Dispersion Compensation Patents (Class 398/81)
  • Patent number: 10637602
    Abstract: A system and method for improving for amplifying a multi-frequency radio signal by using high efficiency amplifiers to amplify one radio frequency carrier at a time. The system further improves performance by providing parallel communication pathways throughout the entire transport and distribution chain. By creating parallel processing paths, both optically and electrically, the interaction of multiple signals are limited thereby avoiding unwanted intermodulation and noise.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: April 28, 2020
    Inventor: Henry Wojtunik
  • Patent number: 10236991
    Abstract: An optical signal transmission can use probabilistically shaped technique to improve performance and increase the transmission capacity. For instance, a 30-Gbit/s/? probabilistically shaped (PS) 1024-QAM DFT-S OFDM was experimentally demonstrated over 40-km SSMF in an intensity modulation-direct detection system. The Achievable Information Rate (AIR) 9.5344-bits/QAM symbol of PS-1024-QAM modulation is first achieved in the experiment and shows feasibility for OFDM.
    Type: Grant
    Filed: March 2, 2018
    Date of Patent: March 19, 2019
    Assignee: ZTE Corporation
    Inventors: Jianjun Yu, Jianyang Shi
  • Patent number: 10177430
    Abstract: An apparatus and a method for electromagnetic signal transition, comprising the steps of receiving an electromagnetic signal having a first physical characteristic arranged to be compatible for the electromagnetic signal to be transmitted on a transmission structure, and transmitting the electromagnetic signal to a substrate integrated waveguide, wherein during the transmission of the electromagnetic signal to the substrate integrated waveguide, the first physical characteristic is converted to a second physical characteristic arranged to be compatible for the electromagnetic signal to be transmitted on the substrate integrated waveguide.
    Type: Grant
    Filed: May 16, 2014
    Date of Patent: January 8, 2019
    Assignee: CITY UNIVERSITY OF HONG KONG
    Inventors: Quan Xue, Peng Wu
  • Patent number: 10126572
    Abstract: A photonic platform based polarization controller providing a fixed target polarization is disclosed. The polarization controller has a polarization rotator splitter splitting the beam into first and second feeds corresponding to first and second orthogonal polarization components. A first Mach-Zehnder interferometer (MZI) stage provides a first phase delay between the first and second feeds based on a first control signal, and a first mixer mixes the first and second feeds to provide third and fourth feeds. A second MZI stage provides a second phase delay between the third and fourth feeds based on a second control signal, and a second mixer mixes the third and fourth feeds to provide fifth and sixth feeds. A third MZI stage provides a third phase delay between the fifth and sixth feeds based on a third control signal, and a third mixer mixes the fifth and sixth feeds to provide the fixed target polarization. An optical tap splits a portion of the beam.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: November 13, 2018
    Assignee: HUAWEI TECHNOLOGIES CO., LTD.
    Inventors: Chunshu Zhang, Jia Jiang, Dominic John Goodwill, Patrick Dumais
  • Patent number: 10090928
    Abstract: Provided is an analog optical transmission system using a dispersion management technique. The analog optical transmission system may include a digital unit (DU) pool including a plurality of DUs to transmit an optical signal; a plurality of radio units (RUs) to receive the optical signal; and one or more dispersion management apparatus to remove a signal distortion component caused by an interaction between a chirp and chromatic dispersion by compensating for the chromatic dispersion before the plurality of RUs receives the optical signal that is transmitted from the DU pool.
    Type: Grant
    Filed: December 14, 2016
    Date of Patent: October 2, 2018
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Min Kyu Sung, Jong Hyun Lee, Hwan Seok Chung, Seung Hyun Cho, Chan Gyo Han
  • Patent number: 9991967
    Abstract: Techniques are described for characterizing a receiver front end of a pluggable optical module. The pluggable optical module receives an optical signal that includes a first portion having a first polarization and a second portion having a second polarization. The first portion and second portion are not coherent with one another and the power of the first portion and second portion is equal.
    Type: Grant
    Filed: August 28, 2017
    Date of Patent: June 5, 2018
    Assignee: Juniper Networks, Inc.
    Inventors: Qiang Wang, Yang Yue, Murat Arabaci
  • Patent number: 9866341
    Abstract: Disclosed is a data transmitter, including: a demultiplexer configured to demultiplex a data subcarrier, and a training sequence or a pilot subcarrier included in a signal which needs to be frequency-shifted among a plurality of signals; a frequency shift unit configured to frequency-shift the demultiplexed data subcarrier based on a predetermined frequency; a superposition unit configured to generate a polarization signal by superimposing the demultiplexed training sequence or pilot subcarrier, and the frequency-shifted data subcarrier; and a polarization antenna configured to transmit a signal which need not be frequency-shifted and the generated polarization signal among the plurality of signals.
    Type: Grant
    Filed: February 3, 2015
    Date of Patent: January 9, 2018
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Jun Woo Kim, Seung Jae Bahng, Go San Noh, Youn Ok Park
  • Patent number: 9467245
    Abstract: It is provided a polarization multiplexing optical transceiver including a polarization multiplexing optical transceiver, a polarization multiplexing optical receiver, a transmission side polarization state control unit and a reception side polarization state control unit. The polarization multiplexing optical receiver includes: a polarization demultiplexing unit; a plurality of information signal reconstruction units configured to receive the reconstructed polarization component on the transmission side as an input, and reconstruct and extract information signals; and an information signal coupling unit configured to one of couple and select the information signals output by the plurality of information signal reconstruction units and output the resultant under control of the reception side polarization state control unit.
    Type: Grant
    Filed: November 17, 2014
    Date of Patent: October 11, 2016
    Assignee: Hitachi, Ltd.
    Inventor: Nobuhiko Kikuchi
  • Patent number: 9407371
    Abstract: A multiplexer/demultiplexer that functions as an extremely small AWG optical filter in order to prepare a miniaturized and low-cost transceiver module necessary to realize a high speed transceiver for Ethernet (registered trademark). An optical multiplexer/demultiplexer includes: at least one input waveguide, a first slab waveguide, an arrayed waveguide group, a second slab waveguide, and at least one output waveguide. Each of the waveguides of the arrayed waveguide group has: a first bent part of which a waveguide extending direction changes 180 degrees or more; and a second bent part of which a waveguide extending direction changes 180 degrees or more in a direction opposite to a direction of the change of the first bent part.
    Type: Grant
    Filed: September 13, 2013
    Date of Patent: August 2, 2016
    Assignee: Nippon Telegraph and Telephone Corporation
    Inventors: Manabu Oguma, Ikuo Ogawa, Yoshiyuki Doi, Masayuki Itoh, Hiroshi Takahashi
  • Patent number: 9331783
    Abstract: A method and device for compensating, within a node of an optical network, chromatic dispersion undergone by optical packets transmitted within time slots of wavelength division multiplexed channels along at least one link of the optical network, a time slot duration corresponding to the sum of a packet duration and an inter-packet gap duration. The method and device demultiplexes the wavelength division multiplexed channels into a plurality of bands, and transmits the bands, via a respective plurality of delay lines having predetermined delays, toward a respective plurality of packet add/drop structures comprising a coherent receiver.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: May 3, 2016
    Assignee: Alcatel Lucent
    Inventors: Christian Simonneau, Yvan Pointurier, Francesco Vacondio
  • Patent number: 9191116
    Abstract: An orthogonal frequency division multiple access-passive optical network including a plurality of optical network units each configured to generate orthogonal frequency division multiplexed signals, which are allocated thereto, based on a central frequency for frequency division multiplexing that is allocated in advance, and to use the generated signals in upstream transmission.
    Type: Grant
    Filed: October 10, 2013
    Date of Patent: November 17, 2015
    Assignee: ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE
    Inventors: Seung-Hyun Cho, Seung-Il Myong, Kyeong-Hwan Doo, Jie-Hyun Lee, Sang-Soo Lee, Jong-Hyun Lee
  • Patent number: 9094148
    Abstract: An optical amplifier that uses software-defined optical networking (SDON) technology, with a centralized controller and flexible physical hardware (the adaptive amplifier here) to optimize the power distribution among different WDM channels in the amplifier. It considers the detailed information for each channel through the information from centralized controller. It is suitable for both single line rate and mixed line rate system, and is suitable for a wavelength division multiplexing WDM system with the same signal type or different signal types.
    Type: Grant
    Filed: May 7, 2014
    Date of Patent: July 28, 2015
    Assignee: NEC Laboratories America, Inc.
    Inventors: Philip Nan Ji, Junqiang Hu, Ting Wang
  • Patent number: 9042730
    Abstract: A method for adjusting an optical signal includes determining a polarization dependent loss (PDL) value associated with the optical signal, determining an angle between the optical signal and one or more axes of PDL, determining an amount of nonlinear phase noise due to PDL and nonlinear effects upon the optical signal based upon the PDL value and the angle, determining a phase rotation based upon the amount of nonlinear phase noise, and applying the phase rotation to the optical signal.
    Type: Grant
    Filed: February 8, 2013
    Date of Patent: May 26, 2015
    Assignee: Fujitsu Limited
    Inventors: Olga Vassilieva, Inwoong Kim, Motoyoshi Sekiya
  • Patent number: 9036998
    Abstract: An undersea long-haul transmission system includes an optical fiber transmission span and a coherent detection and digital signal processing module for providing dispersion compensation. The transmission span includes at least one fiber pair comprising substantially equal lengths of a positive-dispersion first fiber and a negative-dispersion second fiber that are configured to provide a signal output at transmission distances greater than 10,000 km, in which the combined accumulated dispersion across the operating bandwidth does not exceed the dispersion-compensating capacity of the coherent detection and digital signal processing module. Further described is a fiber for use in an undersea long-haul transmission span. At a transmission wavelength of 1550 nm, the fiber has a dispersion coefficient in the range of ?16 to ?25 ps/nm·km, and a dispersion slope in the range of 0.04 to 0.02 ps/nm2·km.
    Type: Grant
    Filed: August 16, 2013
    Date of Patent: May 19, 2015
    Assignee: OFS FITEL, LLC
    Inventor: Ole A Levring
  • Publication number: 20150104179
    Abstract: An optical network unit (ONU) comprising a media access controller (MAC) configured to support biasing a laser transmitter to compensate for temperature related wavelength drift receiving a transmission timing instruction from an optical network control node, obtaining transmission power information for the laser transmitter, estimating a burst mode time period for the laser transmitter according to the transmission timing instruction, and calculating a laser phase fine tuning compensation value for the laser transmitter according to the burst mode time period and the transmission power information, and forwarding the laser phase fine tuning compensation value toward a bias controller to support biasing a phase of the laser transmitter.
    Type: Application
    Filed: October 14, 2014
    Publication date: April 16, 2015
    Inventors: Feng Wang, Xuejin Yan, Bo Gao, Frank Effenberger
  • Patent number: 9000354
    Abstract: Systems for enhancing the sensitivity of detecting an optical signal using nonlinear optics and method of performing the same. In one embodiment, a single-photon detection system includes an optical amplifier realized in a waveguide, and a photodetector coupled to an output of the optical amplifier. A light detection and ranging system includes the optical amplifier coupled to an optical source and one photodetector. In another embodiment, a photodetection system includes a plurality of optical frequency converters, coupled to an optical source, that sequentially convert a wavelength of photons of the optical source to a final wavelength, and a single-photon photodetector coupled to the optical frequency converters to detect single photons produced by the optical source. In another embodiment, an optical sensor includes an optical pump, and a transducer including an optical ring cavity coupled to the optical pump and configured to utilize optical four-wave mixing to detect an external stimulus.
    Type: Grant
    Filed: October 5, 2012
    Date of Patent: April 7, 2015
    Assignee: Telcordia Technologies, Inc.
    Inventors: Ted Woodward, Anjali Agarwal, Nicholas Peters
  • Patent number: 8995844
    Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.
    Type: Grant
    Filed: April 17, 2014
    Date of Patent: March 31, 2015
    Assignee: Teradvance Communications LLC
    Inventors: Marcel F. C. Schemmann, Zoran Maricevic, Antonije R. Djordjevic, Darby Racey
  • Patent number: 8937759
    Abstract: A modular routing node includes a single input port and a plurality of output ports. The modular routing node is arranged to produce a plurality of different deflections and uses small adjustments to compensate for wavelength differences and alignment tolerances in an optical system. An optical device is arranged to receive a multiplex of many optical signals at different wavelengths, to separate the optical signals into at least two groups, and to process at least one of the groups adaptively.
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: January 20, 2015
    Assignee: Thomas Swan & Co. Ltd.
    Inventor: Melanie Holmes
  • Patent number: 8909052
    Abstract: A method is provided for carrying out dispersion compensation in an optical mesh network supporting simultaneously traffic services being provided at two or three different bit rates including a basic bit rate being 10 Gbps and at least one higher bit rate selected from among 40 Gbps and 100 Gbps. The method comprises the following steps: providing in-line dispersion compensation for every span in the network so as to reach positive average residual dispersion RDS per span extending to less than about 3 km; providing start points of possible trails in the network with respective external, pre-compensation negative Dispersion Compensation modules (DCMs), and providing termination points of possible trails in the network with respective external post-compensation positive DCMs.
    Type: Grant
    Filed: August 29, 2012
    Date of Patent: December 9, 2014
    Assignee: ECI Telecom Ltd.
    Inventor: Eyal Lichtman
  • Patent number: 8886051
    Abstract: Compensation for in-phase (I) and quadrature (Q) timing skew and offset in an optical signal may be achieved based on the correlation between derivatives of I and Q samples in the optical signal. The magnitude of the correlation between derivatives is measured to determine the presence of skew. Correlation between derivatives may be coupled with frequency offset information and/or with trials having additional positive and negative skew to determine presence of skew. Correlations are determined according to pre-defined time periods to provide for continued tracking and compensation for timing skew that may result from, for example, thermal drift.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: November 11, 2014
    Assignee: ViaSat, Inc.
    Inventors: Yuri Zelensky, Fan Mo
  • Patent number: 8886050
    Abstract: The present invention provides a wavelength division multiplexing system and a method and device for its residual dispersion compensation, wherein the device for residual dispersion compensation of wavelength division multiplexing system comprises: a performance parameter detecting device for receiving and detecting performance parameter of receiving terminal optical signal and sending detecting result of the performance parameter to a central control device; the central control device for deciding a dispersion regulating mode of a tunable dispersion compensator according to the detecting result of the performance parameter and sending the dispersion regulating mode to a tunable dispersion compensator control device through control signaling; and the tunable dispersion compensator control device for receiving the control signaling sent by the central control device and adjusting dispersion compensation amount of the tunable dispersion compensator according to the control signaling in order to make residual di
    Type: Grant
    Filed: January 10, 2007
    Date of Patent: November 11, 2014
    Assignee: ZTE Corporation
    Inventors: Likun Zhang, Jiaying Wang
  • Patent number: 8879920
    Abstract: The present wavelength multiplexed optical system includes a multimode optical fiber that transmits wavelength multiplexed optical signals and a plurality of multimode modal dispersion compensation optical fibers. Each modal dispersion compensation optical fiber can transmit one of the multiplex wavelengths, and each modal dispersion compensation optical fiber has an optimized index profile such that the modal dispersion for the transmitted wavelength is approximately inversely equal to the modal dispersion induced in the multimode optical fiber. The wavelength multiplexed optical system facilitates an increased bitrate without reducing bandwidth.
    Type: Grant
    Filed: June 23, 2009
    Date of Patent: November 4, 2014
    Assignee: Draka Comteq, B.V.
    Inventors: Yves Lumineau, Denis Molin, Asghar Gholami
  • Patent number: 8861981
    Abstract: Embodiments of the present invention disclose an optical signal compensation device, where, a nonlinear compensation module in the optical signal compensation device adopts a new nonlinear compensation algorithm to perform nonlinear compensation on an optical signal, and during the process of performing the nonlinear compensation, it is no longer required to look up a table. Technical solutions provided in the embodiments of the present invention can effectively increase the processing speed of the nonlinear compensation, thereby reducing the overall processing delay of an optical signal compensation system.
    Type: Grant
    Filed: March 18, 2013
    Date of Patent: October 14, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Ling Liu, Liangchuan Li
  • Patent number: 8849131
    Abstract: Polarization scattering compensation device and method are disclosed. In the device, a time sequence alignment unit aligns time sequences of signals in the first and second polarization state transmitted simultaneously; a polarization scattering estimation unit estimates a scattering coefficient of a scattering by the signal in the first polarization state on the signal in the second polarization state, and a scattering coefficient of a scattering by the signal in the second polarization state on the signal in the first polarization state; and a polarization scattering removal unit removes the scattering by the signal in the first polarization state on the signal in the second polarization state, and the scattering by the signal in the second polarization state on the signal in the first polarization state, in accordance with the scattering coefficients.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: September 30, 2014
    Assignee: Fujitsu Limited
    Inventors: Lei Li, Zhenning Tao, Shoichiro Oda
  • Patent number: 8818193
    Abstract: An embodiment of the invention includes a tunable optical dispersion compensator (TODC) comprising a first beam displacer on an optical path, wherein the first beam displacer separates an optical signal into a first beam and a second beam, and one or more polarizing beam splitters on the optical path, wherein the one or more polarizing beam splitters keep the first beam and the second beam on the optical path. The TODC also comprises one or more etalons on the optical path, wherein the one or more etalons are tunable to introduce a group delay in the first beam and the second beam, and a reflecting mirror on the optical path, wherein the reflecting mirror returns the optical signal back along the optical path. The TODC further comprises a second beam displacer, wherein the second beam displacer combines the first beam and the second beam into an output optical signal.
    Type: Grant
    Filed: September 29, 2009
    Date of Patent: August 26, 2014
    Assignee: Finisar Corporation
    Inventors: Fan Chen, Yongkang Hu, Zhenli Wen, Dongshen Han, Fahua Lan, Kevin Dapeng Zhang
  • Patent number: 8818189
    Abstract: A transmission-path-type specifying apparatus includes an optical filter that extracts a plurality of different wavelength components from light including wavelength components occurring at the time of communication; an optical switch that simultaneously transmits same pulse signals superposed on light of the extracted wavelength components. The apparatus also includes an ASE modulation controlling unit that obtains a delay-time difference among the transmitted pulse signals when arriving at a destination via a transmission path; a characteristic-value calculating unit that calculates a characteristic value of the transmission path corresponding to a reference time varied depending on the obtained delay-time difference and a type of the transmission path; and a fiber-type determining unit that specifies the type of the transmission path based on the calculated characteristic value.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: August 26, 2014
    Assignee: Fujitsu Limited
    Inventor: Futoshi Izumi
  • Patent number: 8805209
    Abstract: In one embodiment, a method for performing nonlinearity compensation on a dispersion-managed optical signal that was transmitted over an optical communication link, the method including virtually dividing the communication link into a plurality of steps, performing lumped dispersion compensation on a received optical signal to obtain a waveform upon which digital backward propagation (DBP) can be performed, performing DBP by performing dispersion compensation and nonlinearity compensation for each step, and generating an estimate of the transmitted signal based upon the performed DBP.
    Type: Grant
    Filed: February 24, 2012
    Date of Patent: August 12, 2014
    Inventors: Guifang Li, Likai Zhu
  • Patent number: 8798483
    Abstract: The present invention discloses an apparatus and method for adaptive dispersion compensation, the apparatus comprising: a coarse-grain tunable dispersion compensator, a receiver with electric adaptive dispersion compensator, and a control logic unit. In the method, firstly it is to perform optical dispersion compensation for the input optical signals; then to perform electric dispersion compensation for the optical signals for which the optical dispersion compensation is performed; it is to detect the performance parameters of the receiving of the optical signals for which the electric dispersion compensation has been performed, and based on the performance parameters, it is to perform optical dispersion compensation adjustment for said input optical signals. With an optical de-multiplexer further, said apparatus can perform adaptive dispersion compensation for the multi-channel system.
    Type: Grant
    Filed: December 20, 2005
    Date of Patent: August 5, 2014
    Assignee: ZTE Corporation
    Inventor: Huade Shu
  • Patent number: 8787755
    Abstract: Techniques, devices and applications are provided for monitoring a polarization mode dispersion (PMD) effect in an optical signal.
    Type: Grant
    Filed: April 15, 2013
    Date of Patent: July 22, 2014
    Assignee: General Photonics Corporation
    Inventor: Xiaotian Steve Yao
  • Patent number: 8787771
    Abstract: The present invention provides an optical networking device for re-amplifying, re-shaping, and re-timing an optical signal, as well as providing distortion compensation and performance monitoring of the optical signal. The optical networking device includes an all-optical regenerator device for one or more of re-amplifying, re-shaping, and re-timing the optical signal; a distortion compensator device for compensating for distortion associated with the optical signal; and a quality-of-signal monitoring device for measuring the quality of the optical signal. Preferably, the all-optical regenerator device, the distortion compensator device, and the quality-of-signal monitoring device are disposed within a single module. The quality-of-signal monitoring device measures the optical signal subsequent to distortion compensation. Alternatively, the quality-of-signal monitoring device measures the optical signal subsequent to distortion compensation and all-optical regeneration.
    Type: Grant
    Filed: October 6, 2006
    Date of Patent: July 22, 2014
    Assignee: Ciena Corporation
    Inventor: Michael Y. Frankel
  • Patent number: 8786930
    Abstract: Embodiments of the invention provide apparatuses and methods for phase correlated seeding of parametric mixer and for generating coherent frequency combs. The parametric mixer may use two phase-correlated optical waves with different carrier frequencies to generate new optical waves centered at frequencies differing from the input waves, while retaining the input wave coherent properties. In the case when parametric mixer is used to generate frequency combs with small frequency pitch, the phase correlation of the input (seed) waves can be achieved by electro-optical modulator and a single master laser. In the case when frequency comb possessing a frequency pitch that is larger than frequency modulation that can be affected by electro-optic modulator, the phase correlation of the input (seed) waves is achieved by combined use of an electro-optical modulator and injection locking to a single or multiple slave lasers.
    Type: Grant
    Filed: May 3, 2013
    Date of Patent: July 22, 2014
    Assignee: Ram Photonics, LLC
    Inventor: Ping Piu Kuo
  • Patent number: 8786821
    Abstract: A polarization controller includes a first polarization controller, a demultiplexer, a second polarization controller, and a multiplexer. The first polarization controller controls the state of polarization of input light such that a part of the wavelength components of the input light is in a first state of polarization. The demultiplexer demultiplexes the light output from the first polarization controller into a plurality of wavelength components. The second polarization controller controls the plurality of wavelength components in a second state of polarization by using liquid crystal modulation devices. The multiplexer multiplexes the plurality of wavelength components output from the second polarization controller.
    Type: Grant
    Filed: May 14, 2010
    Date of Patent: July 22, 2014
    Assignee: Fujitsu Limited
    Inventor: Takashi Shiraishi
  • Publication number: 20140199076
    Abstract: Systems, devices and techniques for processing an optical signal transmitted from a source over a transmission medium having a length L and performing compensation of non-linear distortions include formulating the compensation as a digital back propagation algorithm by logically dividing the length L into N steps and compensating non-linear distortions for each step as a function of an attenuation adjusting constant parameter that can be selected from a range between 0.3 and 0.7.
    Type: Application
    Filed: January 14, 2014
    Publication date: July 17, 2014
    Applicant: ZTE (USA) Inc.
    Inventors: Jianjun Yu, Junwen Zhang
  • Patent number: 8781329
    Abstract: A dispersion compensation design system includes a segment dividing unit to divide an optical network into segments of a linear network or a ring network, a path classifying unit to classify one of paths of the optical network, as a specific type path, the one of the paths being incapable of transmitting an optical signal and contained in a longer path having a route longer than that of the one of the paths and capable of transmitting the optical signal, a segment reconfiguration unit to reconfigure the segments so as to maximize a number of the specific type paths, a dispersion compensation amount computing unit to compute a dispersion compensation amount in any of spans of the optical network so as to minimize the number of the specific type paths within the reconfigured segment, and an update unit to update the dispersion compensation amount with the computed dispersion compensation amount.
    Type: Grant
    Filed: February 1, 2012
    Date of Patent: July 15, 2014
    Assignee: Fujitsu Limited
    Inventors: Yutaka Takita, Tomohiro Hashiguchi, Kazuyuki Tajima
  • Patent number: 8775135
    Abstract: A design method includes calculating a calculated compensation amount of a dispersion compensation module arranged on each of a plurality of wavelength paths in such a way that a residual chromatic dispersion value of each of the wavelength paths which transmits an optical signal between an initial node and a final node satisfies a tolerance condition given in accordance with a priority given to each of the wavelength paths; and deciding a decision value to be applied as the compensation amount of the dispersion compensation module based on the calculated compensation amount based on a plurality of candidate values each being prepared in advance as the candidate for the compensation amount of the dispersion compensation module.
    Type: Grant
    Filed: August 25, 2011
    Date of Patent: July 8, 2014
    Assignee: Fujitsu Limited
    Inventors: Rikiya Watanabe, Takuya Miyashita
  • Patent number: 8755690
    Abstract: An optical network contains dispersion compensation modules with Fiber Bragg Gratings. A photo detector behind the Fiber Bragg Grating detects the not reflected rest of the gratings input signal and therefore the dispersion compensation modules input signal. This information is used to reduce the expenditure and to avoid errors of configuration or administration of the dispersion compensating subsystem of the optical network.
    Type: Grant
    Filed: February 12, 2009
    Date of Patent: June 17, 2014
    Assignee: Xieon Networks S.a.r.l.
    Inventor: Arne Striegler
  • Patent number: 8737843
    Abstract: An optical homodyne communication system and method in which a side carrier is transmitted along with data bands in an optical data signal, and upon reception, the side carrier is boosted, shifted to the center of the data bands, and its polarization state is matched to the polarization state of the respective data bands to compensate for polarization mode dispersion during transmission. By shifting a boosted side carrier to the center of the data bands, and by simultaneously compensating for the effects of polarization mode dispersion, the provided system and method simulate the advantages of homodyne reception using a local oscillator. The deleterious effects of chromatic dispersion on the data signals within the data bands are also compensated for by applying a corrective function to the data signals which precisely counteracts the effects of chromatic dispersion.
    Type: Grant
    Filed: January 5, 2012
    Date of Patent: May 27, 2014
    Assignee: Teradvance Communications, LLC
    Inventors: Marcel F.C. Schemmann, Zoran Maricevic, Antonije R. Djordjevic, Darby Racey
  • Patent number: 8737840
    Abstract: In the optical transmitting system, the optical transmitter transmits a polarization combined signal light obtained by combining a pair of lights having different polarization orientation, and the optical receiver separates the combined signal light. In the optical transmitter, a polarization changer changes a state of polarization of the polarization combined signal light. In the optical receiver, a polarization reverse-changer changes the state of the polarization combined signal light in a reverse direction of the change that polarization changer applies.
    Type: Grant
    Filed: March 14, 2011
    Date of Patent: May 27, 2014
    Assignee: Fujitsu Limited
    Inventor: Hiroshi Nakamoto
  • Patent number: 8737839
    Abstract: A network design apparatus includes an input unit configured to receive network information that indicates nodes connected by optical transmission paths and path information that indicates paths between the nodes; an design unit configured to perform, based on the network information and the path information, wavelength dispersion compensation design using a constraint condition that a path whose span count is larger than a span count of another path that does not satisfy a transmission condition does not satisfy the transmission condition; and an output unit configured to output a result obtained by the design unit.
    Type: Grant
    Filed: August 17, 2010
    Date of Patent: May 27, 2014
    Assignee: Fujitsu Limited
    Inventors: Yutaka Takita, Toru Katagiri, Tomohiro Hashiguchi, Kazuyuki Tajima
  • Patent number: 8718474
    Abstract: Methods and devices for compensating for chromatic dispersion are shown that include receiving an input data signal, applying a filter to the data signal, and outputting a CD compensated signal. Applying the filter includes convolving known filter coefficients with a plurality of delayed versions of the data signal using addition and at least one inverse sign operation or using lookup tables and combining outputs to produce a CD compensated signal.
    Type: Grant
    Filed: October 6, 2011
    Date of Patent: May 6, 2014
    Assignee: NEC Laboratories America, Inc.
    Inventors: Dayou Qian, Junqiang Hu, Ting Wang, Yoshiaki Aono, Tsutomu Tajima
  • Patent number: 8693874
    Abstract: A transmission system is provided with a transmission apparatus that outputs an ASE light from a transmission light amplifier and with a reception apparatus provided with: a tilt detection unit that detects the optical strength levels of at least two probe lights having different wavelengths from a received ASE light; and a reception light amplifier that performs a first-order tilt correction on light to be output in a linear manner so as to reduce the difference in the optical strength level of the two probe lights detected by the tilt detection unit.
    Type: Grant
    Filed: April 23, 2010
    Date of Patent: April 8, 2014
    Assignees: Fujitsu Limited, Fujitsu Telecom Networks Limited
    Inventors: Tomoyuki Suzuki, Kenji Watanabe, Koji Tanonaka, Akihisa Kawaguchi, Takehiro Fujita
  • Publication number: 20140079401
    Abstract: A wavelength-division multiplexing optical communication system and a method for measuring optical performance of an output signal for the system. The optical communication system includes: a service-provider device; a local node; and a plurality of subscriber devices. The service-provider device includes: a plurality of first optical transceivers; a first optical multiplexer/demultiplexer (OD/OM) connected to the plurality of first optical transceivers; and a seed-light source providing seed light. Each subscriber device includes a second optical transceiver. The local node connects the service-provider device and the plurality of subscriber devices to each other using a DWDM link comprising: a second multiplexer/demultiplexer (OD/OM); and a single-mode optical fiber for transmission. Here, the optical intensity of an output signal of the second optical transceiver is determined by compensating for the value of the loss caused when the output signal passes through the second OD/OM of the local node.
    Type: Application
    Filed: May 25, 2012
    Publication date: March 20, 2014
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Han-Hyub Lee, Jie-Hyun Lee, Eon-Sang Kim, Sang-Soo Lee
  • Patent number: 8666251
    Abstract: The invention provides a system and method, for an optical communication network to compensate impairments in the network, using electronic dispersion compensation, said system comprising optical means comprising two or more optical-to-electrical converters for generating at least two electrical signals, comprising amplitude and instantaneous frequency of a received distorted optical signal, and an electrical circuit adapted to perform a full-field reconstruction of the received distorted optical signal using said electrical signals. The system is characterised by a dispersive transmission line circuit with compensation parameters updated at a selected rate to process said full-field reconstructed signal and compensate for coarse chromatic dispersion; and an adaptive electronic equalization circuit with compensation parameters updated at a rate faster than those in the said dispersive transmission line circuit to provide a fine impairment compensation of said reconstructed signals.
    Type: Grant
    Filed: June 23, 2010
    Date of Patent: March 4, 2014
    Assignee: University College Cork—National University of Ireland Cork
    Inventors: Jian Zhao, Mary McCarthy
  • Patent number: 8660438
    Abstract: A digital coherent receiver includes a front end, an A/D convertor, and a processor. The front end converts a light signal into an electric signal by using a signal light and a local oscillator light. The A/D convertor converts the electric signal of the front end into a digital signal. The processor calculates a spectrum gravity center of the digital signal converted by the A/D convertor, estimates a frequency offset of the digital signal based on the calculated spectrum gravity center, and reduces the frequency offset of the digital signal based on the estimated frequency offset.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: February 25, 2014
    Assignee: Fujitsu Limited
    Inventors: Hisao Nakashima, Takeshi Hoshida, Kosuke Komaki
  • Patent number: 8655184
    Abstract: The present invention relates to a higher-order dispersion compensation device (210), the device being adapted to cooperate with a pair of optical components (P1, P2), e.g. a pair of prisms, being arranged to compensate first-order dispersion by separating different wavelengths spatially. The compensation device (210) has the form of a phase plate, wherein the phase change for each wavelength is adjusted by designing the height (h) at the corresponding position (x) of the plate so as to substantially compensate for higher-order dispersion. The invention is advantageous for obtaining a higher-order dispersion compensation device which is relatively simple to construct and use making it a quite cost-effective device. The invention also relates to a corresponding optical system and method for compensating dispersion where this is important, e.g. in a multiple-photon imaging system.
    Type: Grant
    Filed: May 20, 2009
    Date of Patent: February 18, 2014
    Assignee: Koninklijke Philips N.V.
    Inventors: Gert Het Hooft, Bernardus Hendrikus Wilhelmus Hendriks, Mischa Megens
  • Patent number: 8644659
    Abstract: A method for predicting polarization mode dispersion (PMD) in an installed optical fiber. Values of PMD are measured for a first optical fiber at various points in time during the manufacture and installation of the first optical fiber. Values of PMD are identified that correspond to sensitive ones of the various points in time. A set of correlation coefficients is calculated based on the values of PMD corresponding to the sensitive ones of the various points in time. An installed value of PMD for a second optical fiber is predicted based on the set of correlation coefficients.
    Type: Grant
    Filed: November 26, 2012
    Date of Patent: February 4, 2014
    Assignee: Verizon Business Global LLC
    Inventor: John A. Fee
  • Patent number: 8630552
    Abstract: A digital coherent receiver includes a front end, an A/D convertor, and a processor. The front end converts a light signal into an electric signal by using a signal light and a local oscillator light. The A/D convertor converts the electric signal of the front end into a digital signal. The processor calculates a spectrum gravity center of the digital signal converted by the A/D convertor, estimates a frequency offset of the digital signal based on the calculated spectrum gravity center, and reduces the frequency offset of the digital signal based on the estimated frequency offset.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: January 14, 2014
    Assignee: Fujitsu Limited
    Inventors: Hisao Nakashima, Takeshi Hoshida, Kosuke Komaki
  • Patent number: 8615172
    Abstract: A method for arranging relay stations in an optical transmission system including relay stations arranged so that optical signals at a first transmission speed can be transmitted from a transmission end to a reception end, includes: judging whether a transmission of optical signals at a second transmission speed different from the first transmission speed in a section connecting arbitrary two of the relay stations where a regenerative repeater station capable of regenerating optical signals can be arranged is possible; determining a combination of sections judged to be capable of performing transmission that enables a transmission of optical signals from the transmission end to the reception end; and making both ends of respective sections of the determined combination be the relay stations where the regenerative repeater station is arranged, wherein the judging includes a judgment condition which is satisfied in a section including sections but unsatisfied in one of the sections.
    Type: Grant
    Filed: August 9, 2011
    Date of Patent: December 24, 2013
    Assignee: Fujitsu Limited
    Inventor: Takuya Miyashita
  • Patent number: 8611748
    Abstract: A WDM optical transmission system includes a plurality of optical transmission devices, each of which include a first memory that stores a first control program that controls a dispersion compensation amount in a host device; a processor to execute the first control program; a notification frame transmission circuit that transmits an information indicating a setting value of the dispersion compensation amount and a detection result corresponding to the setting value to another device; a third memory that stores a second control program that calculates a control value of the dispersion compensation amount in the another device; and a control frame transmission circuit that transmits the control value to the another device, wherein the processor executes the second control program when a problem occurs in the another device, and controls the dispersion compensation amount in the host device when a problem occurs in the host device.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: December 17, 2013
    Assignee: Fujitsu Limited
    Inventors: Makoto Yoshimi, Yoshiyuki Maeda
  • Patent number: 8606108
    Abstract: The present disclosure relates to dispersion slope compensation and dispersion map management systems and methods in an optical network utilizing a reconfigurable optical add-drop multiplexer (ROADM) with a plurality of different values of dispersion compensation modules (DCMs). The DCMs form a dispersion compensation ladder at certain intermediate nodes in the optical network to provide dispersion slope compensation and dispersion map management. The reconfigurable routing structure of the ROADM enables these intermediate nodes to route individual wavelengths to any one of the DCMs as required for the particular path of the wavelength. Advantageously, the present invention removes the requirement for banded compensation at receiver nodes and allows for dispersion map management at intermediate points along a fiber route as opposed to bulk compensation at the receiver.
    Type: Grant
    Filed: June 25, 2009
    Date of Patent: December 10, 2013
    Assignee: Ciena Corporation
    Inventor: Balakrishnan Sridhar