a system simulation carried out for different modulation format, symbol rates, channel spacing and filter characteristics of the transmitter and receiver. This paper also contains the comparison between results obtained for the N-WDM (Nyquist Wavelength Division Multiplexing) and DWDM (Dense Wavelength Division Multiplexing) system. Two quality indicators are taken into consideration: interchannel crosstalk and symbol error rate for both different system configurations.

  3. 100G WDM Transmission over 100 meter Multimode Fiber

    DEFF Research Database (Denmark)

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

    We present a comparative performance analysis for wavelength-grid selection in WDM shortrange multimode-fibers. We study 100Gbps links over OM2, OM3 and OM4 fibers and show it is feasible to reach over 100 m transmission distances.......We present a comparative performance analysis for wavelength-grid selection in WDM shortrange multimode-fibers. We study 100Gbps links over OM2, OM3 and OM4 fibers and show it is feasible to reach over 100 m transmission distances....

  4. Measurement of radio-frequency temporal phase modulation using spectral interferometry

    Science.gov (United States)

    Jachura, Michał; Szczepanek, Jan; Wasilewski, Wojciech; Karpiński, Michał

    2018-02-01

    We present an optical method to measure radio-frequency electro-optic phase modulation profiles by employing spectrum-to-time mapping realized by highly chirped optical pulses. We directly characterize temporal phase modulation profiles of up to 12.5 GHz bandwidth, with temporal resolution comparable to high-end electronic oscilloscopes. The presented optical setup is a valuable tool for direct characterization of complex temporal electro-optic phase modulation profiles, which is indispensable for practical realization of deterministic spectral-temporal reshaping of quantum light pulses.

  5. Advanced integrated WDM system for POF communication

    Science.gov (United States)

    Haupt, M.; Fischer, U. H. P.

    2009-01-01

    Polymer Optical Fibres (POFs) show clear advantages compared to copper and glass fibres. In essence, POFs are inexpensive, space-saving and not susceptible to electromagnetic interference. Thus, the usage of POFs have become a reasonable alternative in short distance data communication. Today, POFs are applied in a wide number of applications due to these specific advantages. These applications include automotive communication systems and in-house-networks. State-of-the-art is to transmit data with only one channel over POF, this limits the bandwidth. To solve this problem, an integrated MUX/DEMUX-element for WDM over POF is designed and developed to use multiple channels. This integration leads to low costs, therefore this component is suitable for mass market applications. The fundamental idea is to separate the chromatic parts of the light in its monochromatic components by means of a grating based on an aspheric mirror. Due to the high NA of the POF the setup has to be designed in a 3D-approach. Therefore this setup cannot be compared with the planar solutions available on market, they would result high losses in the 3rd dimension. To achieve a fast and optimized design an optical simulation program is used. Particular attention has to be paid to the design of the POF as a light source in the simulation program and the optimisation of the grating. The following realization of the demultiplexer is planed to be done with injection molding. This technology offers easy and very economical processing. These advantages make this technology first choice for optical components in the low-cost array.

  6. Evaluation of correlated digital back propagation and extended Kalman filtering for non-linear mitigation in PM-16-QAM WDM systems

    Science.gov (United States)

    Pakala, Lalitha; Schmauss, Bernhard

    2017-01-01

    We investigate the individual and combined performance of correlated digital back propagation (CDBP) and extended Kalman filtering (EKF) in mitigating inter and intra-channel non-linearities in wavelength division multiplexed (WDM) systems. The afore-mentioned algorithms are verified through numerical simulations on 28 Gbaud polarization multiplexed (PM) 16-quadrature amplitude modulation (16-QAM) 9-channel WDM system with 50 GHz spacing. A single channel CDBP with one-step-per-span based on asymmetric split step Fourier method (A-SSFM) with optimized non-linear coefficient has been employed. We also study an amplitude dependent optimization (AO) of the non-linear coefficient for CDBP which shows an improvement of ≍ 0.8 dB compared to the conventional optimized CDBP, in the non-linear regime. Moreover, our proposed carrier phase and amplitude noise estimation (CPANE) algorithm based on EKF outperforms AO-CDBP in both linear and non-linear regimes with an enhanced performance besides significantly reduced complexity. We further investigate the combined performance of AO-CDBP and EKF which results in an enhanced non-linear tolerance at the expense of increased computational cost trading off to the number of required CDBP steps per span. Furthermore, we also analyze the impact of cross phase modulation (XPM) on the combined performance of AO-CDBP and EKF by varying the number of WDM channels. Numerical results show that the obtained gain from employing AO-CDBP prior to EKF reduces with increasing effects of XPM. Additionally, we also discuss the computational complexity of the aforementioned algorithms.

  7. Asymmetrically pumped Bragg scattering with the effects of nonlinear phase modulation

    DEFF Research Database (Denmark)

    Andersen, Lasse Mejling; Friis, Søren Michael Mørk; Reddy, Dileep V.

    2014-01-01

    We derive exact solutions to asymmetrically pumped Bragg scattering with nonlinear phase-modulation (NPM) and show that this setup allows for the frequency conversion of many temporal modes, while reducing the effects due to NPM....

  8. Widely Tunable Terahertz Phase Modulation with Gate-Controlled Graphene Metasurfaces

    Directory of Open Access Journals (Sweden)

    Ziqi Miao

    2015-11-01

    Full Text Available As the basis of a diverse set of photonic applications, such as hologram imaging, polarization, and wave front manipulation, the local phase control of electromagnetic waves is fundamental in photonic research. However, currently available bulky, passive, range-limited phase modulators pose an obstacle in photonic applications. Here, we propose a new mechanism to achieve a wide phase modulation range, with graphene used as a tunable loss to drive an underdamped to overdamped resonator transition. Based on this mechanism, we present widely tunable phase modulation in the terahertz regime, realized in gate-tuned ultrathin reflective graphene metasurfaces. A one-port resonator model, supported by full-wave simulations, explains the underlying physics of the discovered extreme phase modulation and indicates general strategies for designing tunable photonic devices. As an example, we demonstrate a gate-tunable terahertz (THz polarization modulator with a graphene metasurface. Our findings establish the possibility for photonic applications based on active phase manipulation.

  9. Waveguide Phase Modulator for Integrated Planar Lightwave Circuits in KTP Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I effort proposes the development of a potassium titanyl phosphate (KTP) waveguide phase modulator for future integration into a Planar Lightwave...

  10. Characterisation of random DFB Raman laser amplifier for WDM transmission

    OpenAIRE

    Rosa, Paweł; Rizzelli, Giuseppe; Tan, Mingming; Harper, Paul; Ania-Castañón, Juan Diego

    2015-01-01

    We perform a full numerical characterisation of half-open cavity random DFB Raman fibre laser amplifier schemes for WDM transmission in terms of signal power variation, noise and nonlinear impairments, showcasing the excellent potential of this scheme to provide amplification for DWDM transmission with very low gain variation. © 2015 Optical Society of America

  11. Mode-Locked Laser Arrays for WDM Applications

    Science.gov (United States)

    Forouhar, S.

    1997-01-01

    Colliding pulse mode-locked laser arrays are being developed at 20 GHz for WDM applications. Arrays with 5 wavelengths in the EDFA gain bandwidth have already been demonstrated, with the final goal being a packaged, 10 wavelength mode-locked laser array.

  12. Temporal Probabilistic Constellation Shaping for WDM Optical Communication Systems

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Forchhammer, Søren

    2016-01-01

    Finite state machine sources transmitting QPSK are studied as input to WDM optical fiber systems with ideal distributed Raman amplification. The probabilities of successive constellation symbols are shaped for nonlinear transmission and gains of around 500km (5-10%) are demonstrated...

  13. POLICY BRIEF 1 - WDM Criteria | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-01-18

    Jan 18, 2012 ... ... of technology, it is about managing and moderating our demands for good quality fresh water. It is less a matter of piping and pumps and more a tool for changing the ways we use water and the rates at which we use it. In practice, WDM comes down to three key goals: efficiency, equity and sustainability.

  14. Mitigation of inter-channel nonlinear interference in WDM systems

    CERN Document Server

    Dar, Ronen; Feder, Meir; Mecozzi, Antonio; Shtaif, Mark

    2014-01-01

    We demonstrate mitigation of inter-channel nonlinear interference noise (NLIN) in WDM systems for several amplification schemes. Using a practical decision directed recursive least-squares algorithm, we take advantage of the temporal correlations of NLIN to achieve a notable improvement in system performance.

  15. Characterisation of random DFB Raman laser amplifier for WDM transmission.

    Science.gov (United States)

    Rosa, Paweł; Rizzelli, Giuseppe; Tan, Mingming; Harper, Paul; Ania-Castañόn, Juan Diego

    2015-11-02

    We perform a full numerical characterisation of half-open cavity random DFB Raman fibre laser amplifier schemes for WDM transmission in terms of signal power variation, noise and nonlinear impairments, showcasing the excellent potential of this scheme to provide amplification for DWDM transmission with very low gain variation.

  16. POLICY BRIEF 1 - WDM Criteria | CRDI - Centre de recherches pour ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    18 janv. 2012 ... Water demand management ― WDM ― can be hard to define. More an issue of policy than of technology, it is about managing and moderating our demands for good quality fresh water. It is less a matter of piping and pumps and more a tool for changing the ways we use water and the rates at which we ...

  17. Flexible Transport Network Expansion via Open WDM Interfaces

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Skjoldstrup, Bjarke

    2013-01-01

    This paper presents a successful test-bed implementation of a multi-vendor transport network interconnection via open WDM interfaces. The concept of applying Alien Wavelengths (AWs) for network expansion was successfully illustrated via deployment of multi-domain/multi-vendor end-to-end OTN...

  18. Protocol and networking design issues for local access WDM networks

    NARCIS (Netherlands)

    Salvador, M.R.; Heemstra de Groot, S.M.; Niemegeers, I.G.M.M.

    This report gives an overview of some of the protocol and networking design issues that have been addressed in Flamingo, a major ongoing project which investigates the use of WDM optical technology in local access networks. Quality of service delivery and wavelength assignment are focused on in this

  19. Network Architecture of a Packet-switched WDM

    NARCIS (Netherlands)

    Dey, D.; Koonen, A.M.J.; Salvador, M.R.

    2000-01-01

    We propose a packet-switched WDM slotted ring network with destination release. The total bandwidth of each channel is divided into a fixed number of equal-sized slots. The nodes are equipped with fixed transmitters and tunable receivers. Control information, which is transmitted on a specific

  20. Spectral Compression of Intense Femtosecond Pulses by Self Phase Modulation in Silica Glass

    DEFF Research Database (Denmark)

    Iwaszczuk, Krzysztof; Zhou, Binbin; Bache, Morten

    2012-01-01

    We experimentally demonstrate spectral compression of mJ fs pulses by self phase modulation in silica glass. Spectral narrowing by factor 2.4 of near-transform-limited pulses is shown, with good agreement between experiment and numerical simulation.......We experimentally demonstrate spectral compression of mJ fs pulses by self phase modulation in silica glass. Spectral narrowing by factor 2.4 of near-transform-limited pulses is shown, with good agreement between experiment and numerical simulation....

  1. Brillouin suppression in a fiber optical parametric amplifier by combining temperature distribution and phase modulation

    DEFF Research Database (Denmark)

    Lorenzen, Michael Rodas; Noordegraaf, Danny; Nielsen, Carsten Vandel

    2008-01-01

    We demonstrate an increased gain in optical parametric amplier through suppression of stimulated Brillouin scattering by applying a temperature distribution along the fiber resulting in a reduction of the required phase modulation.......We demonstrate an increased gain in optical parametric amplier through suppression of stimulated Brillouin scattering by applying a temperature distribution along the fiber resulting in a reduction of the required phase modulation....

  2. Independent slab-phase modulation combined with parallel imaging in bilateral breast MRI.

    Science.gov (United States)

    Han, Misung; Beatty, Philip J; Daniel, Bruce L; Hargreaves, Brian A

    2009-11-01

    Independent slab-phase modulation allows three-dimensional imaging of multiple volumes without encoding the space between volumes, thus reducing scan time. Parallel imaging further accelerates data acquisition by exploiting coil sensitivity differences between volumes. This work compared bilateral breast image quality from self-calibrated parallel imaging reconstruction methods such as modified sensitivity encoding, generalized autocalibrating partially parallel acquisitions and autocalibrated reconstruction for Cartesian sampling (ARC) for data with and without slab-phase modulation. A study showed an improvement of image quality by incorporating slab-phase modulation. Geometry factors measured from phantom images were more homogenous and lower on average when slab-phase modulation was used for both mSENSE and GRAPPA reconstructions. The resulting improved signal-to-noise ratio (SNR) was validated for in vivo images as well using ARC instead of GRAPPA, illustrating average SNR efficiency increases in mSENSE by 5% and ARC by 8% based on region of interest analysis. Furthermore, aliasing artifacts from mSENSE reconstruction were reduced when slab-phase modulation was used. Overall, slab-phase modulation with parallel imaging improved image quality and efficiency for 3D bilateral breast imaging. (c) 2009 Wiley-Liss, Inc.

  3. 2R regeneration based on Dispersion-Imbalanced Loop Mirror and its Applications in WDM systems

    DEFF Research Database (Denmark)

    Chi, Nan; Carlsson, Birger; Jeppesen, Palle

    2002-01-01

    2R regeneration based on dispersion-imbalanced loop mirror is investigated including the characteristics of transfer function, output extinction ratio, initial chirp, predispersion, and WDM signals transfer functions. Theoretical results show that the input peak power is a critical parameter for ...... regenerator based on a DILM consisting of a single mode fiber (SMF) and a highly nonlinear dispersion-shifted fiber (DSF) after WDM transmission over 40 km SMF of the WDM signals....

  4. Dynamic traffic grooming for port number optimization in WDM optical mesh networks

    Science.gov (United States)

    Huang, Jun; Zeng, Qingji; Liu, Jimin; Xiao, Pengcheng; Liu, Hua; Xiao, Shilin

    2004-04-01

    In this paper, the objective was optimizing the port number with dynamic traffic grooming of SDH/SONET WDM mesh networks to give useful referenced data to networks design and the cost control of networks. The performances of different path select routing algorithms were evaluated in WDM grooming networks by considering traffic of different bandwidth requests. Finally, the results were presented and compared with in distributed-controlled WDM mesh networks.

  5. Dynamic traffic grooming with multigranularity traffic in WDM optical mesh networks

    Science.gov (United States)

    Huang, Jun; Zeng, Qingji; Liu, Jimin; Xiao, Pengcheng; Liu, Hua; Xiao, Shilin

    2004-04-01

    In this paper, a traffic-grooming problem for multi-granularity traffic of SDH/SONET in WDM grooming mesh networks is investigated. We propose a path select routing algorithm to solve this problem. The performances of this traffic grooming path select routing algorithm are evaluated in WDM grooming networks. Finally, we presented and compared the simulation results of this algorithm in dynamic traffic grooming WDM mesh networks with that of other algorithms.

  6. Impairments Computation for Routing Purposes in a Transparent-Access Optical Network Based on Optical CDMA and WDM

    Science.gov (United States)

    Musa, Ahmed

    2016-06-01

    Optical access networks are becoming more widespread and the use of multiple services might require a transparent optical network (TON). Multiplexing and privacy could benefit from the combination of wavelength division multiplexing (WDM) and optical coding (OC) and wavelength conversion in optical switches. The routing process needs to be cognizant of different resource types and characteristics such as fiber types, fiber linear impairments such as attenuation, dispersion, etc. as well as fiber nonlinear impairments such as four-wave mixing, cross-phase modulation, etc. Other types of impairments, generated by optical nodes or photonic switches, also affect the signal quality (Q) or the optical signal to noise ratio (OSNR), which is related to the bit error rate (BER). Therefore, both link and switch impairments must be addressed and somehow incorporated into the routing algorithm. However, it is not practical to fully integrate all photonic-specific attributes in the routing process. In this study, new routing parameters and constraints are defined that reflect the distinct characteristics of photonic networking. These constraints are applied to the design phase of TON and expressed as a cost or metric form that will be used in the network routing algorithm.

  7. A flexible decision-aided maximum likelihood phase estimation in hybrid QPSK/OOK coherent optical WDM systems

    Science.gov (United States)

    Zhang, Yong; Wang, Yulong

    2016-04-01

    Although decision-aided (DA) maximum likelihood (ML) phase estimation (PE) algorithm has been investigated intensively, block length effect impacts system performance and leads to the increasing of hardware complexity. In this paper, a flexible DA-ML algorithm is proposed in hybrid QPSK/OOK coherent optical wavelength division multiplexed (WDM) systems. We present a general cross phase modulation (XPM) model based on Volterra series transfer function (VSTF) method to describe XPM effects induced by OOK channels at the end of dispersion management (DM) fiber links. Based on our model, the weighted factors obtained from maximum likelihood method are introduced to eliminate the block length effect. We derive the analytical expression of phase error variance for the performance prediction of coherent receiver with the flexible DA-ML algorithm. Bit error ratio (BER) performance is evaluated and compared through both theoretical derivation and Monte Carlo (MC) simulation. The results show that our flexible DA-ML algorithm has significant improvement in performance compared with the conventional DA-ML algorithm as block length is a fixed value. Compared with the conventional DA-ML with optimum block length, our flexible DA-ML can obtain better system performance. It means our flexible DA-ML algorithm is more effective for mitigating phase noise than conventional DA-ML algorithm.

  8. All-optical WDM Regeneration of DPSK Signals using Optical Fourier Transformation and Phase Sensitive Amplification

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Kjøller, Niels-Kristian

    2015-01-01

    We propose a novel all-optical WDM regeneration scheme for DPSK signals based on optical Fourier transformation and phase sensitive amplification. Phase regeneration of a WDM signal consisting of 4x10-Gbit/s phase noise degraded DPSK channels is demonstrated for the first time.......We propose a novel all-optical WDM regeneration scheme for DPSK signals based on optical Fourier transformation and phase sensitive amplification. Phase regeneration of a WDM signal consisting of 4x10-Gbit/s phase noise degraded DPSK channels is demonstrated for the first time....

  9. All-optical ultra-high-speed OFDM to Nyquist-WDM conversion

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

    2015-01-01

    We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER <10−9 performance for all channels.......We propose an all-optical ultra-high-speed OFDM to Nyquist-WDM conversion scheme based on complete OFT. An 8-subcarrier 640 Gbit/s DPSK OFDM super-channel is converted to eight 80-Gbit/s Nyquist-WDM channels with BER

  10. Solutions for 400 Gbit/s inter data center WDM transmission

    DEFF Research Database (Denmark)

    Dochhan, Annika; Eiselt, Nicklas; Griesser, Helmut

    2016-01-01

    We review some currently discussed solutions for 400 Gbit/s inter-data center WDM transmission for up to 100 km. We focus on direct detected solutions, namely PAM4 and DMT, and present two WDM systems based on these formats.......We review some currently discussed solutions for 400 Gbit/s inter-data center WDM transmission for up to 100 km. We focus on direct detected solutions, namely PAM4 and DMT, and present two WDM systems based on these formats....

  11. Detection and processing of phase modulated optical signals at 40 Gbit/s and beyond

    DEFF Research Database (Denmark)

    Geng, Yan

    km post-compensated non-zero dispersion shifted fiber (NZDSF) span. Using orthogonal labeling, an amplitude shift keying (ASK)/DPSK labeled signal using 40 Gbit/s return-to-zero (RZ) payload and 2.5 Gbit/s DPSK label, is generated. WDM transmission and label swapping are demonstrated...... for such a signal. In future all-optical WDM networks, wavelength conversion is an essential functionality to provide wavelength flexibility and avoid wavelength blocking. Using a 50 m long highly nonlinear photonic crystal fiber (HNL-PCF), with a simple four-wave mixing (FWM) scheme, wavelength conversion...... the amplitude regeneration capability based on FWM in a highly nonlinear fiber (HNLF). The first reported experimental demonstration of amplitude equalization of 40 Gbit/s RZ-DPSK signals using a 500 m long HNLF is presented. Using four possible phase levels to carry the information, DQPSK allows generation...

  12. The Gain of Performance of Optical WDM Networks

    Directory of Open Access Journals (Sweden)

    Miroslav Bahleda

    2008-01-01

    Full Text Available We study the blocking probability and performance of single-fiber and multifiber optical networks with wavelength division multiplexing (WDM. We extend the well-known analytical blocking probability model by Barry and Humblet to the general model, which is proposed for both single-fiber and multifiber network paths with any kind of wavelength conversion (no, limited, or full wavelength conversion and for uniform and nonuniform link loads. We investigate the effect of the link load, wavelength conversion degree, and the number of wavelengths, fibers, and hops on blocking probability. We also extend the definition of the gain of wavelength conversion by Barry and Humblet to the gain of performance, which is fully general. Thanks to this definition and implementation of our model, we compare different WDM node architectures and present interesting results.

  13. 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.

  14. WDM Systems and Networks Modeling, Simulation, Design and Engineering

    CERN Document Server

    Ellinas, Georgios; Roudas, Ioannis

    2012-01-01

    WDM Systems and Networks: Modeling, Simulation, Design and Engineering provides readers with the basic skills, concepts, and design techniques used to begin design and engineering of optical communication systems and networks at various layers. The latest semi-analytical system simulation techniques are applied to optical WDM systems and networks, and a review of the various current areas of optical communications is presented. Simulation is mixed with experimental verification and engineering to present the industry as well as state-of-the-art research. This contributed volume is divided into three parts, accommodating different readers interested in various types of networks and applications. The first part of the book presents modeling approaches and simulation tools mainly for the physical layer including transmission effects, devices, subsystems, and systems), whereas the second part features more engineering/design issues for various types of optical systems including ULH, access, and in-building system...

  15. Spectral changes induced by a phase modulator acting as a time lens

    Energy Technology Data Exchange (ETDEWEB)

    Plansinis, B. W. [Univ. of Rochester, Rochester, NY (United States). Inst. of Optics.; Donaldson, W. R. [Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics; Agrawal, G. P. [Univ. of Rochester, Rochester, NY (United States). Inst. of Optics; Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics.

    2015-07-06

    We show both numerically and experimentally that a phase modulator, acting as a time lens in the Fourier-lens configuration, can induce spectral broadening, narrowing, or shifts, depending on the phase of the modulator cycle. These spectral effects depend on the maximum phase shift that can be imposed by the modulator. In our numerical simulations, pulse spectrum could be compressed by a factor of 8 for a 30 rad phase shift. Experimentally, spectral shifts over a 1.35 nm range and spectral narrowing and broadening by a factor of 2 were demonstrated using a lithium niobate phase modulator with a maximum phase shift of 16 rad at a 10 GHz modulation frequency. All spectral changes were accomplished without employing optical nonlinear effects such as self- or cross-phase modulation.

  16. Effects of nonlinear phase modulation on Bragg scattering in the low-conversion regime

    DEFF Research Database (Denmark)

    Andersen, Lasse Mejling; Cargill, D. S.; McKinstrie, C. J.

    2012-01-01

    In this paper, we consider the effects of nonlinear phase modulation on frequency conversion by four-wave mixing (Bragg scattering) in the low-conversion regime. We derive the Green functions for this process using the time-domain collision method, for partial collisions, in which the four fields...... interact at the beginning or the end of the fiber, and complete collisions, in which the four fields interact at the midpoint of the fiber. If the Green function is separable, there is only one output Schmidt mode, which is free from temporal entanglement. We find that nonlinear phase modulation always...... chirps the input and output Schmidt modes and renders the Green function formally nonseparable. However, by pre-chirping the pumps, one can reduce the chirps of the Schmidt modes and enable approximate separability. Thus, even in the presence of nonlinear phase modulation, frequency conversion...

  17. A simplified model for nonlinear cross-phase modulation in hybrid optical coherent system.

    Science.gov (United States)

    Tao, Zhenning; Yan, Weizhen; Oda, Shoichiro; Hoshida, Takeshi; Rasmussen, Jens C

    2009-08-03

    Cross-phase modulation (XPM) has been considered as one of the ultimate obstacles for optical coherent dense wavelength division multiplexing (DWDM) systems. In order to facilitate the XPM analysis, a simplified model was proposed. The model reduced the distributed XPM phenomena to a lumped phase modulation. The XPM phase noise was generated by a linear system which was determined by the DWDM system parameters and whose inputs were undistorted pump channel intensity waveforms. The model limitations induced by the lumped phase modulation and undistorted pumps approximations were intensively discussed and verified. The simplified model showed a good agreement with simulations and experiments for a typical hybrid optical coherent system. Various XPM phenomena were explained by the proposed model.

  18. A single comb laser source for short reach WDM interconnects

    Science.gov (United States)

    Wojcik, Gregory L.; Yin, Dongliang; Kovsh, Alexey R.; Gubenko, Alexey E.; Krestnikov, Igor L.; Mikhrin, Sergey S.; Livshits, Daniil A.; Fattal, David A.; Fiorentino, Marco; Beausoleil, Raymond G.

    2009-02-01

    High-channel-count WDM will eventually be used for short reach optical interconnects since it maximizes link bandwidth and efficiency. An impediment to adoption is the fact that each WDM wavelength currently requires its own DFB laser. The alternative is a single, multi-wavelength laser, but noise, size and/or expense make existing options impractical. In contrast, a new low-noise, diode comb laser based on InAs/GaAs quantum dots provides a practical and timely alternative, albeit in the O-band. Samples are being evaluated in short reach WDM development systems. Tests show this type of Fabry-Perot laser permits >10 Gb/s error-free modulation of 10 to over 50 separate channels, as well as potential for 1.25 Gb/s direct modulation. The paper describes comb laser requirements, noise measurements for external and direct modulation, O-band issues, transmitter photonic circuitry and components, future CMP applications, and optical couplers that may help drive down packaging costs to below a dollar.

  19. Coherent storage and phase modulation of single hard-x-ray photons using nuclear excitons.

    Science.gov (United States)

    Liao, Wen-Te; Pálffy, Adriana; Keitel, Christoph H

    2012-11-09

    The coherent storage and phase modulation of x-ray single-photon wave packets in the resonant scattering of light off nuclei is theoretically investigated. We show that by switching off and on again the magnetic field in the nuclear sample, phase-sensitive storage of photons in the keV regime can be achieved. Corresponding π phase modulation of the stored photon can be accomplished if the retrieving magnetic field is rotated by 180°. The development of such x-ray single-photon control techniques is a first step towards forwarding quantum optics and quantum information to shorter wavelengths and more compact photonic devices.

  20. Picosecond flat-top pulse generation by low-bandwidth electro-optic sinusoidal phase modulation.

    Science.gov (United States)

    Berger, Naum K; Levit, Boris; Fischer, Baruch; Azaña, José

    2008-01-15

    We report the first experimental demonstration to our knowledge of a microwave frequency upshifting system based on phase modulation. A sequence of flat-top optical and RF pulses at a repetition rate of 18.22 GHz, each with a FWHM time width of approximately 25 ps, is generated from a sinusoidal RF tone of only 3.680 GHz, in good agreement with our analytical and numerical calculations. A simple explanation of this technique based on Talbot effect theory is provided. The practical limitations and capabilities of the phase-modulation-based frequency upshifting approach for ultrabroadband RF waveform generation are also discussed.

  1. Investigation of the SIW technology for low cost 60 GHz radio over fiber based array antenna units

    Science.gov (United States)

    Makris, D.; Tsiakas, P.; Voudouris, K.; Thakur, M. P.; Mikroulis, S.

    2015-01-01

    In this paper, a Substrate Integrated Waveguide (SIW) based photonic antenna suitable for RoF applications is presented. The millimeter-wave design is based on a diplexer, two Chebyshev bandpass filters, one for uplink (61,7GHz to 62,7 GHz) and one for downlink (59,3 GHz to 60,3 GHz) and one common 8x8 Slot array antenna, integrated on the same substrate. E/M simulations of a fully integrated planar RF Front End provide very good results, both in diplexer and filters and in antenna characteristics. Finally, a consideration regarding transition requirements for integration with a coplanar waveguide (CPW) photodiode is being presented.

  2. Simultaneous optical carrier and radio frequency re-modulation in radio-over-fiber systems employing reflective SOA modulators

    DEFF Research Database (Denmark)

    Kassar, Carvalho; Calabretta, Nicola; Tafur Monroy, Idelfonso

    2007-01-01

    We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites.......We demonstrate an innovative full-duplex radio-over-fibre transmission system employing a reflective SOA to perform simultaneous reusing of the optical carrier and data re-modulation, thus avoiding the use of local radiofrequency oscillator at the station sites....

  3. Reconfigurable digital receiver for 8PSK subcarrier multiplexed and 16QAM single carrier phase‐modulated radio over fiber links

    DEFF Research Database (Denmark)

    Guerrero Gonzalez, Neil; Zibar, Darko; Yu, Xianbin

    2011-01-01

    A reconfigurable digital receiver based on the k‐means algorithm is proposed for phase‐modulated subcarrier multiplexed (SCM) and quadrature amplitude‐modulated single carrier, phase‐modulated radio‐over‐fiber links. We report successful demodulation after 40 km single mode fiber transmission...

  4. Key lessons — Twelve factors critical to the success of WDM at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2010-12-22

    Key lessons — Twelve factors critical to the success of WDM at the policy and at the operational levels. December 22, 2010. IDRC Communications. Water demand management (WDM) programs have been widely implemented across the MENA region and elsewhere, with varying degrees of success. The criteria below are ...

  5. Key lessons: Twelve factors critical to the success of WDM at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... elsewhere, with varying degrees of success. The criteria below are intended to help policymakers determine how best to develop institutions with the capacity and capability to design, implement and monitor WDM activities and to further the concept of WDM as central to efficient, equitable and sustainable water policy.​

  6. Longest Path Reroute to Optimize the Optical Multicast Routing in Sparse Splitting WDM Networks

    National Research Council Canada - National Science Library

    Liu, Huanlin; Dai, Hongyue; Zhai, Fei; Chen, Yong; Wei, Chengying

    2015-01-01

    ... of the optical fiber and WDM networks [1-6]. The classical multicast requests are realized by the way of repeating unicast in optical layer because of the constraint by network node light-splitting and leading to the problem of low wavelength resource utilization. Therefore, how to support multicast application in optical WDM networks is becoming a ...

  7. Affects of binary and continuous phase modulations on the structure of Bessel beams

    CSIR Research Space (South Africa)

    Dudley, Angela L

    2010-09-01

    Full Text Available The authors implement a novel technique to operate a phase-only spatial light modulator (SLM) in amplitude mode, allowing them to reproduce Durnin’s ring slit on a liquid crystal display (LCD). The affects of binary and continuous phase modulations...

  8. Subpicosecond-pulse generation through cross-phase-modulation-induced modulational instability in optical fibers.

    Science.gov (United States)

    Gouveia-Neto, A S; Faldon, M E; Sombra, A S; Wigley, P G; Taylor, J R

    1988-10-01

    We report subpicosecond-pulse generation at 1.319 microm in a single-mode optical fiber by modulational instability induced through cross-phase modulation by 1.06-microm pulses propagating in the normal dispersion regime. Pulse-repetition rates approaching 300 GHz were achieved.

  9. Multiband carrierless amplitude/phase modulation for ultra-wideband high data rate wireless communications

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Altabas, Jose A.

    2016-01-01

    We report on the first experimental demonstration of carrierless amplitude/phase modulation in a flexible multiband approach for ultrawideband high-data-rate wireless communications. An effective bitrate of 2 GB/s is achieved while complying with the restrictions on the effective radiated power e...

  10. Effects of nonlinear phase modulation on quantum frequency conversion using four-wave mixing Bragg scattering

    DEFF Research Database (Denmark)

    Andersen, Lasse Mejling; McKinstrie, C. J.; Rottwitt, Karsten

    2013-01-01

    Recently, we solved the coupled-mode equations for Bragg scattering (BS) in the low- and high-conversion regimes, but without the effects of nonlinear phase modulation (NPM). We now present solutions and Green functions in the low-conversion regime that include NPM. We find that NPM does not change...

  11. Digital coherent receiver for subcarrier multiplexed phase modulated radio-over-fibre signals

    DEFF Research Database (Denmark)

    Zibar, Darko; Larsen, Knud J.; Tafur Monroy, Idelfonso

    2009-01-01

    Digital coherent detection of multi-channel subcarrier multiplexed optically phase-modulated radio-over-fibre signals is experimentally demonstrated. Successful detection after transmission over a 40 km long fibre link of four or five 25 Mbaud BPSK/QPSK subcarrier channels in 5 GHz bandwidth...... is demonstrated using offline digital signal processing....

  12. Feasibility analysis of WDM links for radar applications

    Directory of Open Access Journals (Sweden)

    D. Meena

    2015-03-01

    Full Text Available Active phased array antennas enhances the performance of modern radars by using multiple low power transmit/receive modules in place of a high power transmitter in conventional radars. Fully distributed phased array radars demand the distribution of various signals in radio frequency (RF and digital domain for real time operation. This is normally achieved through complex and bulky coaxial distribution networks. In this work, we intend to tap the inherent advantages of fiber links with wavelength division multiplexed (WDM technology and a feasibility study to adapt these links for radar applications is carried out. This is done by analysing various parameters like amplitude, delay, frequency and phase variation response of various radar waveforms over WDM links. This also includes performance evaluation of non-linear frequency modulation (NLFM signals, known for better signal to noise ratio (SNR to specific side lobe levels. NLFM waveforms are further analysed using pulse compression (PC technique. Link evaluation is also carried out using a standard simulation environment and is then experimentally verified with other waveforms like RF continuous wave (CW, pulsed RF and digital signals. Synchronization signals are generated from this variable duty cycle digital signals during real time radar operation. During evaluation of digital signals, variable transient effects for different duty cycles are observed from an amplifier configuration. A suppression method is proposed to eliminate this transient effects. Further, the link delay response is investigated using different lengths of fiber spools. It can be inferred from the experimental results that WDM links are capable of handling various signals significant to radar applications.

  13. Traffic Grooming on WDM Rings Using Optical Burst Transport

    Science.gov (United States)

    Hsueh, Yu-Li; Kim, Jaedon; Su, Ching-Fong; Rabbat, Richard; Hamada, Takeo; Tian, Cechan; Kazovsky, Leonid G.

    2006-01-01

    A sublambda traffic-grooming scheme on wavelength-division-multiplexed (WDM) rings, which is called optical burst transport (OBT), is proposed. The network protocol and architecture allow increased flexibility to tailor the transport network behavior for efficient delivery of bursty data traffic. Using different network parameters, its performance is analyzed via simulation, and the implementation issues including the media-access-control (MAC) protocol, tunable-filter controller, and burst-mode receiver are addressed. Finally, the feasibility of the OBT with an experimental testbed built by the authors is demonstrated and a streaming-video application is used to present its overall functionality.

  14. Practical Quantum Communication and Cryptography for WDM Optical Networks

    Science.gov (United States)

    Kumar, Prem

    2004-11-01

    Keeping in mind the ubiquitous standard optical fiber for long-distance transmission and the widespread availability of efficient active and passive fiber devices, we have been developing telecom-band resources for practical quantum communication and cryptography in wave-division-multiplexed (WDM) optical networks. In this talk I present our recent results on two fronts: i) telecom-band in-fiber entanglement generation, storage, and long-distance distribution and ii) quantum-noise protected high-speed data encryption through an optically-amplified WDM line. Along the first front, with our in-fiber entanglement source all four Bell states can be readily produced and we have demonstrated violation of Bell's inequalities by up to 10 standard deviations of measurement uncertainty. With such a source we have demonstrated storage of entanglement for up to 1/8 of a millisecond. Furthermore, when each photon of the entangled pair is propagated in separate 25km-long standard fibers, high visibility quantum interference is still observed, demonstrating that this system is capable of long-distance (> 50 km) entanglement distribution. Along the second front, we have implemented a new quantum cryptographic scheme, based on Yuen's KCQ protocol, in which the inherent quantum noise of coherent states of light is used to perform the cryptographic service of data encryption. In this scheme a legitimate receiver, with use of a short, shared, secret-key, executes a simple binary decision rule on every transmitted bit. An eavesdropper, on the other hand, who does not possess the secret-key, is subjected to an irreducible quantum uncertainty in each measurement, even with the use of ideal detectors. We have implemented this scheme to demonstrate quantum-noise-protected data encryption at 650 Mbps through a 200 km, in-line amplified, WDM line. The line simultaneously carried two 10 Gbps standard data channels, 100 GHz on either side of the encrypted channel, which shows that this scheme

  15. Performance analyses of hybrid WDM/OCDM optical networks

    Directory of Open Access Journals (Sweden)

    Fábio Renan Durand

    2005-02-01

    Full Text Available In this work, optical networks using the hybrid technology of wavelength division multiplexing and optical code division multiplexing (WDM/OCDM are investigated. The architecture of the network is described and it is shown the main advantages of applied optical paths with wavelengths and optical orthogonal codes (OOC to routing and switching virtual optical paths. The main results show that the use of OOC codes together with optical codes converters have a great impact on the decrease of blocking probability for establishing virtual optical paths, increasing network use.

  16. New Heuristic Algorithm for Dynamic Traffic in WDM Optical Networks

    Directory of Open Access Journals (Sweden)

    Arturo Benito Rodríguez Garcia

    2015-12-01

    Full Text Available The results and comparison of the simulation of a new heuristic algorithm called Snake One are presented. The comparison is made with three heuristic algorithms, Genetic Algorithms, Simulated Annealing, and Tabu Search, using blocking probability and network utilization as standard indicators. The simulation was made on the WDM NSFNET under dynamic traffic conditions. The results show a substantial decrease of blocking, but this causes a relative growth of network utilization. There are also load intervals at which its performance improves, decreasing the number of blocked requests.

  17. SOA Based Photonic Integrated WDM Cross-Connects for Optical Metro-Access Networks

    Directory of Open Access Journals (Sweden)

    Nicola Calabretta

    2017-08-01

    Full Text Available We present a novel optical metro node architecture that exploits the Wavelength Division Multiplexing (WDM optical cross-connect nodes for interconnecting network elements, as well as computing and storage resources. The photonic WDM cross-connect node based on semiconductor optical amplifiers (SOA allows switching data signals in wavelength, space, and time for fully exploiting statistical multiplexing. The advantages of using an SOA to realize the WDM cross-connect switch in terms of transparency, switching speed, photonic integrated amplification for loss-less operation, and gain equalization are verified experimentally. The experimental assessment of a 4 × 4 photonic integrated WDM cross-connect confirmed the capability of the cross-connect chip to switch the WDM signal in space and wavelength. Experimental results show lossless operation, low cross-talk <−30 dB, and dynamically switch within few nanoseconds. Moreover, the operation of the cross-connect switch with multiple WDM channels and diverse modulation formats is also investigated and reported. Error-free operation with less than a 2 dB power penalty for a single channel, as well as WDM input operation, has been measured for multiple 10/20/40 Gb/s NRZ-OOK, 20 Gb/s PAM4, and data-rate adaptive DMT traffic. Compensation of the losses indicates that the modular architecture could scale to a larger number of ports.

  18. A Low-Noise Delta-Sigma Phase Modulator for Polar Transmitters

    Directory of Open Access Journals (Sweden)

    Bo Zhou

    2014-01-01

    Full Text Available A low-noise phase modulator, using finite-impulse-response (FIR filtering embedded delta-sigma (ΔΣ fractional-N phase-locked loop (PLL, is fabricated in 0.18 μm CMOS for GSM/EDGE polar transmitters. A simplified digital compensation filter with inverse-FIR and -PLL features is proposed to trade off the transmitter noise and linearity. Experimental results show that the presented architecture performs RF phase modulation well with 20 mW power dissipation from 1.6 V supply and achieves the root-mean-square (rms and peak phase errors of 4° and 8.5°, respectively. The measured and simulated phase noises of −104 dBc/Hz and −120 dBc/Hz at 400-kHz offset from 1.8-GHz carrier frequency are observed, respectively.

  19. A low-noise delta-sigma phase modulator for polar transmitters.

    Science.gov (United States)

    Zhou, Bo

    2014-01-01

    A low-noise phase modulator, using finite-impulse-response (FIR) filtering embedded delta-sigma (ΔΣ) fractional-N phase-locked loop (PLL), is fabricated in 0.18 μ m CMOS for GSM/EDGE polar transmitters. A simplified digital compensation filter with inverse-FIR and -PLL features is proposed to trade off the transmitter noise and linearity. Experimental results show that the presented architecture performs RF phase modulation well with 20 mW power dissipation from 1.6 V supply and achieves the root-mean-square (rms) and peak phase errors of 4° and 8.5°, respectively. The measured and simulated phase noises of -104 dBc/Hz and -120 dBc/Hz at 400-kHz offset from 1.8-GHz carrier frequency are observed, respectively.

  20. Study on measuring vibration displacement by shear interference based on sinusoidal phase modulation

    Science.gov (United States)

    He, Guotian; Tang, Feng; Song, Li; Jiang, Helun

    2009-05-01

    The semiconductor laser (LD) Taimangelin interferometer based on sinusoidal phase modulation is vulnerable to external vibration, temperature changes, vibration, and other air interference which causes great measurement error. This paper presents a new semiconductor laser sinusoidal phase modulation shear interference technology and anti-jamming wavelet transform algorithm which is not sensitive to environment interference. It changes the original optical technology in the plane mirror to three pyramid-shear, causing a certain amount of displacement of reference light and object light. and partial use of high resolution wavelet transform algorithm solves the problem in measuring the vibration displacement of measured object..Vibration shear interferometry expression is launched, and theoretically discusses the measurement principle. Using MATLAB before and after the improvement of the methods to simulate contrast obtains the impact of shear volume size on measurement accuracy with experimental test. Experimental results show that it effectively reduces the impact of outside interference on measurement accuracy.

  1. Method of phase space beam dilution utilizing bounded chaos generated by rf phase modulation

    Directory of Open Access Journals (Sweden)

    Alfonse N. Pham

    2015-12-01

    Full Text Available This paper explores the physics of chaos in a localized phase-space region produced by rf phase modulation applied to a double rf system. The study can be exploited to produce rapid particle bunch broadening exhibiting longitudinal particle distribution uniformity. Hamiltonian models and particle-tracking simulations are introduced to understand the mechanism and applicability of controlled particle diffusion. When phase modulation is applied to the double rf system, regions of localized chaos are produced through the disruption and overlapping of parametric resonant islands and configured to be bounded by well-behaved invariant tori to prevent particle loss. The condition of chaoticity and the degree of particle dilution can be controlled by the rf parameters. The method has applications in alleviating adverse space-charge effects in high-intensity beams, particle bunch distribution uniformization, and industrial radiation-effects experiments.

  2. Multimodal chromatography: Characterization of protein binding and selectivity enhancement through mobile phase modulators.

    Science.gov (United States)

    Wolfe, Leslie S; Barringer, Cartney P; Mostafa, Sigma S; Shukla, Abhinav A

    2014-05-02

    The unique selectivity of mixed mode chromatography resins is driving increasing utilization of these novel selectivities into bioprocess applications. There is a need for improved fundamental understanding of protein binding to these stationary phases to enable the development of efficient and robust purification processes. A panel of four monoclonal antibodies and two model proteins were employed to characterize protein interaction with a mixed-mode chromatographic resin comprising a hydrophobic ligand with cation-exchange functionality. Binding of these proteins was studied as a function of salt concentration and pH in the presence of various mobile phase modulators. This knowledge was applied towards screening mobile phase modulators that could selectively decrease host cell protein levels during monoclonal antibody purification. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Non-contact measuring system in sinusoidal phase modulating interferometry using a laser diode

    Science.gov (United States)

    Pyo, Ki-Young; Lee, Geun-Young; Ryu, Weon-Jae; Kang, Young-June; Park, Nak-Kyu

    2005-12-01

    Recently, laser interferometry is widely used as a measuring system in many fields because of its high resolution and its ability to measure a broad area in real-time all at once. In conventional laser interferometry, for example Out-of-plane ESPI (Electronic Speckle Pattern Interferometry), In plane ESPI, Shearography and Holography, it uses PZT or other components as a phase shift instrumentation to extract 3-D deformation data, vibration mode and others. However, in most cases PZT has some disadvantages, which include nonlinear errors and limited time of use. In the present study, a new type of laser interferometry using a laser diode is proposed. Using Laser Diode Sinusoidal Phase Modulating (LD-SPM) interferometry, the phase modulation can be directly modulated by controlling the laser diode injection current thereby eliminating the need for PZT and its components. This makes the interferometry more compact.

  4. FAULT LOCALIZATION AND ALARM CORRELATION IN OPTICAL WDM NETWORKS

    Directory of Open Access Journals (Sweden)

    G.Ramesh

    2010-06-01

    Full Text Available For several high speed networks, providing resilience against failures is an essential requirement. The main feature for designing next generation optical networks is protecting and restoring high capacity WDM networks from the failures. Quick detection, identification and restoration make networks more strong and consistent even though the failures cannot be avoided. Hence, it is necessary to develop fast, efficient and dependable fault localization or detection mechanisms. In this paper we propose a new fault localization algorithm for WDM networks which can identify the location of a failure on a failed lightpath. Our algorithm detects the failed connection and then attempts to reroute data stream through an alternate path. In addition to this, we develop an algorithm to analyze the information of the alarms generated by the components of an optical network, in the presence of a fault. It uses the alarm correlation in order to reduce the list of suspected components shown to the network operators. By our simulation results, we show that our proposed algorithms achieve less blocking probability and delay while getting higher throughput.

  5. Coherent Control of Photofragment Distributions Using Laser Phase Modulation in the Weak-Field Limit

    DEFF Research Database (Denmark)

    Garcia-Vela, Alberto; Henriksen, Niels Engholm

    2015-01-01

    The possibility of quantum interference control of the final state distributions of photodissociation fragments by means of pure phase modulation of the pump laser pulse in the weak-field regime is demonstrated theoretically for the first time. The specific application involves realistic wave...... to persist for long times (about 200 ps) after the pulse is over due to interference between overlapping resonances in Ne-Br-2(B)....

  6. Digital coherent receiver employing photonic downconversion for phase modulated radio-over-fibre links

    OpenAIRE

    Zibar, Darko; Caballero Jambrina, Antonio; Guerrero Gonzalez, Neil; Schaeffer, Christian; Tafur Monroy, Idelfonso

    2009-01-01

    A digital coherent receiver employing photonic downconversion is presented and experimentally demonstrated for phase-modulated radio-over-fibre optical links. The receiver is capable of operating at frequencies exceeding the bandwidth of electrical analog-to-digital converter by using photonic downconversion to translate the high-frequency input RF signal to the operating frequency range of the analog-to-digital converter. First, using linear digital demodulation scheme we measure SFDR of the...

  7. Injection of a Phase Modulated Source into the Z-Beamlet Laser for Increased Energy Extraction.

    Energy Technology Data Exchange (ETDEWEB)

    Rambo, Patrick K.; Armstrong, Darrell J.; Schwarz, Jens; Smith, Ian C; Shores, Jonathon; Speas, Christopher; Porter, John L.

    2014-11-01

    The Z-Beamlet laser has been operating at Sandia National Laboratories since 2001 to provide a source of laser-generated x-rays for radiography of events on the Z-Accelerator. Changes in desired operational scope have necessitated the increase in pulse duration and energy available from the laser system. This is enabled via the addition of a phase modulated seed laser as an alternative front-end. The practical aspects of deployment are discussed here.

  8. Phase modulation of a neutron wave and diffraction of ultracold neutrons on a moving grating

    Energy Technology Data Exchange (ETDEWEB)

    Frank, A.I.; Balashov, S.N.; Bondarenko, I.V.; Geltenbort, P.; Hoeghoej, P.; Masalovich, S.V.; Nosov, V.G

    2003-05-05

    We report the result of the experiment of UCN diffraction on a moving grating. The resulting spectrum is found to be discrete in good agreement with theory. This purely quantum effect may be interpret as a result of phase modulation of the neutron wave or as diffraction in time. Also, this experiment demonstrates the validity of the Galilean transformation of the neutron wave function in a new and very clear way.

  9. On The Use of A Phase Modulation Method for Decorrelation in Acoustic Feedback Cancellation

    DEFF Research Database (Denmark)

    Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

    2012-01-01

    A major problem in using an adaptive filter in acoustic feedback cancellation systems is that the loudspeaker signal is correlated with the signals entering the microphones of the audio system, leading to biased filter estimates. One possible solution for reducing this problem is by means...... similar frequency shifting decorrelation method. We show that the phase modulation method is suitable for decorrelation in a hearing aid acoustic feedback cancellation system, although the frequency shifting method is in general slightly more effective....

  10. Digital non-linear equalization for flexible capacity ultradense WDM channels for metro core networking

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Zhang, Xu; Larsen, Knud J.

    2011-01-01

    An experimental demonstration of Ultradense WDM with advanced digital signal processing is presented. The scheme proposed allows the use of independent tunable DFB lasers spaced at 12.5 GHz for ultradense WDM PM-QPSK flexible capacity channels for metro core networking. To allocate extremely closed...... carriers, we demonstrate that a digital non-linear equalization allow to mitigate inter-channel interference and improve overall system performance in terms of OSNR. Evaluation of the algorithm and comparison with an ultradense WDM system with coherent carriers generated from a single laser are also...

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

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Darrell J.

    2014-09-01

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

  12. SDN-enabled dynamic WDM networks to address routing information inaccuracy

    CSIR Research Space (South Africa)

    Ravhuanzwo, Lusani

    2016-11-01

    Full Text Available International Conference on Advances in Computing, Communication, & Engineering (ICACCE-2016), Coastlands Umhlanga Hotel & Resorts, Durban, 28-29 November 2016 SDN-enabled dynamic WDM networks to address routing information inaccuracy L. Ravhuanzwo, A...

  13. Constellation Shaping for WDM systems using 256QAM/1024QAM with Probabilistic Optimization

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2016-01-01

    In this paper, probabilistic shaping is numerically and experimentallyinvestigated for increasing the transmission reach of wavelength divisionmultiplexed (WDM) optical communication system employing quadrature amplitudemodulation (QAM). An optimized probability mass function (PMF) of the QAMsymb...

  14. Energy-efficient WDM-OFDM-PON employing shared OFDM modulation modules in optical line terminal

    National Research Council Canada - National Science Library

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Kongtao; Su, Yikai

    2012-01-01

    We propose and experimentally demonstrate a scheme to improve the energy efficiency of wavelength division multiplexing - orthogonal frequency division multiplexing - passive optical networks (WDM-OFDM-PONs). By using an N...

  15. On Finding the Multicast Protection Tree Considering SRLG in WDM Optical Networks

    National Research Council Canada - National Science Library

    Li, Yonggang; Jin, Yaohui; Li, Lemin; Li, Longjiang

    2006-01-01

    ...) in a primary light tree to share protections in WDM optical networks. In previous studies, how to share spare resources with SRLG constraints has not been studied in multicast optical networks...

  16. Polarization Insensitive One-to-Six WDM Multicasting in a Silicon Nanowire

    DEFF Research Database (Denmark)

    Pu, Minhao; Hu, Hao; Peucheret, Christophe

    2012-01-01

    We present polarization insensitive one-to-six WDM multicasting based on nondegenerate four-wave mixing in a silicon nanowire with angled-pump scheme. Bit-error rate measurements are performed and error-free operation is achieved....

  17. Remotely controllable WDM-PON technology for wireless fronthaul/backhaul application

    DEFF Research Database (Denmark)

    Eiselt, Michael H.; Wagner, Christoph; Lawin, Mirko

    2016-01-01

    Low-cost WDM-PON solutions for fronthaul and backhaul applications will include remotely controlled tail-end transceivers. We report on control aspects of these transceivers and how standardization is evolving to enable these applications.......Low-cost WDM-PON solutions for fronthaul and backhaul applications will include remotely controlled tail-end transceivers. We report on control aspects of these transceivers and how standardization is evolving to enable these applications....

  18. Real time algorithm temperature compensation in tunable laser / VCSEL based WDM-PON system

    DEFF Research Database (Denmark)

    Iglesias Olmedo, Miguel; Rodes Lopez, Roberto; Pham, Tien Thang

    2012-01-01

    We report on a real time experimental validation of a centralized algorithm for temperature compensation of tunable laser/VCSEL at ONU and OLT, respectively. Locking to a chosen WDM channel is shown for temperature changes over 40°C.......We report on a real time experimental validation of a centralized algorithm for temperature compensation of tunable laser/VCSEL at ONU and OLT, respectively. Locking to a chosen WDM channel is shown for temperature changes over 40°C....

  19. Optical fronthauling for 5G mobile: A perspective of passive metro WDM technology

    DEFF Research Database (Denmark)

    Zou, Shihuan Jim; Wagner, Christoph; Eiselt, Michael

    2017-01-01

    We discuss the necessity of passive WDM technology in the 5G fronthaul application. The proof-of-concept field trial showed that the proposed system integrated seamlessly with the current wireless equipment and had no impact on services.......We discuss the necessity of passive WDM technology in the 5G fronthaul application. The proof-of-concept field trial showed that the proposed system integrated seamlessly with the current wireless equipment and had no impact on services....

  20. Digital Non-Linear Equalization for Flexible Capacity Ultradense WDM Channels for Metro Core Networking

    DEFF Research Database (Denmark)

    Arlunno, Valeria; Zhang, Xu; Larsen, Knud J.

    2011-01-01

    We experimentally demonstrate that digital non-linear equalization allows for using independent tunable DFB lasers spaced at 12.5 GHz for ultradense WDM PM-QPSK flexible capacity channels for metro core networking.......We experimentally demonstrate that digital non-linear equalization allows for using independent tunable DFB lasers spaced at 12.5 GHz for ultradense WDM PM-QPSK flexible capacity channels for metro core networking....

  1. Novel OSNR Monitoring Technique in Dense WDM Systems using Inherently Generated CW Monitoring Channels

    DEFF Research Database (Denmark)

    Petersen, Martin Nordal

    2007-01-01

    We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing.......We present a simple, yet effective OSNR monitoring technique based on an inherent effect in the optical modulator. Highly accurate OSNR monitoring is demonstrated in a 40 Gb/s dense WDM system with 50 GHz channel spacing....

  2. An optical WDM link simulation at 4·10 Gb/s with the COMSIS software

    Directory of Open Access Journals (Sweden)

    Benameur S.

    2009-01-01

    Full Text Available The evolution of data transmission using optical fiber media has been accelerated since the advent of technical multiplexing wavelengths (WDM, which helps to achieve bit rates of a few Tb/s transported by a single fiber. In this context, we propose in this work, to make a simulation of a system WDM, at 4·10Gb/s with the COMSIS simulator system. We will interest especially to demultiplexing. .

  3. 40 Gbit/s serial data signal regeneration using self-phase modulation in a silicon nanowire

    DEFF Research Database (Denmark)

    Ji, Hua; Wang, Ju; Hu, Hao

    2012-01-01

    We experimentally demonstrate self-phase modulation based all-optical regeneration of a 40 Gbit/s serial data signal in a silicon nanowire. Bit error rate characterization shows 2 dB receiver power improvement....

  4. Comparison of WDM/Pulse-Position-Modulation (WDM/PPM) with Code/Pulse-Position-Swapping (C/PPS) Based on Wavelength/Time Codes

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, A J; Hernandez, V J; Gagliardi, R M; Bennett, C V

    2009-06-19

    Pulse position modulation (PPM) signaling is favored in intensity modulated/direct detection (IM/DD) systems that have average power limitations. Combining PPM with WDM over a fiber link (WDM/PPM) enables multiple accessing and increases the link's throughput. Electronic bandwidth and synchronization advantages are further gained by mapping the time slots of PPM onto a code space, or code/pulse-position-swapping (C/PPS). The property of multiple bits per symbol typical of PPM can be combined with multiple accessing by using wavelength/time [W/T] codes in C/PPS. This paper compares the performance of WDM/PPM and C/PPS for equal wavelengths and bandwidth.

  5. An efficient mechanism for dynamic multicast traffic grooming in overlay IP/MPLS over WDM networks

    Science.gov (United States)

    Yu, Xiaojun; Xiao, Gaoxi; Cheng, Tee Hiang

    2014-08-01

    This paper proposes an efficient overlay multicast provisioning (OMP) mechanism for dynamic multicast traffic grooming in overlay IP/MPLS over WDM networks. To facilitate request provisioning, OMP jointly utilizes a data learning (DL) scheme on the IP/MPLS layer for logical link cost estimation, and a lightpath fragmentation (LPF) based method on the WDM layer for improving resource sharing in grooming process. Extensive simulations are carried out to evaluate the performance of OMP mechanism under different traffic loads, with either limited or unlimited port resources. Simulation results demonstrate that OMP significantly outperforms the existing methods. To evaluate the respective influences of the DL scheme and the LPF method on OMP performance, provisioning mechanisms only utilizing either the IP/MPLS layer DL scheme or the WDM layer LPF method are also devised. Comparison results show that both DL and LPF methods help improve OMP blocking performance, and contribution from the DL scheme is more significant when the fixed routing and first-fit wavelength assignment (RWA) strategy is adopted on the WDM layer. Effects of a few other factors, including definition of connection cost to be reported by the WDM layer to the IP/MPLS layer and WDM-layer routing method, on OMP performance are also evaluated.

  6. Bit Error Rate Performance Limitations Due to Raman Amplifier Induced Crosstalk in a WDM Transmission System

    Science.gov (United States)

    Tithi, F. H.; Majumder, S. P.

    2017-06-01

    Analysis is carried out for a single span wavelength division multiplexing (WDM) transmission system with distributed Raman amplification to find the effect of amplifier induced crosstalk on the bit error rate (BER) with different system parameters. The results are evaluated in terms of crosstalk power induced in a WDM channel due to Raman amplification, optical signal to crosstalk ratio (OSCR) and BER at any distance for different pump power and number of WDM channels. The results show that the WDM system suffers power penalty due to crosstalk which is significant at higher pump power, higher channel separation and number of WDM channel. It is noticed that at a BER 10-9, the power penalty is 8.7 dB and 10.5 dB for the length of 180 km and number of WDM channel N=32 and 64 respectively when the pump power is 20 mW and is higher at high pump power. Analytical results are validated by simulation.

  7. Study on working vacation polling system for WDM

    Science.gov (United States)

    Chen, Haiyan; Tian, Naishuo; Lu, Donghua

    2008-11-01

    In the paper, we propose a digital working vacation scheme cyclic polling system for wavelength division multiplexing (WDM). This system consists of multi-queues (terminals) whose service rate is one of the fast speed and lower speed. the fast speed mode moves cyclically from queue to queue with an exhaustive schedule. Using the decomposition approach, each queue is analyzed as a single server queue with working vacation, which works at a different rate, rather than completely stops during the vacation polling period. Using quasi birth and death chain and matrix geometric solution method, we give some performance parameters, such as the mean number of packet in the queue, throughput, busy period etc. Finally, we analyze the effect of the parameters on the mean queue length and sojourn time through numerical examples.

  8. Massive WDM and TDM Soliton Transmission Systems : a ROSC Symposium

    CERN Document Server

    2002-01-01

    This book summarizes the proceedings of the invited talks presented at the “International Symposium on Massive TDM and WDM Optical Soliton Tra- mission Systems” held in Kyoto during November 9–12, 1999. The symposium is the third of the series organized by Research Group for Optical Soliton C- munications (ROSC) chaired by Akira Hasegawa. The research group, ROSC, was established in Japan in April 1995 with a support of the Japanese Ministry of Post and Telecommunications to promote collaboration and information - change among communication service companies, communication industries and academic circles in the theory and application of optical solitons. The symposium attracted enthusiastic response from worldwide researchers in the field of soliton based communications and intensive discussions were made. In the symposium held in 1997, new concept of soliton transmission based on dispersion management of optical fibers were presented. This new soliton is now called the dispersion managed soliton. The p...

  9. Physical enhanced security strategy implementation in WDM PON

    Science.gov (United States)

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

    2017-06-01

    The enormous growth in data traffic in optical networks has raised the requirement of broadband access networks. Passive Optical Networks (PON) is capable of solving the power, bandwidth and cost problems. Time Division Multiplexed PON (TDM PON) uses a point to multipoint design which is currently being used for data transmission that initiated the requirement of maintaining customer's security in the downstream direction. These security impairments trigger the need of scrutiny for fault monitoring and eavesdropping in PONs. This paper demonstrates the Wavelength Division Multiplexed PONs (WDM-PON) using scrambling and fault monitoring to provide security which is absent in TDM passive optical networks. Results have been validated at 10 Gbps data rate using OPTISYSTEM12 simulation tool.

  10. A Simple Analytical Model for Dense WDM/OOK Systems

    Science.gov (United States)

    1994-06-01

    partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN ELECTRICAL ENGINEERING from the NAVAL POSTGRADUATE SCHOOL June, 1994...Electrical and Computer Engineering ii ABSTRACT We derive the closed form expression for the bit error probability of dense WDM systems employing an...L 2 Af2 -m.+2jRe{ 2jZ ~Z k*O m$O 47 T 1A2A.d.&I(- e 2cT)I _Ajl (e11c __e__) JISACIK ,A- ’’_ 11- A.:T + ± A1 2 1=-L bk+oba 0~ k*0 m*0 +2PRe T~ If2 -3b

  11. Conversion of phase-modulated signals to amplitude-modulated signals in SOAs due to mirror reflections

    DEFF Research Database (Denmark)

    Blaaberg, Søren; Mørk, Jesper

    2009-01-01

    We present theoretical results that show conversion of phase modulated signals to amplitude modulated signals in an SOA. Large-signal and small-signal calculations show significant conversion responses caused by even minute reflections at the end mirrors.......We present theoretical results that show conversion of phase modulated signals to amplitude modulated signals in an SOA. Large-signal and small-signal calculations show significant conversion responses caused by even minute reflections at the end mirrors....

  12. Multilayer recovery mechanism for IP over WDM networks

    Science.gov (United States)

    Liu, Xin; Zeng, Qingji; Wang, Yun

    2004-04-01

    In this article, we mainly focus on the integrated dynamic survivability in IP/MPLS/WDM networks under the peer-modeled architecture. We systematically investigated various integrated dynamic protection and restoration schemes combining knowledge of resource and topology information in both the IP/MPLS and WDM layers. To allocate the restorable bandwidth-guaranteed paths, we propose an integrated routing algorithm: Load-Balanced Physical Resource Minimum Hop (LBPRMH) integrated routing algorithm. In this algorithm, we present a new link cost function used in Dijkstra"s algorithm considering both physical resource and load balancing factors and employ a parameter (relevant to traffic intensity) to control the influence of two kind of information. When network load is low (traffic intensity is small), the main factor in the proposed link cost function is physical resource, which leads to high resource utilization. When network load is high, the idea of load balance becomes more important in routing, which avoids connection requests conflict and increases the efficiency of resource usage. Then extensive simulations are done to analyze and compare the dynamic survival performance of various integrated survival strategies. Resource utilization, protection efficiency, restoration efficiency are employed as metrics to evaluate the survivable performance. We demonstrate that the proposed integrated routing algorithm performs better than some existing approaches in terms of the above three metrics. The simulation results show the high resource utilization in optical layer recovery with wavelength granularity and the high restoration flexibility in IP/MPLS layer recovery with finer granularity. If the recovery action is implemented first in lower layer and then higher layer if the first action failed, the integrated protection and restoration schemes can combine the advantages of both layers and perform better than recovery schemes in either single layer.

  13. Precise control of superluminal and slow light propagation by transverse phase modulation.

    Science.gov (United States)

    Guedes, I; Misoguti, L; Zilio, S C

    2006-06-26

    We have used a heterodyne Z-scan technique to produce both superluminal and slow light propagation in media that present either thermal or Kerr nonlinearities. The sample position determines the magnitude and sign of the group velocity and this property was used to control it, with an experimental setup much simpler than those previously reported in similar investigations. The observed effect is attributed to the transverse phase modulation produced by a focused Gaussian beam, and is capable of producing both positive and negative group velocities in the range 1.5 m/s < |upsilon(g)| < c.

  14. Detection and characterization of single nanoparticles by interferometric phase modulated ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, F.; Bosch, S.; Tort, N.; Arteaga, O. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Sancho-Parramon, J. [Rudjer Boskovic Institute, Bijenicka c. 54, Zagreb 10002 (Croatia); Jover, E.; Bertran, E. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Canillas, A., E-mail: acanillas@ub.ed [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain)

    2011-02-28

    We introduce a new measurement system called Nanopolar interferometer devoted to monitor and characterize single nanoparticles which is based on the interferometric phase modulated ellipsometry technique. The system collects the backscattered light by the particles in the solid angle subtended by a microscope objective and then analyses its frequency components. The results for the detection of 2 {mu}m and 50 nm particles are explained in terms of a cross polarization effect of the polarization vectors when the beam converts from divergent to parallel in the microscope objective. This explanation is supported with the results of the optical modelling using the exact Mie theory for the light scattered by the particles.

  15. Phase Regeneration of a BPSK Data Signal Using a Lithium Niobate Phase Modulator

    DEFF Research Database (Denmark)

    Mulvad, Hans Christian Hansen; Da Ros, Francesco; Galili, Michael

    2015-01-01

    is then achieved in the electrical domain using a ×2 frequency-multiplier and a narrow-band filtering scheme. Subsequently, a superposition of the recovered carrier and the heterodyne detected data signal is used to modulate the CW-LO in a LiNbO3 phase modulator. The result is a parametric mixing process......-of-principle demonstration, the decorrelated data- and LO-carriers are derived from the same CW source. A preliminary test with separate CW sources for data and LO, but without the required electrical narrow-band carrier filtering, is also included. Finally, numerical simulations of the regenerator performance...

  16. Multi-focus two-photon polymerization technique based on individually controlled phase modulation.

    Science.gov (United States)

    Obata, Kotaro; Koch, Jürgen; Hinze, Ulf; Chichkov, Boris N

    2010-08-02

    Multi-focus two-photon polymerization with a spatial light modulator is demonstrated. The spatial light modulator generates multi-focus spots via phase modulation technique controlled by a computer generated hologram (CGH) pattern. Each focus spot can be individually addressed in position and laser intensity. The multi-focus two-photon polymerization technique allows the fabrication of complex 2-D and 3-D structures both symmetric and asymmetric. Smooth sine curved polymerized lines with amplitude of 5 microm and a period of 200 microm were obtained by fast switching of the CGH patterns.

  17. Split Mach-Zehnder interferometer for surface plasmon resonance based phase modulation

    Science.gov (United States)

    Banerjee, Jayeta; Bera, Mahua; Ray, Mina

    2017-11-01

    Split Mach-Zehnder interferometer is proposed for demonstration of phase modulation of p- and s- polarized beams in a surface plasmon resonance based phase sensitive interference imaging platform. Significant phase change has been observed in Al coated prism based SPR configuration for p-polarized beam, whereas practically no phase change occurs for s-polarized beam. Qualitative analysis of SPR modulated interference fringes also validates the observed effects. A proposed Split Mach-Zehnder set up is shown for simultaneous sensing of two different samples.

  18. Auditory Cortex Tracks Both Auditory and Visual Stimulus Dynamics Using Low-Frequency Neuronal Phase Modulation

    Science.gov (United States)

    Luo, Huan; Liu, Zuxiang; Poeppel, David

    2010-01-01

    Integrating information across sensory domains to construct a unified representation of multi-sensory signals is a fundamental characteristic of perception in ecological contexts. One provocative hypothesis deriving from neurophysiology suggests that there exists early and direct cross-modal phase modulation. We provide evidence, based on magnetoencephalography (MEG) recordings from participants viewing audiovisual movies, that low-frequency neuronal information lies at the basis of the synergistic coordination of information across auditory and visual streams. In particular, the phase of the 2–7 Hz delta and theta band responses carries robust (in single trials) and usable information (for parsing the temporal structure) about stimulus dynamics in both sensory modalities concurrently. These experiments are the first to show in humans that a particular cortical mechanism, delta-theta phase modulation across early sensory areas, plays an important “active” role in continuously tracking naturalistic audio-visual streams, carrying dynamic multi-sensory information, and reflecting cross-sensory interaction in real time. PMID:20711473

  19. Photothermal self-phase-modulation technique for absorption measurements on high-reflective coatings.

    Science.gov (United States)

    Steinlechner, Jessica; Jensen, Lars; Krüger, Christoph; Lastzka, Nico; Steinlechner, Sebastian; Schnabel, Roman

    2012-03-10

    We propose and demonstrate a new measurement technique for the optical absorption of high-reflection coatings. Our technique is based on photothermal self-phase modulation and exploits the deformation of cavity Airy peaks that occurs due to coating absorption of intracavity light. The mirror whose coating is under investigation needs to be the input mirror of a high-finesse cavity. Our example measurements were performed on a high-reflection SiO2-Ta2O5 coating in a three-mirror ring-cavity setup at a wavelength of 1064 nm. The optical absorption of the coating was determined to be α=(23.9±2.0)·10(-6) per coating. Our result is in excellent agreement with an independently performed laser calorimetry measurement that gave a value of α=(24.4±3.2)·10(-6) per coating. Since the self-phase modulation in our coating-absorption measurement affects mainly the propagation through the cavity input mirror, our measurement result is practically uninfluenced by the optical absorption of the other cavity mirrors.

  20. Ultrafast optical phase modulation with metallic nanoparticles in ion-implanted bilayer silica

    Energy Technology Data Exchange (ETDEWEB)

    Torres-Torres, C [Seccion de Estudios de Posgrado e Investigacion, ESIME-Z, Instituto Politecnico Nacional, Mexico, DF, 07738 (Mexico); Tamayo-Rivera, L; Silva-Pereyra, H G; Reyes-Esqueda, J A; Rodriguez-Fernandez, L; Crespo-Sosa, A; Cheang-Wong, J C; Oliver, A [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, 04510, Mexico, DF (Mexico); Rangel-Rojo, R [Departamento de Optica, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada Apartado Postal 360, Ensenada, BC, 22860 (Mexico); Torres-Martinez, R, E-mail: crstorres@yahoo.com.mx [Centro de Investigacion en Ciencia Aplicada y TecnologIa Avanzada Unidad Queretaro, Instituto Politecnico Nacional, Santiago de Queretaro, Queretaro, 76090 (Mexico)

    2011-09-02

    The nonlinear optical response of metallic-nanoparticle-containing composites was studied with picosecond and femtosecond pulses. Two different types of nanocomposites were prepared by an ion-implantation process, one containing Au nanoparticles (NPs) and the other Ag NPs. In order to measure the optical nonlinearities, we used a picosecond self-diffraction experiment and the femtosecond time-resolved optical Kerr gate technique. In both cases, electronic polarization and saturated absorption were identified as the physical mechanisms responsible for the picosecond third-order nonlinear response for a near-resonant 532 nm excitation. In contrast, a purely electronic nonlinearity was detected at 830 nm with non-resonant 80 fs pulses. Regarding the nonlinear optical refractive behavior, the Au nanocomposite presented a self-defocusing effect, while the Ag one presented the opposite, that is, a self-focusing response. But, when evaluating the simultaneous contributions when the samples are tested as a multilayer sample (silica-Au NPs-silica-Ag NPs-silica), we were able to obtain optical phase modulation of ultra-short laser pulses, as a result of a significant optical Kerr effect present in these nanocomposites. This allowed us to implement an ultrafast all-optical phase modulator device by using a combination of two different metallic ion-implanted silica samples. This control of the optical phase is a consequence of the separate excitation of the nonlinear refracting phenomena exhibited by the separate Au and Ag nanocomposites.

  1. Quantum coherent optical phase modulation in an ultrafast transmission electron microscope.

    Science.gov (United States)

    Feist, Armin; Echternkamp, Katharina E; Schauss, Jakob; Yalunin, Sergey V; Schäfer, Sascha; Ropers, Claus

    2015-05-14

    Coherent manipulation of quantum systems with light is expected to be a cornerstone of future information and communication technology, including quantum computation and cryptography. The transfer of an optical phase onto a quantum wavefunction is a defining aspect of coherent interactions and forms the basis of quantum state preparation, synchronization and metrology. Light-phase-modulated electron states near atoms and molecules are essential for the techniques of attosecond science, including the generation of extreme-ultraviolet pulses and orbital tomography. In contrast, the quantum-coherent phase-modulation of energetic free-electron beams has not been demonstrated, although it promises direct access to ultrafast imaging and spectroscopy with tailored electron pulses on the attosecond scale. Here we demonstrate the coherent quantum state manipulation of free-electron populations in an electron microscope beam. We employ the interaction of ultrashort electron pulses with optical near-fields to induce Rabi oscillations in the populations of electron momentum states, observed as a function of the optical driving field. Excellent agreement with the scaling of an equal-Rabi multilevel quantum ladder is obtained, representing the observation of a light-driven 'quantum walk' coherently reshaping electron density in momentum space. We note that, after the interaction, the optically generated superposition of momentum states evolves into a train of attosecond electron pulses. Our results reveal the potential of quantum control for the precision structuring of electron densities, with possible applications ranging from ultrafast electron spectroscopy and microscopy to accelerator science and free-electron lasers.

  2. Morphology effect on the light scattering and dynamic response of polymer network liquid crystal phase modulator.

    Science.gov (United States)

    Xiangjie, Zhao; Cangli, Liu; Jiazhu, Duan; Jiancheng, Zeng; Dayong, Zhang; Yongquan, Luo

    2014-06-16

    Polymer network liquid crystal (PNLC) was one of the most potential liquid crystal for submillisecond response phase modulation, which was possible to be applied in submillisecond response phase only spatial light modulator. But until now the light scattering when liquid crystal director was reoriented by external electric field limited its phase modulation application. Dynamic response of phase change when high voltage was applied was also not elucidated. The mechanism that determines the light scattering was studied by analyzing the polymer network morphology by SEM method. Samples were prepared by varying the polymerization temperature, UV curing intensity and polymerization time. The morphology effect on the dynamic response of phase change was studied, in which high voltage was usually applied and electro-striction effect was often induced. The experimental results indicate that the polymer network morphology was mainly characterized by cross linked single fibrils, cross linked fibril bundles or even both. Although the formation of fibril bundle usually induced large light scattering, such a polymer network could endure higher voltage. In contrast, although the formation of cross linked single fibrils induced small light scattering, such a polymer network cannot endure higher voltage. There is a tradeoff between the light scattering and high voltage endurance. The electro-optical properties such as threshold voltage and response time were taken to verify our conclusion. For future application, the monomer molecular structure, the liquid crystal solvent and the polymerization conditions should be optimized to generate optimal polymer network morphology.

  3. Additive-subtractive phase-modulated speckle interferometry: Fringe visibility under partial decorrelation

    Science.gov (United States)

    Krishnaswamy, Sridhar; Pouet, Bruno F.; Chatters, Tom C.

    1997-02-01

    Additive-subtractive phase modulated speckle interferometry (ASPMSI) is a technique that minimizes the susceptibility of speckle methods to environmental noise while providing fringes of good visibility. The method requires the acquisition of two consecutive video frames of additive-speckle images of the same two deformed states of an object at a rapid enough rate such that ambient noise is not a problem. The additive-speckle images as expected are of very poor visibility due to the presence of the self-interference term. An interframe phase-modulation is introduced and the two additive-speckle images are digitally subtracted to improve the fringe visibility by removing the self-interference term. The ASPM-SI method works with in-plane and out-of-plane deformation sensitive ESPI as well as with displacement-gradient sensitive speckle-shearing interferometry. It is shown that the ASPM-SI scheme has higher visibility than conventional additive-SI and performs consistently better than subtractive-SI schemes in the presence of partial interframe speckle decorrelating optical noise. Furthermore, it is shown that the fringe visibility of the out-of-plane displacement sensitive interferometer which uses a protected reference beam separate from the object beam can be made to be essentially unity even at complete interframe decorrelation.

  4. Effect of local absorption changes on phase-shift measurement using phase modulation spectroscopy

    Science.gov (United States)

    Cui, Weijia; Ostrander, Lee E.

    1993-09-01

    Recently, researchers have used phase modulation of photons (PMP) at near infrared wavelengths to assess in vivo tissue blood perfusion. The incident light intensity is amplitude modulated in the megahertz to gigahertz range and the phase shift is measured at the detector for the photon waves that have migrated through biological tissue. The obtained phase shift is related to the pathlength for the detected photons. In the past, the models for this process have not considered the effect upon phase produced by inhomogeneities within the in vivo tissue. The phase shift is a function of the distribution of the optical properties within the medium. We used a simple experimental model to investigate the effect upon phase shift of the location for optical changes. A mathematical model has been developed to describe this effect. The results demonstrate that a measured phase shift depends upon the location at which the optical properties are changed, as well as upon the magnitude of change in the optical properties. In vivo tissue is inhomogeneous so that its optical properties are also inhomogeneous. It is therefore important to consider the optical property distribution of the in vivo tissue when assessing blood perfusion using phase modulation measurements.

  5. Perencanaan Arrayed Waveguide Grating (AWG untuk Wavelength Division Multiplexing (WDM pada C-Band

    Directory of Open Access Journals (Sweden)

    Frezza Oktaviana Hariyadi

    2015-12-01

    Full Text Available Teknologi Arrayed Waveguide Grating (AWG, salah satu solusi membagi kanal menjadi sub kanal lebih kecil dengan mengatur selisih panjang array tetap. Dalam Makalah ini, dilakukan perencanaan desain parameter AWG beroperasi pada kanal C-Band (1530-1560 nm, untuk mendukung kebutuhan kanal WDM, baik coarse-WDM (CWDM, dense-WDM (CWDM maupun very high density-WDM (VHDWDM. Perencanaan dilakukan lewat perhitungan teoritis dan menggunakan bantuan tool berupa WDM_Phasar.Perhitungan parameter AWG secara teoritis bertujuan menghasilkan  parameter desain ideal, sementara lewat  WDM_phasar dengan menambahkan batasan ukuran devais, crosstalk dan nonuniformity, diharapkan akan diperoleh parameter desain yang lebih realistis. Adapun parameter yang diamati meliputi besarnya orde difraksi (m, panjang free propagation range (FPR, perbedaan panjang array (ΔL, jumlah array (Narray, jumlah kanal I/O (Nmax  dan free spectral range (FSR.Dengan contoh spasi kanal 100 GHz pada C-band,  dihasilkan parameter hitungan teoritis sebesar 1308,61 μm, 25,1698 μm, 43,7143, 108 buah, 27 kanal dan 21,211 nm, masing-masing untuk nilai FPR, ΔL, m, Narray, Nmax dan FSR. Sedangkan lewat bantuan WDM_Phasar dengan batasan ukuran devais (15000x9000 μm2, crosstalk (-35 dB dan nonuniformity (0,5, menghasilkan parameter AWG 1197,347 μm(FSR, 23,764 μm(ΔL, 41(m, 56 (Narray, 16(Nmax dan 11,2 nm(FSR. Semakin besar spasi kanal, jumlah bit yang bisa diangkut juga semakin banyak.

  6. BER analysis of SS-WDM based FSO system for Vellore weather conditions

    Science.gov (United States)

    Prabu, K.; Charanya, S.; Jain, Mehul; Guha, Debapriya

    2017-11-01

    Spectrum Slicing Wavelength Division Multiplexing (SS-WDM) has been advanced to boost the long distance communication in FSO channel which assists immense bit rate due to its high capacity and efficiency. It is a substitute to WDM systems having multiple coherent lasers with different wavelengths which is expensive. This paper is subjected to investigate the characteristics and quality of communication links of data rate 1.56 GB/s and wavelength of 1550 nm. The SS-WDM technique has been inspected for 4, 8 and 16 channels to increase the performance of communication under various weather conditions. The proposed model is susceptible to system degradation due to turbulences where wind velocity, refractive index and height of buildings have been majorly focused. A case study has been experimented on how the height of buildings around VIT, Vellore campus interfere the transmission of light in free space. Based on the above study, the results shows that the benefits of spectrum slicing wavelength division multiplexing (SS-WDM) have been worked up on for the climatic conditions which enhance performance of system. Moreover, the graphs plotted against bit error rate (BER), attenuation and distance makes the analysis better which highlights the characteristic features of SS-WDM.

  7. Dynamic link load balancing based integrated routing algorithm in IP-over-WDM networks

    Science.gov (United States)

    Zhang, Zhizhong; Zhang, Yunlin; Zeng, Qingji; Wang, Jianxin; Ye, Tong; Zhou, Yuli

    2004-04-01

    Integrated routing is a routing approach to support the peer interconnection model in IP over WDM networks. To have a better network link load distribution and network usage in IP over WDM networks, in which network nodes may have the ability to handle traffic in fine granularities, it is important to take into account the combined routing at the IP and WDM layers. Based upon this, this paper develops an algorithm for integrated dynamic routing of bandwidth guaranteed paths in IP over WDM networks. For newly dynamic arriving requests, as the developed algorithm takes into account the combined topology and resource usage information at the IP and WDM layers, and the routing procedure makes full use of the statistic information of the users" bandwidth requirement and considers carefully both the routing cost and the corresponding length of the routing path, thus a better link load balancing and network usage can be achieved. Simulation results show that the developed scheme performs well in terms of performance metrics such as the number of rejected demands and the network link load balancing.

  8. All-optical 40Gbit/s OTDM to 2x20Gbit/s WDM signal-format translation

    DEFF Research Database (Denmark)

    Jørgensen, Carsten; Danielsen, Søren Lykke; Mikkelsen, Benny

    1996-01-01

    40Gbit/s OTDM to 2 x 20 Gbit/s WDM signal-format translation is demonstrated using a cross-gain modulation in a semiconductor optical amplifier designed for high-speed operation. Excellent performance is demonstrated by polarisation-independent operation, showing clear eye diagrams and high...... extinction ratios for the translated WDM-channels....

  9. Experimental Investigation of WDM transmission properties for optical labeled signals using orthogonal IM/FSK modulation format

    DEFF Research Database (Denmark)

    Holm-Nielsen, Pablo Villanueva; Zhang, Jianfeng; Olmos, J. J. Vegas

    2004-01-01

    In this paper we report on WDM transmission of optical labeled signals using the orthogonal IM/FSK modulation format aimed for optical packet/burst switching. WDM transmission in both a point-to-point transmission system and a demonstration network with a label-swapping node are implemented....

  10. Characterisation and efficient simulation of thermal phenomena in SIMOX thermo-optic phase modulators

    CERN Document Server

    Clark, S A

    2001-01-01

    device has been designed to minimize power requirements, 3dB bandwidths in excess of 1kHz have been achieved for less than 10mW of drive power. A basic set of design parameters is developed which allow estimation of bandwidth and power requirements based on an initial knowledge of the material system and the intended modulator architecture. Silicon can be very effectively exploited in integrated optics due to its well-defined process chemistry and the availability of techniques developed primarily for the semiconductor industry which allow control over dimensions and the creation of arbitrary two dimensional structures with great precision and repeatability. In this thesis the complete design and simulation of thermo-optic phase modulators, realised in silicon-on-insulator (SOI), is presented. Since material thermal and optical parameters vary with temperature, anomalous departure between first-order theory and experimentation can exist when operating under conditions whereby material parameters are markedly ...

  11. Dynamic characterization of photo-alignment of azo-dye-doped polymer using phase modulated polarimetry

    Science.gov (United States)

    Chuang, Chun-I.; Lin, Shiuan-Huei; Chao, Yu-Faye

    2013-01-01

    Using a combination of two-probe-beam phase modulated polarimetry and a waveform extraction technique, we show it is possible to determine all the optical parameters of an anisotropic medium. Particularly, we have measured the dynamic changes of refractive index ellipsoid of the disperse red 19-doped poly(methyl methacrylate) under the irradiation of linear polarized lights. The long axis of the trans molecule can be aligned to the propagation direction of P-polarized light while it is irritated by two crossed polarized lights. The refractive indices and orientation angles can be determined in one cycle of modulation (20 μs) with sufficient precision of 10-6 and 0.1°, respectively. This work shows a new way to simultaneously monitor and control the photo-alignment process of azobenzene molecules in a polymer matrix.

  12. Pseudo-random-bit-sequence phase modulation for reduced errors in a fiber optic gyroscope.

    Science.gov (United States)

    Chamoun, Jacob; Digonnet, Michel J F

    2016-12-15

    Low noise and drift in a laser-driven fiber optic gyroscope (FOG) are demonstrated by interrogating the sensor with a low-coherence laser. The laser coherence was reduced by broadening its optical spectrum using an external electro-optic phase modulator driven by either a sinusoidal or a pseudo-random bit sequence (PRBS) waveform. The noise reduction measured in a FOG driven by a modulated laser agrees with the calculations based on the broadened laser spectrum. Using PRBS modulation, the linewidth of a laser was broadened from 10 MHz to more than 10 GHz, leading to a measured FOG noise of only 0.00073  deg/√h and a drift of 0.023  deg/h. To the best of our knowledge, these are the lowest noise and drift reported in a laser-driven FOG, and this noise is below the requirement for the inertial navigation of aircraft.

  13. Phase-shifting optical fiber sensing with rectangular-pulse binary phase modulation

    Science.gov (United States)

    Ren, Zhongjie; Li, Jianxin; Zhu, Rihong; Cui, Ke; He, Qing; Wang, Hailin

    2018-01-01

    We propose and demonstrate a new method of phase-shifting optical fiber sensing, wherein rectangular-pulse binary phase modulation is imposed on the laser source of an interferometric fiber optic sensor to generate three phase-shifting steps of - π / 2 , 0, and π/2 radians at the output, and the phase shifts that carry the vibration signals are demodulated with an orthogonal demodulation algorithm. This approach offers the advantages of high efficiency and low complexity because it is simple in design and implementation. Moreover, this method can be applied to successfully realize the demodulation of multiplexed systems based on different multiplexing techniques. The techniques are theoretically analyzed and experimentally demonstrated with recovering the sinusoid wave applied to the sensor. Also, in this paper, a simple multiplexed system is proposed and discussed.

  14. Self-phase modulation of a single-cycle THz pulse

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, M. C.

    2013-01-01

    We demonstrate self-phase modulation (SPM) of a single-cycle THz pulse in a semiconductor, using bulk n-GaAs as a model system. The SPM arises from the heating of free electrons in the electric field of the THz pulse. Electron heating leads to an ultrafast reduction of the plasma frequency, which...... results in a strong modification of the THz-range dielectric function of the material. THz SPM is observed directly in the time domain as a characteristic reshaping of single-cycle THz pulse. In the frequency domain, it corresponds to a strong frequency-dependent refractive index nonlinearity of n......-GaAs, which is found to be both positive and negative within the broad spectrum of the THz pulse. The spectral position of zero nonlinearity is defined by the electron momentum relaxation rate. Nonlinear spectral broadening and compression of the single-cycle THz pulse was also observed....

  15. Characterization of coherent quantum frequency combs using electro-optic phase modulation

    Science.gov (United States)

    Imany, Poolad; Odele, Ogaga D.; Jaramillo-Villegas, Jose A.; Leaird, Daniel E.; Weiner, Andrew M.

    2018-01-01

    We demonstrate a two-photon interference experiment for phase coherent biphoton frequency combs (BFCs), created through spectral amplitude filtering of biphotons with a continuous broadband spectrum. By using an electro-optic phase modulator, we project the BFC lines into sidebands that overlap in frequency. The resulting high-visibility interference patterns provide an approach to verify frequency-bin entanglement even with slow single-photon detectors; we show interference patterns with visibilities that surpass the classical threshold for qubit and qutrit states. Additionally, we show that with entangled qutrits, two-photon interference occurs even with projections onto different final frequency states. Finally, we show the versatility of this scheme for weak-light measurements by performing a series of two-dimensional experiments at different signal-idler frequency offsets to measure the dispersion of a single-mode fiber.

  16. Self-phase modulation of a single-cycle THz pulse

    Directory of Open Access Journals (Sweden)

    Hoffmann M. C.

    2013-03-01

    Full Text Available We demonstrate self-phase modulation (SPM of a single-cycle THz pulse in a semiconductor, using bulk n-GaAs as a model system. The SPM arises from the heating of free electrons in the electric field of the THz pulse. Electron heating leads to an ultrafast reduction of the plasma frequency, which results in a strong modification of the THz-range dielectric function of the material. THz SPM is observed directly in the time domain as a characteristic reshaping of single-cycle THz pulse. In the frequency domain, it corresponds to a strong frequency-dependent refractive index nonlinearity of n-GaAs, which is found to be both positive and negative within the broad spectrum of the THz pulse. The spectral position of zero nonlinearity is defined by the electron momentum relaxation rate. Nonlinear spectral broadening and compression of the single-cycle THz pulse was also observed.

  17. A novel binaural pitch elicited by phase-modulated noise: MEG and psychophysical observations.

    Science.gov (United States)

    Witton, Caroline; Hillebrand, Arjan; Furlong, Paul L; Henning, G Bruce

    2012-06-01

    Binaural pitches are auditory percepts that emerge from combined inputs to the ears but that cannot be heard if the stimulus is presented to either ear alone. Here, we describe a binaural pitch that is not easily accommodated within current models of binaural processing. Convergent magnetoencephalography (MEG) and psychophysical measurements were used to characterize the pitch, heard when band-limited noise had a rapidly changing interaural phase difference. Several interesting features emerged: First, the pitch was perceptually lateralized, in agreement with the lateralization of the evoked changes in MEG spectral power, and its salience depended on dichotic binaural presentation. Second, the frequency of the pure tone that matched the binaural pitch lay within a lower spectral sideband of the phase-modulated noise and followed the frequency of that sideband when the modulation frequency or center frequency and bandwidth of the noise changed. Thus, the binaural pitch depended on the processing of binaural information in that lower sideband.

  18. Study on 8DPSK of multi-phase modulation technology based on CSRZ

    Science.gov (United States)

    Zhang, Xia; Xu, Heng-ying; Niu, Hui-juan; Zhang, Min; Wang, Fang; Bai, Cheng-lin; Zhang, Xiao-guang

    2011-03-01

    A new modulation format in optical fiber communication system, the eight differential phase shift keying (8DPSK) of multi-phase modulation technology based on carrier-suppressed return-to-zero (CSRZ) is proposed in this paper. The formulae of CSRZ-8DPSK modem methods are derived theoretically and the methods are demonstrated. Spectra based on CSRZ and CSRZ-8DPSK modulation methods and their eye diagrams by simulation with MATLAB are obtained. The results show that the CSRZ-8DPSK modulation methods have narrower spectra with higher efficiency. The performance of eye diagrams is also much satisfactory after demodulation, suggesting some possible applications of the methods in the next generation of optical fiber communications.

  19. Digital coherent receiver employing photonic downconversion for phase modulated radio-over-fibre links

    DEFF Research Database (Denmark)

    Zibar, Darko; Caballero Jambrina, Antonio; Guerrero Gonzalez, Neil

    2009-01-01

    A digital coherent receiver employing photonic downconversion is presented and experimentally demonstrated for phase-modulated radio-over-fibre optical links. The receiver is capable of operating at frequencies exceeding the bandwidth of electrical analog-to-digital converter by using photonic...... downconversion to translate the high-frequency input RF signal to the operating frequency range of the analog-to-digital converter. First, using linear digital demodulation scheme we measure SFDR of the link at microwave frequency of 5 GHz. Thereafter, successful signal demodulation of 50 Mbit/s binary phase...... shift keying (BPSK) modulated data signal at 5 GHz RF carrier frequency is experimentally demonstrated by using an analog-to-digital converter with only 1 GHz bandwidth. We successfully demonstrate signal demodulation, using the proposed digital coherent receiver with photonic downconversion, after 40...

  20. PSB beam longitudinal blow-up by phase modulation with the digital LLRF prototype system

    CERN Document Server

    Angoletta, M E; Butterworth, A; Findlay, A; Jaussi, M; Leinonen, P; Molendijk, J; Sanchez-Quesada, J

    2014-01-01

    The PSB will be upgraded to a new, Digital Low-Level RF (DLLRF) system in 2014 at the injectors’ restart after LS1. This DLLRF is an evolution of that successfully deployed in LEIR and comprises new hardware, software and implementation strategies. Machine development studies have been carried out in the PSB over recent years with the existing LEIR-style hardware installed in PSB ring four. These studies have allowed testing approaches and validating implementation strategies. This note focuses on a series of MDs carried out during the 2011 run where a new implementation of the longitudinal beam blow-up obtained by phase modulation was tested. Test results and effects on the beam are show for a CNGS-type beam. Finally, an overview is given of the final longitudinal blow-up implementation planned with the new hardware, which will be operationally deployed in 2014.

  1. Performance analysis of variable speed multiphase induction motor with pole phase modulation

    Directory of Open Access Journals (Sweden)

    Liu Huijuan

    2016-09-01

    Full Text Available The pole phase modulation (PPM technique is an effective method to extend speed range and torque capabilities for an integrated starter and hybrid electric vehicles applications. In this paper, the five pole-phase combination types of a multiphase induction motor (IM with 36 stator slots and 36 stator conductors are presented and compared quantitatively by using the time-stepping finite element method (TS-FEM. The 36 stator conductors of the proposed multiphase IM are fed by a 36 leg inverter and the current phase angle and amplitude of each stator conductor can be controlled independently. This paper focuses on the winding connection, the PPM technique and the performance comparative analysis of each pole-phase combination types of the proposed multiphase IM. The flux distribution, air-gap flux density, output torque, core losses and efficiency of five pole-phase combination types have been investigated.

  2. Submillisecond-response and scattering-free infrared liquid crystal phase modulators.

    Science.gov (United States)

    Sun, Jie; Chen, Yuan; Wu, Shin-Tson

    2012-08-27

    We demonstrate a submillisecond-response and scattering-free infrared phase modulator using a polymer network liquid crystal (PNLC). The required voltage for achieving 2π phase change at λ = 1.06 µm is 70V (or 5.8 V/μm) and the measured response time is ~200 µs at 25°C and 30 µs at 70°C. Opposite to our conventional understanding, a high viscosity LC helps to achieve small domain size during polymerization process, which in turn reduces the response time and light scattering. We use Rayleigh-Gans-Debye scattering model to analyze the voltage-on state transmission spectra. When the domain size is comparable to the wavelength, the model fits with experimental results well. But when the domain size is smaller than the wavelength, the simple Rayleigh model works well.

  3. Phase modulation in horizontal metal-insulator-silicon-insulator-metal plasmonic waveguides.

    Science.gov (United States)

    Zhu, Shiyang; Lo, G Q; Kwong, D L

    2013-04-08

    An extremely compact Si phase modulator is proposed and validated, which relies on effective modulation of the real part of modal index of horizontal metal-insulator-Si-insulator-metal plasmonic waveguides by a voltage applied between the metal cover and the Si core. Proof-of-concept devices are fabricated on silicon-on-insulator substrates using standard complementary metal-oxide-semiconductor technology using copper as the metal and thermal silicon dioxide as the insulator. A modulator with a 1-μm-long phase shifter inserted in an asymmetric Si Mach-Zehnder interferometer exhibits 9-dB extinction ratio under a 6-V/10-kHz voltage swing. Numerical simulations suggest that high speed and low driving voltage could be achieved by shortening the distance between the Si core and the n(+)-contact and by using a high-κ dielectric as the insulator, respectively.

  4. Multiwavelength 25-GHz picosecond pulse generation with phase modulation and double-side Mamyshev reshaping.

    Science.gov (United States)

    Huo, Li; Li, Hongfeng; Wang, Dong; Wang, Qiang; Lou, Caiyun

    2015-06-20

    We demonstrate a simple, robust, and cost-effective method of generating high-speed multiwavelength picosecond optical pulses. This method is based on chirp compression of phase-modulated light, followed by nonlinear pulse compression and reshaping with a double-side Mamyshev reshaper. We show that this method becomes power efficient when the repetition rate is increased to 25 GHz. Wavelength-tunable optical pulses with a repetition rate of 25 GHz and pulse width of ∼2  ps, which can be temporally multiplexed to 100 GHz, are experimentally obtained over a large spectral range with moderate electrical and optical power. Simultaneous pulse generation on four wavelengths is demonstrated.

  5. Optical phase modulation based on directly modulated reflection-mode OIL-VCSEL.

    Science.gov (United States)

    Guo, Peng; Sun, Tao; Yang, Weijian; Parekh, Devang; Zhang, Cheng; Xie, Xiaopeng; Chang-Hasnain, Connie J; Xu, Anshi; Chen, Zhangyuan

    2013-09-23

    Optical phase modulation based on directly modulated reflection-mode optically injection-locked VCSEL is investigated based on standard OIL rate equations and reflection-mode OIL model. The phase information of both static and dynamic state is simulated. The difference of static state phase information between transmission- and reflection-mode OIL is numerically analyzed. With specific OIL parameters, the output power of directly modulated OIL-VCSEL remains constant and phase deviation of 0.934π rad is obtained. Results show that a directly modulated OIL-VCSEL can function as a key component in QPSK or 8PSK transmitters. Preliminary 2.5 Gb/s PSK modulation characteristic is demonstrated experimentally.

  6. Spectral Phase Modulation and chirped pulse amplification in High Gain Harmonic Generation

    CERN Document Server

    Wu, Zilu; Krinsky, Sam; Loos, Henrik; Murphy, James; Shaftan, Timur; Sheehy, Brian; Shen, Yuzhen; Wang, Xijie; Yu Li Hua

    2004-01-01

    High Gain Harmonic Generation (HGHG), because it produces longitudinally coherent pulses derived from a coherent seed, presents remarkable possibilities for manipulating FEL pulses. If spectral phase modulation imposed on the seed modulates the spectral phase of the HGHG in a deterministic fashion, then chirped pulse amplification, pulse shaping, and coherent control experiments at short wavelengths become possible. In addition, the details of the transfer function will likely depend on electron beam and radiator dynamics and so prove to be a useful tool for studying these. Using the DUVFEL at the National Synchrotron Light Source at Brookhaven National Laboratory, we present spectral phase analyses of both coherent HGHG and incoherent SASE ultraviolet FEL radiation, applying Spectral Interferometry for Direct Electric Field Reconstruction (SPIDER), and assess the potential for employing compression and shaping techniques.

  7. All-Optical Ultra-High-Speed OFDM to Nyquist-WDM Conversion Based on Complete Optical Fourier Transformation

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Mulvad, Hans Christian Hansen

    2016-01-01

    We propose a novel all-optical ultra-high-speed orthogonal frequency-division multiplexing (OFDM) to Nyquist wavelength-division multiplexing (Nyquist-WDM) conversion scheme, achieved by exchanging the temporal and spectral profiles using a complete optical Fourier transformation (OFT). This scheme...... enables high-speed OFDM to Nyquist-WDM conversion without complex optical/electrical/optical conversion. The all-optical OFDM transmitter is based on the generation of OFDM symbols with a low duty cycle by rectangular temporal gating, which in combination with optical time-division multiplexing yields...... a higher symbol-rate OFDM signal. In the receiver, the converted Nyquist-WDM super-channel is WDM demultiplexed into individual Nyquist-WDM channels using a rectangular optical bandpass filter, followed by optical sampling at the intersymbol-interference free point. In the experimental demonstration...

  8. WDM extended reach passive optical networks using OFDM-QAM.

    Science.gov (United States)

    Chow, Chi-Wai; Yeh, Chien-Hung; Wang, Chia-Hsuan; Shih, Fu-Yuan; Pan, Ci-Ling; Chi, Sien

    2008-08-04

    In order to reduce the cost for delivering future broadband services, network operators are inclined to simplify the network architectures by integrating the metro and access networks into a single system. Hence, extended reach passive optical networks (ER-PONs) have been proposed. ER-PON usually has four new features: high data rate in both upstream and downstream signals (>1 Gb/s); reach extension to >100 km; a high split ratio (>100); and using wavelength division multiplexing (WDM). In this work, we propose and demonstrate a highly spectral efficient ER-PON using 4 Gb/s OFDM-QAM for both upstream and downstream signals, while achieving a high split-ratio of 256. The ER-PON employs optical components optimized for GPON (bandwidth of approximately 1 GHz) and reaches 100 km without dispersion compensation. Numerical analysis using 16, 64 and 256-QAM OFDM are also performed to study the back-to-back receiver sensitivities and power penalties at different electrical driving ratios.

  9. Fiber-optic perimeter security system based on WDM technology

    Science.gov (United States)

    Polyakov, Alexandre V.

    2017-10-01

    Intelligent underground fiber optic perimeter security system is presented. Their structure, operation, software and hardware with neural networks elements are described. System allows not only to establish the fact of violation of the perimeter, but also to locate violations. This is achieved through the use of WDM-technology division spectral information channels. As used quasi-distributed optoelectronic recirculation system as a discrete sensor. The principle of operation is based on registration of the recirculation period change in the closed optoelectronic circuit at different wavelengths under microstrain exposed optical fiber. As a result microstrain fiber having additional power loss in a fiber optical propagating pulse, which causes a time delay as a result of switching moments of the threshold device. To separate the signals generated by intruder noise and interference, the signal analyzer is used, based on the principle of a neural network. The system detects walking, running or crawling intruder, as well as undermining attempts to register under the perimeter line. These alarm systems can be used to protect the perimeters of facilities such as airports, nuclear reactors, power plants, warehouses, and other extended territory.

  10. A Dynamic Resilience Approach for WDM Optical Networks

    Science.gov (United States)

    Garg, Amit Kumar

    2017-12-01

    Optical fibres have been developed as a transmission medium to carry traffic in order to provide various services in telecommunications platform. Failure of this fibre caused loss of data which can interrupt communication services. This paper has been focused only on survivable schemes in order to guarantee both protection and restoration in WDM optical networks. In this paper, a dynamic resilience approach has been proposed whose objective is to route the flows in a way which minimizes the total amount of bandwidth used for working and protection paths. In the proposed approach, path-based protection is utilized because it yields lower overhead and is also suitable for global optimization where, in case of a single link failure, all the flows utilizing the failed link are re-routed to a pre-computed set of paths. The simulation results demonstrate that proposed approach is much more efficient as it provides better quality of services (QoS) in terms of network resource utilization, blocking probability etc. as compared to conventional protection and restoration schemes. The proposed approach seems to offer an attractive combination of features, with both ring like speed and mesh-like efficiency.

  11. Photonic bandgap quasi-crystals for integrated WDM devices

    Science.gov (United States)

    Yankov, Vladimir V.; Babin, Sergey; Ivonin, Igor; Goltsov, Alexander Y.; Morozov, Anatolii; Polonskiy, Leonid; Spector, Michael; Talapov, Andrei; Kley, Ernst-Bernhard; Schmidt, Holger; Dahlgren, Robert P.

    2003-06-01

    A novel concept of Photonic Bandgap Quasi-Crystal (PBQC) as a platform for planar integrated WDM optical devices is proposed. The PBQC can be lithographically fabricated in a planar waveguide as a computer-generated two-dimensional hologram. In this approach the spectral selectivity of Bragg gratings, focusing properties of elliptical mirrors, superposition properties of thick holograms, photonic bandgaps of periodic structures, and flexibility of lithography on planar waveguides are combined. In distinction to conventional combination of independent planar Bragg gratings, in PBQC we create multiple bandgaps by synthesizing a synergetic super-grating of a number of individual sub-gratings. The device spectral selectivity is determined by those of the sub-gratings. The super-grating comprises million(s) of dashes etched on an interface of a planar waveguide. Each dash is a binary feature placed by a computer program to serve simultaneously many channels. For realization of PBQC devices the software for generating super-gratings (GDS-II format) and 2-D simulation of its transfer function was developed. Direct e-beam writing and photolithography were used for manufacturing PBQC structures. For verification of the ideas behind the concept a number of multichannel MUX/DEMUX devices have been manufactured and experimentally tested. The results of detailed experimental study of 4- and 16-channel devices will be presented. Channel isolation ~30 dB was achieved in the 4-channel devices. The applications of PBQC platform for integrated light wave circuits are discussed.

  12. Efficient traffic grooming in SONET/WDM BLSR Networks

    Energy Technology Data Exchange (ETDEWEB)

    Awwal, A S; Billah, A B; Wang, B

    2004-04-02

    In this paper, we study traffic grooming in SONET/WDM BLSR networks under the uniform all-to-all traffic model with an objective to reduce total network costs (wavelength and electronic multiplexing costs), in particular, to minimize the number of ADMs while using the optimal number of wavelengths. We derive a new tighter lower bound for the number of wavelengths when the number of nodes is a multiple of 4. We show that this lower bound is achievable. All previous ADM lower bounds except perhaps that in were derived under the assumption that the magnitude of the traffic streams (r) is one unit (r = 1) with respect to the wavelength capacity granularity g. We then derive new, more general and tighter lower bounds for the number of ADMs subject to that the optimal number of wavelengths is used, and propose heuristic algorithms (circle construction algorithm and circle grooming algorithm) that try to minimize the number of ADMs while using the optimal number of wavelengths in BLSR networks. Both the bounds and algorithms are applicable to any value of r and for different wavelength granularity g. Performance evaluation shows that wherever applicable, our lower bounds are at least as good as existing bounds and are much tighter than existing ones in many cases. Our proposed heuristic grooming algorithms perform very well with traffic streams of larger magnitude. The resulting number of ADMs required is very close to the corresponding lower bounds derived in this paper.

  13. Wavelength dimensioning for wavelength-routed WDM satellite network

    Directory of Open Access Journals (Sweden)

    Liu Zhe

    2016-06-01

    Full Text Available Internet and broadband applications driven by data traffic demand have become key drivers for satellite constellations. The key technology to satisfy the high capacity requirements between satellites is optical satellite networks by means of wavelength division multiplexing inter-satellite links (ISLs with wavelength routing (WDM-OSN. Due to the limited optical amplifier bandwidth onboard the satellite, it is important to minimize the wavelength requirements to provision requests. However, ISLs should be dynamically established and deleted for each satellite according to its visible satellites. Furthermore, different link assignments will result in different topologies, hence yielding different routings and wavelength assignments. Thus, a perfect match model-based link assignment scheme (LAS-PMM is proposed to design an appropriate topology such that shorter path could be routed and less wavelengths could be assigned for each ISL along the path. Finally, simulation results show that in comparison to the regular Manhattan street network (MSN topology, wavelength requirements and average end-to-end delay based on the topology generated by LAS-PMM could be reduced by 24.8% and 12.4%, respectively.

  14. Ion beam focusing with cone optics for WDM experiments

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Jun, E-mail: jun.hasegawa@es.titech.ac.jp [Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kondo, Kotaro; Oguri, Yoshiyuki [Research Laboratory for Nuclear Reactors, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Horioka, Kazuhiko [Department of Energy Sciences, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan)

    2014-01-01

    Beam focusing properties of cone optics were systematically investigated by Monte Carlo simulations under various combinations of beam and cone parameters. To optimize the cone optic design for accelerator-driven WDM experiments, the beam intensity gains after cone focusing were evaluated from the simulation results as functions of cone wall material and shape parameters such as taper angle and wall curvature. The uniformity of the cone-focused beam was also examined by considering not only various cone parameters but also the cases involving the misalignment of the cone optic. From the results, a parabolic gold cone was found to be the best choice at least for relatively light ions such as lithium having MeV energies. It is also found that although smaller taper angle improves the total beam transport efficiency in the optic, it brings more difficulties in the alignment of the optic because the alignment accuracy should be less than a half of the taper angle to obtain acceptable uniformity in the beam energy deposition on the target.

  15. Quantification of Doppler broadening in path length resolved diffusive light scattering using phase modulated low-coherence interferometry

    Science.gov (United States)

    Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton G.; Steenbergen, Wiendelt

    2007-02-01

    We describe path length resolved Doppler measurements of the multiply scattered light in turbid media using phase modulated low coherence Mach-Zehnder interferometer, with separate fibers for illumination and detection. A Doppler broadened phase modulation interference peak observed at the modulation frequency shows an increase in the average Doppler shift with optical path length. The path length dependent Doppler broadening of scattered light due to the detection of multiple scattered light is measured from the Lorentzian linewidth and the results are compared with the predictions of Diffusive Wave Spectroscopy. For particles with small scattering anisotropy, the diffusion approximation shows good agreement with our experimental results. For anisotropic scatterers, the experimental results show deviations from the Diffusion theory. The optical path lengths are determined experimentally from the Zero order moment of the phase modulation peak around the modulation frequency and the results are validated with the Monte Carlo technique.

  16. High angle phase modulated low coherence interferometry for path length resolved Doppler measurements of multiply scattered light

    Science.gov (United States)

    Varghese, Babu; Rajan, Vinayakrishnan; Van Leeuwen, Ton G.; Steenbergen, Wiendelt

    2008-02-01

    We describe an improved method for coherence domain path length resolved measurements of multiply scattered photons in turbid media. An electro-optic phase modulator sinusoidally modulates the phase in the reference arm of a low coherence fiber optic Mach-Zehnder interferometer, at a high phase modulation angle. For dynamic turbid media this results in Doppler broadened phase modulation interference peaks at the modulation frequency and its multiples. The signal to noise ratio is increased by almost one order or magnitude for large modulation angles and the shape of the spectral peaks resulting from the interference of Doppler shifted sample waves and reference light is not changed. The path length dependent Doppler broadening is compared with the theoretical predictions in the single scattered and diffusive regimes. The experimentally measured optical path lengths are validated with the Monte Carlo technique.

  17. Unravelling the role of quantum interference in the weak-field laser phase modulation control of photofragment distributions.

    Science.gov (United States)

    García-Vela, Alberto; Henriksen, Niels E

    2016-02-14

    The role played by quantum interference in the laser phase modulation coherent control of photofragment distributions in the weak-field regime is investigated in detail in this work. The specific application involves realistic wave packet calculations of the transient vibrational populations of the Br2(B,vf) fragment produced upon predissociation of the Ne-Br2(B) complex, which is excited to a superposition of overlapping resonance states using different fixed bandwidth pulses where the linear chirps are varied. The postpulse transient phase modulation effects observed on fragment populations for a long time window are explained in terms of the mechanism of interference between overlapping resonances. A detailed description of how the interference mechanism affects the magnitude and the time window of the phase control effects is also provided. In the light of the results, the conditions to maximize phase modulation control on fragment distributions are discussed.

  18. Bi-directional small form pluggable optical transceiver using an integrated WDM optical subassembly

    Science.gov (United States)

    Yoon, Hyun-Jae; Cho, Hyun-Woo; Cho, Young-Uk; Kim, Ki-Dae

    2006-09-01

    The 1.3/1.55 μm bi-directional small form pluggable (SFP) optical transceiver with an integrated wavelength division multiplexing (WDM) subassembly using accurate ceramic blocks has been developed. The WDM subassembly on which a laser diode (LD), a receiver photodiode (r-PD), a WDM filter, and two micro lenses are integrated is only 2.0 x 2.1 x 0.6 mm 3 in size and inserted in a TO-CAN package. The SFP transceiver coupled with single mode fiber has been operated at a 622Mbps data rate. The transmitted optical output power is -2.8 dBm and the measured value of sensitivity is -32 dBm at 10 -10 Bit Error Rate (BER).

  19. Energy-efficient WDM-OFDM-PON employing shared OFDM modulation modules in optical line terminal.

    Science.gov (United States)

    Hu, Xiaofeng; Zhang, Liang; Cao, Pan; Wang, Kongtao; Su, Yikai

    2012-03-26

    We propose and experimentally demonstrate a scheme to improve the energy efficiency of wavelength division multiplexing - orthogonal frequency division multiplexing - passive optical networks (WDM-OFDM-PONs). By using an N × M opto-mechanic switch in optical line terminal (OLT), an OFDM modulation module is shared by several channels to deliver data to multiple users with low traffic demands during non-peak hours of the day, thus greatly reducing the number of operating devices and minimizing the energy consumption of the OLT. An experiment utilizing one OFDM modulation module to serve three optical network units (ONUs) in a WDM-OFDM-PON is performed to verify the feasibility of our proposal. Theoretical analysis and numerical calculation show that the proposed scheme can achieve a saving of 23.6% in the energy consumption of the OFDM modulation modules compared to conventional WDM-OFDM-PON.

  20. Measurement of higher harmonics in periodic vibrations using phase-modulated TV holography with digital image processing.

    Science.gov (United States)

    Løkberg, O J; Pedersen, H M; Valø, H; Wang, G

    1994-08-01

    We separately measure the higher harmonics vibration patterns of a periodic vibrating object by using time-average TV holography and phase modulation. During measurements the frequency of the phase modulation is adjusted to each harmonic component while the excitation of the object is set low enough to record all components on the linear part of the fringe function. Using acoustical phase stepping and calibration of the fringe function, we compute the amplitude and phase distributions of the frequency component. We measure components up to the 65th harmonic by using square-wave excitation.

  1. Nonlinearity and Phase Noise Tolerant 75-110 GHz Signal over Fiber System Using Phase Modulation Technique

    DEFF Research Database (Denmark)

    Deng, Lei; Pang, Xiaodan; Zhang, Xu

    2013-01-01

    We report on the transmission of 8 Gb/s 0 dB PAPR 16QAM-OFDM W-band (75-110 GHz) signals over 22.8km SMF without phase noise compensation by using a phase modulator in the optical heterodyne up-convertor.......We report on the transmission of 8 Gb/s 0 dB PAPR 16QAM-OFDM W-band (75-110 GHz) signals over 22.8km SMF without phase noise compensation by using a phase modulator in the optical heterodyne up-convertor....

  2. Comparison of photothermal and piezoacoustic excitation methods for frequency and phase modulation atomic force microscopy in liquid environments

    OpenAIRE

    Labuda, A.; Kobayashi, K; D. Kiracofe; Suzuki, K; P. H. Grütter; Yamada, H

    2011-01-01

    In attempting to perform frequency modulation atomic force microscopy (FM-AFM) in liquids, a non-flat phase transfer function in the self-excitation system prevents proper tracking of the cantilever natural frequency. This results in frequency-and-phase modulation atomic force microscopy (FPM-AFM) which lies in between phase modulation atomic force microscopy (PM-AFM) and FM-AFM. We derive the theory necessary to recover the conservative force and damping in such a situation, where standard F...

  3. Field Trial of 40 Gb/s Optical Transport Network using Open WDM Interfaces

    DEFF Research Database (Denmark)

    Fagertun, Anna Manolova; Ruepp, Sarah Renée; Petersen, Martin Nordal

    2013-01-01

    An experimental field-trail deployment of a 40Gb/s open WDM interface in an operational network is presented, in cross-carrier interconnection scenario. Practical challenges of integration and performance measures for both native and alien channels are outlined.......An experimental field-trail deployment of a 40Gb/s open WDM interface in an operational network is presented, in cross-carrier interconnection scenario. Practical challenges of integration and performance measures for both native and alien channels are outlined....

  4. Combined Optical and Electrical Spectrum Shaping for High-Baud-Rate Nyquist-WDM Transceivers

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Borkowski, Robert; Preussler, Stefan

    2016-01-01

    . To investigate the benefits of the proposed approach, we demonstrate 32 the first WDM Nyquist-OTDM signal generation based on the periodic train of sinc pulses 33 and electrical spectrum shaping. Straight line transmission of five 112.5-Gbd Nyquist- 34 OTDM dual-polarization quadrature phase-shift keying (QPSK...... bandwidth is related to the optical comb parameters 25 and the pulse shaping of the modulating waveforms in the electrical domain. Such de- 26 pendence may result in broadening of the modulated spectra, which can degrade the 27 performance of Nyquist-WDM systems due to interchannel crosstalk penalties...

  5. 16 channel WDM regeneration in a single phase-sensitive amplifier through optical Fourier transformation

    DEFF Research Database (Denmark)

    Guan, Pengyu; Da Ros, Francesco; Lillieholm, Mads

    2016-01-01

    We demonstrate simultaneous phase regeneration of 16-WDM DPSK channels using optical Fourier transformation and a single phase-sensitive amplifier. The BERs of 16-WDM×10-Gbit/s phase noise degraded DPSK signals are improved by 0.4-1.3 orders of magnitude......We demonstrate simultaneous phase regeneration of 16-WDM DPSK channels using optical Fourier transformation and a single phase-sensitive amplifier. The BERs of 16-WDM×10-Gbit/s phase noise degraded DPSK signals are improved by 0.4-1.3 orders of magnitude...

  6. Fiber nonlinearity compensation of an 8-channel WDM PDM-QPSK signal using multiple phase conjugations

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Dinu, M.

    2013-01-01

    We demonstrate compensation of fiber nonlinearities using optical phase conjugation of an 8-chamiel WDM 32-Gbaud PDM QPSK signal. Conjugating phase every 600 km in a fiber loop enabled a 6000 km transmission over True Wave fiber. © 2013 Optical Society of America.......We demonstrate compensation of fiber nonlinearities using optical phase conjugation of an 8-chamiel WDM 32-Gbaud PDM QPSK signal. Conjugating phase every 600 km in a fiber loop enabled a 6000 km transmission over True Wave fiber. © 2013 Optical Society of America....

  7. Multifold clock recovery and demultiplexing based on a polarization-dependent phase modulator incorporated frequency-doubling optoelectronic oscillator

    Science.gov (United States)

    Tang, Yu; Wang, Muguang; Sun, Jian; Wu, Beilei; Zhang, Jing; Ding, Qi; Li, Tangjun

    2017-11-01

    A novel multifold clock recovery structure with demultiplexing function based on a frequency-doubling optoelectronic oscillator (FD-OEO) incorporating a common commercial phase modulator (PM) is proposed and experimentally demonstrated. A special phase modulation is obtained thanks to polarization-sensitive feature of LiNbO3 crystal of the PM. The special phase modulated signal is then split two parts connected by two pairs of polarization controllers (PCs) and polarizers to perform polarization interference and phase modulation to intensity modulation conversion. By controlling the PCs, the joint use of PC and polarizer in the loop is to guarantee an OEO with fundamental frequency self-oscillation, while the other outside of the OEO obtains frequency-doubled microwave signal at the output of the photodetector. Additionally, an optical filter can be inserted into the outside branch to only allow ±2nd-order sidebands pass through and realize frequency quadrupling after beating at the PD. Therefore, a prescaled clock at 10 GHz, a line-rate clock at 20 GHz and a 40 GHz frequency-doubled clock can be extracted from the injection-locked OEO respectively when a 2 × 10 Gb / s optical time division multiplexing (OTDM) data signal is injected. A twofold time division demultiplexing is demonstrated. Theoretical analysis is developed, which is validated by an experiment.

  8. Optical wavelength conversion by cross-phase modulation of data signals up to 640 Gb/s

    DEFF Research Database (Denmark)

    Galili, Michael; Oxenløwe, Leif Katsuo; Mulvad, Hans Christian Hansen

    2008-01-01

    In this paper, all-optical wavelength conversion by cross-phase modulation in a highly nonlinear fiber is investigated. Regenerative properties of the wavelength converter are demonstrated, and the effect of adding Raman gain to enhance the performance of the wavelength converter is shown...

  9. Quantification of Optical Doppler broadening and optical path lengths of multiply scattered light with phase modulated low coherence interferometry

    NARCIS (Netherlands)

    Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton; Steenbergen, Wiendelt

    2007-01-01

    We show experimental validation of a novel technique to measure optical path length distributions and path length resolved Doppler broadening in turbid media for different reduced scattering coefficients and anisotropies. The technique involves a phase modulated low coherence Mach-Zehnder

  10. High angle phase modulated low coherence interferometry for path length resolved Doppler measurements of multiply scattered light

    NARCIS (Netherlands)

    Varghese, Babu; Rajan, Vinayakrishnan; van Leeuwen, Ton; Steenbergen, Wiendelt

    2008-01-01

    We describe an improved method for coherence domain path length resolved measurements of multiply scattered photons in turbid media. An electro-optic phase modulator sinusoidally modulates the phase in the reference arm of a low coherence fiber optic Mach–Zehnder interferometer, at a high phase

  11. Suppression of Brillouin scattering in fibre-optical parametric amplifier by applying temperature control and phase modulation

    DEFF Research Database (Denmark)

    Lorenzen, Michael Rodas; Noordegraaf, Danny; Nielsen, Carsten Vandel

    2009-01-01

    An increased gain in a fibre-optical parametric amplifier through suppression of stimulated Brillouin scattering is demonstrated by applying a temperature distribution along the fibre for a fixed phase modulation of the pump. The temperature distribution slightly impacts the gain spectrum....

  12. Forward error correction supported 150 Gbit/s error-free wavelength conversion based on cross phase modulation in silicon

    DEFF Research Database (Denmark)

    Hu, Hao; Andersen, Jakob Dahl; Rasmussen, Anders

    2013-01-01

    We build a forward error correction (FEC) module and implement it in an optical signal processing experiment. The experiment consists of two cascaded nonlinear optical signal processes, 160 Gbit/s all optical wavelength conversion based on the cross phase modulation (XPM) in a silicon nanowire...

  13. Self phase modulation and stimulated raman scattering due to high power femtosecond pulse propagation in silicon-on-insulator waveguides

    NARCIS (Netherlands)

    Mégret, P.; Dekker, R.; Wuilpart, M.; Klein, E.J.; Niehusmann, J.; Bette, S.; Staquet, N.; Först, M.; Ondracek, F.; Ctyroky, J.; Usechak, N.; Driessen, A.

    2005-01-01

    Self Phase Modulation (SPM) and Stimulated Raman Scattering (SRS) in silicon waveguides have been observed and will be discussed theoretically using a modified Nonlinear Schrödinger Equation. The high optical peak powers needed for the experiments were obtained by coupling sub-picosecond (200fs)

  14. 10Gb/s Ultra-Wideband Wireless Transmission Based on Multi-Band Carrierless Amplitude Phase Modulation

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Vegas Olmos, Juan José

    2016-01-01

    In this paper, for the first time, a record UWB transmission of 10Gb/s is experimentally demonstrated employing a multi-band approach of carrierless amplitude phase modulation (MultiCAP). The proposed solution complies with the restrictions on the effective radiated power established by both...

  15. Self-phase modulation enabled, wavelength-tunable ultrafast fiber laser sources: an energy scalable approach.

    Science.gov (United States)

    Liu, Wei; Li, Chen; Zhang, Zhigang; Kärtner, Franz X; Chang, Guoqing

    2016-07-11

    We propose and demonstrate a new approach to implement a wavelength-tunable ultrafast fiber laser source suitable for multiphoton microscopy. We employ fiber-optic nonlinearities to broaden a narrowband optical spectrum generated by an Yb-fiber laser system and then use optical bandpass filters to select the leftmost or rightmost spectral lobes from the broadened spectrum. Detailed numerical modeling shows that self-phase modulation dominates the spectral broadening, self-steepening tends to blue shift the broadened spectrum, and stimulated Raman scattering is minimal. We also find that optical wave breaking caused by fiber dispersion slows down the shift of the leftmost/rightmost spectral lobes and therefore limits the wavelength tuning range of the filtered spectra. We show both numerically and experimentally that shortening the fiber used for spectral broadening while increasing the input pulse energy can overcome this dispersion-induced limitation; as a result, the filtered spectral lobes have higher power, constituting a powerful and practical approach for energy scaling the resulting femtosecond sources. We use two commercially available photonic crystal fibers to verify the simulation results. More specific, use of 20-mm fiber NL-1050-ZERO-2 enables us to implement an Yb-fiber laser based ultrafast source, delivering femtosecond (70-120 fs) pulses tunable from 825 nm to 1210 nm with >1 nJ pulse energy.

  16. Negative Kerr nonlinearity of graphene as seen via chirped-pulse-pumped self-phase modulation

    CERN Document Server

    Vermeulen, Nathalie; Cheng, JinLuo; Pasternak, Iwona; Krajewska, Aleksandra; Ciuk, Tymoteusz; Strupinski, Wlodek; Thienpont, Hugo; Van Erps, Jurgen

    2016-01-01

    We experimentally demonstrate a negative Kerr nonlinearity for quasi-undoped graphene. Hereto, we introduce the method of chirped-pulse-pumped self-phase modulation and apply it to graphene-covered silicon waveguides at telecom wavelengths. The extracted Kerr-nonlinear index for graphene equals n2,gr = -10^(-13) m^2/W. Whereas the sign of n2,gr turns out to be negative in contrast to what has been assumed so far, its magnitude is in correspondence with that observed in earlier experiments. Graphene's negative Kerr nonlinearity strongly impacts how graphene should be exploited for enhancing the nonlinear response of photonic (integrated) devices exhibiting a positive nonlinearity. It also opens up the possibility of using graphene to annihilate unwanted nonlinear effects in such devices, to develop unexplored approaches for establishing Kerr processes, and to extend the scope of the "periodic poling" method often used for second-order nonlinearities towards third-order Kerr processes. Because of the generic na...

  17. Plasmonic phase modulator based on novel loss-overcompensated coupling between nanoresonator and waveguide

    Science.gov (United States)

    Im, Song-Jin; Ho, Gum-Song; Yang, Da-Jie; Hao, Zhong-Hua; Zhou, Li; Kim, Nam-Chol; Kim, Il-Gwang; Wang, Qu-Quan

    2016-01-01

    We present that surface plasmon polariton, side-coupled to a gain-assisted nanoresonator where the absorption is overcompensated, exhibits a prominent phase shift up to π maintaining the flat unity transmission across the whole broad spectra. Bandwidth of this plasmonic phase shift can be controlled by adjusting the distance between the plasmonic waveguide and the nanoresonator. For a moderate distance, within bandwidth of 100 GHz, the phase shift and transmission are constantly maintained. The plasmonic phase can be shift-keying-modulated by a pumping signal in the gain-assisted nanoresonator. A needed length in our approach is of nanoscale while already suggested types of plasmonic phase modulator are of micrometer scale in length. The energy consumption per bit, which benefits from the nano size of this device, is ideally low on the order of 10 fJ/bit. The controllable plasmonic phase shift can find applications in nanoscale Mach–Zehnder interferometers and other phase-sensitive devices as well as directly in plasmonic phase shift keying modulators. PMID:26733338

  18. Two-dimensional action spectroscopy of excitonic systems: Explicit simulation using a phase-modulation technique

    Science.gov (United States)

    Damtie, Fikeraddis A.; Wacker, Andreas; Pullerits, Tõnu; Karki, Khadga J.

    2017-11-01

    Two-dimensional (2D) spectroscopy has been intensively used to study electronic and vibronic coherences in biological systems and semiconductors. This technique studies coherent as well as incoherent signals that arise from the nonlinear interaction of a sequence of laser pulses. In this paper we present a direct evaluation of the 2D signal based on elementary quantum kinetics in order to compare with the common approximate diagrammatic approaches. Here we consider incoherent action signals such as fluorescence or photocurrent as the observable, which is easily accessible in a measurement. These observables are calculated by solving the time evolution of the density matrix in the Lindblad form, which can take into account all possible decoherence processes. The phase modulation technique is used to separate the relevant nonlinear signals from the other possible interaction pathways. The approach can be used to calculate 2D spectra of any quantum system. For our model system we find a good agreement for the quantum beating between the coupled states.

  19. Photon-counting 1.0 GHz-phase-modulation fluorometer

    Science.gov (United States)

    Mizuno, T.; Nakao, S.; Mizutani, Y.; Iwata, T.

    2015-04-01

    We have constructed an improved version of a photon-counting phase-modulation fluorometer (PC-PMF) with a maximum modulation frequency of 1.0 GHz, where a phase domain measurement is conducted with a time-correlated single-photon-counting electronics. While the basic concept of the PC-PMF has been reported previously by one of the authors, little attention has been paid to its significance, other than its weak fluorescence measurement capability. Recently, we have recognized the importance of the PC-PMF and its potential for fluorescence lifetime measurements. One important aspect of the PC-PMF is that it enables us to perform high-speed measurements that exceed the frequency bandwidths of the photomultiplier tubes that are commonly used as fluorescence detectors. We describe the advantages of the PC-PMF and demonstrate its usefulness based on fundamental performance tests. In our new version of the PC-PMF, we have used a laser diode (LD) as an excitation light source rather than the light-emitting diode that was used in the primary version. We have also designed a simple and stable LD driver to modulate the device. Additionally, we have obtained a sinusoidal histogram waveform that has multiple cycles within a time span to be measured, which is indispensable for precise phase measurements. With focus on the fluorescence intensity and the resolution time, we have compared the performance of the PC-PMF with that of a conventional PMF using the analogue light detection method.

  20. Evaluation expérimentale des performances d'un système hybride WDM/DS-OCDMA

    OpenAIRE

    Cordette, Steevy; Fsaifes, Ihsan; Kibler, Bertrand; Ware, Cédric; Lepers, Catherine; Finot, Christophe; Millot, Guy

    2010-01-01

    National audience; Nous étudions expérimentalement une solution hybride WDM/DS-OCDMA pour l'application réseau d'accès optique haut débit. Cette solution permet d'augmenter la capacité de multiplexage du réseau WDM en y ajoutant une dimension supplémentaire : le code temporel. Le système est réalisé dans une configuration mono-canal WDM. Les performances de la transmission, en termes de taux d'erreurs binaires, sont évaluées après 20 km de transmission.

  1. Power consumption comparison between point-to-point WDM and OTDM systems

    DEFF Research Database (Denmark)

    Xu, Jing; Peucheret, Christophe; Jeppesen, Palle

    2010-01-01

    an energy efficiency point of view. Our analysis shows that in order to be comparable to WDM systems in power consumption aspect, the topology of the demultiplexing unit in OTDM systems must be carefully chosen and optimized and trade-offs have to be made between speed and power consumption using state...

  2. OTDM to WDM format conversion based on cascaded SHG/DFG in a single PPLN waveguide

    OpenAIRE

    Liu, S.; Lee, K. J.; Parmigiani, F.; Ibsen, M.; Petropoulos, P.; Richardson, D.J.; K Gallo

    2010-01-01

    We propose and experimentally demonstrate error-free OTDM to WDM format conversion based on cSHG/DFG within a 30mm-long PPLN waveguide and a time-to-frequency domain conversion approach, which relies upon switching a linearly chirped pulse.

  3. Demonstration of digital fronthaul over self-seeded WDM-PON in commercial LTE environment.

    Science.gov (United States)

    Ma, Yiran; Xu, Zhiguang; Zhang, Chengliang; Lin, Huafeng; Wang, Qing; Zhou, Min; Wang, Heng; Yu, Jingwen; Wang, Xiaomu

    2015-05-04

    CPRI between BBU and RRU equipment is carried by self-seeded WDM-PON prototype system within commercial LTE end-to-end environment. Delay and jitter meets CPRI requirements while services demonstrated show the same performance as bare fiber.

  4. GigaWaM—Next-Generation WDM-PON Enabling Gigabit Per-User Data Bandwidth

    DEFF Research Database (Denmark)

    Prince, Kamau; Gibbon, Timothy Braidwood; Rodes Lopez, Roberto

    2012-01-01

    The “Gigabit access passive optical network using wavelength division multiplexing” project aims to implement 64-Gb/s data transmission over 20-km single-mode fiber. Per-user symmetric data rates of 1-Gb/s will be achieved using wavelength division multiplexing passive optical network (WDM...

  5. Twelve factors critical to the success of WDM at the policy and at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    generally causes only minor economic disruption, but similar rural initiatives can be more disruptive. 5. Urban WDM agencies can be independent and prioritize pricing. ... is no single model that works for all audiences in all countries or regions. Finding the right model is likely to involve a careful process of trial and error.

  6. Experimental Study of Nonlinear Phase Noise and its Impact on WDM Systems with DP-256QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2016-01-01

    A probabilistic method for mitigating the phase noise component of the non-linear interference in WDM systems with Raman amplification is experimentally demonstrated. The achieved gains increase with distance and are comparable to the gains of single-channel digital back-propagation....

  7. Key lessons: Twelve factors critical to the success of WDM at the ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Water demand management (WDM) programs have been widely implemented across the MENA region and elsewhere, with varying degrees of success. The criteria below are intended to help policymakers determine how best to develop institutions with the capacity and capability to design, implement and monitor WDM ...

  8. Tailored design of WDM filters in BCB embedded PhC membranes

    DEFF Research Database (Denmark)

    Malaguti, Stefania; Bellanca, Gaetano; Ottaviano, Luisa

    2013-01-01

    We propose a design strategy for wavelength division multiplexing (WDM) filters in BCB embedded photonic crystal membranes. Due to the weaker vertical confinement determined by the material embedding the whole structure, accurate tailoring of the resonant cavity and of both bus and drop waveguide...

  9. Integration of Optically Generated Impulse Radio UWB Signals into Baseband WDM-PON

    DEFF Research Database (Denmark)

    Pham, Tien Thang; Yu, Xianbin; Dittmann, Lars

    2011-01-01

    We propose a compact integration system to simultaneously provide wireline and wireless (baseband and ultra-wide band (UWB)) services to end-users in a WDM-PON. A 1-Gbps UWB signal is optically generated and shares the same wavelength with the baseband signal. Error-free performance was achieved ...

  10. Increasing the cost-constrained availability of WDM Networks with Degree-3 Structured Topologies

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Georgakilas, Kostas; Katrinis, Kostas

    2010-01-01

    This paper studies the impact of node degree distribution to availability and capital and deployment expenditure of optical WDM transport networks. Three structured degree-3 graphs with fair node degree distribution are proposed in this context. Using a realistic network optimization framework...

  11. Electronic post-compensation of WDM transmission impairments using coherent detection and digital signal processing.

    Science.gov (United States)

    Li, Xiaoxu; Chen, Xin; Goldfarb, Gilad; Mateo, Eduardo; Kim, Inwoong; Yaman, Fatih; Li, Guifang

    2008-01-21

    A universal post-compensation scheme for fiber impairments in wavelength-division multiplexing (WDM) systems is proposed based on coherent detection and digital signal processing (DSP). Transmission of 10 x 10 Gbit/s binary-phase-shift-keying (BPSK) signals at a channel spacing of 20 GHz over 800 km dispersion shifted fiber (DSF) has been demonstrated numerically.

  12. On-chip, CMOS-compatible, hardware-compressive integrated photonic beamformer based on WDM

    NARCIS (Netherlands)

    Burla, M.; Zhuang, L.; Marpaung, D.A.I.; Khan, M.R.H.; Leinse, Arne; Beeker, Willem; Hoekman, M.; Heideman, Rene; Roeloffzen, C.G.H.

    2013-01-01

    We propose and experimentally demonstrate a novel, hardware-compressive architecture for broadband and continuously tunable integrated optical true-time-delay beamformers. The architecture is based on on-chip wavelength division multiplexing (WDM) that, in conjunction with the frequency-periodic

  13. A 80 km reach fully passive WDM-PON based on reflective ONUs

    DEFF Research Database (Denmark)

    Presi, Marco; Proietti, Roberto; Prince, Kamau

    2008-01-01

    We propose a novel line coding combination (Inverse RZ coding in downlink and RZ in uplink) that extends the reach of WDM Passive Optical Networks based on Reflective SOAs with no in-line amplification. We achieved full downstream remodulation even when feeding the reflective SOA with power level...

  14. Simultaneous regeneration of two 160 Gbit/s WDM channels in a single highly nonlinear fiber

    DEFF Research Database (Denmark)

    Wang, Ju; Ji, Hua; Hu, Hao

    2013-01-01

    We experimentally demonstrate simultaneous all-optical regeneration of two 160-Gbit/s wavelength-division multiplexed (WDM) channels in a single highly nonlinear fiber (HNLF). The multi-channel regeneration performance is confirmed by bit-error rate (BER) measurements. The receiver powers at a BER...

  15. WDM packet switch architectures and analysis of the influence of tunable wavelength converters on the performance

    DEFF Research Database (Denmark)

    Danielsen, Søren Lykke; Mikkelsen, Benny; Jørgensen, Carsten

    1997-01-01

    A detailed analytical traffic model for a photonic wavelength division multiplexing (WDM) packet switch block is presented and the requirements to the buffer size is analyzed. Three different switch architectures are considered, each of them representing different complexities in terms of component...

  16. Incoherent population mixing contributions to phase-modulation two-dimensional coherent excitation spectra

    Science.gov (United States)

    Grégoire, Pascal; Srimath Kandada, Ajay Ram; Vella, Eleonora; Tao, Chen; Leonelli, Richard; Silva, Carlos

    2017-09-01

    We present theoretical and experimental results showing the effects of incoherent population mixing on two-dimensional (2D) coherent excitation spectra that are measured via a time-integrated population and phase-sensitive detection. The technique uses four collinear ultrashort pulses and phase modulation to acquire two-dimensional spectra by isolating specific nonlinear contributions to the photoluminescence or photocurrent excitation signal. We demonstrate that an incoherent contribution to the measured line shape, arising from nonlinear population dynamics over the entire photoexcitation lifetime, generates a similar line shape to the expected 2D coherent spectra in condensed-phase systems. In those systems, photoexcitations are mobile such that inter-particle interactions are important on any time scale, including those long compared with the 2D coherent experiment. Measurements on a semicrystalline polymeric semiconductor film at low temperatures show that, in some conditions in which multi-exciton interactions are suppressed, the technique predominantly detects coherent signals and can be used, in our example, to extract homogeneous line widths. The same method used on a lead-halide perovskite photovoltaic cell shows that incoherent population mixing of mobile photocarriers can dominate the measured signal since carrier-carrier bimolecular scattering is active even at low excitation densities, which hides the coherent contribution to the spectral line shape. In this example, the intensity dependence of the signal matches the theoretical predictions over more than two orders of magnitude, confirming the incoherent nature of the signal. While these effects are typically not significant in dilute solution environments, we demonstrate the necessity to characterize, in condensed-phase materials systems, the extent of nonlinear population dynamics of photoexcitations (excitons, charge carriers, etc.) in the execution of this powerful population-detected coherent

  17. Time lens based optical fourier transformation for advanced processing of spectrally-efficient OFDM and N-WDM signals

    DEFF Research Database (Denmark)

    Guan, Pengyu; Røge, Kasper Meldgaard; Morioka, Toshio

    2016-01-01

    We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals.......We review recent progress in the use of time lens based optical Fourier transformation for advanced optical signal processing, with focus on all-optical generation, detection and format conversion of spectrally-efficient OFDM and N-WDM signals....

  18. Photonic crystal fibers used in a multi-wavelength source and as transmission fiber in a WDM system

    DEFF Research Database (Denmark)

    Andersen, Peter Andreas; Zsigri, Beata; Peucheret, Christophe

    2004-01-01

    We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF.......We present a WDM system based entirely on photonic crystal fibers. It includes a novel dispersion flattened highly nonlinear PCF to generate supercontinuum used in a multiwavelength pulse source and a 5.6 km transmission PCF....

  19. Quantification of optical Doppler broadening and optical path lengths of multiply scattered light by phase modulated low coherence interferometry.

    Science.gov (United States)

    Varghese, B; Rajan, V; van Leeuwen, T G; Steenbergen, W

    2007-07-23

    We show experimental validation of a novel technique to measure optical path length distributions and path length resolved Doppler broadening in turbid media for different reduced scattering coefficients and anisotropies. The technique involves a phase modulated low coherence Mach-Zehnder interferometer, with separate fibers for illumination and detection. Water suspensions of Polystyrene microspheres with high scattering and low absorption levels are used as calibrated scattering phantoms. The path length dependent diffusion broadening or Doppler broadening of scattered light is shown to agree with Diffusive Wave Spectroscopy within 5%. The optical path lengths are determined experimentally from the zero order moment of the phase modulation peak around the modulation frequency in the power spectrum and the results are validated with Monte Carlo simulations.

  20. Quantification of optical Doppler broadening and optical path lengths of multiply scattered light by phase modulated low coherence interferometry

    Science.gov (United States)

    Varghese, B.; Rajan, V.; van Leeuwen, T. G.; Steenbergen, W.

    2007-07-01

    We show experimental validation of a novel technique to measure optical path length distributions and path length resolved Doppler broadening in turbid media for different reduced scattering coefficients and anisotropies. The technique involves a phase modulated low coherence Mach-Zehnder interferometer, with separate fibers for illumination and detection. Water suspensions of Polystyrene microspheres with high scattering and low absorption levels are used as calibrated scattering phantoms. The path length dependent diffusion broadening or Doppler broadening of scattered light is shown to agree with Diffusive Wave Spectroscopy within 5%. The optical path lengths are determined experimentally from the zero order moment of the phase modulation peak around the modulation frequency in the power spectrum and the results are validated with Monte Carlo simulations.

  1. Suppression of phase-induced intensity noise in fibre optic delay line signal processors using an optical phase modulation technique.

    Science.gov (United States)

    Chan, Erwin H W

    2010-10-11

    A technique that can suppress the dominant phase-induced intensity noise in fibre optic delay line signal processors is presented. It is based on phase modulation of the optical carrier to distribute the phase noise at the information band into a high frequency band which can be filtered out. This technique is suitable for suppressing the phase noise in various delay line structures and for integrating in the conventional fibre optic links. It can also suppress the coherent interference effect at the same time. A model for predicting the amount of phase noise reduction in various delay line structures using the optical phase modulation technique is presented for the first time and is experimentally verified. Experimental results demonstrate the technique can achieve a large phase noise reduction in various fibre optic delay line signal processors.

  2. Phase Modulator Programming to Get Flat Pulses with Desired Length and Power from the CTF3 Pulse Compressors

    CERN Document Server

    Shaker, Seyd Hamed; Skowronski, Piotr; Syratchev, Igor; Tecker, Frank

    2010-01-01

    The pulse compressor is located after the klystron to increase the power peak by storing the energy at the beginning and releasing it near the end of klystron output pulse. In the CTF3 pulse compressors a doubling of the peak power is achieved according to our needs and the machine parameters. The magnitude of peak power, pulse length and flatness can be controlled by using a phase modulator for the input signal of klystrons. A C++ code is written to simulate the pulse compressor behaviour according to the klystron output pulse power. By manually changing the related parameters in the code for the best match, the quality factor and the filling time of pulse compressor cavities can be determined. This code also calculates and sends the suitable phase to the phase modulator according to the klystron output pulse power and the desired pulse length and peak power

  3. Rapid phase-modulated water-excitation steady-state free precession for fat-suppressed cine cardiovascular MR

    Directory of Open Access Journals (Sweden)

    Raman Subha V

    2008-05-01

    Full Text Available Abstract Background The purpose of this article is to describe a steady-state free precession (SSFP sequence for fat-suppressed cine cardiovascular magnetic resonance (CMR. A rapid phase-modulated binomial water-excitation (WE pulse is utilized to minimize repetition time and acquisition time. Methods Three different water-excitation pulses were combined with cine-SSFP for evaluation. The frequency response of each sequence was simulated and examined in phantom imaging studies. The ratio of fat to water signal amplitude was measured in phantoms to evaluate the fat-suppression capabilities of each method. Six volunteers underwent CMR of the heart at 1.5T to compare retrospectively-gated cine-SSFP with and without water-excitation. The ratio of fat to myocardium signal amplitude was measured for conventional cine-SSFP and phase-modulated WE-SSFP. The proposed WE-SSFP method was tested in one patient referred for CMR to characterize a cardiac mass. Results and discussion The measured frequency response in a phantom corresponded to the numerical Bloch equation simulation demonstrating the widened stop-band around the fat resonant frequency for all water-excitation pulses tested. In vivo measurements demonstrated that a rapid, phase-modulated water-excitation pulse significantly reduced the signal amplitude ratio of fat to myocardium from 6.92 ± 2.9 to 0.8 ± 0.13 (mean ± SD without inducing any perceptible artifacts in SSFP cine CMR. Conclusion fat-suppression can be achieved in SSFP cine CMR while maintaining steady-state equilibrium using rapid, phase modulated, binomial water-excitation pulses.

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

    Science.gov (United States)

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

    2017-07-01

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

  5. Performance Analysis of Wavelet Channel Coding in COST207-based Channel Models on Simulated Radio-over-Fiber Systems at the W-Band

    DEFF Research Database (Denmark)

    Cavalcante, Lucas Costa Pereira; Silveira, Luiz F. Q.; Rommel, Simon

    2016-01-01

    , such systems use diversity schemes in combination with digital signal processing (DSP) techniques to overcome effects such as fading and inter-symbol interference (ISI). Wavelet Channel Coding (WCC) has emerged as a technique to minimize the fading effects of wireless channels, which is a mayor challenge...

  6. Optical response of a d-fiber antenna in a finite-element analysis intended for radio-over-fiber applications.

    Science.gov (United States)

    Bhatti, A; Al-Raweshidy, H S; Murtaza, G

    2000-07-20

    An all-fiber antenna with a piezoelectric polymer-coated circular-core D fiber has been characterized by finite-element analysis. The response of the D-fiber antenna was determined over a wide frequency range from 1 to 500 MHz. The modeling predicts an electric-field-induced phase shift of 2.43 x 10(-5) rad/(V/m)/m at 5 MHz. At frequencies higher than 8 MHz the optical response is dominated by radial resonances of the D-fiber-coating composite. From the simulation results a minimum detectable electric field of 41-muV/m has been achieved with a 1-km length of coated D fiber. In addition, a D-fiber antenna network intended for microcellular communications has been analyzed by shot-noise-limited detection.

  7. An orthogonal wavelet division multiple-access processor architecture for LTE-advanced wireless/radio-over-fiber systems over heterogeneous networks

    Science.gov (United States)

    Mahapatra, Chinmaya; Leung, Victor CM; Stouraitis, Thanos

    2014-12-01

    The increase in internet traffic, number of users, and availability of mobile devices poses a challenge to wireless technologies. In long-term evolution (LTE) advanced system, heterogeneous networks (HetNet) using centralized coordinated multipoint (CoMP) transmitting radio over optical fibers (LTE A-ROF) have provided a feasible way of satisfying user demands. In this paper, an orthogonal wavelet division multiple-access (OWDMA) processor architecture is proposed, which is shown to be better suited to LTE advanced systems as compared to orthogonal frequency division multiple access (OFDMA) as in LTE systems 3GPP rel.8 (3GPP, http://www.3gpp.org/DynaReport/36300.htm). ROF systems are a viable alternative to satisfy large data demands; hence, the performance in ROF systems is also evaluated. To validate the architecture, the circuit is designed and synthesized on a Xilinx vertex-6 field-programmable gate array (FPGA). The synthesis results show that the circuit performs with a clock period as short as 7.036 ns (i.e., a maximum clock frequency of 142.13 MHz) for transform size of 512. A pipelined version of the architecture reduces the power consumption by approximately 89%. We compare our architecture with similar available architectures for resource utilization and timing and provide performance comparison with OFDMA systems for various quality metrics of communication systems. The OWDMA architecture is found to perform better than OFDMA for bit error rate (BER) performance versus signal-to-noise ratio (SNR) in wireless channel as well as ROF media. It also gives higher throughput and mitigates the bad effect of peak-to-average-power ratio (PAPR).

  8. Broadband photonic single sideband frequency up-converter based on the cross polarization modulation effect in a semiconductor optical amplifier for radio-over-fiber systems.

    Science.gov (United States)

    Lee, Seung-Hun; Kim, Hyoung-Jun; Song, Jong-In

    2014-01-13

    A broadband photonic single sideband (SSB) frequency up-converter based on the cross polarization modulation (XPolM) effect in a semiconductor optical amplifier (SOA) is proposed and experimentally demonstrated. An optical radio frequency (RF) signal in the form of an optical single sideband (OSSB) is generated by the photonic SSB frequency up-converter to solve the power fading problem caused by fiber chromatic dispersion. The generated OSSB RF signal has almost identical optical carrier power and optical sideband power. This SSB frequency up-conversion scheme shows an almost flat electrical RF power response as a function of the RF frequency in a range from 31 GHz to 75 GHz after 40 km single mode fiber (SMF) transmission. The photonic SSB frequency up-conversion technique shows negligible phase noise degradation. The phase noise of the up-converted RF signal at 49 GHz for an offset of 10 kHz is -93.17 dBc/Hz. Linearity analysis shows that the photonic SSB frequency up-converter has a spurious free dynamic range (SFDR) value of 79.51 dB · Hz(2/3).

  9. An all-optical frequency up-converter utilizing four-wave mixing in a semiconductor optical amplifier for sub-carrier multiplexed radio-over-fiber applications.

    Science.gov (United States)

    Kim, Hyoung-Jun; Song, Jong-In; Song, Ho-Jin

    2007-03-19

    A novel all-optical frequency up-converter utilizing four-wave mixing (FWM) in a semiconductor optical amplifier (SOA) was proposed and experimentally demonstrated. The frequency up-converter converted an optical intermediate frequency (IF) signal (f(IF) = 2.5 GHz) to an optical radio frequency (RF) signal (f(RF) = 35 and 40 GHz) through mixing with an optical local oscillator (LO) signal (f(LO) = 37.5 GHz). The up-converter showed positive conversion efficiency of 5.77 dB for the optical IF power of -22 dBm and the optical LO power of -13 dBm. This scheme showed broad bandwidths with respect to both LO and IF frequencies. The up-converter showed a phase noise of -84.5 dBc/Hz for the LO frequency of 37.5 GHz (f(LO)) and the offset frequency of 10 kHz after the frequency up-conversion.

  10. An integrated routing protocol in next-generation IP over WDM networks

    Science.gov (United States)

    Yin, Yong; Kuo, Geng-Sheng

    2004-09-01

    In next-generation IP over WDM networks, lightpaths are set up or torn down dynamically. Traditionally, OSPF in IP layer and OSPF-TE in optical layer disseminate routing information independently. Obviously, this 2-layer routing mechanism is complex and O&M cost is high. Furthermore, in a dynamic environment, both OSPF-TE and OSPF have very heavy control overheads when lightpaths change frequently. In this paper, an integrated routing protocol is proposed. The link state information of both IP layer and optical layer is disseminated simultaneously using the same routing protocol messages. The proposed protocol also advertises wavelength availability information if necessary in order to reduce the blocking probability of routing and wavelength assignment (RWA) algorithm. This proposed integrated protocol is very simple. Furthermore, its control overhead can be reduced from several to about ten times. In addition, RWA's performance is also improved. Hence, the performance of the IP over WDM networks will be improved greatly and significantly.

  11. All-optical code routing in interconnected optical CDMA and WDM ring networks.

    Science.gov (United States)

    Deng, Yanhua; Fok, Mable P; Prucnal, Paul R; Wang, Ting

    2010-11-01

    We propose an all-optical hybrid network composed of optical code division multiple access (CDMA) rings interconnecting through a reconfigurable wavelength division multiplexing (WDM) metro area ring. This network retains the advantages of both the optical CDMA and WDM techniques, including asynchronous access and differentiated quality of service, while removing the hard limit on the number of subscribers and increasing network flexibility. The all-optical network is enabled by using nonlinear optical loop mirrors in an add/drop router (ADR) that performs code conversion, dropping, and switching asynchronously. We experimentally demonstrate the functionalities of the ADR in the proposed scheme asynchronously and obtain error-free performance. The bit-error rate measurements show acceptable power penalties for different code routes.

  12. Transmission performance analysis of WDM systems based on bismuth-doped phosphate glass fiber amplifiers

    Science.gov (United States)

    Ji, Jianhua; Huang, Qian; Wang, Ke; Xu, Ming; Jiang, Chun

    2018-01-01

    In this paper transmission performance of Allwave fiber WDM systems cascaded by bismuth-doped phosphate glass fiber amplifiers pumped by 808 nm lasers is analyzed for the first time, to the best of our knowledge. The rate and power propagation equations of a three-level system are used to model the signal amplification and noise figure in the doped fibers. The simulation results show that the channels in the 1460-1470 nm wavelength region in 32 × 40 Gbit/s WDM system with 10 nm channel space can reach a BER less than 1 × 10-9 with the transmission distance more than 600 km, but when the channel space is reduced to 1 nm, the performance of the system is degraded greatly.

  13. Remote interrogation of WDM fiber-optic intensity sensors deploying delay lines in the virtual domain.

    Science.gov (United States)

    Montero, David Sánchez; Vázquez, Carmen

    2013-05-07

    In this work a radio-frequency self-referencing WDM intensity-based fiber-optic sensor operating in reflective configuration and using virtual instrumentation is presented. The use of virtual delay lines at the reception stage, along with novel flexible self-referencing techniques, and using a single frequency, avoids all-optical or electrical-based delay lines approaches. This solution preserves the self-referencing and performance characteristics of the proposed WDM-based optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points in a sensor network. Results are presented for a displacement sensor demonstrating the concept feasibility.

  14. Optical diversity transmission using WDM signal and phase-conjugate lights through multi-core fiber.

    Science.gov (United States)

    Koga, Masafumi; Moroi, Mitsuki; Takara, Hidehiko

    2016-05-02

    This paper proposes a maximum-ratio combining (MRC) scheme for a WDM signal and phase-conjugate pair (PCP) diversity transmission to cancel nonlinear phase-shift. A transfer function approximation for nonlinear phase-shift cancellation is formulated. It shows, with the help of a numerical calculation, that span-by-span chromatic dispersion compensation is more effective than the lumped equivalent at the receiver. This is confirmed in a 2-core diversity 5 channel WDM transmission experiment over 3-spans of 60km MCF with 25 Gbit/s-QPSK PCP. The peak Q-value was enhanced by 3.6dB through MRC, resulting in superior bitrate-distance product and optical power density limit, compared to twice the single core transmission.

  15. Tradeoffs in process strategy games with application in the WDM reconfiguration problem

    DEFF Research Database (Denmark)

    Cohen, Nathann; Coudert, David; Mazauric, Dorian

    2011-01-01

    We consider a variant of the graph searching games that models the routing reconfiguration problem in WDM networks. In the digraph processing game, a team of agents aims at processing, or clearing, the vertices of a digraph D. We are interested in two different measures: (1) the total number...... of agents used, and (2) the total number of vertices occupied by an agent during the processing of D. These measures, respectively, correspond to the maximum number of simultaneous connections interrupted and to the total number of interruptions during a routing reconfiguration in a WDM network. Previous...... works have studied the problem of independently minimizing each of these parameters. In particular, the corresponding minimization problems are APX-hard, and the first one is known not to be in APX. In this paper, we give several complexity results and study tradeoffs between these conflicting...

  16. Fiber nonlinearity-insensitive OSNR monitoring for coherent PM-QPSK-Nyquist-WDM system

    Science.gov (United States)

    Zhang, Peiyu; Xi, Lixia; Yuan, Jin; Tang, Xianfeng; Zhang, Wenbo; Li, Jianping; Zhang, Xiaoguang

    2017-07-01

    We propose a promising fiber nonlinearity-tolerant optical signal-to-noise ratio (OSNR) monitoring technique for high speed long haul polarization multiplexed-quadrature phase shift keying (PM-QPSK) Nyquist wavelength division multiplexing (WDM) coherent optical fiber transmission system, in which the correlation function between the symbols in all states of polarization as well as neighboring channels are exploited instead of the traditional GN model, thus it does not need the prior knowledge of the fiber transmission link nor the complicated integrals. The method is demonstrated to have the OSNR measurement error below 1.28 dB over a wide OSNR range from 10 dB to 28 dB in 100 Gb/s per channel PM-QPSK-Nyquist-WDM system when the launch power is up to 4 dBm and transmission distance is as long as 1600 km.

  17. A Grooming Nodes Optimal Allocation Method for Multicast in WDM Networks

    Directory of Open Access Journals (Sweden)

    Chengying Wei

    2016-01-01

    Full Text Available The grooming node has the capability of grooming multicast traffic with the small granularity into established light at high cost of complexity and node architecture. In the paper, a grooming nodes optimal allocation (GNOA method is proposed to optimize the allocation of the grooming nodes constraint by the blocking probability for multicast traffic in sparse WDM networks. In the proposed GNOA method, the location of each grooming node is determined by the SCLD strategy. The improved smallest cost largest degree (SCLD strategy is designed to select the nongrooming nodes in the proposed GNOA method. The simulation results show that the proposed GNOA method can reduce the required number of grooming nodes and decrease the cost of constructing a network to guarantee a certain request blocking probability when the wavelengths per fiber and transmitter/receiver ports per node are sufficient for the optical multicast in WDM networks.

  18. Remote Interrogation of WDM Fiber-Optic Intensity Sensors Deploying Delay Lines in the Virtual Domain

    Directory of Open Access Journals (Sweden)

    Carmen Vázquez

    2013-05-01

    Full Text Available In this work a radio-frequency self-referencing WDM intensity-based fiber-optic sensor operating in reflective configuration and using virtual instrumentation is presented. The use of virtual delay lines at the reception stage, along with novel flexible self-referencing techniques, and using a single frequency, avoids all-optical or electrical-based delay lines approaches. This solution preserves the self-referencing and performance characteristics of the proposed WDM-based optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points in a sensor network. Results are presented for a displacement sensor demonstrating the concept feasibility.

  19. Simultaneous Regeneration of Two 160 Gbit/s WDM Channels in a Single Highly Nonlinear Fiber

    DEFF Research Database (Denmark)

    Wang, Ju; Ji, Hua; Hu, Hao

    2012-01-01

    We experimentally demonstrate simultaneous all-optical regeneration of two 160 Gbit/s WDM channels in a single HNLF using fiber optical parametric amplification. Receiver sensitivities at a BER of 10-9 are improved by about 2.1 dB and 4.9 dB for the two channels, respectively. The BER is not degr......We experimentally demonstrate simultaneous all-optical regeneration of two 160 Gbit/s WDM channels in a single HNLF using fiber optical parametric amplification. Receiver sensitivities at a BER of 10-9 are improved by about 2.1 dB and 4.9 dB for the two channels, respectively. The BER...

  20. Nonlinear Phase Noise Compensation in Experimental WDM Systems with 256QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Da Ros, Francesco; Porto da Silva, Edson

    2017-01-01

    Nonlinear phase noise (NLPN) is studied in an experimental wavelength division multiplexed (WDM) system operating at 256QAM. Extremely narrow linewidth lasers (... on the experimental data, the autocorrelation function of the NLPN is estimated and it matches the theoretical predictions. Several algorithms are examined as candidates for tracking and compensating the NLPN. It is shown that algorithms which exploit the distribution of the NLPN achieve higher gains than standard...

  1. Wavelength locking of silicon photonics multiplexer for DML-based WDM transmitter

    OpenAIRE

    Grillanda, Stefano; Ji, Ruiqiang; Morichetti, Francesco; Carminati, Marco; Ferrari, Giorgio; Guglielmi, Emanuele; Peserico, Nicola; Annoni, Andrea; Dede, Alberto; Nicolato, Danilo; Vannucci, Antonello; Klitis, Charalambos; Holmes, Barry; Sorel, Marc; Fu, Shengmeng

    2017-01-01

    We present a wavelength locking platform enabling the feedback control of silicon (Si) microring resonators (MRRs) for the realization of a 4 × 10 Gb/s wavelength-division-multiplexing (WDM) transmitter. Four thermally tunable Si MRRs are employed to multiplex the signals generated by four directly modulated lasers (DMLs) operating in the L-band, as well as to improve the quality of the DMLs signals. Feedback control is achieved through a field-programmable gate array controller by monitoring...

  2. INVESTIGATION ON HYBRID WDM (DWDM+CWDM FREE SPACE OPTICAL COMMUNICATION SYSTEM

    Directory of Open Access Journals (Sweden)

    S. Robinson

    2015-12-01

    Full Text Available Free Space Optical (FSO communication is being realized as an effective solution for future accessing networks, offering light passed through air. The performance of FSO can be primarily degraded by various atmospheric attenuation namely, rain, fog, haze and snow. At present, hybridization of Dense Wavelength Division Multiplexing (DWDM with Coarse Wavelength Division Multiplexing (CWDM becomes necessary to scale the speed and high bandwidth of the services. In this paper, hybrid WDM system is proposed, designed and the network parameters such as Bit Error Rate (BER, Quality Factor and receiver sensitivity are analyzed with respect to link distance for various weather conditions. For investigation, 4 CWDM and 8 DWDM channels are considered whose corresponding channel spacing is 20nm and 0.8nm, respectively. From the simulation, it is investigated that the average link distance of proposed hybrid WDM-FSO system for DWDM and CWDM system at very clear condition are around 810km and 780km. The proposed hybrid WDM based FSO system is designed to handle the quality of transmission for 12 users, each at a data rate of 2.5Gbps.

  3. W-Band Millimeter-Wave Vector Signal Generation Based on Precoding-Assisted Random Photonic Frequency Tripling Scheme Enabled by Phase Modulator

    National Research Council Canada - National Science Library

    Li, Xinying; Xu, Yuming; Xiao, Jiangnan; Yu, Jianjun

    2016-01-01

    We propose W-band photonic millimeter-wave (mm-wave) vector signal generation employing a precoding-assisted random frequency tripling scheme enabled by a single phase modulator cascaded with a wavelength selective switch (WSS...

  4. Electro-optic millimeter-wave harmonic downconversion and vector demodulation using cascaded phase modulation and optical filtering.

    Science.gov (United States)

    Pagán, Vincent R; Murphy, Thomas E

    2015-06-01

    We describe and demonstrate an electro-optic technique to simultaneously downconvert and demodulate vector-modulated millimeter-wave signals. The system uses electro-optic phase modulation and optical filtering to perform harmonic downconversion of the RF signal to an intermediate frequency (IF) or to baseband. We demonstrate downconversion of RF signals between 7 and 70-GHz to IFs below 20-GHz. Furthermore, we show harmonic downconversion and vector demodulation of 2.5-Gb/s QPSK and 5-Gb/s 16-QAM signals at carrier frequencies of 40-GHz to baseband.

  5. 10Gb/s Ultra-Wideband Wireless Transmission Based on Multi-Band Carrierless Amplitude Phase Modulation

    DEFF Research Database (Denmark)

    Puerta Ramírez, Rafael; Rommel, Simon; Vegas Olmos, Juan José

    2016-01-01

    In this paper, for the first time, a record UWB transmission of 10Gb/s is experimentally demonstrated employing a multi-band approach of carrierless amplitude phase modulation (MultiCAP). The proposed solution complies with the restrictions on the effective radiated power established by both...... the United States Federal Communications Commission and the European Electronic Communications Committee, achieving a BER below the limit for a 7% overhead FEC of 3.8 · 10−3 up to respective wireless distances of 3.5m and 2m....

  6. Self-phase modulation of a single-cycle terahertz pulse by nonlinear free-carrier response in a semiconductor

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias C.

    2012-01-01

    We investigate the self-phase modulation (SPM) of a single-cycle terahertz pulse in a semiconductor, using bulk n-GaAs as a model system. The SPM arises from the heating of free electrons in the electric field of the terahertz pulse, leading to an ultrafast reduction of the plasma frequency...... the broad spectrum of the terahertz pulse, with the zero-nonlinearity point defined by the electron momentum relaxation rate. We also observed the nonlinear spectral broadening and compression of the terahertz pulse....

  7. Unravelling the role of quantum interference in the weak-field laser phase modulation control of photofragment distributions

    DEFF Research Database (Denmark)

    García-Vela, Alberto; Henriksen, Niels Engholm

    2016-01-01

    The role played by quantum interference in the laser phase modulation coherent control of photofragment distributions in the weak-field regime is investigated in detail in this work. The specific application involves realistic wave packet calculations of the transient vibrational populations...... for a long time window are explained in terms of the mechanism of interference between overlapping resonances. A detailed description of how the interference mechanism affects the magnitude and the time window of the phase control effects is also provided. In the light of the results, the conditions...

  8. Simultaneous self-phase modulation and two-photon absorption measurement by a spectral homodyne Z-scan method.

    Science.gov (United States)

    Fischer, Martin C; Liu, Henry C; Piletic, Ivan R; Warren, Warren S

    2008-03-17

    We developed a technique to simultaneously measure self-phase modulation and two-photon absorption using shaped femtosecond laser pulses. In the conventional Z-scan measurement technique the amount of nonlinearity is determined by measuring the change in shape and intensity of a transmitted laser beam. In contrast, our method sensitively measures nonlinearity-induced changes in the pulse spectrum. In this work we demonstrate the technique in nonlinear absorptive and dispersive samples, quantify the obtained signal, and compare the measurements with traditional Z-scans. This technique is capable of measuring these nonlinearities in highly scattering samples.

  9. Preparation of starch stabilized silver nanoparticles with spatial self-phase modulation properties by laser ablation technique

    Energy Technology Data Exchange (ETDEWEB)

    Zamiri, Reza; Azmi, B.Z.; Sadrolhosseini, Amir R.; Husin, M.S.; Zaidan, A.W. [Universiti Putra Malaysia, Department of Physics, Faculty of Science, UPM Serdang, Selangor (Malaysia); Darroudi, Majid [Universiti Putra Malaysia, Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, UPM Serdang, Selangor (Malaysia); Mahdi, M.A. [Universiti Putra Malaysia, Wireless and Photonics Networks Research Center, Faculty of Engineering, UPM Serdang, Selangor (Malaysia)

    2011-01-15

    Silver nanoparticles inside the starch solution have been successfully fabricated by laser ablation of a silver plate immersed in starch solution. The ablation has been done using a Q-switched Nd:YAG laser at 10 Hz repetition rate. The starch solution allows for the formation of silver nanoparticles with uniform particle diameters and well dispersed. The ablation was performed at different time durations to study the influence of the laser ablation time on efficiency of particle formation and sizes. The Spatial Self-phase modulation phenomena which can determine the nonlinear optical property of the samples were also investigated for starch solutions containing silver nanoparticles. (orig.)

  10. Single-PPLN-assisted wavelength-/time-selective switching/dropping/swapping for 100-GHz-spaced WDM signals.

    Science.gov (United States)

    Wang, Jian; Fu, Hongyan; Geng, Dongyu; Willner, Alan E

    2013-02-11

    We propose an approach to implementing wavelength- and time-selective optical switching, dropping and swapping based on the sum-frequency generation (SFG) or cascaded sum- and difference-frequency generation (cSFG/DFG) in a periodically poled lithium niobate (PPLN) waveguide. Analytical solutions are derived, showing the parametric depletion effect for optical switching and the narrow-band operation due to quasi-phase matching (QPM) condition of PPLN. Using parametric depletion effect of SFG process, we demonstrate wavelength- and time-selective optical switching for ITU-grid compatible 40-Gbit/s wavelength-division multiplexed (WDM) signals with a channel spacing of 100 GHz. Less than 1-dB power penalty at a bit-error rate (BER) of 10(-9) is measured for the wavelength- and time-selective switching channel. Negligible impacts are observed on other channels of WDM signals. Using combined effects of parametric depletion and wavelength conversion of cSFG/DFG processes, we demonstrate wavelength- and time-selective optical dropping for ITU-grid compatible 100-GHz-spaced 40-Gbit/s WDM signals. Moreover, we demonstrate optical swapping between two 100-GHz-spaced 40-Gbit/s signals. The obtained theoretical and experimental results confirm single-PPLN-assisted wavelength- and time-selective optical switching, dropping and swapping for 100-GHz-spaced WDM signals, which might potentially be extended to WDM signals with narrower channel spacing.

  11. A receiver-initiated WDM multicast tree construction protocol to support IP dense mode multicast routing in all-optical Lambda-switched networks

    NARCIS (Netherlands)

    Niemegeers, I.G.M.M.; Salvador, M.R.; Heemstra de Groot, S.M.; Dey, D.

    We describe a source-rooted WDM multicast tree construction protocol to support IP dense mode multicast routing protocols in all-optical lambda-switched networks. Using a receiver-initiated approach, the protocol relies on a mechanism that collects information on the capabilities of WDM nodes. This

  12. Spectral broadening of 25 fs laser pulses via self-phase modulation in a neon filled hollow core fibre

    Energy Technology Data Exchange (ETDEWEB)

    Weichert, Stefan

    2017-05-15

    The goal of this work was the realisation of a setup for spectral broadening and subsequent compression of 25 fs laser pulses provided by a commercial Ti:Sapphire based CPA laser system by means of the hollow core fibre chirped mirror compressor technique. For the spectral broadening a vessel containing the hollow waveguide filled with a noble gas serving as the nonlinear medium was set up and an alignment procedure was developed. Neon was chosen as the nonlinear medium for the self-phase modulation of the pulses. With this setup spectral broadening, sufficient for supporting sub 5 fs pulses, was observed. The spectra at different input energies and neon gas pressures were measured and the stability of these and their respective Fourier transform-limited pulses determined in order to find an operating point. For the compression of the self-phase modulated pulses a chirped mirror compressor was designed and set up, but not tested yet. The layout of a single-shot intensity autocorrelator capable of estimating the pulse duration of sub 10 fs pulses was given.

  13. Comparison of photothermal and piezoacoustic excitation methods for frequency and phase modulation atomic force microscopy in liquid environments

    Directory of Open Access Journals (Sweden)

    A. Labuda

    2011-06-01

    Full Text Available In attempting to perform frequency modulation atomic force microscopy (FM-AFM in liquids, a non-flat phase transfer function in the self-excitation system prevents proper tracking of the cantilever natural frequency. This results in frequency-and-phase modulation atomic force microscopy (FPM-AFM which lies in between phase modulation atomic force microscopy (PM-AFM and FM-AFM. We derive the theory necessary to recover the conservative force and damping in such a situation, where standard FM-AFM theory no longer applies. Although our recovery procedure applies to all cantilever excitation methods in principle, its practical implementation may be difficult, or even impossible, if the cantilever is driven piezoacoustically. Specifically, we contrast the piezoacoustic excitation method to the photothermal method in the context of force spectroscopy of hydration structures at the mica-water interface. The results clearly demonstrate that photothermal excitation is superior to piezoacoustic excitation, as it allows for accurate quantitative interpretation of the acquired data.

  14. Optical coherent and envelope detection for photonic wireless communication links

    DEFF Research Database (Denmark)

    Prince, Kamau; Zibar, Darko; Yu, Xianbin

    We present two novel optical detection techniques for radio over fiber (RoF) communication links. Firstly, we present recent results obtained with optical digital coherent detection of optical phase-modulated ROF signals supporting error-free transmission over 25 km standard SMF with BPSK and QPSK...

  15. Bidirectional 120 Gbps SDM-WDM-PON with colourless ONU using 10 Gbps optical components without DSP

    DEFF Research Database (Denmark)

    Hu, Hao; Asif, Rameez; Ye, Feihong

    2016-01-01

    We demonstrate an SDM-WDM-PON system with symmetric aggregated capacity of 120 Gbps (3×scores, 4×wavelengths, 10 Gbps each). The light sources are distributed through the center core of the 7-core fiber, facilitating colorless ONU.......We demonstrate an SDM-WDM-PON system with symmetric aggregated capacity of 120 Gbps (3×scores, 4×wavelengths, 10 Gbps each). The light sources are distributed through the center core of the 7-core fiber, facilitating colorless ONU....

  16. Perspectives of Long-Haul WDM Transmission Systems Based on Phase-Insensitive Fiber-Optic Parametric Amplifiers

    DEFF Research Database (Denmark)

    Jazayerifar, M.; Sackey, I.; Elschner, R.

    2015-01-01

    The deployment of phase-insensitive fiber-opticparametric amplifiers (PI-FOPAs) as inline amplifiers in longhaul WDM transmission systems is discussed, and it is outlined how to design PI-FOPAs to be a valuable upgrade option for this application.......The deployment of phase-insensitive fiber-opticparametric amplifiers (PI-FOPAs) as inline amplifiers in longhaul WDM transmission systems is discussed, and it is outlined how to design PI-FOPAs to be a valuable upgrade option for this application....

  17. Experimental analysis of pilot-based equalization for probabilistically shaped WDM systems with 256QAM/1024QAM

    DEFF Research Database (Denmark)

    Yankov, Metodi Plamenov; Porto da Silva, Edson; Da Ros, Francesco

    2017-01-01

    Pilot based equalization is studied in a 5x10 Gbaud WDM transmission experiment. The equalization is independent of the modulation format and is demonstrated for 256/1024QAM with uniform and probabilistically optimized distribution using an optimized pilot insertion rate of 2-5%.......Pilot based equalization is studied in a 5x10 Gbaud WDM transmission experiment. The equalization is independent of the modulation format and is demonstrated for 256/1024QAM with uniform and probabilistically optimized distribution using an optimized pilot insertion rate of 2-5%....

  18. Energy-Saving Mechanism in WDM/TDM-PON Based on Upstream Network Traffic

    Directory of Open Access Journals (Sweden)

    Paola Garfias

    2014-08-01

    Full Text Available One of the main challenges of Passive Optical Networks (PONs is the resource (bandwidth and wavelength management. Since it has been shown that access networks consume a significant part of the overall energy of the telecom networks, the resource management schemes should also consider energy minimization strategies. To sustain the increased bandwidth demand of emerging applications in the access section of the network, it is expected that next generation optical access networks will adopt the wavelength division/time division multiplexing (WDM/TDM technique to increase PONs capacity. Compared with traditional PONs, the architecture of a WDM/TDM-PON requires more transceivers/receivers, hence they are expected to consume more energy. In this paper, we focus on the energy minimization in WDM/TDM-PONs and we propose an energy-efficient Dynamic Bandwidth and Wavelength Allocation mechanism whose objective is to turn off, whenever possible, the unnecessary upstream traffic receivers at the Optical Line Terminal (OLT. We evaluate our mechanism in different scenarios and show that the proper use of upstream channels leads to relevant energy savings. Our proposed energy-saving mechanism is able to save energy at the OLT while maintaining the introduced penalties in terms of packet delay and cycle time within an acceptable range. We might highlight the benefits of our proposal as a mechanism that maximizes the channel utilization. Detailed implementation of the proposed algorithm is presented, and simulation results are reported to quantify energy savings and effects on network performance on different network scenarios.

  19. Solving the RWA Problem in WDM Optical Networks Using the BCO Meta-Heuristic

    Directory of Open Access Journals (Sweden)

    V. S. Aćimović-Raspopović

    2010-06-01

    Full Text Available This paper researches the routing and wavelength assignment (RWA problem in wavelength routed optical WDM networks with the wavelength conversion capability at different network nodes. We studied the static case in which all connection requests are known in advance, thus a routing decision can be made based on the complete knowledge of the traffic to be served by the network. The Bee Colony Optimization (BCO metaheuristic is applied to solve the RWA problem. We carried out a comprehensive simulation study of the performance of the proposed BCORWA algorithm for different network topologies and traffic scenarios. The obtained simulation results are analyzed and compared.

  20. 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.

  1. Cost and Availability Analysis of 2- and 3-Connected WDM Networks Physical Interconnection

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Riaz, M. Tahir; Pedersen, Jens Myrup

    2012-01-01

    Our future in personal and professional lives is becoming more attached to the evolution of communication technologies and their applications. Consequently, the way Next Generation Network are currently being planned and deployed, might have a great impact on common people depending on how networks...... for the best trade-off among the relevant parameters for the network. In this paper we analyze this trade-off by studying 2-and 3-connected graphs to be used as WDM (Wavelength Division Multiplexing) networks physical infrastructure. The experiments show how the way links are distributed to interconnect...

  2. A Fibre Bragg Grating Interrogation Technique Based on High Birefringence Fibre Loop Mirror and WDM

    Directory of Open Access Journals (Sweden)

    Zhang Xun

    2016-01-01

    Full Text Available In this paper, a fibre Bragg grating (FBG interrogation technique based on high Birefringence fibre loop mirror (Hi-Bi FLM and wavelength division multiplexer (WDM is proposed and demonstrated. The approximate linear edge of the transmittance of the Hi-Bi FLM, which is a sinusoidal function of wavelength, is used to interrogate the sensing FBGs and WDMs is used to realize wavelength discrimination .Suitable for both static and dynamic sensing, this interrogation method has the advantages of all fibre design and high stability.

  3. Experimental Analysis and Reduction of FWM Using Optical Rectangle Filter for WDM

    Directory of Open Access Journals (Sweden)

    Ghulam Fizza

    2016-01-01

    Full Text Available Nonlinearities implanted by refractive index and scattering degrade the performance of optical networks. In this paper, FWM (Four Wave Mixing has been analyzed for four different channels with 10 nm spacing. Due to the presence of resonant frequency, FWM interface of different channels in WDM (Wavelength Division Multiplexing hinders the performance of the system. The system is affected by nonlinear cross talk. A system with the bandwidth of 10 Gbps has been investigated using External Modulation and an optical rectangle filter as a key parameter to improve the system performance with respect to FWM effect

  4. Rapid and noncontact photoacoustic tomography imaging system using an interferometer with high-speed phase modulation technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jun [School of Physics and Telecom Engineering, South China Normal University, Guangzhou 510006 (China); Tang, Zhilie; Wu, Yongbo [School of Physics and Telecom Engineering, South China Normal University, Guangzhou 510006 (China); GuangDong Province Key Laboratory of Quantum Engineering and Quantum Materials, South China Normal University, IMOT, Guangzhou 510006 (China); Wang, Yi [School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao 066004 (China)

    2015-04-15

    We designed, fabricated, and tested a rapid and noncontact photoacoustic tomography (PAT) imaging system using a low-coherence interferometer with high-speed phase modulation technique. Such a rapid and noncontact probing system can greatly decrease the time of imaging. The proposed PAT imaging system is experimentally verified by capturing images of a simulated tissue sample and the blood vessels within the ear flap of a mouse (pinna) in vivo. The axial and lateral resolutions of the system are evaluated at 45 and ∼15 μm, respectively. The imaging depth of the system is 1 mm in a special phantom. Our results show that the proposed system opens a promising way to realize noncontact, real-time PAT.

  5. Switchable microwave photonic filter between high Q bandpass filter and notch filter with flat passband based on phase modulation.

    Science.gov (United States)

    Yu, Yuan; Xu, Enming; Dong, Jianji; Zhou, Lina; Li, Xiang; Zhang, Xinliang

    2010-11-22

    We propose and demonstrate a novel switchable microwave photonic filter based on phase modulation. Both a microwave high Q bandpass filter and a microwave notch filter with flat passband are achieved respectively. And the switchability between them by tuning the two tunable optical bandpass filters is demonstrated. We also present a theoretical model and analytical expression for the proposed scheme. A frequency response of a high Q bandpass filter with a Q factor of 327 and a rejection ratio of exceeding 42 dB, and a frequency response of a notch filter with flat passband with a rejection ratio exceeding 34 dB are experimentally obtained. The operation frequency of microwave photonic filter is around 20 GHz.

  6. Quasi-Coherent Noise Jamming to LFM Radar Based on Pseudo-random Sequence Phase-modulation

    Directory of Open Access Journals (Sweden)

    N. Tai

    2015-12-01

    Full Text Available A novel quasi-coherent noise jamming method is proposed against linear frequency modulation (LFM signal and pulse compression radar. Based on the structure of digital radio frequency memory (DRFM, the jamming signal is acquired by the pseudo-random sequence phase-modulation of sampled radar signal. The characteristic of jamming signal in time domain and frequency domain is analyzed in detail. Results of ambiguity function indicate that the blanket jamming effect along the range direction will be formed when jamming signal passes through the matched filter. By flexible controlling the parameters of interrupted-sampling pulse and pseudo-random sequence, different covering distances and jamming effects will be achieved. When the jamming power is equivalent, this jamming obtains higher process gain compared with non-coherent jamming. The jamming signal enhances the detection threshold and the real target avoids being detected. Simulation results and circuit engineering implementation validate that the jamming signal covers real target effectively.

  7. Multicolor optical Nyquist pulse generation based on self-phase modulation without line-by-line control

    Science.gov (United States)

    Wang, Dong; Huo, Li; Jiang, Xiangyu; Lou, Caiyun

    2016-12-01

    Multicolor optical Nyquist pulse generation based on self-phase modulation without line-by-line control is proposed and experimental demonstrated. By 1.4-ps nearly chirp-free optical Gaussian pulse pumping of a high nonlinearity fiber, a 25-GHz spacing, flat-topped supercontinuum (SC) over 17.8 nm within 3.6 dB power variation at a modest pump power of 21.8 dBm is performed. As the phase of the central 90 tones is almost linear to the wavelength after dispersion compensation, spatial light modulator placed after SC for precise line-by-line control both of amplitude and phase can be replaced by conventional optical band-pass filter (OBPF). With an array of quasi-rectangular OBPFs, nearly transform-limited optical Nyquist pulses with a duty cycle of 5.5% on 4 wavelengths are achieved simultaneously.

  8. Electronic origin of spatial self-phase modulation: Evidenced by comparing graphite with C{sub 60} and graphene

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Y. L.; Zhu, L. L. [College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China); Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Q.; Sun, F.; Wei, J. K.; Tian, Y. C.; Wang, W. L.; Bai, X. D.; Zhao, Jimin, E-mail: jmzhao@iphy.ac.cn, E-mail: xzuonku@outlook.com [Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zuo, Xu, E-mail: jmzhao@iphy.ac.cn, E-mail: xzuonku@outlook.com [College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071 (China)

    2016-06-13

    We report unambiguous observation of spatial self-phase modulation (SSPM) in a dispersive suspension of graphite flakes. This coherent nonlinear optical effect in bulk graphite is found to be broadband and large, with a third-order nonlinear susceptibility χ{sup (3)} of 2.2 × 10{sup −9} esu (i.e., 3.1 × 10{sup −17} m{sup 2}/V{sup 2} in SI units) at 532 nm excitation. Comparison with other carbon allotropes shows that this value is 5 × 10{sup 7} times higher than that of C{sub 60} but ∼50 times lower than that of graphene, fully exhibiting the electronic origin of SSPM.

  9. Path-length-resolved measurements of multiple scattered photons in static and dynamic turbid media using phase-modulated low-coherence interferometry.

    Science.gov (United States)

    Varghese, Babu; Rajan, Vinayakrishnan; Van Leeuwen, Ton G; Steenbergen, Wiendelt

    2007-01-01

    In optical Doppler measurements, the path length of the light is unknown. To facilitate quantitative measurements, we develop a phase-modulated Mach-Zehnder interferometer with separate fibers for illumination and detection. With this setup, path-length-resolved dynamic light scattering measurements of multiple scattered light in static and dynamic turbid media are performed. Optical path length distributions spanning a range from 0 to 11 mm are measured from the area under the phase modulation peak around the modulation frequency in the power spectrum. A Doppler-broadened phase modulation interference peak is observed that shows an increase in the average Doppler shift with optical path length, independent of absorption. Validation of the estimated path length distributions is done by measuring their deformation for increasing absorption and comparing these observations with predictions based on Lambert-Beer's law.

  10. Multi-granularity Bandwidth Allocation for Large-Scale WDM/TDM PON

    Science.gov (United States)

    Gao, Ziyue; Gan, Chaoqin; Ni, Cuiping; Shi, Qiongling

    2017-12-01

    WDM (wavelength-division multiplexing)/TDM (time-division multiplexing) PON (passive optical network) is being viewed as a promising solution for delivering multiple services and applications, such as high-definition video, video conference and data traffic. Considering the real-time transmission, QoS (quality of services) requirements and differentiated services model, a multi-granularity dynamic bandwidth allocation (DBA) in both domains of wavelengths and time for large-scale hybrid WDM/TDM PON is proposed in this paper. The proposed scheme achieves load balance by using the bandwidth prediction. Based on the bandwidth prediction, the wavelength assignment can be realized fairly and effectively to satisfy the different demands of various classes. Specially, the allocation of residual bandwidth further augments the DBA and makes full use of bandwidth resources in the network. To further improve the network performance, two schemes named extending the cycle of one free wavelength (ECoFW) and large bandwidth shrinkage (LBS) are proposed, which can prevent transmission from interruption when the user employs more than one wavelength. The simulation results show the effectiveness of the proposed scheme.

  11. Research on Transmission Performance of Different Modulation Formats Based on Re-modulation WDM-PON

    Science.gov (United States)

    Li, Li; Feng, He

    2017-05-01

    Dispersion and nonlinear effects will increase the effect on the system when the optical information transmits in high speed and long distance. The new optical modulation technology can reduce the attenuation caused by transmission procedure. In this paper, OptiSystem and Matlab were combined to set a model by comparing the dispersion tolerance and nonlinear effect of different code modulation formats. After that, the better performance code of IRZ (Inverse Return-to-Zero) and DQPSK (Differential Quadrature Phase Shifted Keying) will be used to study their properties in 10Gbit/s re-modulation WDM-PON access model. The DQPSK was used in downlink, IRZ modulation was used in uplink adopts the IRZ modulation was used in 10 Gbit/s re-modulation WDM passive optical network access model uplink on the basis of the above method. A simulation analysis is also made between the different duty ratios of the DQPSK and IRZ. Compared with the NRZ type, the IRZ has a better anti-dispersion property, channel crosstalk suppression ability and higher spectrum efficiency although it costs 3 dB powers. At the same time, it simplifies the structure of the ONU on the premise of not increasing the power and the cost. So, it fits the large capacity requirements between user stations and the central office in the future.

  12. An agent-based QoS provisioning mechanism for WDM optical networks

    Science.gov (United States)

    Ouyang, Yong; Zeng, Qingji; Yue, Ling

    2004-04-01

    This paper addresses QoS provisioning mechanisms in the WDM optical networks. With the appearance of metropolitan optical network, a hierarchical metro and wide area optical network will be envisioned in the near future. This hierarchical optical transport network is often divided into optical domains by geography, administration and technology, which usually employ different QoS routing algorithms and policies. To provide end-to-end optical QoS is becoming a new challenge for the optical network design. In this paper, we first give an overview of issues on the QoS provisioning in data, control and management planes of the WDM optical network. And then three provisioning approaches are analyzed and compared. Finally, we propose an agent-based hybrid centralized/distributed QoS provisioning mechanism based on the concept of domain agent. This agent-based hybrid mechanism employs centralized approach in the domain and distributed approach between domains. It offers scalability and intra-domain optimal QoS routing. It also keeps independence and interoperability between domains.

  13. P-cycle-based protection design for IP over WDM networks

    Science.gov (United States)

    Zhang, Zhizhong; Zhang, Yunlin; Zeng, Qingji; Zhao, Zhengfu; Luo, Jiangtao; Cao, Junwen

    2004-04-01

    P-cycle based protection has been proved to be an effective way for WDM networks" survivability design. In IP over WDM networks, p-cycle can also be constructed through GMPLS technology to protect a number of IP links. In this paper, we demonstrate that there are some drawbacks associated with the current p-cycle searching algorithms, e.g., 1) none of the them take the hop-count constraint into account, which means some requests may not able to be protected by their associated p-cycles; 2) to protect those failures occurred on the straddling links, the algorithms demand the traffic to be split in half over each p-cycle segment, which may not be a resource efficient solution, and the routing procedure may be prohibited by hop-count constraints, also, it may introduce extra link propagation delays and causes IP packets to arrive out of order. We propose an improved object function, and give a novel p-cycle searching algorithm. Simulation results obtained from CERNET-like physical topology and the national backbone networks show that the developed algorithm performs well in terms of performance metrics such as the connection blocking probability and the success rate of the protection.

  14. An Optical Multicast Routing with Minimal Network Coding Operations in WDM Networks

    Directory of Open Access Journals (Sweden)

    Huanlin Liu

    2014-01-01

    Full Text Available Network coding can improve the optical multicast routing performance in terms of network throughput, bandwidth utilization, and traffic load balance. But network coding needs high encoding operations costs in all-optical WDM networks due to shortage of optical RAM. In the paper, the network coding operation is defined to evaluate the number of network coding operation cost in the paper. An optical multicast routing algorithm based on minimal number of network coding operations is proposed to improve the multicast capacity. Two heuristic criteria are designed to establish the multicast routing with low network coding cost and high multicast capacity. One is to select one path from the former K shortest paths with the least probability of dropping the multicast maximal capacity. The other is to select the path with lowest potential coding operations with the highest link shared degree among the multiple wavelength disjoint paths cluster from source to each destination. Comparing with the other multicast routing based on network coding, simulation results show that the proposed multicast routing algorithm can effectively reduce the times of network coding operations, can improve the probability of reaching multicast maximal capacity, and can keep the less multicast routing link cost for optical WDM networks.

  15. Transmission Performance Analysis of Fiber Optical Parametric Amplifiers for WDM System

    Directory of Open Access Journals (Sweden)

    Xiaohong Jiang

    2009-01-01

    Full Text Available A numerical analysis is presented on the long-haul wavelength-division multiplexing (WDM transmission system employing fiber-optic parametric amplifier (FOPA cascades based on one-pump FOPA model with Raman Effect taken into account. The end-to-end equalization scheme is applied to optimize the system features in terms of proper output powers and signal-to-noise ratios (SNRs in all the channels. The numerical results show that—through adjusting the fiber spans along with the number of FOPAs as well as the channel powers at the terminals in a prescribed way—the transmission distance and system performance can be optimized. By comparing the results generated by different lengths of fiber span, we come to the optimal span length to achieve the best transmission performance. Furthermore, we make a comparison among the long-haul WDM transmission systems employing different inline amplifiers, namely, FOPA, erbium-doped fiber amplifier (EDFA, and Fiber Raman Amplifier (FRA. FOPA demonstrates its advantage over the other two in terms of system features.

  16. Constellation Shaping for WDM systems using 256QAM/1024QAM with Probabilistic Optimization

    CERN Document Server

    Yankov, Metodi P; da Silva, Edson P; Forchhammer, Søren; Larsen, Knud J; Oxenløwe, Leif K; Galili, Michael; Zibar, Darko

    2016-01-01

    In this paper, probabilistic shaping is numerically and experimentally investigated for increasing the transmission reach of wavelength division multiplexed (WDM) optical communication system employing quadrature amplitude modulation (QAM). An optimized probability mass function (PMF) of the QAM symbols is first found from a modified Blahut-Arimoto algorithm for the optical channel. A turbo coded bit interleaved coded modulation system is then applied, which relies on many-to-one labeling to achieve the desired PMF, thereby achieving shaping gain. Pilot symbols at rate at most 2% are used for synchronization and equalization, making it possible to receive input constellations as large as 1024QAM. The system is evaluated experimentally on a 10 GBaud, 5 channels WDM setup. The maximum system reach is increased w.r.t. standard 1024QAM by 20% at input data rate of 4.65 bits/symbol and up to 75% at 5.46 bits/symbol. It is shown that rate adaptation does not require changing of the modulation format. The performanc...

  17. Sampled fiber grating for WDM signal queuing with picosecond time interval

    Science.gov (United States)

    Zhao, Weiqian; Liu, Shuai; Qi, Haifeng; Peng, Gangding; Shen, Mingya

    2017-12-01

    A new sampled fiber grating scheme is investigated for WDM signal queuing in time domain. The queuing is aimed at achieving very short constant time intervals down to picoseconds (ps) for many wavelength channels by a single fiber device. Theory and modeling predict that a consistence of linear spectral profiles exists between reflectivity or transmission spectrum and time delay spectrum. A sampled fiber grating based on Gaussian beam writing is proposed to offer a large number of wavelength channels and time delays within an approximate linear profile. Results for simulating a Gaussian sampled fiber grating show that the time delay minima of 8 channels within a section of the spectral profile have an average time delay step of 2.83 ps and standard deviation of 7.4% from linearity. Fiber gratings were successfully written by Gaussian laser beam in fabrication. A Gaussian sampled fiber grating was measured for time delay spectrum of 4 wavelength channels. An average time delay step of 9.67 ps is obtained. Some issues and related analysis and discussion are given. Our preliminary experiment suggests that the sampled fiber grating scheme can achieve ps-time steps for WDM signal queuing such as high-resolution time delay lines.

  18. Testing FSO WDM communication system in simulation software optiwave OptiSystem in different atmospheric environments

    Science.gov (United States)

    Vanderka, Ales; Hajek, Lukas; Bednarek, Lukas; Latal, Jan; Vitasek, Jan; Hejduk, Stanislav; Vasinek, Vladimir

    2016-09-01

    In this article the author's team deals with using Wavelength Division Multiplexing (WDM) for Free Space Optical (FSO) Communications. In FSO communication occurs due to the influence of atmospheric effect (attenuation, and fluctuation of the received power signal, influence turbulence) and the WDM channel suffers from interchannel crosstalk. There is considered only the one direction. The behavior FSO link was tested for one or eight channels. Here we will be dealing with modulation schemes OOK (On-Off keying), QAM (Quadrature Amplitude Modulation) and Subcarrier Intensity Modulation (SIM) based on a BPSK (Binary Phase Shift Keying). Simulation software OptiSystem 14 was used for tasting. For simulation some parameters were set according to real FSO link such as the datarate 1.25 Gbps, link range 1.4 km. Simulated FSO link used wavelength of 1550 nm with 0.8 nm spacing. There is obtained the influence of crosstalk and modulation format for the BER, depending on the amount of turbulence in the propagation medium.

  19. Multipath Routing and Wavelength Assignment Technique in Optical WDM Mesh Networks

    Science.gov (United States)

    Kavitha, T.; Shiyamala, S.; Rajamani, V.

    2017-12-01

    A routing and wavelength assignment (RWA) technique for supporting multipath traffic in optical wavelength-division multiplexing (WDM) mesh network is proposed in this paper. The network can be preceded by accomplishing two processes: one is establishing connection node and the second one is identifying the multipath and assigning wavelength. The connection node is selected based on the load and current traffic-carrying capacity of that node. During wavelength allocation mechanism, cost function is considered as the major criterion. Based on the cost involved in every path, the wavelengths are selected such that wavelength with the minimum cost is allocated to that particular path. This technique efficiently allocates the wavelength to the selected multiple paths and the traffic is routed to the destination using multiple paths with wavelength allocation. For simulation, NS2 simulator is used by applying the optical WDM network simulator patch. The proposed multipath RWA technique is compared with the existing RWA technique. We achieved a throughput of 12,625 packets for ten numbers of wavelengths. But the existing approach achieved a throughput of 10,189 packets only for the same numbers of wavelengths. Channel utilization is more, and delay is less compared with the existing technique. Hence, the proposed method is very efficient, since the router effectively routes the traffic within the network.

  20. Path length resolved Doppler measurements of multiple scattered photons in turbid media for various absorptions using phase modulated low-coherence interferometry

    Science.gov (United States)

    Varghese, Babu; Rajan, Vinayakrishnan; Van Leeuwen, Ton G.; Steenbergen, Wiendelt

    2006-04-01

    We report the development of non-invasive, path length resolved Doppler measurements of the multiply scattered light in turbid media, for different absorptions using phase modulated Mach-Zehnder low coherence interferometer, with separate fibers for illumination and detection. A Doppler broadened phase modulation interference peak is observed that shows an increase in the average Doppler shift with optical path length, independent of absorption. The estimated path length distributions indicate suppression and narrowing for increasing absorption and can be related by Lambert-Beer's law.

  1. Transmission of OFDM wired-wireless quintuple-play services along WDM LR-PONs using centralized broadband impairment compensation.

    Science.gov (United States)

    Alves, Tiago M F; Morant, Maria; Cartaxo, Adolfo V T; Llorente, Roberto

    2012-06-18

    The simultaneous transmission of four orthogonal frequency-division multiplexing (OFDM)-based signals used to provide quintuple-play services along wavelength division multiplexing (WDM) long-reach passive optical networks (LR-PONs) is demonstrated experimentally. Particularly, the transmission performance of custom signal bearing Gigabit Ethernet data, Worldwide Interoperability for Microwave Access, Long Term Evolution and Ultra Wideband (sub-bands 2 and 3) signals is evaluated for different LR-PONs reaches, considering single-wavelength and WDM transmission, and using a centralized impairment compensation technique at the central office that is transparent to the services provided.It is shown that error vector magnitude-compliant levels are obtained for all the OFDM-based signals in WDM LR-PONs reaching 100 km and that negligible inter-channel crosstalk is obtained for a channel spacing of 100 GHz regardless the OFDM-based signal considered. The successful multi-format OFDM transmission along the 100 km-long WDM LR-PON is achieved in the absence of optical dispersion compensation or single sideband modulation, and it is enabled by the performance improvement provided by the centralized impairment compensation realized.

  2. 1.2 Tb/s Ultredense WDM Long Reach and Spectral Efficiency Access Link with Digital Detection

    DEFF Research Database (Denmark)

    Zhang, Xu; Arlunno, Valeria; Jensen, Jesper Bevensee

    2011-01-01

    We experimentally demonstrate an ultradense WDM system with sub-channel spacing at the baud rate, achieving 4.0 b/s/Hz spectral efficiency and aggregate capacity of 1.2 Tb/s data transmission over 80-km SMF, for long reach access networking....

  3. Root cause analysis and solution to the degradation of wavelength division multiplexing (WDM) couplers in high power fiber amplifier system.

    Science.gov (United States)

    Peng, Xiang; Kim, Kyungbum; Gu, Xinhua; Mielke, Michael; Jennings, Stephen; Rider, Andy; Fisher, Norman; Woodbridge, Toby; Dionne, Rene; Trepanier, Francois

    2013-08-26

    In the evaluation a fused biconical taper 1480/1580 nm WDM's ability to handle high power cascaded Raman laser throughput (>100 W) a significant degradation in performance was observed. A systematic root cause investigation was conducted and it is experimentally confirmed that the WDM degradation was caused by an interaction between the high power 1480 nm line, an out-of-band Stokes line, and the -OH content of the glass optical fiber. Slanted fiber Bragg grating (SFBG) was introduced to filter out the 1390 nm out-of-band Stokes line in an attempt to avoid this interaction. Ultimately a series of tests were conducted and it was confirmed that the addition of a 1390 nm SFBG in between a high power Raman laser and the high power WDM has successfully prevented the degradation which therefore allowed the continued high power operation of the WDM. NAVAIR Public Release SPR 2013-469 Distribution Statement A-"Approved for Public release; distribution is unlimited".

  4. Highly Effective Crosstalk Mitigation Method Using Counter-Propagation in Semiconductor Optical Amplifier for Remodulation WDM-PONs

    Directory of Open Access Journals (Sweden)

    Quang Thai Pham

    2014-01-01

    Full Text Available Remodulation-induced crosstalk mitigation in WDM-PON using remodulation approach is presented in this paper. Utilizing all-optical signal processing, the proposed method has been able to significantly improve system performance in terms of bit error rate (BER and bit rate distance product. Moreover, the proposed method could be used for both baseband and modulated downstream electrical signals.

  5. An improved approximate network blocking probability model for all-optical WDM Networks with heterogeneous link capacities

    Science.gov (United States)

    Khan, Akhtar Nawaz

    2017-11-01

    Currently, analytical models are used to compute approximate blocking probabilities in opaque and all-optical WDM networks with the homogeneous link capacities. Existing analytical models can also be extended to opaque WDM networking with heterogeneous link capacities due to the wavelength conversion at each switch node. However, existing analytical models cannot be utilized for all-optical WDM networking with heterogeneous structure of link capacities due to the wavelength continuity constraint and unequal numbers of wavelength channels on different links. In this work, a mathematical model is extended for computing approximate network blocking probabilities in heterogeneous all-optical WDM networks in which the path blocking is dominated by the link along the path with fewer number of wavelength channels. A wavelength assignment scheme is also proposed for dynamic traffic, termed as last-fit-first wavelength assignment, in which a wavelength channel with maximum index is assigned first to a lightpath request. Due to heterogeneous structure of link capacities and the wavelength continuity constraint, the wavelength channels with maximum indexes are utilized for minimum hop routes. Similarly, the wavelength channels with minimum indexes are utilized for multi-hop routes between source and destination pairs. The proposed scheme has lower blocking probability values compared to the existing heuristic for wavelength assignments. Finally, numerical results are computed in different network scenarios which are approximately equal to values obtained from simulations. Since January 2016, he is serving as Head of Department and an Assistant Professor in the Department of Electrical Engineering at UET, Peshawar-Jalozai Campus, Pakistan. From May 2013 to June 2015, he served Department of Telecommunication Engineering as an Assistant Professor at UET, Peshawar-Mardan Campus, Pakistan. He also worked as an International Internship scholar in the Fukuda Laboratory, National

  6. Self-phase modulation induced transmission penalty reduction in a 5 Gbit/s FM/AM conversion system experiment over 205 km of standard fiber

    DEFF Research Database (Denmark)

    Jørgensen, Bo Foged; Pedersen, Rune Johan Skullerud; Jørgensen, Carsten Gudmann

    1994-01-01

    The transmission penalty of a standard non-dispersion shifted fiber is experimentally demonstrated to be reduced by self-phase modulation due to the optical Kerr effect. A 2 dB reduction of transmission penalty is achieved in a 5 Gbit/s FM/AM conversion system experiment over 205 km of fiber...

  7. Optical phase conjugation for nonlinearity compensation in WDM PDM 16-QAM transmission over dispersion-compensated and dispersion-uncompensated links

    DEFF Research Database (Denmark)

    Da Ros, Francesco; Sackey, I.; Jazayerifar, M.

    2015-01-01

    Kerr nonlinearity compensation by optical phase conjugation is demonstrated in a WDM PDM 16-QAM system. Improved received signal quality is reported for both dispersion-compensated and dispersion-uncompensated transmission and a comparison with digital backpropagation is provided.......Kerr nonlinearity compensation by optical phase conjugation is demonstrated in a WDM PDM 16-QAM system. Improved received signal quality is reported for both dispersion-compensated and dispersion-uncompensated transmission and a comparison with digital backpropagation is provided....

  8. One-to-six WDM multicasting of DPSK signals based on dual-pump four-wave mixing in a silicon waveguide

    DEFF Research Database (Denmark)

    Pu, Minhao; Hu, Hao; Ji, Hua

    2011-01-01

    We present WDM multicasting based on dual-pump four-wave mixing in a 3-mm long dispersion engineered silicon waveguide. One-to-six phase-preserving WDM multicasting of 10-Gb/s differential phase-shiftkeying (DPSK) data is experimentally demonstrated with bit-error rate measurements. All the six...... multicast signals show error-free performance with power penalty less than 3.8 dB....

  9. Fiber nonlinearity compensation by repeated phase conjugation in 2.048-Tbit/s WDM transmission of PDM 16-QAM channels

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Gnauck, A. H.

    2016-01-01

    We demonstrate compensation of fiber nonlinearities using repeated optical phase conjugation (OPC) in a WDM system with eight 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC.......We demonstrate compensation of fiber nonlinearities using repeated optical phase conjugation (OPC) in a WDM system with eight 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC....

  10. All-optical equalization of power transients on four 40 Gbit/s WDM channels using a fiber-based device

    DEFF Research Database (Denmark)

    Kjær, Rasmus; Oxenløwe, Leif Katsuo; Palsdottir, Bera

    2008-01-01

    Simultaneous transient suppression of four transient-impaired 40 Gbit/s RZ-ASK WDM channels is demonstrated. Sensitivity improvements are in excess of 5 dB and transmission penalties are significantly reduced.......Simultaneous transient suppression of four transient-impaired 40 Gbit/s RZ-ASK WDM channels is demonstrated. Sensitivity improvements are in excess of 5 dB and transmission penalties are significantly reduced....

  11. High-power Microwave Pulse Compression of Klystrons by Phase-Modulation of High-Q Storage Cavities

    CERN Document Server

    Bossart, Rudolf; Mourier, J; Syratchev, I V; Tanner, L

    2004-01-01

    At the CERN linear electron accelerators LIL and CTF, the peak RF power from the 3GHz-klystrons was doubled by means of LIPS microwave pulse compressors. To produce constant RF power from the cavity-based pulse compressors, the klystrons were driven by a fast RF-phase modulation program. For the CLIC Test Facility CTF3, a new type of a Barrel Open Cavity (BOC) with a high quality factor Q0 has been developed. Contrary to LIPS with two resonant cavities, BOC operates with a single cavity supporting two orthogonal resonant modes TM 10,1,1 in the same cavity. For both LIPS and BOC storage cavities, it is important that the RF power reflected back to the klystron is minimal. This implies that the resonant frequencies, Q-factors and coupling factors of the two resonant modes of a pulse compressor are closely matched, and that the resonant frequencies are accurate to within a few KHz. The effects of small differences between the two orthogonal modes of the BOC cavity have been investigated. The dynamic pulse respon...

  12. Polarization rotation of light propagating through a medium with efficient four-wave mixing and cross-phase modulation

    Science.gov (United States)

    Sahoo, Sushree S.; Bhowmick, Arup; Mohapatra, Ashok K.

    2017-03-01

    We have studied the rotation of an elliptically polarized light propagating through thermal rubidium vapor with efficient four-wave mixing (FWM) and cross-phase modulation (XPM). These nonlinear processes are enhanced by Zeeman coherence within the degenerate sub-levels of the two-level atomic system. The elliptically polarized light with small ellipticity is considered as the superposition of a strong-linearly-polarized pump beam and a weak-orthogonal-polarized probe beam. The interference of the probe and the newly generated light field due to degenerate FWM and their gain in the medium due to a large XPM induced by the pump beam leads to the rotation of the elliptical polarized light. A theoretical analysis of the probe propagation through the nonlinear medium was used to explain the experimental observation and the fitting of the experimental data gives the estimates of the third-order non-linear susceptibilities associated with FWM and XPM. Our study can provide useful parameters for the generation of efficient squeezed vacuum states and squeezed polarization states of light. Furthermore our study finds application in controlling the diffraction of a linearly-polarized light beam traversing the medium.

  13. Electrical power inverter having a phase modulated, twin-inverter, high frequency link and an energy storage module

    Science.gov (United States)

    Pitel, Ira J.

    1987-02-03

    The present invention provides an electrical power inverter method and apparatus, which includes a high frequency link, for converting DC power into AC power. Generally stated, the apparatus includes a first high frequency module which produces an AC voltage at a first output frequency, and a second high frequency inverter module which produces an AC voltage at a second output frequency that is substantially the same as the first output frequency. The second AC voltage is out of phase with the first AC voltage by a selected angular phase displacement. A mixer mixes the first and second output voltages to produce a high frequency carrier which has a selected base frequency impressed on the sidebands thereof. A rectifier rectifies the carrier, and a filter filters the rectified carrier. An output inverter inverts the filtered carrier to produce an AC line voltage at the selected base frequency. A phase modulator adjusts the relative angular phase displacement between the outputs of the first and second high frequency modules to control the base frequency and magnitude of the AC line voltage.

  14. Coherent control of flexural vibrations in dual-nanoweb fibers using phase-modulated two-frequency light

    Science.gov (United States)

    Koehler, J. R.; Noskov, R. E.; Sukhorukov, A. A.; Novoa, D.; Russell, P. St. J.

    2017-12-01

    Coherent control of the resonant response in spatially extended optomechanical structures is complicated by the fact that the optical drive is affected by the backaction from the generated phonons. Here we report an approach to coherent control based on stimulated Raman-like scattering, in which the optical pressure can remain unaffected by the induced vibrations even in the regime of strong optomechanical interactions. We demonstrate experimentally coherent control of flexural vibrations simultaneously along the whole length of a dual-nanoweb fiber, by imprinting steps in the relative phase between the components of a two-frequency pump signal, the beat frequency being chosen to match a flexural resonance. Furthermore, sequential switching of the relative phase at time intervals shorter than the lifetime of the vibrations reduces their amplitude to a constant value that is fully adjustable by tuning the phase modulation depth and switching rate. The results may trigger new developments in silicon photonics, since such coherent control uniquely decouples the amplitude of optomechanical oscillations from power-dependent thermal effects and nonlinear optical loss.

  15. Method of optical coherence tomography with parallel depth-resolved signal reception and fibre-optic phase modulators

    Energy Technology Data Exchange (ETDEWEB)

    Morozov, A N; Turchin, I V [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

    2013-12-31

    The method of optical coherence tomography with the scheme of parallel reception of the interference signal (P-OCT) is developed on the basis of spatial paralleling of the reference wave by means of a phase diffraction grating producing the appropriate time delay in the Mach–Zehnder interferometer. The absence of mechanical variation of the optical path difference in the interferometer essentially reduces the time required for 2D imaging of the object internal structure, as compared to the classical OCT that uses the time-domain method of the image construction, the sensitivity and the dynamic range being comparable in both approaches. For the resulting field of the interfering object and reference waves an analytical expression is derived that allows the calculation of the autocorrelation function in the plane of photodetectors. For the first time a method of linear phase modulation by 2π is proposed for P-OCT systems, which allows the use of compact high-frequency (a few hundred kHz) piezoelectric cell-based modulators. For the demonstration of the P-OCT method an experimental setup was created, using which the images of the inner structure of biological objects at the depth up to 1 mm with the axial spatial resolution of 12 μm were obtained. (optical coherence tomography)

  16. Low-cost phase-modulation fluorometer for measuring nanosecond lifetimes using a lock-in amplifier

    Science.gov (United States)

    Harms, Peter D.; Rao, Govind

    1999-05-01

    A Stanford Research Systems SR844 lock-in amplifier was used to build a sub $10,000 phase-modulation fluorometer capable of measuring nanosecond fluorescence lifetimes. The lock-in directly provided both the DC bias and the AC signal used to modulate the intensity of a blue LED excitation source. A photomultiplier tube measured the emission, and the resulting signal was sent back through a DC block to the lock-in with no external signal processing or heterodyning required. A simple computer program was developed to automate the measuring process and correct for the most common sources of error, namely coherent pickup and stray ambient light. Several standard fluorophores were measured, and the results compare favorably with those from a research grade cross-correlation phase fluorometer up to frequencies of 100 MHz. This system can operate in several configurations, each with benefits and limitations. The system is particularly well suited for fluorescence lifetime based sensing applications, demonstrated by measuring dissolved carbon dioxide online in a bacterial fermentation.

  17. Single and Dual Physical Link Failures Stability Effect on Degree Three WDM Networks

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Georgakilas, Konstantinos; Riaz, M. Tahir

    2010-01-01

    This paper studies the effects of Single and Dual physical link failures to the stability of WDM networks when deployed as regular 3-degree structures. The failure impact on the source-destination pair connections is evaluated for the different topology scenarios. In this way it is possible...... to provide an overview of the failure effects and their relation to network metrics such as availability or cost. The results quantify how much the different network interconnection designs are affected by Single and Dual Physical link failures. The case study treats a realistic scenario, the interconnection...... of the NSFNET topology nodes. The main conclusions show that, when networks are designed under the same conditions, there is a linear relation between average downtime and ratio of connections affected by failures. Moreover, the most expensive optimized topologies to deploy provide higher availability....

  18. A Hybrid TDM/WDM-PON System With FWM-Generated Source of Multiwavelength Optical Signals

    Science.gov (United States)

    Lyashuk, I.; Shchemelev, A.; Ivanov, G.

    2010-01-01

    A new approach to FTTx solutions is proposed, in the framework of which a hybrid TDM/WDM system using cascaded FWM-generated optical signals is evaluated by calculating the BER parameter and the optical power budget. Computer simulation is employed as the main method of calculations, with the results presented both in numerical and graphical forms. The results show that the use of a forward error correction allows the power margin of 4 dB to be achieved for the system to work reliably. The system can provide the total number of users up to 128 (8γx16 TDM users) with a bandwidth of multiple hundreds of Mbit/s p.u. by means of the existing passive optical networking infrastructure, with only minor improvements needed.

  19. Mitigation of time-varying distortions in Nyquist-WDM systems using machine learning

    Science.gov (United States)

    Granada Torres, Jhon J.; Varughese, Siddharth; Thomas, Varghese A.; Chiuchiarelli, Andrea; Ralph, Stephen E.; Cárdenas Soto, Ana M.; Guerrero González, Neil

    2017-11-01

    We propose a machine learning-based nonsymmetrical demodulation technique relying on clustering to mitigate time-varying distortions derived from several impairments such as IQ imbalance, bias drift, phase noise and interchannel interference. Experimental results show that those impairments cause centroid movements in the received constellations seen in time-windows of 10k symbols in controlled scenarios. In our demodulation technique, the k-means algorithm iteratively identifies the cluster centroids in the constellation of the received symbols in short time windows by means of the optimization of decision thresholds for a minimum BER. We experimentally verified the effectiveness of this computationally efficient technique in multicarrier 16QAM Nyquist-WDM systems over 270 km links. Our nonsymmetrical demodulation technique outperforms the conventional QAM demodulation technique, reducing the OSNR requirement up to ∼0.8 dB at a BER of 1 × 10-2 for signals affected by interchannel interference.

  20. Integration of FBG Strain Sensors in WDM Networks, Effects on Quality Factor

    Directory of Open Access Journals (Sweden)

    Ali Al-Lawati

    2009-06-01

    Full Text Available A study of the effect of integrating an FBG sensor in a four wavelength WDM communications system operating at 1550 nm is presented. The simulations considered focus on the mutual effects of both the sensing and the communications systems. The effect of power levels of the interrogating optical source on the performance of the two systems is also investigated under excitation levels of up to 10 dBm. The network layout used in the simulations is based on an actual optical link in Oman having a variety of spans. The results obtained at data rates of 2.5 and 10 Gbps with variable strains up to ±600 μs show a good tolerance in terms of quality of transmission for the two systems. However, the greater the strain values, the more noticeable are the degradations of transmission quality parameters of the communications system.

  1. Restorability on 3-connected WDM Networks Under Single and Dual Physical Link Failures

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Jensen, Michael; Riaz, Tahir

    2013-01-01

    This work studies the influence the network interconnection has over restoration techniques. The way physical links are distributed to interconnect network nodes has a great impact on parameters such as path distances when failures occur and restoration is applied. The work focuses on single...... and dual physical link failures restorability on WDM transport networks. This failure scenarios are tested over several 3-connected topologies, and studied in graph theory and network planning terms. In connection with the graphs, the resulting hop path distances and lengths are evaluated. In relation...... to network planning, the trade-off network length vs. performance of the different topological options is studied. The results show how 3-connected graphs could provide a reasonable trade-off between costs, link failure rates, and restored path parameters....

  2. Influence of Transmitting Pointing Errors on High Speed WDM-AMI-Is-OWC Transmission System

    Science.gov (United States)

    Shatnawi, Abdallah Ahmad; Bin Mohd Warip, Mohd Nazri; Safar, Anuar Mat

    2017-12-01

    Inter-satellite communication is one of the revolutionary techniques that can be used to transmit the high speed date between satellites. However, space turbulences such as transmitting pointing errors play a significant role while designing inter-satellite communication systems. Those turbulences cause shutdown of inter-satellite link due to increase of attenuation during data transmission through link. The present work aims to develop an integrated data transmission system incorporating alternate mark inversion (AMI), wavelength division multiplexing (WDM), and polarization interleaving (PI) scheme for transmitting data 160 Gbps over inter-satellite link of 1,000 km under the influence of space turbulences. The performance of the integrated data transmission of 160 Gbps data up to 1,000 km will be evaluated under the influence of space turbulences by means of signal to noise ratio (SNR), total received power, bit error rate and eye diagram.

  3. Development of Compact and Low-Crosstalk PLC-WDM Filters for Hybrid-Integrated Bidirectional Optical Transceivers

    Science.gov (United States)

    Kim, Kyoung-Youm; Kim, Se Yoon; Kim, Myoung Won; Jung, Suntae

    2005-05-01

    This paper reports on the development of planar-lightwave-circuit wavelength-division-multiplexing (PLC-WDM) filters based on double polynomial curve directional couplers, which will be integrated into compact and low-cost bidirectional optical transceivers for FTTx systems. Silica-based PLC-WDM filters smaller than 5 mm x 100 m for Ethernet passive optical network (E-PON) applications were designed and fabricated to have low bidirectional crosstalk (lower than -40 dB) as well as low insertion losses (lower than 1 dB) within the operating temperatures of -40 to 80 ° C. Several features and design guides that can reduce the size of directional couplers and improve the level of bidirectional crosstalk are discussed.

  4. Parametric amplification and wavelength conversion of a 2.048-Tbit/s WDM PDM 16-QAM signal

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, R. M.; Gnauck, A. H.

    2014-01-01

    We demonstrate polarisation-insensitive parametric amplification in highly nonlinear fibre of a 2.048-Tbit/s dense WDM PDM 16-QAM signal with ∼10 dB on-off gain and simultaneous wavelength conversion and phase conjugation, with mean Q2 penalties of only 0.6 dB and 0.4 dB.......We demonstrate polarisation-insensitive parametric amplification in highly nonlinear fibre of a 2.048-Tbit/s dense WDM PDM 16-QAM signal with ∼10 dB on-off gain and simultaneous wavelength conversion and phase conjugation, with mean Q2 penalties of only 0.6 dB and 0.4 dB....

  5. 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

    -based zero forcing (ZF) channel estimation algorithm is designed to compensate the polarization rotation and wireless multipath fading. A 797 Mb/s net data rate QPSK-OFDM signal with error free (OFDM signal with BER performance of 1.2 × 10......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...

  6. Mitigation of Nonlinear Effects on WDM QAM Signals Enabled by Optical Phase Conjugation with Efficient Bandwidth Utilization

    OpenAIRE

    Yoshima, S.; Sun, Y.; Liu, Z.; Bottrill, K. R. H.; Parmigiani, F.; Richardson, D J; Petropoulos, P.

    2016-01-01

    We present nonlinear impairment mitigation of wavelength division multiplexed (WDM) signals, through optical phase conjugation (OPC). We conduct our experiments on a 400-km long installed fiber link equipped with erbium-doped fiber amplifiers (EDFAs), with the OPC placed close to the middle of the link. Our OPC configuration realizes efficient reuse of the signal bandwidth, avoiding the loss of half of the spectral band typical of most phase conjugating schemes. We demonstrate the operation o...

  7. 8×40 Gb/s 55-km WDM transmission over conventional fiber using a new RZ optical source

    OpenAIRE

    Yu, Jianjun; Zheng, Xueyan; Liu, Fenghai; Peucheret, Christophe; Jeppesen, Palle

    2000-01-01

    A multiwavelength RZ optical source with equal amplitudes and pulsewidths is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of a common dispersion shifted fiber. The converted wavelengths of the eight signal pulses are in agreement with the ITU-T proposal and a commercial arrayed-waveguide grating is used for demultiplexing in the frequency-domain. By using the new source 8×40 Gb/s WDM transmission over 55 km conventional fiber was realized.

  8. 8×40 Gb/s 55-km WDM transmission over conventional fiber using a new RZ optical source

    DEFF Research Database (Denmark)

    Yu, Jianjun; Zheng, Xueyan; Liu, Fenghai

    2000-01-01

    A multiwavelength RZ optical source with equal amplitudes and pulsewidths is successfully obtained by using wavelength conversion in a nonlinear optical loop mirror consisting of a common dispersion shifted fiber. The converted wavelengths of the eight signal pulses are in agreement with the ITU-......-T proposal and a commercial arrayed-waveguide grating is used for demultiplexing in the frequency-domain. By using the new source 8×40 Gb/s WDM transmission over 55 km conventional fiber was realized....

  9. 10-m 9.51-Gb/s RGB laser diodes-based WDM underwater wireless optical communication.

    Science.gov (United States)

    Kong, Meiwei; Lv, Weichao; Ali, Tariq; Sarwar, Rohail; Yu, Chuying; Qiu, Yang; Qu, Fengzhong; Xu, Zhiwei; Han, Jun; Xu, Jing

    2017-08-21

    The availability of the underwater wireless optical communication (UWOC) based on red (R), green (G) and blue (B) lights makes the realization of the RGB wavelength division multiplexing (WDM) UWOC system possible. By properly mixing RGB lights to form white light, the WDM UWOC system has prominent potentiality for simultaneous underwater illumination and high-speed communication. In this work, for the first time, we experimentally demonstrate a 9.51-Gb/s WDM UWOC system using a red-emitting laser diode (LD), a single-mode pigtailed green-emitting LD and a multi-mode pigtailed blue-emitting LD. By employing 32-quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) modulation in the demonstration, the red-light, the green-light and the blue-light LDs successfully transmit signals with the data rates of 4.17 Gb/s, 4.17 Gb/s and 1.17 Gb/s, respectively, over a 10-m underwater channel. The corresponding bit error rates (BERs) are 2.2 × 10-3, 2.0 × 10-3 and 2.3 × 10-3, respectively, which are below the forward error correction (FEC) threshold of 3.8 × 10-3.

  10. High-peak-power, single-frequency, single-mode, linearly polarized, nanosecond all-fiber laser based on self-phase modulation compensation.

    Science.gov (United States)

    Su, Rongtao; Zhou, Pu; Ma, Pengfei; Lü, Haibin; Xu, Xiaojun

    2013-10-20

    We demonstrated a high-peak-power, single-frequency, single-mode, linearly polarized, nanosecond all-fiber laser in master oscillator power amplifier configuration. The pulsed seed was generated by modulating a single-frequency continuous wave laser at 1064 nm. The short pulse width (∼3.2  ns) of the pulsed seed prevented the onset of stimulated Brillouin scattering in the 10 μm-core single-transverse-mode polarization-maintaining ytterbium-doped fiber of the main amplifier. In order to compensate self-phase modulation-induced spectral broadening, a phase modulator was employed to control the phase of the pulsed seed, and the linewidth of the output pulses were reduced from ∼1.22  GHz to ∼185  MHz at the peak power of 1.47 kW.

  11. Doping Liquid Crystal Cells with Photocurable Monomer via Holographic Exposure to Realize Optical-Scattering-Free Infrared Phase Modulators with Fast Response Time

    Directory of Open Access Journals (Sweden)

    Chun-Yu Chien

    2017-07-01

    Full Text Available Photocurable monomer-doped liquid crystal (LC cells were processed via holographic exposure using a low-power He–Ne laser to generate holographic polymer networks. The polymer network LC (PNLC cells are used to fabricate infrared phase modulators at 1550 nm wavelength possessing favorable electro-optical performance. Compared with our previous work, the percentages of ingredients in the LC mixture filled in PNLC cells underwent a slight change. The 2 wt% concentration of anisotropic monomer RM257 were in place of isotropic monomer N–vinyl–2–pyrrolidinone (NVP. As a result, the fabricated phase modulators also maintained well homogeneous LC alignments and optical-scattering-free characteristics. Furthermore, NVP dopant successfully reduced the operating voltages from 95 Vrms to 79 Vrms to prevent polymer network deformation when electrically operating with higher voltages. The fabricated infrared phase modulators had a good average response time (i.e., rising time of 0.88 ms and falling time of 0.40 ms.

  12. Heuristic approaches for energy-efficient shared restoration in WDM networks

    Science.gov (United States)

    Alilou, Shahab

    In recent years, there has been ongoing research on the design of energy-efficient Wavelength Division Multiplexing (WDM) networks. The explosive growth of Internet traffic has led to increased power consumption of network components. Network survivability has also been a relevant research topic, as it plays a crucial role in assuring continuity of service with no disruption, regardless of network component failure. Network survivability mechanisms tend to utilize considerable resources such as spare capacity in order to protect and restore information. This thesis investigates techniques for reducing energy demand and enhancing energy efficiency in the context of network survivability. We propose two novel heuristic energy-efficient shared protection approaches for WDM networks. These approaches intend to save energy by setting on sleep mode devices that are not being used while providing shared backup paths to satisfy network survivability. The first approach exploits properties of a math series in order to assign weight to the network links. It aims at reducing power consumption at the network indirectly by aggregating traffic on a set of nodes and links with high traffic load level. Routing traffic on links and nodes that are already under utilization makes it possible for the links and nodes with no load to be set on sleep mode. The second approach is intended to dynamically route traffic through nodes and links with high traffic load level. Similar to the first approach, this approach computes a pair of paths for every newly arrived demand. It computes these paths for every new demand by comparing the power consumption of nodes and links in the network before the demand arrives with their potential power consumption if they are chosen along the paths of this demand. Simulations of two different networks were used to compare the total network power consumption obtained using the proposed techniques against a standard shared-path restoration scheme. Shared

  13. Research of differentiated QoS routing in GMPLS-based IP/WDM networks

    Science.gov (United States)

    Wang, YiYun; Zeng, QingJi; Cao, JunWen

    2004-04-01

    At this point in technology's evolution, the simplicity, elegance, extensibility, and broad compatibility of the Internet protocol suite has made it the automatic choice for most forms of communication. The attempts at resolution of this apparent dichotomy consist of a collection of technologies and philosophies known as Quality of Service. In an IP network, QoS defines the ability to compensate for traffic characteristics without compromising average throughput. Clearly, optimizing QoS performance for all traffic types on an IP network presents a daunting challenge. To partially address this challenge, several Internet Engineering Task Force groups have been working on standardized approaches for IP-based QoS technologies. The IETF"s approaches fall into four categories: prioritization using differentiated services, reservation using integrated services, label switching using multi-protocol label switching, bandwidth management using the subnet bandwidth manager. Differentiated services classify per-hop behaviors on the basis of a Diffserv code point attached to the type of service byte in each packet"s IP header. This DSCP approach represents a form of soft QoS that rather coarsely classifies services through packet marking. The differentiated QoS routing in GMPLS-based IP/WDM Networks are a promising candidate for the next generation optical Internet networks. By using a unified control plane, such networks make more efficient usage of network resources both at the IP layer and the WDM optical layer. In this paper, we consider prioritized routing of bandwidth-guaranteed Label Switched paths (LSPs) providing service differentiation between classes of high and normal priority traffic. The QoS delay requirements are assumed to be translated into bandwidth and O-E-O conversion requirements. We present a graphical representation of the integrated network state which is different from other conventional graphical representations in that it models the cost of usage of

  14. Novel iterative P-cycle configure model in WDM intelligent optical network

    Science.gov (United States)

    Li, Bin; Huang, Shanguo; Zhang, Yongjun; Gu, Wanyi; Zu, Yunxiao

    2009-11-01

    In this paper, a p-cycle generation algorithm is proposed that can protect service of static traffic model in WDM network. As the basic p-cycle sets calculated by algorithm such as the straddle link algorithm (SLA) always contain a straddle link in it. That is why the protection efficiency is higher than bidirectional line switch ring (BLSR). Any idle resource can be used for traffic restoration. But if the resource is not configured carefully then not all the resource of idle state can be utilized efficiently. Some extensions of algorithms are brought into effect to improve the protection capability. Based on these extensions, a novel iterative expanding p-cycle is introduced. A platform is constructed in OPNET modeler to verify the performance of this algorithm. Simulation results show that after several expansions for the basic p-cycle sets, the efficiency is improved. The pre-configured resource is deployed before any requests come. Comparison between different network topologies is studied. Finally, the results are analyzed and some directivity is given for further research.

  15. Optimization of WDM optical packet switches with sparse wavelength converters and nondegenerate fiber delay lines

    Science.gov (United States)

    Zhang, Zhizhong; Cheng, Fang; Yuan, Shufang; Zhao, Huandong; Zeng, Qingji; Wang, Jianxin

    2004-05-01

    In this paper, we investigate the somewhat untraditional approach of contention resolution in WDM optical packet switches. The most striking characteristics of the developed switch architecture are that (1) contention resolution is achieved by a combined sharing of fiber delay-lines (FDLs) and tunable optical wavelength converters (TOWCs); (2) FDLs used for contention resolution is in non-degenerate form, i.e., buffers are achieved by non-uniform distribution of the delay lines; (3) TOWCs just can achieve wavelength conversion in partial continuous wavelength channels, i.e., sparse wavelength conversion. We describe and analyze the concrete configuration of FDLs and TOWCs under non-bursty and bursty traffic scenarios. Simulation results demonstrate that for a prefixed packet loss probability constraint, e.g., 10-6, the developed architecture provides a different point of view in the optical packet switching (OPS) design. That is, combined sharing of FDLs and TOWCs can, effectively, obtain a good tradeoff between the switch size and the cost, and TOWCs which are achieved in sparse form can also decrease the implementing complexity.

  16. Improving performance of channel equalization in RSOA-based WDM-PON by QR decomposition.

    Science.gov (United States)

    Li, Xiang; Zhong, Wen-De; Alphones, Arokiaswami; Yu, Changyuan; Xu, Zhaowen

    2015-10-19

    In reflective semiconductor optical amplifier (RSOA)-based wavelength division multiplexed passive optical network (WDM-PON), the bit rate is limited by low modulation bandwidth of RSOAs. To overcome the limitation, we apply QR decomposition in channel equalizer (QR-CE) to achieve successive interference cancellation (SIC) for discrete Fourier transform spreading orthogonal frequency division multiplexing (DFT-S OFDM) signal. Using an RSOA with a 3-dB modulation bandwidth of only ~800 MHz, we experimentally demonstrate a 15.5-Gb/s over 20-km SSMF DFT-S OFDM transmission with QR-CE. The experimental results show that DFTS-OFDM with QR-CE attains much better BER performance than DFTS-OFDM and OFDM with conventional channel equalizers. The impacts of several parameters on QR-CE are investigated. It is found that 2 sub-bands in one OFDM symbol and 1 pilot in each sub-band are sufficient to achieve optimal performance and maintain the high spectral efficiency.

  17. Fiber nonlinearity mitigation of WDM-PDM QPSK/16-QAM signals using fiber-optic parametric amplifiers based multiple optical phase conjugations

    DEFF Research Database (Denmark)

    Hu, Hao; Jopson, Robert M.; Gnauck, Alan H.

    2017-01-01

    We demonstrate fiber nonlinearity mitigation by using multiple optical phase conjugations (OPCs) in the WDM transmission systems of both 8 x 32-Gbaud PDM QPSK channels and 8 x 32-Gbaud PDM 16-QAM channels, showing improved performance over a single mid-span OPC and no OPC in terms of nonlinear...... threshold and a best achievable Q(2) factor after transmission. In addition, after an even number of OPCs, the signal wavelength can be preserved after transmission. The performance of multiple OPCs for fiber nonlinearity mitigation was evaluated independently for WDM PDM QPSK signals and WDM PDM 16QAM...... to 1 dB compared to the case of mid-span OPC. The improvements in the best achievable Q(2) factors were more modest, ranging from 0.2 dB to 1.1 dB for the results presented. (C) 2017 Optical Society of America...

  18. Experimental Comparison of Gains in Achievable Information Rates from Probabilistic Shaping and Digital Backpropagation for DP-256QAM/1024QAM WDM Systems

    DEFF Research Database (Denmark)

    Porto da Silva, Edson; Yankov, Metodi Plamenov; Da Ros, Francesco

    2016-01-01

    Gains in achievable information rates from probabilistic shaping and digital backpropagation are compared for WDM transmission of 5 × 10 GBd DP-256QAM/1024QAM up to 1700 km of reach. The combination of both techniques its shown to provide gains of up to ∼0.5 bits/QAM symbol......Gains in achievable information rates from probabilistic shaping and digital backpropagation are compared for WDM transmission of 5 × 10 GBd DP-256QAM/1024QAM up to 1700 km of reach. The combination of both techniques its shown to provide gains of up to ∼0.5 bits/QAM symbol...

  19. Multi-channel WDM RZ-to-NRZ format conversion at 50 Gbit/s based on single silicon microring resonator

    DEFF Research Database (Denmark)

    Ding, Yunhong; Peucheret, Christophe; Pu, Minhao

    2010-01-01

    We comprehensively analyze multiple WDM channels RZ-to- NRZ format conversion using a single microring resonator. The scheme relies on simultaneous suppression of the first order harmonic components in the spectra of all the RZ channels. An optimized silicon microring resonator with free spectral...... range of 100 GHz and Q value of 7900 is designed and fabricated for this purpose. Multi-channel RZ-to-NRZ format conversion is demonstrated experimentally at 50 Gbit/s for WDM channels with 200 GHz channel spacing using the fabricated device. Bit error rate (BER)measurements show very good conversion...

  20. 4x10Gb/s WDM Bi-directional Gating in a Semiconductor Optical Amplifier by Using Polarization Multiplexing Technique

    DEFF Research Database (Denmark)

    Yu, Jianjun; Jeppesen, Palle

    2000-01-01

    Bi-directional SOA gating can further reduce the number of gating elements in the space switch, we demonstrate that a conventional SOA employing polarization multiplexing technique (PMT) can be used for bi-directional WDM gating operation at 10Gb/s.......Bi-directional SOA gating can further reduce the number of gating elements in the space switch, we demonstrate that a conventional SOA employing polarization multiplexing technique (PMT) can be used for bi-directional WDM gating operation at 10Gb/s....

  1. Kerr nonlinearity compensation in a 5×28-GBd PDM 16-QAM WDM system using fiber-based optical phase conjugation

    DEFF Research Database (Denmark)

    Da Ros, Francesco; Sackey, I.; Elschner, R.

    2014-01-01

    Effective Kerr nonlinearity mitigation is experimentally demonstrated using optical phase conjugation in the middle of an 800-km dispersion-compensated link for a 5-channel WDM 28-GBd PDM 16-QAM signal. A Q-factor improvement of 0.9 dB over no mitigation allows a BER......Effective Kerr nonlinearity mitigation is experimentally demonstrated using optical phase conjugation in the middle of an 800-km dispersion-compensated link for a 5-channel WDM 28-GBd PDM 16-QAM signal. A Q-factor improvement of 0.9 dB over no mitigation allows a BER...

  2. SOLUTION METHOD OF DYNAMIC ROUTING AND WAVE LENGTH ASSIGNMENT PROBLEM FOR WDM NETWORKS WITH TAKING INTO ACCOUNT FOUR-WAVE MIXING EFFECT

    Directory of Open Access Journals (Sweden)

    D. V. Ageyev

    2016-05-01

    Full Text Available The problem of dynamic route selection and wavelengths assignment in WDM networks is solved. This problem is important in WDM network management when requests are serviced for short-term connection installation and excess traffic is transferred. The proposed solution method is heuristic and is an improvement of the previously known method by taking into account the influence of four-wave mixing and using the new metric for finding the routes prospective for application. This makes it possible to reduce the probability of blocking calls during the connections at the average of 13% and the value of Q factor at 0.812.

  3. 10 Gb/s 1550 nm VCSEL transmission over 23.6 km SMF with no Dispersion Compensation and no Injection Locking for WDM PONs

    DEFF Research Database (Denmark)

    Gibbon, Timothy Braidwood; Prince, Kamau; Neumeyer, Christian

    2010-01-01

    demonstrate 10Gb/s VCSEL transmission for WDM PON over 23.6km single mode fiber. Dispersion penalty is limited to 2.9dB by introducing a wavelength offset with respect to the remote array waveguide grating to reduce chirp.......demonstrate 10Gb/s VCSEL transmission for WDM PON over 23.6km single mode fiber. Dispersion penalty is limited to 2.9dB by introducing a wavelength offset with respect to the remote array waveguide grating to reduce chirp....

  4. Quad 14Gbps L-Band VCSEL-based System for WDM Migration of 4-lanes 56 Gbps Optical Data Links

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel; Rodes Lopez, Roberto; Pham, Tien Thang

    2012-01-01

    We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty.......We report on migrating multiple lane link into a single WDM L-band VCSEL-based system. Experimental validation successfully achieves 10 km of SMF reach with 4x14Gbps and less than 0.5dB inter-channel crosstalk penalty....

  5. A New Wavelength Optimization and Energy-Saving Scheme Based on Network Coding in Software-Defined WDM-PON Networks

    Science.gov (United States)

    Ren, Danping; Wu, Shanshan; Zhang, Lijing

    2016-09-01

    In view of the characteristics of the global control and flexible monitor of software-defined networks (SDN), we proposes a new optical access network architecture dedicated to Wavelength Division Multiplexing-Passive Optical Network (WDM-PON) systems based on SDN. The network coding (NC) technology is also applied into this architecture to enhance the utilization of wavelength resource and reduce the costs of light source. Simulation results show that this scheme can optimize the throughput of the WDM-PON network, greatly reduce the system time delay and energy consumption.

  6. Non-Degenerate Four-Wave Mixing in a Silicon Nanowire and its Application for One-to-Six WDM Multicasting

    DEFF Research Database (Denmark)

    Pu, Minhao; Hu, Hao; Ji, Hua

    2011-01-01

    We present WDM multicasting based on non-degenerate four-wave mixing in a silicon nanowire. A one-to-six phase-preserving wavelength multicasting of 10 Gb/s differential phase-shift-keying data is experimentally demonstrated with bit-error rate measurements.......We present WDM multicasting based on non-degenerate four-wave mixing in a silicon nanowire. A one-to-six phase-preserving wavelength multicasting of 10 Gb/s differential phase-shift-keying data is experimentally demonstrated with bit-error rate measurements....

  7. Optimal Golomb Ruler Sequences Generation for Optical WDM Systems: A Novel Parallel Hybrid Multi-objective Bat Algorithm

    Science.gov (United States)

    Bansal, Shonak; Singh, Arun Kumar; Gupta, Neena

    2017-02-01

    In real-life, multi-objective engineering design problems are very tough and time consuming optimization problems due to their high degree of nonlinearities, complexities and inhomogeneity. Nature-inspired based multi-objective optimization algorithms are now becoming popular for solving multi-objective engineering design problems. This paper proposes original multi-objective Bat algorithm (MOBA) and its extended form, namely, novel parallel hybrid multi-objective Bat algorithm (PHMOBA) to generate shortest length Golomb ruler called optimal Golomb ruler (OGR) sequences at a reasonable computation time. The OGRs found their application in optical wavelength division multiplexing (WDM) systems as channel-allocation algorithm to reduce the four-wave mixing (FWM) crosstalk. The performances of both the proposed algorithms to generate OGRs as optical WDM channel-allocation is compared with other existing classical computing and nature-inspired algorithms, including extended quadratic congruence (EQC), search algorithm (SA), genetic algorithms (GAs), biogeography based optimization (BBO) and big bang-big crunch (BB-BC) optimization algorithms. Simulations conclude that the proposed parallel hybrid multi-objective Bat algorithm works efficiently as compared to original multi-objective Bat algorithm and other existing algorithms to generate OGRs for optical WDM systems. The algorithm PHMOBA to generate OGRs, has higher convergence and success rate than original MOBA. The efficiency improvement of proposed PHMOBA to generate OGRs up to 20-marks, in terms of ruler length and total optical channel bandwidth (TBW) is 100 %, whereas for original MOBA is 85 %. Finally the implications for further research are also discussed.

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

    Directory of Open Access Journals (Sweden)

    Jose Mora

    2014-12-01

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

  9. Tilted fibre Bragg grating based 800nm WDM interrogation system for strain, temperature and refractive index sensing

    OpenAIRE

    Suo, Rui; Chen, Xianfeng F.; Zhou, Kaiming; Zhang, Lin; Bennion, Ian; Liu, Bo

    2008-01-01

    We report the implementation of a low-cost high-resolution WDM interrogation system operating around 800nm region with bandwidth up to 60 nm and resolution of 13 pm by utilising a tilted fibre Bragg grating as an out-coupling device and a CCD-array detector. The system has been evaluated for interrogating fibre Bragg grating based strain, temperature sensors, giving sensitivities of 0.6 pm/µe and 5.6 pm/°C which are in good agreement with previously reported values. Furthermore, the system ha...

  10. Rede convergente IP com tecnologia WDM e SDH utilizando cabos OPGW em linhas de transmissão de energia

    OpenAIRE

    Silva, Rosemberg Lobato

    2011-01-01

    Esse trabalho trata de uma contribuição para o desenvolvimento de Redes Convergentes com tecnologia WDM e SDH utilizando cabos OPGW em linhas de transmissão de energia. O objetivo desse estudo é mostrar um caso ímpar no cenário nacional de uma rede convergente gerenciada por uma Empresa do setor elétrico; bem como essa Empresa justificou a migração de vários serviços e as vantagens e desvantagens. Neste trabalho é mostrado também uma ferramenta de calculo de enlace desenvolvida para o planeja...

  11. Building WDM wide area resilient transport network from 4-node semi-mesh and mesh sub-networks

    DEFF Research Database (Denmark)

    Limal, Emmanuel; Mikkelsen, Benny; Stubkjær, Kristian

    1997-01-01

    This paper deals with optical transport network design using wavelength division multiplexing (WDM) facilities. It proposes a method for building networks from sub-network combinations. Two types of 4-node sub-networks and their properties are presented. For each sub-network, any fiber break can...... be recovered using re-routing paths. A European network set-up illustrates the method capabilities. The network has 19 nodes connected through 39 links distributed within 9 semi-mesh sub-networks. Comparison is made between local and non-local re-routing and between channel capacities of 2.5 and 10 Gb...

  12. Lifetime improvement and beam stabilization by longitudinal phase modulation at the DELTA electron storage ring; Lebensdauerverbesserung und Strahlstabilisierung durch longitudinale Phasenmodulation am Elektronenspreicherring DELTA

    Energy Technology Data Exchange (ETDEWEB)

    Fuersch, Jonathan

    2014-10-16

    In DELTA especially at high beam currents often the occurence of an instability of a longitudinal oscillation mode is observed. In the framework of the present thesis first with different procedure the cause of the longitudinal oscillation mode, which is especially strongly excited at high beam currents, is searched for. Thereby connections between the occurrence of this mode and parameters from the region of the storage-ring high-frequency system is observed. It is shown by comparison of different procedures, simulation calculations, and experimental pre-examinations, that especially by a phase modulation of the storage-ring high frequency an essential improvement of especially the longitudinal beam stability and the beam lifetime can be reached. For the durable and reliable improvement of these beam properties in the framework of the present thesis a system for the longitudinal phase modulation of the after-acceleration voltage in the cavity resonator of the DELTA storage ring is concipated, developed, constructed, taken in operation, and tested. Finally the results aimed hereby are presented and discussed.

  13. Demonstration of a WDM/TDM hybrid PON based on a colorless frame-level reach extender

    Science.gov (United States)

    Kim, Kwang-Ok; Lee, Jie-Hyun; Lee, Sang-Soo; Jang, Youn-Seon

    2012-07-01

    We propose a hybrid passive optical network (PON) consisting of a 2.5 Gb/s reflective semiconductor optical amplifier (RSOA)-based 32 channel loopback wavelength division multiplexing-passive optical network (WDM-PON) and a colorless OEO-based frame-level reach extender (RE). This hybrid PON is designed to support a 128-way split over a 50 km transmission distance per single wavelength channel. We experimentally demonstrate the feasibility of this design through downstream and upstream packet transmission with a commercial gigabit-capable PON (GPON) product. Even if the colorless frame-level RE uses active devices at the remote node, it is still possible to increase the optical link budget through backward compatibility with existing GPON products. This design also provides wavelength conversion and an upstream burst-to-continuous mode conversion between the WDM-PON and GPON. The proposed hybrid PON can satisfy a packet loss ratio (PLR) of 10-10 at the downstream and upstream transmission including the use of forward error correction (FEC).

  14. A new design of WDM-based optical inter-satellite links in modern small satellite constellations

    Science.gov (United States)

    Yu, Zhihua; Luo, Fengguang; Zong, Liangjia; Tao, Qing

    2008-12-01

    Through the detail analysis of inter-satellites links in modern small satellite constellations, a new optical filters-based four-channel wavelength division multiplexer was designed and fabricated. This WDM device working at 0.85, 1.06, 1.31 and 1.55μm is designed to build an optical inter-satellites link, which provide two data streams at 0.85 and 1.55μm, an inter-satellite tracking channel at 1.06μm, and an different orbit communication channel at 1.31μm. Through experiments, we got the channel download efficiencies at 0.85, 1.06, 1.31 and 1.55μm are 49.7%, 42.3%, 33.4% and 25.1% and the channel interval is 5mm. The features of small size and light weight make this WDM device quite attractive for space borne applications and the big channel interval could also accommodate the wavelength shifts due to Doppler Effect, temperature variations and radiation effects in space.

  15. Simulation and Comparison of Advanced Modulation Formats for Wavelength Reuse in High-SpeedWDM-PON System

    Energy Technology Data Exchange (ETDEWEB)

    Han Chenyang; Hong Wei, E-mail: younghan@live.cn [Room B209, Wuhan National Lab.for Optoelectronics, Huazhong University of Science and Technology, Loyu Road 1037, Wuhan, Hubei Province (China)

    2011-02-01

    In recent years, the innovation in devices and schemes of physical layer plays an important role in promoting the development of WDM-PON (Wavelength Division MultiplexingPassive Optical Network). Among the key technologies adopted in the WDM-PON system, advanced modulation formats at downstream and remodulations at upstream attract the most attention. DPSK (Differential Phase Shift Keying Modulation), FSK(Frequency-Shift Keying), IRZ(Inverted Return-to-Zero) and Manchester are four of the most common formats and each of them was studied before, but, however, nobody compared and analyzed them together.So, we will do the job by numeralsimulation in this paper. During our simulation, the 40-Gbit/s FSK is generated through the demodulation of two DPSK signals and 40-Gbit/s Manchester signal bases of employing a delay interferometer (DI) and an optical delay line as format conversion device to convert RZ-DPSK(Return to Zero-Differential Phase Shift Keying Modulation) coding to Manchester coding, both of the two format generation schemes are novel.Meanwhile,this paper emphasizes the input optical power and dispersion tolerance, which both related to the sensitivity of the system. Analyze the sensitivity with DPSK, FSK, IRZ and Manchester, and then compare the four advanced modulation formats.

  16. Practical 12.5-Gb/s, 12.5-GHz spaced ultra-dense WDM PON.

    Science.gov (United States)

    Shim, H K; Kim, Hoon; Chung, Y C

    2014-11-17

    We report a practical 12.5-Gb/s, 12.5-GHz-spaced ultra-dense wavelength-division-multiplexed passive optical network (UD-WDM PON). For the cost-effectiveness, we implement the downstream links by using electro-absorption modulated lasers (EMLs) in the 4-level pulse amplitude modulation (4PAM) format and PIN receivers, and the upstream links by using reflective semiconductor optical amplifiers (RSOAs) modulated in the quadrature phase-shift-keying (QPSK) format and low-cost self-homodyne receivers. To further enhance its cost-effectiveness, we also utilize an optical frequency comb generator, instead of a large number of wavelength-selected lasers, to provide the seed light for these colorless RSOAs. We optimize the operating conditions of the EMLs and RSOAs to maximize the power margins in the presence of the crosstalk arising from closely spaced neighboring channels and the inter-symbol interference (ISI) caused by the narrow passband of the cascaded arrayed-waveguide gratings (AWGs) as well as the limited modulation bandwidths of RSOAs. The experimental results show that we can secure the power margins of >2.5 dB for both upstream and downstream links of the proposed UD-WDM PON.

  17. On the influence of optical accuracy of the band-pass thin-film filter design for coexistence-type colorless WDM-PON

    Science.gov (United States)

    Korček, Dušan; Müllerová, Jarmila

    2010-12-01

    The future coexistence of Gigabit-capable passive optical networks (GPON) and wavelength division multiplexing PON (WDM-PON) requires the wavelength band separation of optical signals for GPON downstream (1480 - 1500 nm) and WDM-PON (1500 - 1620 nm). A new multi-layer thin-film structure of the band separation filter is proposed and numerically investigated to separate these spectral bands at the wavelength of 1500 nm with the spectral transmittance edge as steep as possible and at least of 32 dB insertion loss at 1500 nm. This article is focused on modeling transmission characteristics of the design of a GPON and WDM-PON band separation thin-film filter with the aim of detecting the impact of optical properties of materials involved, namely the number of the designed layers and material dispersion. Additionally, we report on the investigation of the influence of layer thickness deviations on the transmission characteristics of the band-pass filter aimed for separating GPON and WDM-PON wavelength regions.

  18. Quad 14 Gbps L-band VCSEL-based system for WDM migration of 4-lanes 56 Gbps optical data links

    DEFF Research Database (Denmark)

    Estaran Tolosa, Jose Manuel; Rodes Lopez, Roberto; Pham, Tien Thang

    2012-01-01

    We report on migrating multiple-lane link into an L-band VCSEL-based WDM system. Experimental validation achieves successful transmission over 10 km of SMF at 4x14Gbps. Inter-channel crosstalk penalty is observed to be less than 0.5 dB and a transmission penalty around 1 dB. The power budget margin...

  19. Theoretical Design of a Depolarized Interferometric Fiber-Optic Gyroscope (IFOG) on SMF-28 Single-Mode Standard Optical Fiber Based on Closed-Loop Sinusoidal Phase Modulation with Serrodyne Feedback Phase Modulation Using Simulation Tools for Tactical and Industrial Grade Applications.

    Science.gov (United States)

    Pérez, Ramón José; Álvarez, Ignacio; Enguita, José María

    2016-04-27

    This article presents, by means of computational simulation tools, a full analysis and design of an Interferometric Fiber-Optic Gyroscope (IFOG) prototype based on a closed-loop configuration with sinusoidal bias phase- modulation. The complete design of the different blocks, optical and electronic, is presented, including some novelties as the sinusoidal bias phase-modulation and the use of an integrator to generate the serrodyne phase-modulation signal. The paper includes detailed calculation of most parameter values, and the plots of the resulting signals obtained from simulation tools. The design is focused in the use of a standard single-mode optical fiber, allowing a cost competitive implementation compared to commercial IFOG, at the expense of reduced sensitivity. The design contains an IFOG model that accomplishes tactical and industrial grade applications (sensitivity ≤ 0.055 °/h). This design presents two important properties: (1) an optical subsystem with advanced conception: depolarization of the optical wave by means of Lyot depolarizers, which allows to use a sensing coil made by standard optical fiber, instead by polarization maintaining fiber, which supposes consequent cost savings and (2) a novel and simple electronic design that incorporates a linear analog integrator with reset in feedback chain, this integrator generating a serrodyne voltage-wave to apply to Phase-Modulator (PM), so that it will be obtained the interferometric phase cancellation. This particular feedback design with sawtooth-wave generated signal for a closed-loop configuration with sinusoidal bias phase modulation has not been reported till now in the scientific literature and supposes a considerable simplification with regard to previous designs based on similar configurations. The sensing coil consists of an 8 cm average diameter spool that contains 300 m of standard single-mode optical-fiber (SMF-28 type) realized by quadrupolar winding. The working wavelength will be

  20. Theoretical Design of a Depolarized Interferometric Fiber-Optic Gyroscope (IFOG on SMF-28 Single-Mode Standard Optical Fiber Based on Closed-Loop Sinusoidal Phase Modulation with Serrodyne Feedback Phase Modulation Using Simulation Tools for Tactical and Industrial Grade Applications

    Directory of Open Access Journals (Sweden)

    Ramón José Pérez

    2016-04-01

    Full Text Available This article presents, by means of computational simulation tools, a full analysis and design of an Interferometric Fiber-Optic Gyroscope (IFOG prototype based on a closed-loop configuration with sinusoidal bias phase- modulation. The complete design of the different blocks, optical and electronic, is presented, including some novelties as the sinusoidal bias phase-modulation and the use of an integrator to generate the serrodyne phase-modulation signal. The paper includes detailed calculation of most parameter values, and the plots of the resulting signals obtained from simulation tools. The design is focused in the use of a standard single-mode optical fiber, allowing a cost competitive implementation compared to commercial IFOG, at the expense of reduced sensitivity. The design contains an IFOG model that accomplishes tactical and industrial grade applications (sensitivity ≤ 0.055 °/h. This design presents two important properties: (1 an optical subsystem with advanced conception: depolarization of the optical wave by means of Lyot depolarizers, which allows to use a sensing coil made by standard optical fiber, instead by polarization maintaining fiber, which supposes consequent cost savings and (2 a novel and simple electronic design that incorporates a linear analog integrator with reset in feedback chain, this integrator generating a serrodyne voltage-wave to apply to Phase-Modulator (PM, so that it will be obtained the interferometric phase cancellation. This particular feedback design with sawtooth-wave generated signal for a closed-loop configuration with sinusoidal bias phase modulation has not been reported till now in the scientific literature and supposes a considerable simplification with regard to previous designs based on similar configurations. The sensing coil consists of an 8 cm average diameter spool that contains 300 m of standard single-mode optical-fiber (SMF-28 type realized by quadrupolar winding. The working

  1. Precision distance measurement using a two-photon absorption process in a silicon avalanche photodiode with saw-tooth phase modulation.

    Science.gov (United States)

    Tanaka, Yosuke; Tominaka, Seiji; Kurokawa, Takashi

    2015-10-01

    We present a novel configuration of a precision laser distance measurement based on the two-photon absorption (TPA) photocurrent from a silicon avalanche photodiode (Si-APD). The proposed system uses saw-tooth phase modulation, known as serrodyne modulation, in order to shift the frequency of the reference light from that of the probe light. It suppresses the coherent interference noise between the probe and the reference. The serrodyne modulation also enables lock-in detection of the TPA photocurrent. Furthermore, it contributes to the reduction of the system components. The precision measurement is experimentally demonstrated by measuring a fiber length difference of 2.6 m with a standard deviation of 27 μm under constant temperature. The high-precision displacement measurement is also demonstrated by measuring the temperature-induced change in the optical path length difference of a fiber interferometer.

  2. Experimental study of cross-phase modulation reduction in hybrid systems with co-propagating 100G PM-QPSK and 10G OOK.

    Science.gov (United States)

    Searcy, Steven; Tibuleac, Sorin

    2013-12-16

    We experimentally investigate various methods for reducing cross-phase modulation in hybrid networks with mixed 100G and 10G traffic. The experimental results over standard single-mode and non-zero dispersion-shifted fiber types demonstrate the effectiveness of several different XPM reduction techniques as well as the interplay between them. Nonlinear transmission performance is quantified using the Nonlinear Threshold metric as a function of key system features, including DCM type, dispersion map, spectral guard bands, and carrier phase estimation window size. Fiber Bragg grating-based DCMs are shown to offer a distinct advantage over fiber-based DCMs under certain conditions, particularly in dispersion-managed systems with very strong XPM. The average walk-off per span is introduced as a simple yet effective metric to compare different methods of XPM mitigation.

  3. All-Optical 1-to-8 Wavelength Multicasting at 20 Gbit/s Exploiting Self-Phase Modulation in Dispersion Flattened Highly Nonlinear Photonic Crystal Fiber

    Directory of Open Access Journals (Sweden)

    Zhan-Qiang Hui

    2014-01-01

    Full Text Available All-optical multicasting of performing data routing from single node to multiple destinations in the optical domain is promising for next generation ultrahigh-peed photonic networks. Based on the self-phase modulation in dispersion flattened highly nonlinear photonic crystal fiber and followed spectral filtering, simultaneous 1-to-8 all-optical wavelength multicasting return-to-zero (RZ signal at 20 Gbit/s with 100 GHz channel spaced is achieved. Wavelength tunable range and dynamic characteristic of proposed wavelength multicasting scheme is further investigated. The results show our designed scheme achieve operation wavelength range of 25 nm, OSNR of 32.01 dB and Q factor of 12.8. Moreover, the scheme has simple structure as well as high tolerance to signal power fluctuation.

  4. Integration of GaAs-based VCSEL array on SiN platform with HCG reflectors for WDM applications

    Science.gov (United States)

    Kumari, Sulakshna; Gustavsson, Johan S.; Wang, Ruijun; Haglund, Emanuel P.; Westbergh, Petter; Sanchez, Dorian; Haglund, Erik; Haglund, Åsa; Bengtsson, Jörgen; Le Thomas, Nicolas; Roelkens, Gunther; Larsson, Anders; Baets, Roel

    2015-02-01

    We present a GaAs-based VCSEL structure, BCB bonded to a Si3N4 waveguide circuit, where one DBR is substituted by a free-standing Si3N4 high-contrast-grating (HCG) reflector realized in the Si3N4 waveguide layer. This design enables solutions for on-chip spectroscopic sensing, and the dense integration of 850-nm WDM data communication transmitters where individual channel wavelengths are set by varying the HCG parameters. RCWA shows that a 300nm-thick Si3N4 HCG with 800nm period and 40% duty cycle reflects strongly (HCG's influence on the VCSEL wavelength, allowing for a 15-nm-wide wavelength setting range with low threshold gain (<1000 cm-1).

  5. Impacts of environmental factors to bi-directional 2×40 Gb/s WDM free-space optical communication

    Science.gov (United States)

    Liaw, Shien-Kuei; Hsu, Kuang-Yu; Yeh, Jai-Ger; Lin, Yu-Ming; Yu, Yi-Lin

    2017-08-01

    Bi-directional short-range free-space optical (FSO) communication with bi-directional 2×4×10 Gb/s wavelength division multiplexing (WDM) channel signals is demonstrated by using a transmission distance of 25 m. The single-mode-fiber components are used in the optical terminals for both optical transmitting and receiving functions. The measured power penalties for the 25-m bi-directional four-channel FSO communication compared with the back-to-back link and uni-directional transmission system are less than 0.8 dB and 0.2 dB, respectively. The environmental factor effects, including the oblique incidence through the building window glasses, thermally induced non-uniform air index as well as rainfall on the FSO performance are investigated and analyzed. The experimental results show that rainfall is influential for free space optical transmission.

  6. Silicon/III-V laser with super-compact diffraction grating for WDM applications in electronic-photonic integrated circuits.

    Science.gov (United States)

    Wang, Yadong; Wei, Yongqiang; Huang, Yingyan; Tu, Yongming; Ng, Doris; Lee, Cheewei; Zheng, Yunan; Liu, Boyang; Ho, Seng-Tiong

    2011-01-31

    We have demonstrated a heterogeneously integrated III-V-on-Silicon laser based on an ultra-large-angle super-compact grating (SCG). The SCG enables single-wavelength operation due to its high-spectral-resolution aberration-free design, enabling wavelength division multiplexing (WDM) applications in Electronic-Photonic Integrated Circuits (EPICs). The SCG based Si/III-V laser is realized by fabricating the SCG on silicon-on-insulator (SOI) substrate. Optical gain is provided by electrically pumped heterogeneous integrated III-V material on silicon. Single-wavelength lasing at 1550 nm with an output power of over 2 mW and a lasing threshold of around 150 mA were achieved.

  7. Towards a SFP+ module for WDM applications using an ultra-widely-tunable high-speed MEMS-VCSEL

    Science.gov (United States)

    Paul, Sujoy; Cesar, Julijan; Malekizandi, Mohammadreza; Haidar, Mohammad T.; Heermeier, Niels; Ortsiefer, Markus; Neumeyr, Christian; Gréus, Christoph; Eiselt, Michael H.; Ibrahim, Irfan; Schmidt, Henning; Schmidt, Jörg; Küppers, Franko

    2017-02-01

    In this work, we have used a tunable VCSEL for high-speed optical data transmission. To obtain wide tunability, a MEMS-DBR is surface micromachined onto a short-cavity high-speed VCSEL operating at 1550 nm. Ultra-wide continuous tuning is realized with electro-thermal actuation of the MEMS with built-in stress gradient within SiOx/SiNy dielectric layers. The MEMS-VCSEL operates in single-mode with SMSR > 40 dB across the entire tuning range. Quasi-error-free transmission of direct-modulation at record 15 Gbps is reported for 20 nm tuning, showing the potential towards the standard requirements for the SFP+ modules in the tail-ends of the WDM transmission system.

  8. Bandwidth efficient bidirectional 5 Gb/s overlapped-SCM WDM PON with electronic equalization and forward-error correction.

    Science.gov (United States)

    Buset, Jonathan M; El-Sahn, Ziad A; Plant, David V

    2012-06-18

    We demonstrate an improved overlapped-subcarrier multiplexed (O-SCM) WDM PON architecture transmitting over a single feeder using cost sensitive intensity modulation/direct detection transceivers, data re-modulation and simple electronics. Incorporating electronic equalization and Reed-Solomon forward-error correction codes helps to overcome the bandwidth limitation of a remotely seeded reflective semiconductor optical amplifier (RSOA)-based ONU transmitter. The O-SCM architecture yields greater spectral efficiency and higher bit rates than many other SCM techniques while maintaining resilience to upstream impairments. We demonstrate full-duplex 5 Gb/s transmission over 20 km and analyze BER performance as a function of transmitted and received power. The architecture provides flexibility to network operators by relaxing common design constraints and enabling full-duplex operation at BER ∼ 10(-10) over a wide range of OLT launch powers from 3.5 to 8 dBm.

  9. WDM mid-board optics for chip-to-chip wavelength routing interconnects in the H2020 ICT-STREAMS

    Science.gov (United States)

    Kanellos, G. T.; Pleros, N.

    2017-02-01

    Multi-socket server boards have emerged to increase the processing power density on the board level and further flatten the data center networks beyond leaf-spine architectures. Scaling however the number of processors per board puts current electronic technologies into challenge, as it requires high bandwidth interconnects and high throughput switches with increased number of ports that are currently unavailable. On-board optical interconnection has proved the potential to efficiently satisfy the bandwidth needs, but their use has been limited to parallel links without performing any smart routing functionality. With CWDM optical interconnects already a commodity, cyclical wavelength routing proposed to fit the datacom for rack-to-rack and board-to-board communication now becomes a promising on-board routing platform. ICT-STREAMS is a European research project that aims to combine WDM parallel on-board transceivers with a cyclical AWGR, in order to create a new board-level, chip-to-chip interconnection paradigm that will leverage WDM parallel transmission to a powerful wavelength routing platform capable to interconnect multiple processors with unprecedented bandwidth and throughput capacity. Direct, any-to-any, on-board interconnection of multiple processors will significantly contribute to further flatten the data centers and facilitate east-west communication. In the present communication, we present ICT-STREAMS on-board wavelength routing architecture for multiple chip-to-chip interconnections and evaluate the overall system performance in terms of throughput and latency for several schemes and traffic profiles. We also review recent advances of the ICT-STREAMS platform key-enabling technologies that span from Si in-plane lasers and polymer based electro-optical circuit boards to silicon photonics transceivers and photonic-crystal amplifiers.

  10. Optical phase conjugation by an As(2)S(3) glass planar waveguide for dispersion-free transmission of WDM-DPSK signals over fiber.

    Science.gov (United States)

    Pelusi, M D; Luan, F; Choi, D-Y; Madden, S J; Bulla, D A P; Luther-Davies, B; Eggleton, B J

    2010-12-06

    We report the first demonstration of optical phase conjugation (OPC) transmission of phase encoded and wavelength-division multiplexed (WDM) signals by the Kerr effect in a planar structured waveguide. The phase conjugated electric field of the signal is produced by four wave mixing pumped by a CW laser during co-propagating with the signal in a highly nonlinear waveguide fabricated in As(2)S(3) glass. Experiments demonstrate the capability of the device to perform dispersion-free transmission through up to 225 km of standard single mode fiber for a 3 × 40 Gb/s WDM signal, with its channels encoded as return-to-zero differential phase shift keying and spaced either 100 or 200 GHz apart. This work represents an important milestone towards demonstrating advanced signal processing of high-speed and broadband optical signals in compact planar waveguides, with the potential for monolithic optical integration.

  11. A WDM-PON with DPSK modulated downstream and OOK modulated upstream signals based on symmetric 10 Gbit/s wavelength reused bidirectional reflective SOA

    Science.gov (United States)

    El-Nahal, Fady I.

    2017-01-01

    We investigate a wavelength-division-multiplexing passive optical network (WDM-PON) with centralized lightwave and direct detection. The system is demonstrated for symmetric 10 Gbit/s differential phase-shift keying (DPSK) downstream signals and on-off keying (OOK) upstream signals, respectively. A wavelength reused scheme is employed to carry the upstream data by using a reflective semiconductor optical amplifier (RSOA) as an intensity modulator at the optical network unit (ONU). The constant-intensity property of the DPSK modulation format can keep high extinction ratio ( ER) of downstream signal and reduce the crosstalk to the upstream signal. The bit error rate ( BER) performance of our scheme shows that the proposed 10 Gbit/s symmetric WDM-PON can achieve error free transmission over 25-km-long fiber transmission with low power penalty.

  12. Multifunctional switching unit for add/drop, wavelength conversion, format conversion, and WDM multicast based on bidirectional LCoS and SOA-loop architecture.

    Science.gov (United States)

    Wang, Danshi; Zhang, Min; Qin, Jun; Lu, Guo-Wei; Wang, Hongxiang; Huang, Shanguo

    2014-09-08

    We propose a multifunctional optical switching unit based on the bidirectional liquid crystal on silicon (LCoS) and semiconductor optical amplifier (SOA) architecture. Add/drop, wavelength conversion, format conversion, and WDM multicast are experimentally demonstrated. Due to the bidirectional characteristic, the LCoS device cannot only multiplex the input signals, but also de-multiplex the converted signals. Dual-channel wavelength conversion and format conversion from 2 × 25Gbps differential quadrature phase-shift-keying (DQPSK) to 2 × 12.5Gbps differential phase-shift-keying (DPSK) based on four-wave mixing (FWM) in SOA is obtained with only one pump. One-to-six WDM multicast of 25Gbps DQPSK signals with two pumps is also achieved. All of the multicast channels are with a power penalty less than 1.1 dB at FEC threshold of 3.8 × 10⁻³.

  13. A rigorous analysis of digital pre-emphasis and DAC resolution for interleaved DAC Nyquist-WDM signal generation in high-speed coherent optical transmission systems

    Science.gov (United States)

    Weng, Yi; Wang, Junyi; He, Xuan; Pan, Zhongqi

    2018-02-01

    The Nyquist spectral shaping techniques facilitate a promising solution to enhance spectral efficiency (SE) and further reduce the cost-per-bit in high-speed wavelength-division multiplexing (WDM) transmission systems. Hypothetically, any Nyquist WDM signals with arbitrary shapes can be generated by the use of the digital signal processing (DSP) based electrical filters (E-filter). Nonetheless, in actual 100G/ 200G coherent systems, the performance as well as DSP complexity are increasingly restricted by cost and power consumption. Henceforward it is indispensable to optimize DSP to accomplish the preferred performance at the least complexity. In this paper, we systematically investigated the minimum requirements and challenges of Nyquist WDM signal generation, particularly for higher-order modulation formats, including 16 quadrature amplitude modulation (QAM) or 64QAM. A variety of interrelated parameters, such as channel spacing and roll-off factor, have been evaluated to optimize the requirements of the digital-to-analog converter (DAC) resolution and transmitter E-filter bandwidth. The impact of spectral pre-emphasis has been predominantly enhanced via the proposed interleaved DAC architecture by at least 4%, and hence reducing the required optical signal to noise ratio (OSNR) at a bit error rate (BER) of 10-3 by over 0.45 dB at a channel spacing of 1.05 symbol rate and an optimized roll-off factor of 0.1. Furthermore, the requirements of sampling rate for different types of super-Gaussian E-filters are discussed for 64QAM Nyquist WDM transmission systems. Finally, the impact of the non-50% duty cycle error between sub-DACs upon the quality of the generated signals for the interleaved DAC structure has been analyzed.

  14. Quad 14 Gbps L-band VCSEL-based system for WDM migration of 4-lanes 56 Gbps optical data links.

    Science.gov (United States)

    Estaran, Jose; Rodes, Roberto; Pham, Tien Thang; Ortsiefer, Markus; Neumeyr, Christian; Rosskopf, Jürgen; Monroy, Idelfonso Tafur

    2012-12-17

    We report on migrating multiple-lane link into an L-band VCSEL-based WDM system. Experimental validation achieves successful transmission over 10 km of SMF at 4x14Gbps. Inter-channel crosstalk penalty is observed to be less than 0.5 dB and a transmission penalty around 1 dB. The power budget margin ranges within 6 dB and 7 dB.

  15. W-waveform Standing Surface Acoustic Waves with Two Equilibrium Positions under Linear Phase Modulation for Patterning Microparticles into Alternate Grid Patterns

    CERN Document Server

    Lee, Junseok

    2016-01-01

    This paper presents W-waveform Standing Surface Acoustic Waves (W-SSAW), and as its application, patterning of two groups of microparticles with different sizes alternately without fixing firstly patterned particles. W-SSAW is constructed by two standing surface acoustic waves of frequencies $f$ and $2f$. Combined with linear phase modulation to translate Gor'kov potential at a constant speed, W-SSAW can selectively trap particles. The trapped particles follow the moving Gor'kov potential maintaining force equilibrium between Stokes' drag and the radiation force by W-SSAW. There exist two asymmetric equilibrium positions every period, and by the asymmetry, each group of particles is trapped at different equilibrium positions to form an alternate pattern. This technique is extended to two-dimensional alternate patterning by maintaining phase difference $90^\\circ$ between X- and Y-directional W-SSAWs. The patterning method utilizing W-SSAW is advantageous over SSAW-based patterning in that it does not require t...

  16. FPGA-based photon-counting phase-modulation fluorometer and a brief comparison with that operated in a pulsed-excitation mode

    Science.gov (United States)

    Iwata, Tetsuo; Taga, Takanori; Mizuno, Takahiko

    2017-12-01

    We have constructed a high-efficiency, photon-counting phase-modulation fluorometer (PC-PMF) using a field-programmable gate array, which is a modified version of the photon-counting fluorometer (PCF) that works in a pulsed-excitation mode (Iwata and Mizuno in Meas Sci Technol 28:075501, 2017). The common working principle for both is the simultaneous detection of the photoelectron pulse train, which covers 64 ns with a 1.0-ns resolution time (1.0 ns/channel). The signal-gathering efficiency was improved more than 100 times over that of conventional time-correlated single-photon-counting at the expense of resolution time depending on the number of channels. The system dead time for building a histogram was eliminated, markedly shortening the measurement time for fluorescent samples with moderately high quantum yields. We describe the PC-PMF and make a brief comparison with the pulsed-excitation PCF in precision, demonstrating the potential advantage of PC-PMF.

  17. Distinguishing thermal lens effect from electronic third-order nonlinear self-phase modulation in liquid suspensions of 2D nanomaterials.

    Science.gov (United States)

    Wang, Yanan; Tang, Yingjie; Cheng, Peihong; Zhou, Xufeng; Zhu, Zhuan; Liu, Zhaoping; Liu, Dong; Wang, Zhiming; Bao, Jiming

    2017-03-09

    The interaction of light with atomically thin nanomaterials has attracted enormous research interest in order to understand two-dimensional (2D) electron systems and develop novel opto-electronic devices. The observations of spatial self-phase modulation and the associated multiple diffraction ring patterns in liquid suspensions of 2D nanomaterials are believed to be excellent examples of strong laser interaction with 2D nanomaterials and this phenomenon has been attributed to their large electronic third-order susceptibilities. By performing a series of control experiments with liquid suspensions of graphene and graphene oxide flakes in different solvents at various temperatures under an increasing modulation frequency of laser illumination, we first show that the diffraction ring pattern has little dependence on the type of nanomaterial but strongly depends on the duration of laser illumination. A laser induced local refractive index change is then monitored by a weaker probe beam, resulting in the divergent diffraction of the probe beam that indicates a lower self-induced refractive index in the center of the pump laser beam than at its periphery: a clear signature of the thermal lens effect. Finally, we use computational fluid dynamics to simulate laser induced temperature and index changes of the suspensions. The evolution of diffraction rings is well correlated to the transient temperature distribution. Our understanding of complex laser interactions with nanomaterial suspensions and the associated thermal lens effect paves the way for further basic studies and fluid opto-electronic applications of 2D nanomaterials.

  18. Combined effects of potassium chloride and ethanol as mobile phase modulators on hydrophobic interaction and reversed-phase chromatography of three insulin variants.

    Science.gov (United States)

    Johansson, Karolina; Frederiksen, Søren S; Degerman, Marcus; Breil, Martin P; Mollerup, Jørgen M; Nilsson, Bernt

    2015-02-13

    The two main chromatographic modes based on hydrophobicity, hydrophobic interaction chromatography (HIC) and reversed-phase chromatography (RPC), are widely used for both analytical and preparative chromatography of proteins in the pharmaceutical industry. Despite the extensive application of these separation methods, and the vast amount of studies performed on HIC and RPC over the decades, the underlying phenomena remain elusive. As part of a systematic study of the influence of mobile phase modulators in hydrophobicity-based chromatography, we have investigated the effects of both KCl and ethanol on the retention of three insulin variants on two HIC adsorbents and two RPC adsorbents. The focus was on the linear adsorption range, separating the modulator effects from the capacity effects, but some complementary experiments at higher load were included to further investigate observed phenomena. The results show that the modulators have the same effect on the two RPC adsorbents in the linear range, indicating that the modulator concentration only affects the activity of the solute in the mobile phase, and not that of the solute-ligand complex, or that of the ligand. Unfortunately, the HIC adsorbents did not show the same behavior. However, the insulin variants displayed a strong tendency toward self-association on both HIC adsorbents; on one in particular. Since this causes peak fronting, the retention is affected, and this could probably explain the lack of congruity. This conclusion was supported by the results from the non-linear range experiments which were indicative of double-layer adsorption on the HIC adsorbents, while the RPC adsorbents gave the anticipated increased tailing at higher load. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Using single side-band modulation for colorless OFDM-WDM access network to alleviate Rayleigh backscattering effects.

    Science.gov (United States)

    Yeh, Chien-Hung; Chow, Chi-Wai

    2016-05-16

    In this investigation, we demonstrate a new colorless orthogonal-frequency-division-multiplexing (OFDM) wavelength-division-multiplexing passive optical network (WDM-PON) system with Rayleigh backscattering (RB) noise mitigation. Here, only a single laser source at the central office (CO) is needed to produce the downstream signal and distributed continuous-wave (CW) carrier, which will then be modulated at the optical networking unit (ONU) to produce the upstream signal. Single side-band (SSB) modulation is used to wavelength-shift the distributed CW carrier, which will be launched into a reflective semiconductor optical amplifier (RSOA) based ONU for directly modulation of 5.15 Gbps OFDM upstream signal. To avoid the radio-frequency (RF) power fading and chromatic fiber dispersion, the four-band OFDM modulation is proposed to generate a 40 Gbps downstream when a Mach-Zehnder modulator (MZM) with -0.7 chirp parameter is used. Hence, the RB circumvention can be centralized in the CO. Moreover, the signal performances of downstream and upstream are also studied and discussed in this measurement.

  20. 10 Gbps WDM transmission performance limits using in-line SOAs and an optical phase conjugator based on four-wave mixing in SOAs as a mid-span spectral inversion technique.

    Science.gov (United States)

    Hur, Sub; Kim, Yonggyou; Jang, Hodeok; Jeong, Jichai

    2006-05-29

    We have theoretically investigated the transmission performance limits of all semiconductor optical amplifiers (SOA)-based 10 Gb/s wavelength division multiplexing (WDM) systems using in-line SOAs and an optical phase conjugator (OPC) based on four-wave mixing in SOAs as a mid-span spectral inversion technique. With a verified numerical model of SOAs, we have found that the crosstalk from SOAs in OPC is a dominant factor to limit the number of channels in WDM systems. In order to increase the available number of channels, we optimize the input optical power and the injection current to SOAs in OPC with using a reservoir channel in in-line SOAs. All SOA-based 10 Gb/s WDM systems using the OPC can transmit 16 channel signals up to 240 km distance with a 3 dB power penalty.

  1. ANALYSIS OF PROCESSES IN AN INDEPENDENT GENERATOR WITH A NONCONTACT CASCADE THREE-PHASE MODULATED EXCITER VIA A STAR-CONNECTED CIRCUIT WITH A COMMON MODULATOR PHASE CONNECTION UNDER OPERATION TO AN INDUCTION MOTORS SITE

    Directory of Open Access Journals (Sweden)

    K.M. Vasyliv

    2013-04-01

    Full Text Available By means of a mathematical experiment, electromagnetic and electromechanical processes in an independent electric power supply system based on an asynchronized generator with a three-phase modulated exciter are investigated. The processes are analyzed to specify the working capacity of the power supply system during its operation to an induction motors site. Regularities of the electromagnetic and electromechanical processes behavior versus load intensity and the switch control system parameters are identified.

  2. A COMPARATIVE ANALYSIS OF PROCESSES IN AN INDEPENDENT GENERATOR WITH A NONCONTACT CASCADE THREE-PHASE MODULATED EXCITER VIA A STAR-CONNECTED CIRCUIT UNDER ACTIVE-INDUCTIVE LOADING

    Directory of Open Access Journals (Sweden)

    K.M. Vasyliv

    2013-02-01

    Full Text Available By means of mathematical experiment, the author investigates electromagnetic and electromechanical processes in an independent electric power supply system based on an asynchronized generator with a three-phase modulated exciter. The processes are analyzed to specify the working capacity of the power supply system during its operation under active-inductive loading. Regularities of the electromagnetic and electromechanical processes behavior versus load intensity and the modulator scheme are identified.

  3. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves by a polarization-insensitive optical parametric amplifier for fiber-nonlinearity-tolerant transmission

    OpenAIRE

    Liu, Xiang(Research Center for Hadron and CSR Physics, Lanzhou University, Institute of Modern Physics of CAS, Lanzhou 730000, China); Hu, Hao; Chandrasekhar, S.; Jopson, R. M.; Gnauck, A. H.; Dinu, M.; Xie, C; Winzer, P. J.

    2014-01-01

    We experimentally demonstrate the generation of 1.024-Tb/s Nyquist-WDM phase-conjugated vector twin waves (PCTWs), consisting of eight 128-Gb/s polarization-division-multiplexed QPSK signals and their idlers, by a broadband polarization-insensitive fiber optic parametric amplifier. This novel all-optical signal processing approach to generate WDM-PCTWs enables a 2-fold reduction in the needed optical transmitters as compared to the conventional approach where each idler is generated by a dedi...

  4. Watershed Data Management (WDM) database for West Branch DuPage River streamflow simulation, DuPage County, Illinois, January 1, 2007, through September 30, 2013

    Science.gov (United States)

    Bera, Maitreyee

    2017-10-16

    The U.S. Geological Survey (USGS), in cooperation with the DuPage County Stormwater Management Department, maintains a database of hourly meteorological and hydrologic data for use in a near real-time streamflow simulation system. This system is used in the management and operation of reservoirs and other flood-control structures in the West Branch DuPage River watershed in DuPage County, Illinois. The majority of the precipitation data are collected from a tipping-bucket rain-gage network located in and near DuPage County. The other meteorological data (air temperature, dewpoint temperature, wind speed, and solar radiation) are collected at Argonne National Laboratory in Argonne, Ill. Potential evapotranspiration is computed from the meteorological data using the computer program LXPET (Lamoreux Potential Evapotranspiration). The hydrologic data (water-surface elevation [stage] and discharge) are collected at U.S.Geological Survey streamflow-gaging stations in and around DuPage County. These data are stored in a Watershed Data Management (WDM) database.This report describes a version of the WDM database that is quality-assured and quality-controlled annually to ensure datasets are complete and accurate. This database is named WBDR13.WDM. It contains data from January 1, 2007, through September 30, 2013. Each precipitation dataset may have time periods of inaccurate data. This report describes the methods used to estimate the data for the periods of missing, erroneous, or snowfall-affected data and thereby improve the accuracy of these data. The other meteorological datasets are described in detail in Over and others (2010), and the hydrologic datasets in the database are fully described in the online USGS annual water data reports for Illinois (U.S. Geological Survey, 2016) and, therefore, are described in less detail than the precipitation datasets in this report.

  5. Design of universal fiber with demonstration of full system reaches over 100G SR4, 40G sWDM, and 100G CWDM4 transceivers.

    Science.gov (United States)

    Chen, Xin; Hurley, Jason E; Stone, Jeffery S; Zakharian, Aramais R; Coleman, Doug; Li, Ming-Jun

    2016-08-08

    Universal fiber has an LP01 mode field diameter approximately matched to that of standard single mode fiber, while being a multimode fiber. We analyzed the dependence of the mode field diameter on the core diameter for different core delta values. Guided by the analysis, a universal fiber having a delta of 1.2% was fabricated, showing significantly reduced coupling loss of ~2.3 dB with conventional multimode fiber. We demonstrated that the fiber can transmit with full system reach in both single mode and VCSEL-based multimode transmissions, including 100G SR4, 40G sWDM, and 100G CWDM4 for the first time.

  6. Improvement of input power dynamic range for 20 Gbit/s optical WDM switch nodes using an integrated Michelson wavelength converter

    DEFF Research Database (Denmark)

    Danielsen, Søren Lykke; Hansen, Peter Bukhave; Jørgensen, Carsten

    1997-01-01

    The implementation of photonic wavelength-division multiplexing (WDM) switch nodes with wavelength converters allows for higher throughput and easier management, as well as wavelength reuse. Furthermore, semiconductor optical amplifiers (SOAs) are attractive for space switching in the nodes because...... saturation. We show that even at a high bit-rate of 20 Gbit/s the latter imperfection can be compensated by the extinction ratio enhancing capability of interferometric wavelength converters (IWCs). Consequently, the input power dynamic range for switch blocks using IWCs together with SOA gates can...

  7. Efectos no lineales y su relación con los parámetros de transmisión de una red WDM

    Directory of Open Access Journals (Sweden)

    Juan Pablo Agredo

    2011-07-01

    Full Text Available Se analizan las degradaciones ópticas en una red de Multiplexación por División de Longitud de Onda (WDM –Wavelength Division Multiplexing– y se estudia el impacto de los parámetros de transmisión en los efectos no lineales; además, se determinan las variaciones que se deben llevar a cabo en dichos parámetros, con la finalidad de minimizar este tipo de degradaciones y optimizar el desempeño de la red.

  8. Efectos no lineales y su relación con los parámetros de transmisión de una red WDM

    Directory of Open Access Journals (Sweden)

    José Giovanny López Perafán

    2012-05-01

    Full Text Available Se analizan las degradaciones ópticas en una red de Multiplexación por División de Longitud de Onda (WDM –Wavelength Division Multiplexing– y se estudia el impacto de los parámetros de transmisión en los efectos no lineales; además, se determinan las variaciones que se deben llevar a cabo en dichos parámetros, con la finalidad de minimizar este tipo de degradaciones y optimizar el desempeño de la red.

  9. Optical chaos and hybrid WDM/TDM based large capacity quasi-distributed sensing network with real-time fiber fault monitoring.

    Science.gov (United States)

    Luo, Yiyang; Xia, Li; Xu, Zhilin; Yu, Can; Sun, Qizhen; Li, Wei; Huang, Di; Liu, Deming

    2015-02-09

    An optical chaos and hybrid wavelength division multiplexing/time division multiplexing (WDM/TDM) based large capacity quasi-distributed sensing network with real-time fiber fault monitoring is proposed. Chirped fiber Bragg grating (CFBG) intensity demodulation is adopted to improve the dynamic range of the measurements. Compared with the traditional sensing interrogation methods in time, radio frequency and optical wavelength domains, the measurand sensing and the precise locating of the proposed sensing network can be simultaneously interrogated by the relative amplitude change (RAC) and the time delay of the correlation peak in the cross-correlation spectrum. Assisted with the WDM/TDM technology, hundreds of sensing units could be potentially multiplexed in the multiple sensing fiber lines. Based on the proof-of-concept experiment for axial strain measurement with three sensing fiber lines, the strain sensitivity up to 0.14% RAC/με and the precise locating of the sensors are achieved. Significantly, real-time fiber fault monitoring in the three sensing fiber lines is also implemented with a spatial resolution of 2.8 cm.

  10. Single Source 5-dimensional (Space-, Wavelength-, Time-, Polarization-, Quadrature-) 43 Tbit/s Data Transmission of 6 SDM × 6 WDM × 1.2 Tbit/s Nyquist-OTDM-PDM-QPSK

    DEFF Research Database (Denmark)

    Hu, Hao; Ye, Feihong; Medhin, Ashenafi Kiros

    2014-01-01

    We demonstrate 43-Tbit/s transmission over 67.4-km seven-core fiber using a single source. Each of the 6 outer cores carries 6 Nyquist-WDM channels using 320-Gbaud Nyquist- OTDM-PDM-QPSK 330-GHz spaced, and the center core carries 10-GHz clock pulses....

  11. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves through polarization-insensitive optical parametric amplification enabling transmission over 4000-km dispersion-managed TWRS fiber

    DEFF Research Database (Denmark)

    Liu, Xiang; Hu, Hao; Chandrasekhar, S.

    2013-01-01

    We experimentally demonstrate the first Tb/s Nyquist-WDM phase-conjugated twin waves, consisting of eight 128-Gb/s PDM-QPSK signals and their idlers, by a broadband polarization-insensitive fiber optical parametric amplifier, enabling more than doubled reach in dispersion-managed transmission...

  12. A Novel Dynamic Physical Layer Impairment-Aware Routing and Wavelength Assignment (PLI-RWA) Algorithm for Mixed Line Rate (MLR) Wavelength Division Multiplexed (WDM) Optical Networks

    Science.gov (United States)

    Iyer, Sridhar

    2016-12-01

    The ever-increasing global Internet traffic will inevitably lead to a serious upgrade of the current optical networks' capacity. The legacy infrastructure can be enhanced not only by increasing the capacity but also by adopting advance modulation formats, having increased spectral efficiency at higher data rate. In a transparent mixed-line-rate (MLR) optical network, different line rates, on different wavelengths, can coexist on the same fiber. Migration to data rates higher than 10 Gbps requires the implementation of phase modulation schemes. However, the co-existing on-off keying (OOK) channels cause critical physical layer impairments (PLIs) to the phase modulated channels, mainly due to cross-phase modulation (XPM), which in turn limits the network's performance. In order to mitigate this effect, a more sophisticated PLI-Routing and Wavelength Assignment (PLI-RWA) scheme needs to be adopted. In this paper, we investigate the critical impairment for each data rate and the way it affects the quality of transmission (QoT). In view of the aforementioned, we present a novel dynamic PLI-RWA algorithm for MLR optical networks. The proposed algorithm is compared through simulations with the shortest path and minimum hop routing schemes. The simulation results show that performance of the proposed algorithm is better than the existing schemes.

  13. A Energy-Saving Path-Shared Protection Based on Diversity Network Coding for Multi-rate Multicast in WDM Mesh Networks

    Science.gov (United States)

    Zheng, Danling; Lv, Lei; Liu, Huanlin

    2017-08-01

    For improving the survivability and energy saving of multi-rate multicast, a novel energy-saving path-shared protection based on diversity network coding (EPP-DNC) for multi-rate multicast in wavelength division multiplexing (WDM) mesh networks is proposed in the paper. In the EPP-DNC algorithm, diversity network coding on the source node for multi-rate multicast is adopted to reduce the coding energy consumption by avoiding network coding on the network's intermediate nodes. To decrease the transmission energy, shortest path shared based on heuristic is proposed to transmit the protection information for the request. To provision request's working paths efficiency, the working paths are routed on the preselected P-cycles with minimum required links and minimum energy consumption. Simulation results show that the proposed EPP-DNC can save energy consumption and improve bandwidth utilization.

  14. On-the-field performance of quintuple-play long-reach OFDM-based WDM-PON optical access networks.

    Science.gov (United States)

    Llorente, Roberto; Morant, Maria; Pellicer, Eloy; Herman, Milan; Nagy, Zsolt; Alves, Tiago; Cartaxo, Adolfo; Herrera, Javier; Correcher, Jose; Quinlan, Terence; Walker, Stuart; Rodrigues, Cláudio; Cluzeaud, Pierre; Schmidt, Axel; Piesiewicz, Radoslaw; Sambaraju, Rakesh

    2014-03-24

    In this paper the on-the-field performance of a WDM-PON optical access providing quintuple-play services using orthogonal frequency division multiplexing (OFDM) modulation is evaluated in a real fiber-to-the-home (FTTH) network deployed by Towercom operator in Bratislava (Slovakia). A bundle of quintuple-play services comprising full-standard OFDM-based signals (LTE, WiMAX, UWB and DVB-T) and an ad-hoc OFDM-GbE signal is transmitted in coexistence per single user. Both downstream and upstream transmission performances are evaluated in different on-the-field long-reach optical link distance configurations. Four wavelength multi-user transmission of quintuple-play OFDM services is demonstrated exceeding 60.8 km reach in standard single mode fiber.

  15. Generation of 1.024-Tb/s Nyquist-WDM phase-conjugated twin vector waves by a polarization-insensitive optical parametric amplifier for fiber-nonlinearity-tolerant transmission

    DEFF Research Database (Denmark)

    Liu, Xiang; Hu, Hao; Chandrasekhar, S.

    2014-01-01

    We experimentally demonstrate the generation of 1.024-Tb/s Nyquist-WDM phase-conjugated vector twin waves (PCTWs), consisting of eight 128-Gb/s polarization-division-multiplexed QPSK signals and their idlers, by a broadband polarization-insensitive fiber optic parametric amplifier. This novel all...... reach in a dispersion-managed transmission link. We further study the impact of polarization-mode dispersion on the performance gain brought by the phase-conjugated twin waves, showing a gain of ∼3.8 dB in signal quality factors.......-optical signal processing approach to generate WDM-PCTWs enables a 2-fold reduction in the needed optical transmitters as compared to the conventional approach where each idler is generated by a dedicated transmitter. Digital coherent superposition of the twin waves at the receiver enables more than doubled...

  16. Photonic Implementation of 4-QAM/QPSK Electrical Modulation at Millimeter-Wave Frequency

    DEFF Research Database (Denmark)

    Yu, Xianbin; Jensen, Jesper Bevensee; Tafur Monroy, Idelfonso

    2008-01-01

    We propose a photonic method for generating millimeter-wave 4-QAM/QPSK modulated signals. The method is based on optical phase modulation by multilevel electrical signals and optical carrier-suppression. Simulation results are presented for 2.5 Gsymbol/s 4-QAM and QPSK signals at a 36 GHz carrier....... Furthermore, this method can be extended to generate millimeter-wave m-PSK signals and can be incorporated into broadband radio-over-fiber systems to support wireless/ wireline converged access network....

  17. Évaluation d’un module électro-optique hybride combinant la photonique sur silicium et sur verre pour des applications de multiplexage en longueur d’onde (WDM)

    OpenAIRE

    Ayi-Yovo, Folly Eli

    2017-01-01

    The ever-increasing demand for telecommunications needs has highlighted the intrinsic limitations of electronics. Photonics has proven to be a suitable solution to its limitations. STMicroelectronics has developed a silicon photonic platform called PIC25G that allows single-channel transmission at 25 Gb/s. The data rate increase with wavelength division multiplexing (WDM) encounter some constraints. The proposed solution is based on a hybrid approach integrating silicon photonics and glass io...

  18. The use of phase modulation optimization for power lasers. Minimizing the FM-AM conversion while preserving spectral broadening functionalities required for fusion; Optimisation de la modulation de phase utilisee pour les lasers de puissance. Minimisation de la conversion FM-AM tout en conservant les fonctionnalites d'elargissement spectral necessaires a la fusion

    Energy Technology Data Exchange (ETDEWEB)

    Hocquet, St

    2009-11-15

    This research thesis deals with the problem of phase modulations in power lasers (such as the MegaJoule laser which is developed in France) and their impact of different physical phenomena like the suppression of the stimulated Brillouin scattering (which is necessary to avoid optics damage) and the optical smoothing which allows a spatial homogenisation of focal stains. The author deeply discusses the phase modulation counterparts, and more particularly the FM-AM conversion which is the source of unwanted intensity modulation and of energy loss. He reports the development of a comprehensive modelling of phenomena generating FM-AM conversion on a power laser chain. He theoretically and experimentally studies two methods allowing the FM-AM conversion to be reduced to a given spectral distortion: the compensation of transfer functions and the modification of the phase modulation signal to make it less sensitive to spectral distortion effects. For this last method, he determines the ideal spectrum shape for the phase modulation, and proposes a method to approach it. He shows the feasibility of such a method and reports experiments showing to which extent these solutions may improve performance of power lasers. Finally, he proposed optimised solutions for the MegaJoule Laser.

  19. Performance analysis of a threshold-based parallel multiple beam selection scheme for WDM-based systems for Gamma-Gamma distributions

    KAUST Repository

    Nam, Sung Sik

    2017-03-02

    In this paper, we statistically analyze the performance of a threshold-based parallel multiple beam selection scheme (TPMBS) for Free-space optical (FSO) based system with wavelength division multiplexing (WDM) in cases where a pointing error has occurred for practical consideration over independent identically distributed (i.i.d.) Gamma-Gamma fading conditions. Specifically, we statistically analyze the characteristics in operation under conventional heterodyne detection (HD) scheme for both adaptive modulation (AM) case in addition to non-AM case (i.e., coherentnon-coherent binary modulation). Then, based on the statistically derived results, we evaluate the outage probability (CDF) of a selected beam, the average spectral efficiency (ASE), the average number of selected beams (ANSB), and the average bit error rate (BER). Some selected results shows that we can obtain the higher spectral efficiency and simultaneously reduce the potential increasing of the complexity of implementation caused by applying the selection based beam selection scheme without a considerable performance loss.

  20. Performance analysis of 112 Gb/s×4-channel WDM PDM-DQPSK optical label switching system with spectral amplitude code labels

    Science.gov (United States)

    Aboagye, Isaac Adjaye; Chen, Fushen; Cao, Yongsheng

    2017-03-01

    We present the performance analysis of 112 Gb/s×4 wavelength division multiplexing (WDM) 100 GHz channel spacing polarization division multiplexed-differential quadrature phase shift keying (PDM-DQPSK) optical label switching system with frequency swept coherent detected spectral amplitude code labels. Direct detection is chosen to demodulate the payload by applying a polarization tracker, while 4-bits of 156 Mb/s spectral amplitude code label is coherently detected with a scheme of frequently-swept coherent detection. We optimize the payload laser linewidth as well as the frequency spacing between the payload and label. The label and payload signal performances are assessed by the eye-diagram opening factor (EOF) and bit-error rate (BER) at 10-9 as a function of the received optical power (ROP) and the optical signal to noise ratio (OSNR). The payload could well be demodulated after 900 km at a bit error rate of 10‒3 using forward error correction (FEC).