Power Control Patents (Class 398/94)
  • Patent number: 9973295
    Abstract: A method, an optical node, and an optical network include a power controller configured to bring channels in-service in parallel over multiple cascaded optical nodes quickly, efficiently, and in a non-service affecting manner. The method, node, and network utilize multiple states of a control loop that maintains a stable response in downstream optical nodes as channels are added in parallel. Further, the power controller is configured to operate independently alleviating dependencies on other power controllers and removing the need for coordination between power controllers. The method, node, and network provide efficient turn up of dense wave division multiplexing (DWDM) services which is critical to optical layer functionality including optical layer restoration.
    Type: Grant
    Filed: January 20, 2016
    Date of Patent: May 15, 2018
    Assignee: Ciena Corporation
    Inventors: Choudhury Al Sayeed, David C. Bownass, Loren S. Berg, David W. Boertjes
  • Patent number: 9397749
    Abstract: A method and apparatus for performing an automatic power adjustment wherein a signal power level of an optical signal transmitted by an optical transceiver via an optical span to a far-end device is adjusted automatically in response to a determined span loss of the optical span to achieve a predetermined desired receive signal power level of the optical signal at the far-end device.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: July 19, 2016
    Assignee: ADVA OPTICAL NETWORKING SE
    Inventors: J. David Portier, Sorin Tibuleac
  • Patent number: 9178641
    Abstract: Consistent with the present disclosure, chromatic dispersion is introduced into an optical communication path including multiple segments or spans of dispersion shifted fiber (DSF). The chromatic dispersion generates phase mismatching between optical signals propagating along the optical communication path, i.e., the optical signals are decorrelated, such that mixing products are reduced inmagnitude, and the noise attributable to four wave mixing is correspondingly reduced.
    Type: Grant
    Filed: July 6, 2011
    Date of Patent: November 3, 2015
    Assignee: Infinera Corporation
    Inventors: Hai Xu, Michael Francis Van Leeuwen, Emily F. Burmeister, Stephen G. Grubb
  • Patent number: 9154227
    Abstract: An OCM monitors a plurality of SW ports each receiving an optical signal by switching the SW ports. The OCM includes a PD, a control circuit, and an arithmetic circuit. The PD detects an optical power level on wavelengths spaced at predetermined intervals in each of the SW ports to be monitored. The control circuit determines, in each of the SW ports, whether arithmetic processing using a waveform estimated from the optical power level is executed, depending on presence or absence of a change in the optical power level detected by the PD. The arithmetic circuit performs the arithmetic processing by using the waveform when the control circuit determines execution of the arithmetic processing.
    Type: Grant
    Filed: March 31, 2014
    Date of Patent: October 6, 2015
    Assignee: FUJITSU LIMITED
    Inventor: Toshihiro Ohtani
  • Patent number: 9112608
    Abstract: An optical receiver comprising a frontend configured to receive an optical signal and convert the optical signal into a plurality of digital electrical signals comprising a plurality of spectrally shaped subcarrier signals carrying symbol mapped data information, and a digital signal processor (DSP) unit coupled to the frontend and configured to receive the digital signals from the frontend, demulitplex the digital signals into the subcarrier signals, and compensate chromatic dispersion (CD) for each of the subcarrier signals by applying an equalizer, wherein each of the subcarrier signals is associated with a unique tone frequency and a unique spectral shape. Also disclosed is an optical transmitter comprising a digital signal processor (DSP) unit configured to map data symbols onto a plurality of electrical subcarrier signals that are non-overlapping and spectrally shaped in a frequency domain.
    Type: Grant
    Filed: October 8, 2013
    Date of Patent: August 18, 2015
    Assignee: Futurewei Technologies, Inc.
    Inventors: Yu Sheng Bai, Yanjun Zhu, Qing Guo, Yan Cui, Fei Zhu
  • Patent number: 9059800
    Abstract: Optical communication apparatuses capable of performing appropriate communication according to a distance to a receiving apparatus, optical communication methods, and an optical communication system are provided. A transmitting apparatus transmits an optical signal corresponding to data. The transmitting apparatus modulates intensity of the optical signal into intensity corresponding to a distance over which the data is to be delivered and outputs this intensity-modulated optical signal. This allows the transmitting apparatus to change the intensity of the optical signal corresponding to the data according to a distance to a receiving apparatus that receives the data, which thus allows the receiving apparatus to surely receive the data.
    Type: Grant
    Filed: September 13, 2006
    Date of Patent: June 16, 2015
    Assignee: KYOCERA Corporation
    Inventors: Yasuyuki Irie, Makoto Chishima, Keijiro Minami
  • Patent number: 9037002
    Abstract: A pre-emphasis control method includes calculating an average value of transmission characteristics based on transmission characteristics of a plurality of light beams received by a receiver, and determining that, among signals of the plurality of light beams, a wavelength with a deviation from the average value is a wavelength at which control is to be performed, determining that the wavelength at which control is to be performed and a wavelength adjacent thereto are a group of wavelengths at which control is to be performed, obtaining an average of transmission characteristics of the group of wavelengths at which control is to be performed, and based on a difference between averaged transmission characteristics and respective transmission characteristics of the group of wavelengths at which control is to be performed, changing a light intensity output from each transmitter that transmits a group of wavelengths at which control is to be performed.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: May 19, 2015
    Assignee: FUJITSU LIMITED
    Inventors: Jyunji Tanaka, Shinichi Kaneko, Takeo Osaka
  • Patent number: 9008515
    Abstract: An apparatus includes an array of lasers, an array of electrical drivers, and optical filter. Each laser is configured to produce light in a corresponding wavelength-channel, wherein the wavelength-channels of different ones of the lasers are different. The electrical drivers are connected to directly modulate the lasers. Each driver produces a first driving current or voltage to cause a corresponding one of the lasers to be in a first lasing state and produces a different second driving current or voltage to cause the corresponding one of the lasers to be in a different second lasing state. The optical filter is connected to receive light output by the lasers. The optical filter selectively attenuates light from each of the lasers in the first lasing states thereof and to selectively pass light from each of the lasers in second lasing states thereof.
    Type: Grant
    Filed: January 31, 2011
    Date of Patent: April 14, 2015
    Assignee: Alcatel Lucent
    Inventors: David Thomas Neilson, Pietro Arturo Bernasconi
  • Patent number: 8995832
    Abstract: The present principles are directed to a transponder aggregator-based optical loopback in a multi-degree colorless, directionless, contention-less, reconfigurable optical add/drop multiplexer. The multiplexer includes a reconfigurable optical add/drop multiplexer section for performing connect operations for wavelength division multiplexing signals among all degrees. The section has a plurality of subsections. Each of the subsections corresponds to a respective one of the degrees and has an optical separator at an input side and an optical combiner at an output side. The multiplexer further includes a transponder aggregator section having a split-and-select switch-based transponder aggregator. The multiplexer also includes an optical line loopback having a connection path between the optical separator at the input side and the optical combiner at the output side of at least one of the subsections.
    Type: Grant
    Filed: April 2, 2013
    Date of Patent: March 31, 2015
    Assignees: NEC Laboratories America, Inc., NEC Corporation
    Inventors: Philip N. Ji, Yoshiaki Aono, Ting Wang
  • Patent number: 8965201
    Abstract: An optical transmission device includes a first power monitor to monitor a first signal into which second signals with respectively different wavelengths are multiplexed so as to measure received power of the first signal; an amplifier to amplify the first signal, to generate a third signal; a driver to drive the amplifier; a demultiplexer to separate the third signal into fourth signals with the different respectively wavelengths; second power monitors each to monitor each of the fourth signals so as to measure received power of each of the fourth signals; a memory to store therein data related to gain in the amplifier, the data corresponding to each of wavelengths of the second signals, with respect to parameters which are the received power measured by the first power monitor and driving condition; and a processor to calculate power of each of the second signals.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: February 24, 2015
    Assignee: Fujitsu Optical Components Limited
    Inventors: Naoki Kuwata, Koji Otsubo
  • Patent number: 8897639
    Abstract: Systems and methods according to these exemplary embodiments provide for methods and systems that allow for either reducing signal loss or improving the optical signal strength in a PON for increasing optical signal range.
    Type: Grant
    Filed: November 27, 2007
    Date of Patent: November 25, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (Publ)
    Inventors: Elmar Trojer, Stefan Dahlfort
  • Patent number: 8891957
    Abstract: A method of managing fault recovery in a trunk-branched OADM network may include determining that an optical power level over data channels of a first communications link between a first and a second terminal of the branched optical network exceeds an optical power limit. The method may further include increasing optical power sent over spare channels of the first communications link to a first level at which the optical power level over the data channels decreases to a second level below the optical power limit.
    Type: Grant
    Filed: July 13, 2011
    Date of Patent: November 18, 2014
    Assignee: Tyco Electronics Subsea Communications LLC
    Inventors: Ruomei Mu, Ekaterina A. Golovchenko, Frank W. Kerfoot, III
  • Patent number: 8842999
    Abstract: Provided is an optical network unit saving power. The optical network unit may include a processor checking whether at least one downward physical block, the upward physical block and a data switching block operate in an idle mode, sequentially transiting at least one downward physical block, an upward physical block and a data switching block to a sleep mode according to the checking result and sequentially transiting an optical transmission-reception block and the medium access control block to a sleep mode by judging whether or not a medium access control block transits to a sleep mode.
    Type: Grant
    Filed: September 20, 2011
    Date of Patent: September 23, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Sung Chang Kim, Geun Yong Kim, Hark Yoo, Youngsuk Lee, Sim-Kwon Yoon, Jong Deog Kim
  • Patent number: 8818190
    Abstract: An embodiment of the invention is an optical node configured to transmit/receive a wavelength-division-multiplexed signal. An optical monitoring unit monitors power levels of the wavelength-division-multiplexed signal on a wavelength-by-wavelength basis to acquire wavelength-by-wavelength power level values of the optical signals. A comparison arithmetic unit performs a comparison between each of the acquired wavelength-by-wavelength power level values of the optical signals, and a predetermined upper limit value and a predetermined lower limit value. A target value calculation unit determines target values of power levels at wavelengths whose acquired power level values exceed the upper limit value to be values between a center value and the upper limit value, and determines target values of power levels at wavelengths whose acquired power level values fall below the lower limit value to be values between the center value and the lower limit value.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: August 26, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Yukio Hayashi, Kenro Sekine, Yoshiyuki Niwa, Shuuji Furumoto
  • Patent number: 8798464
    Abstract: A method of determining a power correction factor for an optical power of an optical channel of a wavelength division multiplexed communications network. The method comprises configuring an optical source of the communications network to generate an unmodulated optical carrier signal for the optical channel. The method further comprises determining the optical power of the unmodulated optical carrier signal (PHIGH). The method further comprises configuring the optical source to apply a test modulation pattern to the optical carrier signal, to generate a modulated optical carrier signal. The method further comprises determining the optical power of the modulated optical carrier signal (PMOD). The method further comprises determining a power correction factor for the optical channel by determining the difference between the optical powers of the unmodulated optical carrier signal and the modulated optical carrier signal.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: August 5, 2014
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Gianmarco Bruno, Riccardo Ceccatelli, Edoardo Mongiardini
  • Patent number: 8798473
    Abstract: The present invention enables to prevent transmission characteristics from deteriorating due to the nonlinear effect in the transmission path caused by an increase in the channel power when a cable disconnection occurs.
    Type: Grant
    Filed: March 16, 2010
    Date of Patent: August 5, 2014
    Assignee: NEC Corporation
    Inventor: Takanori Inoue
  • Patent number: 8699585
    Abstract: Transmitters for data communication can include a pattern generator configured to generate parallel data stream composed of k bits, k being a natural number greater than 2, a serializer configured to convert the parallel data stream into a serial data stream, a pre-emphasis circuit configured to pre-emphasize the serial data stream based on a pre-emphasis control value, to transmit the pre-emphasized serial data stream to a receiver via a first transmission line, and a pre-emphasis controller configured to receive measured values of transmission errors of the pre-emphasized serial data stream from the receiver via a second transmission line, and configured to set the pre-emphasis control value corresponding to a minimum measured value of the transmission errors, to an optimum pre-emphasis control value.
    Type: Grant
    Filed: July 31, 2009
    Date of Patent: April 15, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Hitoshi Okamura
  • Patent number: 8682167
    Abstract: An optical apparatus includes a first optical amplifier for adjusting an output value to a constant level; an optical signal processor located before the first optical amplifier and processing the optical signal; a second optical amplifier located before the optical signal processor and subjected to automatic gain control for adjusting a gain constant; and a controller detecting a level of the optical signal at an output of the second optical amplifier. The controller adjusts a level of an output value of the first optical amplifier such that the level of the optical signal at the output of the second optical amplifier is held at the optimum value if the detected level of the optical signal differs from an optimum value, compensates for a loss caused in the optical signal processor and maintains the level of the optical signal at the output of the second optical amplifier at the optimum value.
    Type: Grant
    Filed: December 18, 2008
    Date of Patent: March 25, 2014
    Assignee: Fujitsu Limited
    Inventors: Hideki Kobayashi, Takehiro Fujita
  • Patent number: 8670671
    Abstract: An optical source includes a set of N light sources that provide a corresponding set of N optical signals having N carrier wavelengths. These optical signals are combined into a seed optical signal and transported to a substrate using an optical fiber. This substrate includes a set of K optical amplifiers that amplify the seed optical signal and provide a set of M output optical signals on a corresponding set of M output optical waveguides (where M is less than K). In this way, a total power of the set of M output optical signals may be significantly larger than that of the seed optical signal, thereby ensuring that a majority of a power efficiency of the optical source is associated with power efficiencies of the set of K optical amplifiers instead of power efficiencies of the set of N light sources.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: March 11, 2014
    Assignee: Oracle International Corporation
    Inventors: Ashok V. Krishnamoorthy, Xuezhe Zheng, John E. Cunningham
  • Patent number: 8670077
    Abstract: A method of performing a service scan for available channels across a bandwidth of an input signal, the method comprising the steps of: acquiring a power spectrum of the input signal bandwidth; analyzing the power spectrum to identify a list of candidate channels, each candidate channel being identified by at least a center frequency; processing each of the candidate channels in a receiver unit to extract service information, if present, relating to the candidate channel; and storing the service information for the channel in a memory.
    Type: Grant
    Filed: September 14, 2010
    Date of Patent: March 11, 2014
    Assignee: NXP B.V.
    Inventors: Ewout Brandsma, Klaas de Waal, Konstantinos Doris, Erwin Janssen
  • Patent number: 8670676
    Abstract: The invention relates to an optical modulator control system implemented in an optical burst mode transmitter, said control system comprising means for measuring a plurality of optical power sample values and associated optical wavelength data values from a modulator at a first sampling rate, wherein an average power table is generated from said values for each sample period and stored in a memory. The control system also comprises means for performing a control error calculation from two or more stored average power tables at a second sampling rate to calculate a single error value to provide gain and/or bias control signals, wherein the second sample rate is sampled at a slower rate than the first sample rate. The control system described optimises the modulator performance over temperature and lifetime in an optical network.
    Type: Grant
    Filed: November 12, 2010
    Date of Patent: March 11, 2014
    Assignee: Intune Networks Limited
    Inventor: Richard Oberland
  • Patent number: 8660435
    Abstract: A system for delivering optical power over optical conduits includes more than one optical power source and an optical power distribution node configured for selectively delivering optical power to multiple optical power sinks.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: February 25, 2014
    Assignee: The Invention Science Fund I, LLC
    Inventors: Alistair K. Chan, Roderick A. Hyde, Muriel Y. Ishikawa, Jordin T. Kare, Lowell L Wood, Jr.
  • Patent number: 8660437
    Abstract: A fiber optic network reduces distortion present in modulated optical signals received at an optical receiver from an optical transmitter via a fiber optic link. The optical receiver analyzes a received modulated optical signal, where the wavelength of the received signal is periodically varied at the transmitter around a center wavelength over a wavelength range. Based on the analysis, the receiver generates a link transmission curve indicative of the optical power of the received signal over the wavelength range. The network disclosed herein subsequently uses the link transmission curve to reduce the distortion caused by misalignment between the operating wavelength of a transmitter laser and a peak power wavelength at the peak power of the link transmission curve. For example, the transmitter may adjust the laser operating wavelength based on a control signal received from the receiver and generated at the receiver based on the link transmission curve.
    Type: Grant
    Filed: February 25, 2011
    Date of Patent: February 25, 2014
    Assignee: Emcore Corporation
    Inventor: Henry A. Blauvelt
  • Patent number: 8620160
    Abstract: An optical transmission apparatus includes a reception part for receiving a wavelength division multiplexed (WDM) signal reached via optical amplifiers; a measuring part for measuring an optical power level of each wavelength of the WDM signal received by the reception part; a determination part for determining whether an amount of tilt of the WDM signal calculated based on measurement results of the measuring part is suitable or not; an operation part for calculating the tilt correction amount to be applied to tilt correction processing performed by the optical amplifiers if the amount of tilt of the WDM signal is not suitable; and a notification part for notifying the optical amplifiers of the tilt correction amount.
    Type: Grant
    Filed: July 8, 2008
    Date of Patent: December 31, 2013
    Assignee: Fujitsu Limited
    Inventor: Miki Onaka
  • Patent number: 8615167
    Abstract: A WDM optical transmission system includes a plurality of optical nodes optically coupled by a transmission line, a processor that is operative to calculate an amount of adjustment of a reception level capable of increasing an optical signal-to-noise ratio for each channel of the WDM light reaching the optical node positioned at a receiving end of the unit section based on information on amplification operation of the WDM light in at least one optical-amplification repeating node disposed on the optical transmission line in the unit section, and to adjust a power level corresponding to each channel of the WDM light transmitted on the transmission line from the optical node positioned at a transmission end of the unit section in accordance with a calculation result of the calculation.
    Type: Grant
    Filed: September 12, 2011
    Date of Patent: December 24, 2013
    Assignee: Fujitsu Limited
    Inventors: Yasushi Sugaya, Takehiro Fujita, Satoru Okano
  • Patent number: 8571420
    Abstract: An apparatus for driving a wavelength-independent light source is provided. The apparatus includes a seed light signal generation unit configured to generate seed light signals with one or more wavelengths based on a wavelength identification signal, a wavelength light detection unit configured to detect the wavelength identification signal from the seed light signals, an extraction unit configured to extract wavelength information corresponding to the detected wavelength identification signal and extract a driving condition of a wavelength-independent light source corresponding to the extracted wavelength information, and a driving unit configured to drive the wavelength-independent light source according to the extracted driving condition.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: October 29, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Seung-Hyun Cho, Han-Hyub Lee, Jie-Hyun Lee, Jong-Hoon Lee, Eun-Gu Lee, Eui-Suk Jung, Sang-Soo Lee
  • Patent number: 8565604
    Abstract: An optical signal adjustment apparatus detects an optical signal intensity level of signal light components with multiple different wavelengths for each of the wavelengths in an optical detection unit and adjusts the signal light components with the wavelengths for each of the wavelengths in a variable optical attenuator to make the optical signal intensity levels of the signal light components uniform. The apparatus includes a control unit configured to successively select a detection signal associated with each of the wavelengths from the optical detection unit and generate a control signal for the wavelength based on the selected detection signal. The control signal generated by the control unit is supplied to the variable optical attenuator associated with the selected detection signal.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: October 22, 2013
    Assignee: Fujitsu Limited
    Inventors: Hideaki Koyano, Kazukiyo Ogawa
  • Patent number: 8565615
    Abstract: An optical modulation apparatus includes a first modulator, a second modulator, a multiplexer, a detector and an adjustor. The first modulator modulates light emitted by a light source using a first input signal and outputs a first modulated signal. The second modulator modulates the light using a second input signal and outputs a second modulated signal. The multiplexer multiplexes the first and second modulated signals and outputs a multiplexed signal. The detector is configured to detect a dip where power in a waveform of the multiplexed signal is equal to or smaller than a predetermined value. The adjustor is configured to adjust a delay of the first and second input signals based on power at the dip.
    Type: Grant
    Filed: March 15, 2011
    Date of Patent: October 22, 2013
    Assignee: Fujitsu Limited
    Inventors: Masato Nishihara, Tomoo Takahara, Takeshi Hoshida
  • Patent number: 8548322
    Abstract: A channel power estimator for estimating the power of each channel in a wavelength division multiplexed (WDM) signal, comprising filter means to select and output a sub-band of an incoming WDM signal, function application means to apply a weighting function at least once to the output from the filter means and then output the weighted signal to reconstruction means, storage means for storing optical characteristic data on at least the function application means, wherein the reconstruction means calculates an estimation of the power distribution of the incoming WDM signal using the weighted signal and the optical characteristic data.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: October 1, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventor: Gianmarco Bruno
  • Patent number: 8542991
    Abstract: An optical communication serial interface is employed to power up a device from a powered down state to a powered on state. An optical receiver element receives serial optical signals transmitted by at least one optical fiber and converts the received serial optical signals to electrical signals. A low level reception converter detects and decodes the electrical signals to provide data and control words from detected and decoded normal electrical signals for a high level command processor. A power supply maintains low level power to at least the optical receiver element and the low level reception converter of the optical communication serial interface while the device is in the powered down state. The low level reception converter detects a particular abnormal sequence of electrical signals; and in response to detecting the particular abnormal sequence of electrical signals, asserts a control signal to power up the device controllable power supply.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: September 24, 2013
    Assignee: International Business Machines Corporation
    Inventors: Louie Arthur Dickens, Timothy A Johnson, Craig Anthony Klein, Gregg Steven Lucas, Daniel James Winarski
  • Patent number: 8543010
    Abstract: An apparatus and method for controlling bias in an optical modulator is disclosed. The method is particularly applicable to controlling multi-wavelength modulators and wavelength-tunable transmitters. At a calibration stage, a desired optical performance of the modulator is achieved, and an amplitude of a peak-to-peak variation of the output optical signal at a pre-determined amount of dither is stored in a memory as a reference. At operating stage, a controller of the optical modulator adjusts a bias voltage of the modulator until the measured peak-to-peak optical signal variation matches the reference value stored at the calibration stage. For multi-wavelength modulators and tunable transmitters, the calibration is repeated at each wavelength, and corresponding peak-to-peak optical signal variations are stored in the memory.
    Type: Grant
    Filed: February 23, 2011
    Date of Patent: September 24, 2013
    Assignee: JDS Uniphase Corporation
    Inventors: Yuxin Zhou, Hock Gin Lim
  • Publication number: 20130188958
    Abstract: A feedback light tuning device and the optical communication system and method using the same are provided. By tuning the feedback light, the mechanism can completely correct the mean-wavelength drift up to 30 nm or 19400 ppm. The mechanism can be applied to various harsh environments which cause the mean-wavelength drift, so as to achieve a required stable mean-wavelength for the light source and to increase the acceptable range of radiation dose.
    Type: Application
    Filed: July 3, 2012
    Publication date: July 25, 2013
    Applicant: NATIONAL TAIWAN UNIVERSITY
    Inventors: Tz Shiuan PENG, Lon Wang
  • Patent number: 8494369
    Abstract: Consistent with the present disclosure optical interleaver and deinterleaver circuits are integrated onto a substrate. The inputs to the interleaver and the outputs of the deinterleaver are each coupled to a corresponding variable optical attenuator (VOA) and optical tap, which are also provided on the substrate. The optical taps supply a portion of the output of each VOA to a corresponding photodetector. A control circuit, which is coupled to the photodetector, in turn, supplies a control signal to each VOA based on the output of the photodetector. Accordingly, optical multiplexing and demultiplexing components, as well as monitoring and power regulating components are provided on the same chip. Such a chip may be compact, relatively inexpensive, and has reduced power consumption compared to optical multiplexer and demultiplexer equipment including discrete components.
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: July 23, 2013
    Assignee: Infinera Corporation
    Inventors: Matthew L. Mitchell, Michael Van Leeuwen
  • Patent number: 8447184
    Abstract: A system and method for Raman amplification of optical signals in a wavelength division multiplexing (WDM) optical transmission system includes transmitting optical signals within a transmission band via an optical waveguide between a transmitter and a receiver, Raman-amplifying the optical signals with at least one pump so as to distort an amplification profile of the Raman amplification within the transmission band, and rectifying the distorted amplification profile so as to compensate for the distortion.
    Type: Grant
    Filed: June 3, 2006
    Date of Patent: May 21, 2013
    Assignee: Deutsche Telekom AG
    Inventors: Matthias Gunkel, Ralph Leppla, Malte Schneiders, Sascha Vorbeck, Werner Weiershausen, Michael Bousonville
  • Patent number: 8428463
    Abstract: Consistent with the present disclosure, a method and apparatus for providing a uniform spectral gain of an optical amplifier is provided. Namely, a “balancing” step is carried out in which an optical channel having the lowest power level input to an optical circuit, such as an dynamic gain equalizer (DGE), is assigned a zero “attenuation error” and is substantially un-attenuated by the DGE. The lowest power level optical signal does not require further attenuation and effectively serves as a reference power level, which the power levels of the remaining optical signals are set to. For example, remaining optical signals are assigned either positive or negative attenuation errors relative to the zero attenuation error based on optical signal input powers to the DGE and accumulated DGE attenuations over time. Those optical signals having a negative attenuation error are substantially unattenuated by the DGE, because such optical signals are adequately attenuated and do not require further attenuation.
    Type: Grant
    Filed: May 10, 2010
    Date of Patent: April 23, 2013
    Assignee: Infinera Corporation
    Inventors: Benjamin A. Warren, Saurabh Kumar, Abhijeet D. Deore, Brian B. Shia, Ganesh Sundaresan
  • Patent number: 8396374
    Abstract: In a digital signal processing optical transmission apparatus such as a predistortion or OFDM type one, optical transmission at a stable S/N ratio is intended to be able to be made by controlling an output of an optical transmission signal with fixed average power, even if a peak to average power ratio of the optical transmission signal changes. The apparatus is provided with an average power calculation unit (30) that calculates the average power of a digital signal outputted from a digital signal processing circuit (2), and an optical power variable unit (31) that serves to make constant the average power of an optical transmission signal outputted from an optical vector modulator (5).
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: March 12, 2013
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takashi Mizuochi, Yoshiaki Konishi, Tatsuya Kobayashi
  • Patent number: 8346082
    Abstract: According to a method of reducing power in an optical access network, upon the application of power, an optical network terminal (ONT) operates normally in an activation mode. The ONT then determines whether the requirements for switching from activation mode to power-saving mode are satisfied. If the requirements are satisfied, the ONT transmits a sleep signal to an optical line terminal (OLT), which is a message notifying that the ONT will soon switch to power-saving mode. Thereafter, the ONT switches to power-saving mode and cuts off power for all functions except for power for monitoring and controlling external inputs. The ONT then determines whether the requirements for switching from power-saving mode to activation mode are satisfied. If the requirements are satisfied, the ONT transmits a wake-up signal to the OLT and switches to the activation mode for normal operation.
    Type: Grant
    Filed: May 22, 2008
    Date of Patent: January 1, 2013
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Bin-Yeong Yoon, Sung-Chang Kim, Geun-Yong Kim
  • Patent number: 8340525
    Abstract: A method for stabilizing multi-channel optical signal wavelengths includes the following steps. A first detecting signal is stacked on a plurality of driving signals in sequence. A plurality of optical signals generated after being driven by the plurality of driving signals is combined into one optical total signal. A wavelength detection is performed on the optical total signal. A second detecting signal with a frequency band the same as that of the first detecting signal is extracted from the signals obtained after the wavelength detection. The wavelength of the optical signal in the corresponding channel among the multiple channels is controlled according to the second detecting signal. A device for stabilizing multi-channel optical signal wavelengths is also provided. Using the above method or device, the multi-channel optical signal wavelengths can be stabilized, which requires less elements, and has a simple circuit structure, a high integration level, and a low cost.
    Type: Grant
    Filed: April 29, 2009
    Date of Patent: December 25, 2012
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Yusheng Bai, Naisheng Zhang, Changgui Xiao
  • Patent number: 8331787
    Abstract: Even during a protection period in which a state transition is not caused from an ALC state to an ALD state, when an output light level that is inputted is below a threshold for ALC transition read from a memory, a processor causes a transition by switching an internal state from an ALC state to an ALD state. Then, an ALD operation is started, outputting a control voltage to a VAT control unit so as to achieve a predetermined fixed attenuation amount.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: December 11, 2012
    Assignee: Fujitsu Limited
    Inventors: Takeshi Noma, Haruki Tanaka, Yoshikazu Nakanishi, Makoto Ohtou, Hideaki Sugiya, Ichiro Nakajima, Toshihiro Suzuki
  • Patent number: 8326152
    Abstract: A signal strength corresponding to an incoming optical burst from each of a plurality of optical nodes is measured. The measurements can be performed at system start-up, configuration/installation of the optical nodes and/or at certain intervals of operation of the optical nodes. Signal strength information for the optical nodes based on the measurements is stored in memory. When scheduling the optical nodes for transmission, a preferred transmission order is determined in response to the stored signal strength information. In an embodiment, the preferred order is determined to reduce differences in signal strength levels between consecutive optical bursts.
    Type: Grant
    Filed: April 15, 2010
    Date of Patent: December 4, 2012
    Assignee: Alcatel Lucent
    Inventors: Doutje T. Van Veen, Adriaan J. De Lind Van Wijngaarden, Dusan Suvakovic
  • Patent number: 8320758
    Abstract: A method for estimating optical power in an optical channel includes determining a tunable filter full-width, FWF, by measuring a response of the tunable filter to a known signal and mapping the response to frequency. A portion of an optical channel is coupled to an input of the tunable optical filter. A peak power response, PR, and a full width tunable filter response, FWR, to the optical channel are determined by measuring a response of the tunable filter to the optical channel and mapping the response to frequency. A signal power, PS, is then calculated from the peak power response, PR, and a ratio of the full width tunable filter response, FWR, to the tunable filter full-width, FWF.
    Type: Grant
    Filed: April 30, 2009
    Date of Patent: November 27, 2012
    Assignee: Aegis Lightwave, Inc.
    Inventor: Michael Cahill
  • Patent number: 8275264
    Abstract: According to an aspect of an embodiment, an apparatus for controlling optical waveform, comprises: an input port for inputting a signal light having a modulating frequency and a signal light power; a pump light generator generating pulsed pump light having a frequency higher than the modulating frequency of the signal light and a pulsed pump light power; a nonlinear optical medium for transmitting the signal light from the input port and the pulsed pump light, the nonlinear optical medium having a gain of the signal light based on a nonlinear optical effect; and a power adjustor for adjusting a gain of the signal light saturates in the nonlinear optical medium by a nonlinear optical effect by adjusting at least one of the signal light power or the pulsed pump light power.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: September 25, 2012
    Assignee: Fujitsu Limited
    Inventor: Shigeki Watanabe
  • Patent number: 8275256
    Abstract: An optical communication serial interface is employed to power up a device from a powered down state to a powered on state. An optical receiver element receives serial optical signals transmitted by at least one optical fiber and converts the received serial optical signals to electrical signals. A low level reception converter detects and decodes the electrical signals to provide data and control words from detected and decoded normal electrical signals for a high level command processor. A power supply maintains low level power to at least the optical receiver element and the low level reception converter of the optical communication serial interface while the device is in the powered down state. The low level reception converter detects a particular abnormal sequence of electrical signals; and in response to detecting the particular abnormal sequence of electrical signals, asserts a control signal to power up the device controllable power supply.
    Type: Grant
    Filed: August 14, 2009
    Date of Patent: September 25, 2012
    Assignee: International Business Machines Corporation
    Inventors: Louie Arthur Dickens, Timothy A Johnson, Craig Anthony Klein, Gregg Steven Lucas, Daniel James Winarski
  • Patent number: 8260141
    Abstract: A system for enabling reconfiguration of a Wavelength Division Multiplexed (WDM) optical communications network. A plurality of channel transmitters are provided for generating respective optical signals within corresponding wavelength channels of the network. A broadband light source generates a broadband continuous wave light having a bandwidth corresponding to a channel band of the network. A wavelength selective switch includes a first switch port connected to receive optical signals from the channel transmitters. A second switch port is connected to receive the broadband continuous wave light from the broadband light source. The wavelength selective switch is configured to comb the broadband continuous wave light into a plurality of narrowband lights respectively corresponding with wavelength channels of the network. A common-OUT port of the wavelength selective switch outputs a WDM signal for transmission through a downstream fiber span of the network.
    Type: Grant
    Filed: March 12, 2010
    Date of Patent: September 4, 2012
    Assignee: Ciena Corporation
    Inventor: Loren Berg
  • Patent number: 8208812
    Abstract: A control-target-value setting unit sets a control target value corresponding to the number of multiplexed wavelengths measured by a number-of-multiplexed-wavelengths measuring unit. A controller controls the variable optical attenuator based on the control target value. An optical amplifier performs an optical amplification with a constant gain regardless of power of a wavelength-multiplexed light. The controller performs feedback control of the variable optical attenuator such that a result of measurement of the total power of the wavelength-multiplexed light coincides with the control target value.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: June 26, 2012
    Assignee: Mitsubishi Electric Corporation
    Inventors: Toshiyuki Tokura, Katsuhiro Shimizu, Kazuyuki Ishida, Kuniaki Motoshima
  • Patent number: 8195052
    Abstract: An optical wavelength multiplexing system includes transmission-side and reception-side optical wavelength multiplexers, and terminal devices, which are connected to each other by optical fiber cables. Optical wavelength converters in the transmission-side optical wavelength multiplexers are connected to ports respectively. The optical wavelength converter converts an input optical signal into an arbitrary preset wavelength to generate a converted optical signal. The port has a predetermined wavelength preset therein. Each optical power level of input converted optical signals is compared with each optical power level of optical signals of respective wavelengths set in the ports. When a difference is detected in the comparison result, it is determined that an optical wavelength converter is incorrectly connected to the port.
    Type: Grant
    Filed: December 6, 2007
    Date of Patent: June 5, 2012
    Assignee: Fujitsu Limited
    Inventors: Makoto Ohtou, Akira Yamamoto, Tatsuo Nagayoshi, Katsumi Sugawa, Hideaki Sugiya
  • Patent number: 8170418
    Abstract: A protected light source for generating seed light for at least two wavelength division multiplexed passive optical networks (WDM-PONs). The protected light source includes an optical coupler having N?2 input ports and M?2 output ports, each output port being optically connected to supply seed light to a respective set of one or more WDM-PONs. A respective multi-wavelength light source (MWLS) is optically coupled to supply seed light to each input port of the optical coupler. A controller unit controls operation of each multi-wavelength light source (MWLS).
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: May 1, 2012
    Assignee: Nortel Networks Limited
    Inventors: Richard Habel, Kim B. Roberts
  • Patent number: 8160446
    Abstract: The present invention provides methods and systems to stabilize an optical network against nodal gain changes through two nested control loops for controlling node gain and node output power. The present invention includes two nested control-loops running at different update speeds including: an inner, faster, control-loop which sets the gains and losses within a node to achieve a node-gain target, and a node-gain target for the inner loop is set by an outer, slower, control loop that whose target is the node output power. Advantageously, the present invention reduces the problem of concatenated overshoot by minimizing the control-loop response to events that occur at other nodes.
    Type: Grant
    Filed: December 10, 2010
    Date of Patent: April 17, 2012
    Assignee: Ciena Corporation
    Inventors: Brandon C. Collings, Douglas J. Beckett, Sanjay Choudhary
  • Publication number: 20120087669
    Abstract: In an optical node, a transmitter produces an optical supervisory signal for supervising an optical network, a processor is operative to control a power level of the optical supervisory signal according to a per-wavelength power level of an optical communication signal when the optical node has no post amplifiers, and a multiplexer combines the controlled optical supervisory signal with the optical communication signal to be transmitted to another optical node located downstream.
    Type: Application
    Filed: October 4, 2011
    Publication date: April 12, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Koji BIWA, Kosuke KOMAKI
  • Patent number: 8135280
    Abstract: Methods and systems for controlling power fluctuations in a network including a plurality of nodes are disclosed. A node in the network may be configured to modify power levels in accordance with either an active state or an inactive state. The node may transition to an inactive state in response to a power change that exceeds a power change threshold. The role of the node in controlling the power fluctuation in the network is reduced in the inactive state.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: March 13, 2012
    Assignees: NEC Laboratories America, Inc., NEC Corporation
    Inventors: Lei Zong, Ting Wang, Takefumi Oguma, Katsuyuki Mino, Osamu Matsuda