Specific Optical Elements Patents (Class 398/207)
  • Patent number: 8989596
    Abstract: An optical communication system has a receiver that includes a plurality of photon counting sensors that each receive photons and generate pulses based on the received photons, and an electronic circuit that aggregates the number of pulses from the plurality of photon counting sensors into a merged pulse count. A demodulator samples the merged pulse count at predetermined time intervals to determine a number of photons received by the plurality of photon counting sensors during different sampling time intervals.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: March 24, 2015
    Assignee: Northrop Grumman Systems Corporation
    Inventor: Oliver W. Saunders
  • Patent number: 8971701
    Abstract: A universal optical receiver may include an optical channel monitor configured to acquire spectral data for an optical signal on at least one selected optical channel, a tunable local oscillator configured to be tuned to a center frequency of the optical signal on the at least one selected optical channel, a storage device configured to store data associated with the optical signal responsive to acquisition of the spectral data and tuning of the tunable local oscillator, and processing circuitry configured to execute an algorithm that employs a plurality of binary distinctions based on physical characteristics of the optical signal and employs at least one calculation of figure of merit associated with a series of parameter values of the optical signal to identify a format of the optical signal.
    Type: Grant
    Filed: September 4, 2012
    Date of Patent: March 3, 2015
    Assignee: The Johns Hopkins University
    Inventors: Eric J. Adles, Michael L. Dennis, Raymond M. Sova, Joseph E. Sluz, Michael G. Taylor, Curtis R. Menyuk, John W. Zweck
  • Patent number: 8965211
    Abstract: A system and method of digitizing an analog signal without an amplitude channel is disclosed. The system and method includes receiving an analog signal comprising a voltage v(t) and a frequency f1, producing a series of optical pulses at a sampling frequency f2 with a pulsed laser, splitting the series of optical pulses into a first optical signal and an optical reference signal, phase modulating the first optical signal with the analog signal to produce a sampled optical signal such that phase shifts between adjacent samples in the sampled optical signal does not exceed ? radians, and receiving the sampled optical signal and the optical reference signal at a photonic signal processor.
    Type: Grant
    Filed: September 29, 2011
    Date of Patent: February 24, 2015
    Assignee: Rockwell Collins, Inc.
    Inventors: Raymond Zanoni, Kim S. Jepsen, Oliver S. King, Mark A. Laliberte
  • Patent number: 8891978
    Abstract: At least one cell implementing a sensor array embraces a photoelectric-conversion accumulation element configured to generate and accumulate signal charges, a potential detection circuit configured to detect the signal charges generated by the photoelectric-conversion accumulation element as a potential change, and an amplification circuit configured to amplify the potential change and to transmit to an output-signal line. The photoelectric-conversion accumulation element and the potential detection circuit are connected in series between a first potential terminal and a second potential terminal, and the potential detection circuit has an insulated-gate transistor, which detects the potential change in a weak inversion state, in a period when an optical-communication signal is received.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: November 18, 2014
    Assignee: National University Corporation Shizuoka University
    Inventors: Shoji Kawahito, Isamu Takai, Michinori Ando
  • Patent number: 8873968
    Abstract: An optical field receiver comprises an optical branching circuit for branching a received optical multilevel signal into first and second optical signals, a first optical delayed demodulator for performing delayed demodulation on the first optical signal at a delay time T (T=symbol time), a second optical delayed demodulator for performing delayed demodulation on the second optical signal at the delay time T with an optical phase difference deviating from the first optical delayed demodulator by 90°, first and second optical receivers for converting each of the delayed demodulation signals representing x and y components of complex signals output from the first and second delayed demodulators into first and second electrical signals, and a field processing unit fort generating a first reconstructed signal representing an inter-symbol phase difference or a phase angle of a received symbol from the first and second electrical signals for each symbol time T.
    Type: Grant
    Filed: May 11, 2006
    Date of Patent: October 28, 2014
    Assignee: Hitachi, Ltd.
    Inventor: Nobuhiko Kikuchi
  • Patent number: 8867920
    Abstract: An electro-optical device includes an optical de-multiplexing portion operative to output a first optical signal having a first wavelength and a second optical signal having a second wavelength, an array of photodetectors, and a switching logic portion communicatively connected to the array of photodetectors, the switching logic portion operative to determine which photodetector of the array of photodetectors is converting the first optical signal into a first electrical signal and output the first electrical signal from a first output node associated with the first optical signal.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: October 21, 2014
    Assignee: International Business Machines Corporation
    Inventors: Solomon Assefa, Douglas M. Gill, Jonathan E. Proesel, Alexander V. Rylyakov, Clint L. Schow
  • Patent number: 8861979
    Abstract: The present disclosure relates to the field of communications, and in particular, to a coherent receiver apparatus and a chromatic dispersion compensation method. The apparatus includes a polarization beam splitter and a chromatic dispersion compensation module. An optical splitter is disposed in front of the polarization beam splitter, and a chromatic dispersion monitoring module is connected between the optical splitter and the chromatic dispersion compensation module. The optical splitter is configured to split a modulated optical signal received by the coherent receiver apparatus and then transmit the split modulated optical signal to the chromatic dispersion monitoring module and the polarization beam splitter.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: October 14, 2014
    Assignee: Huawei Technologies Co., Ltd.
    Inventor: Ning Liu
  • Patent number: 8861982
    Abstract: When designing a demodulator for a DPSK-modulated signal, it is required that optical phase modulation is performed fast and the demodulator has a long lifetime. To achieve this object, a delay line interferometer inside the demodulator performs adjustment of phase difference between two split lights caused to interfere, using a first optical phase modulation unit such as a Piezo actuator and a second optical phase modulation unit such as a heating element that operates slower in modulation speed than the first optical phase modulation unit and is slower in deterioration speed.
    Type: Grant
    Filed: January 6, 2011
    Date of Patent: October 14, 2014
    Assignee: Oclaro Japan, Inc.
    Inventors: Hideharu Mikami, Taichi Kogure
  • Patent number: 8861980
    Abstract: A loop filter include: a register that stores a result of arithmetic operation performed on a complex signal and outputs the stored complex signal; a first multiplier that multiplies the complex signal output from the register and a predetermined coefficient; an absolute value judging unit that outputs a multiplier coefficient used to control such that the amplitude of the complex signal output from the register is held in a predetermined range; a multiplier that multiplies an output from the first multiplier and the multiplier coefficient; a second multiplier that multiplies an input signal and a value (1?the predetermined coefficient); and an adder that adds an output from the multiplier to an output from the second multiplier and inputs a result of addition into the register.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: October 14, 2014
    Assignee: Fujitsu Limited
    Inventors: Yasuo Ohtomo, Nobukazu Koizumi
  • Patent number: 8805206
    Abstract: In a coherent optical receiver of an optical communications system, methods and systems for receiving a data signal x(t) modulated on an optical signal. A linearly polarized LO light is generated, which has a frequency of f1=f0±?f, where f0 is a frequency of a narrowband carrier of the optical signal, and ?f corresponds with a band-width fB of the data signal x(t). The LO light and a received light of the optical signal are heterodyned on a photodetector. An analog signal generated by the photodetector is low-pass filtered to generate a filtered signal, using a filter characteristic having a sharp cut-off at a frequency of ?f+nfB, where n is an integer multiple. An analog-to digital (A/D) converter samples the filtered signal at a sample rate of 2(?f+nfB) to generate a corresponding multi-bit digital sample stream. The multi-bit digital sample stream is digitally processed to recover respective In-Phase and Quadrature components of the received light of the optical signal.
    Type: Grant
    Filed: September 29, 2010
    Date of Patent: August 12, 2014
    Assignee: Ciena Corporation
    Inventors: Kim B. Roberts, Shahab Oveis Gharan
  • Patent number: 8768179
    Abstract: A power management arrangement for low power optical transceiver such as those that may be integrated into a personal computer or server may periodically put itself into a power conservation or sleep mode which assures the transceiver is available upon wake-up.
    Type: Grant
    Filed: March 8, 2012
    Date of Patent: July 1, 2014
    Assignee: Intel Corporation
    Inventors: Hui-chin Wu, Miaobin Gao, Hengju Cheng
  • Patent number: 8744276
    Abstract: An optical receiving apparatus includes a combining unit that combines signal light and reference light; a optoelectric converting unit that converts, into electrical signals, two or more optical signals that enable reconstruction of a complex electric field signal of the signal light obtained by the combining unit; and a sampling clock generating unit that generates a sampling clock that has a frequency preset based on a symbol rate of the signal light and is asynchronous with the signal light. The optical receiving apparatus further includes a digital converting unit that samples at the frequency of the sampling clock signal, an electrical signal obtained by the optoelectric converting unit and converts the electrical signal into a digital signal; and a digital signal processing unit that demodulates a received signal based on a complex digital signal obtained from the digital signal obtained by the digital converting unit.
    Type: Grant
    Filed: March 20, 2009
    Date of Patent: June 3, 2014
    Assignee: Fujitsu Limited
    Inventors: Hisao Nakashima, Takeshi Hoshida, Takahito Tanimura, Lei Li, Ling Liu
  • Patent number: 8724999
    Abstract: An optical communication system includes a polarization multiplexed orthogonal frequency-division multiplexing POLMUX-OFDM transmitter for generating a POLMUX-OFDM double sideband signal, an optical processing path for processing the double sideband signal from the transmitter; an analog-to-digital convert ADC-OFDM receiver coupled to the optical processing path for receiving the double sideband signal processed by the optical path; and a block-diagonal multiple-input multiple-output MIMO equalizer responsive to the receiver for enabling correct operation for a completely random incoming signal polarization state without adaptive polarization control at said receiver, which enables complexity.
    Type: Grant
    Filed: April 13, 2012
    Date of Patent: May 13, 2014
    Assignee: NEC Laboratories America, Inc.
    Inventors: Neda Cvijetic, Yue-Kai Huang, Narayan Prasad, Ting Wang
  • Patent number: 8693881
    Abstract: An optical heterodyne device includes an optical meta-material exhibiting non-linear behavior. The optical meta-material mixes an input signal and a local signal to produce a heterodyne signal.
    Type: Grant
    Filed: November 19, 2010
    Date of Patent: April 8, 2014
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Wei Wu, Shih-Yuan (SY) Wang, Alexandre M. Bratkovski
  • Patent number: 8655192
    Abstract: A polarization diversity optical system device includes: a polarization split unit that splits a first coherent light into a first split light and a second split light whose polarization components are orthogonal to each other, and splits a second coherent light into a third split light and a fourth split light whose polarization components are orthogonal to each other; and a light combining unit that combines the first split light with one of the third split light and the fourth split light, and combines the second split light with the other of the third split light and the fourth split light.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: February 18, 2014
    Assignee: Oclaro Japan, Inc.
    Inventors: Kentaro Osawa, Hideharu Mikami
  • Patent number: 8649690
    Abstract: A system configured to maintain a consistent local-oscillator-power-to-primary-signal-power ratio (LO/SIG ratio).
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: February 11, 2014
    Assignee: Cisco Technology, Inc.
    Inventors: Soren Gehrke, Theodor Kupfer, James Whiteaway
  • Publication number: 20140023381
    Abstract: A method and apparatus for optical communication. A plurality of optical signals having a plurality of different frequencies is received at a receiver. The plurality of optical signals received at the receiver is sent through a non-linear optical element in the receiver such that a resulting optical signal is generated that has a frequency based on at least one of the plurality of different frequencies. Information is identified in the resulting optical signal.
    Type: Application
    Filed: July 20, 2012
    Publication date: January 23, 2014
    Applicant: THE BOEING COMPANY
    Inventors: Jeffrey H. Hunt, Nicholas Koumvakalis
  • Patent number: 8620166
    Abstract: An optical receiver may include a unitary transformation operator to receive an n-symbol optical codeword associated with a codebook, and to perform a unitary transformation on the received optical codeword to generate a transformed optical codeword, where the unitary transformation is based on the codebook. The optical receiver may further include n optical detectors, where a particular one of the n optical detectors is to detect a particular optical symbol of the transformed optical codeword, and to determine whether the particular optical symbol corresponds to a first optical symbol or a second optical symbol. The optical receiver may also include a decoder to construct a codeword based on the determinations, and to decode the constructed codeword into a message using the codebook. The optical receiver may attain superadditive capacity, and, with an optimal code, may attain the Holevo limit to reliable communication data rates.
    Type: Grant
    Filed: November 30, 2011
    Date of Patent: December 31, 2013
    Assignee: Raytheon BBN Technologies Corp.
    Inventor: Saikat Guha
  • Patent number: 8611763
    Abstract: A method (10) of compensating phase noise in a coherent optical communications network. The method comprises: receiving a traffic sample (12); receiving an optical carrier and determining a phase noise estimate for the optical carrier (14); and removing the phase noise estimate from the traffic sample to form a phase noise compensated traffic sample (16).
    Type: Grant
    Filed: September 2, 2010
    Date of Patent: December 17, 2013
    Assignee: Telefonaktiebolaget L M Ericsson (publ)
    Inventors: Marco Secondini, Tommaso Foggi, Giulio Colavolpe, Gianluca Meloni, Luca Poti, Enrico Forestieri
  • Patent number: 8582979
    Abstract: From an real valued OFDM signal (S0(t)) is a baseband signal (SB(t)) derived and converted into a complex single sideband modulation signal (n(t)). This is modulated onto an optical carrier (fOC) to generate a SSB transmission signal (SOT) having a small bandwidth an carrying the information in the envelope or in the power of the envelope. According to the modulation direct detection is possible. Only a small bandwidth is necessary for the transmission.
    Type: Grant
    Filed: August 18, 2008
    Date of Patent: November 12, 2013
    Assignee: Nokia Siemens Networks OY
    Inventors: Christian Alexander Bunge, Matthias Schuster, Bernhard Spinnler
  • Patent number: 8577225
    Abstract: Provided is an optical receiver which accurately demodulates an optical signal obtained by the differential phase shift modulation method. The optical receiver includes: an interferometer which branches the inputted optical signal into two parts and gives a one-bit phase difference to the resultant two optical signals so that the two optical signals after addition of the phase difference are made to interfere each other to output two output lights; reflection means which reflects one of the output lights from the interferometer so as to return to the interferometer; detection means which detects the return light which has been reflected by the reflection means and propagates through the interferometer in the different direction from the inputted optical signal, for output; and phase difference control means which adjusts the phase difference given by the interferometer according to the intensity of the return light detected by the detection means.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: November 5, 2013
    Assignee: Sumitomo Osaka Cement Co., Ltd.
    Inventors: Masahito Mure, Norikazu Miyazaki, Toshio Kataoka, Kaoru Higuma
  • Patent number: 8538278
    Abstract: In a polarization-multiplexing optical communications system, a method and system for coherent reception of polarization-multiplexed optical communications. Training and data sequences are recovered from a plurality of orthogonally polarized signals, such that training and data sequences may be used on a single channel without loss of spectral efficiency. This is accomplished by estimating a channel response for each orthogonally polarized signal based on the mean of the signal and distinguishing between a data sequence and a training sequence in each orthogonally polarized signal. Such distinguishing is accomplished according to an iterative linear minimum mean-square equalization based on the respective channel response estimate.
    Type: Grant
    Filed: February 9, 2010
    Date of Patent: September 17, 2013
    Assignee: NEC Laboratorie America, Inc
    Inventors: Hussam G. Batshon, Lei Xu, Ting Wang, Ivan B. Djordjevic
  • Patent number: 8538271
    Abstract: An apparatus comprising an optical receiver configured to receive an optical signal, and a combined level and clock recovery circuit coupled to the optical receiver and configured to update a signal threshold and a clock phase substantially simultaneously. Also included is an apparatus comprising at least one processor configured to implement a method comprising recognizing reception of a signal, and adjusting a threshold and a clock phase associated with the signal using a rising time for the signal and a falling time for the signal. Also included is a method comprising receiving a signal, and adjusting a threshold level of the signal to establish level recovery using a clock recovery scheme.
    Type: Grant
    Filed: November 23, 2009
    Date of Patent: September 17, 2013
    Assignee: Futurewei Technologies, Inc.
    Inventor: Frank J. Effenberger
  • Patent number: 8526832
    Abstract: Shuttering eyewear used to view 3D imagery and/or dual-view images may utilize an IR receiver filter with moderate to wide bandwidth to pass data sidebands of an on-off keying signal while strongly rejecting nearby interference sources. Filtering of the signal may be achieved via a circuit for passing data sidebands of infrared signals. The circuit may include a band pass filter with a low value of Q operable to filter out a first type of interference signal from a signal, a plurality of mixers operable to receive the signal from the band pass filter, wherein the plurality of mixers down converts the signal to baseband signals, and a plurality of low pass filters operable to receive the baseband signals from the plurality of mixers, wherein the plurality of low pass filters rejects a second type of interference.
    Type: Grant
    Filed: May 6, 2011
    Date of Patent: September 3, 2013
    Assignee: RealD Inc.
    Inventors: Robert R. Rotzoll, Roger Landowski, Douglas J Gorny
  • Patent number: 8521029
    Abstract: An arrangement of gravity modulator and gravity-modulation receiver where photons or electromagnetic radiation is modulated electronically or mechanically to reach either a solid, liquid or mixed target possibly through or followed by a surrounding medium to produce gravity modulation in the target to effect gravity signaling which is received by a gravity-modulation receiver in or not in physical contact with the target. In the receiver, one or more piezo-electric transducer/s or quartz crystal/s receive the gravity modulation amplified for further signal processing. When not in physical contact with the target, the piezo-electric transducer/s is/are loaded with a resonator mass of natural resonant frequency either equal to, half, one third or one fifth of the frequency of the gravity modulator, the quartz crystal/s is/are gravity biased with a high-density metal piece along one direction of the oscillation mode of the crystal/s with natural resonant frequency similar to the resonator mass.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: August 27, 2013
    Inventor: Anadish Kumar Pal
  • Patent number: 8509628
    Abstract: A first optical splitter splits an input optical signal and outputs it to first and second optical paths. A second optical splitter outputs the optical signal from the first optical path to third and fourth optical paths. A third optical splitter outputs the optical signal from the second optical path to fifth and sixth optical paths. In the second optical path, 1-symbol delay element and ?/4 phase shifter element are configured. In the fourth optical path, ?/2 phase shifter element is configured. First and second adjuster circuits adjust the optical path length of the second and the fourth optical paths, respectively, by temperature control. A first optical coupler couples optical signals transmitted via the third and the fifth optical paths. A second optical coupler couples optical signals transmitted via the fourth and the sixth optical paths. Photodetectors convert the optical signals from the optical couplers into electrical signals.
    Type: Grant
    Filed: September 24, 2009
    Date of Patent: August 13, 2013
    Assignee: Fujitsu Limited
    Inventors: Kazuo Hironishi, Takeshi Hoshida
  • Patent number: 8483574
    Abstract: An optical transmitter utilizing a multi-level data modulator to produce a PDM-QPSK signal, a one-bit delay interferometer configured to correlate the multi-level data modulated signal and an optical filter configured to combine the correlated multi-level data modulated signal with one or more neighboring signals prior to transmitting over one of a plurality of optical channels. The PDM-QPSK correlated signal is configured to reduce the signal spectrum thereby increasing spectral efficiency of the transmitted signal.
    Type: Grant
    Filed: October 15, 2010
    Date of Patent: July 9, 2013
    Assignee: Tyco Electronics Subsea Communications, LLC
    Inventors: Hongbin Zhang, Yu Sun, Carl Davidson, Yi Cai
  • Patent number: 8472812
    Abstract: Transmission-side communication apparatus 100 using a DQPSK (differential quadrature phase-shift keying) scheme is provided with: optical carrier generation section 102 which generates an optical carrier the frequency of which switches among a plurality of different frequencies within one symbol period; and modulation section 103 with which DQPSK-modulates the optical carrier generated by the optical carrier generation means in accordance with a modulation signal at an interval of the symbol period. There are provided: single delay interference section 121 which receives an optical signal obtained by DQPSK-modulating an optical carrier the frequency of which switches among a plurality of different frequencies within one symbol period and outputs an output light obtained by causing the optical signal 104 and a delay optical signal thereof to interfere with each other; and photoelectric conversion section 124 which converts the output light outputted by the delay interference means to an electric signal.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: June 25, 2013
    Assignee: NEC Corporation
    Inventors: Satomi Shioiri, Toshiharu Ito, Kiyoshi Fukuchi
  • Patent number: 8463141
    Abstract: A digital version of both amplitude and phase of at least one generic polarization component of a received optical signal is developed using dual-polarization direct differential detection with digital signal processing. The received signal is split into orthogonal polarization components, each of which is split into three copies. For each orthogonal polarization component a) an intensity profile is conventionally obtained using a copy and b) phase information is obtained by supplying each remaining copy to a respective one of a pair of optical delay interferometers having orthogonal phase offsets, followed by respective balanced intensity detectors. The outputs the balanced intensity detectors and the intensity profiles are converted into digital representations and used to develop, via signal processing, the optical field information of at least one generic polarization component of the received optical signal. Compensation of impairments, such as PMD, is realized through further processing.
    Type: Grant
    Filed: December 14, 2007
    Date of Patent: June 11, 2013
    Assignee: Alcatel Lucent
    Inventor: Xiang Liu
  • Patent number: 8463140
    Abstract: A reception device includes at least a light receiving unit, a phase calculation unit, and a demodulation unit. The light receiving unit receives intensity-modulated light from a transmission device. The transmission device executes phase modulation to a bit stream as an object to be transmitted and emits the intensity-modulated light which has an intensity changing at a preset time cycle and a phase changing in response to the phase modulation, and the phase is maintained during M cycles. The phase calculation unit detects the intensity of the intensity-modulated light p times per cycle of the intensity-modulated light and repeatedly calculates the phase of the intensity-modulated light on the basis of a result of the detection. The demodulation unit executes demodulation, which corresponds to the phase modulation, to the phase calculated by the phase calculation unit, and generates transmitted bit stream.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: June 11, 2013
    Assignee: Honda Motor Co., Ltd.
    Inventor: Chiaki Aoyama
  • Patent number: 8406635
    Abstract: An optical receiver for receiving an optical signal that transmits a first data signal and a second data signal, including: an optical front-end configured to generate a digital signal that represents the optical signal; a detector configured to detect a state of the optical signal by using the digital signal and output state information that represents the state of the optical signal; a state controller configured to control the digital signal on the basis of the state information in order to recover the first data signal; and a data recovery configured to recover the second data signal on the basis of the state information.
    Type: Grant
    Filed: November 16, 2009
    Date of Patent: March 26, 2013
    Assignee: Fujitsu Limited
    Inventors: Hisao Nakashima, Takeshi Hoshida
  • Patent number: 8401401
    Abstract: To provide a polarization-diverse, heterodyne optical receiving system, a light signal is transmitted into an optical fiber having a plurality of optical sensors that are distinguishable using a multiplexing arrangement. A return light signal from the optical fiber is mixed with an optical local oscillator light signal, where the mixing outputs plural output signal portions having different polarizations. A birefringence of a particular optical sensor is determined based on the plural signal portions.
    Type: Grant
    Filed: October 14, 2009
    Date of Patent: March 19, 2013
    Assignee: Schlumberger Technology Corporation
    Inventors: Arthur H. Hartog, Dominic Brady, Maxwell R. Hadley
  • Patent number: 8396375
    Abstract: A method for enabling bidirectional data communication using a single optical carrier and a single laser source with the aid of an integrated, colorless demodulator and detector for frequency modulated signals, and a reflective modulator. A receiving optical system holds a technique for demodulation and detection of optical frequency modulated signals, enabling remodulation of the incoming signal to establish bidirectional communication with the transmitting optical system, without introducing a high penalty. A colorless demodulator and detector, which provides the functionality of a periodic filtering device for demodulation of the downstream, and also detection capability. The principle of operation of the CDD relies on the introduction of a comb transfer function with the help of a Semiconductor Optical Amplifier, by providing a reflected feedback signal to the CDD's active element.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: March 12, 2013
    Assignee: Universitat Politecnica de Catalunya
    Inventors: Bernhard Schrenk, José Antonio Lázaro Villa, Christophe Kazmierski, Josep Joan Prat Gomà
  • Patent number: 8335438
    Abstract: According to particular embodiments, a signal communicated from a transmitter to a receiver is received. A frequency offset estimate of the signal is determined. The frequency offset estimate indicates a frequency difference between the transmitter and the receiver. The frequency offset estimate is provided as feedback. A next frequency offset is compensated for according to the feedback.
    Type: Grant
    Filed: October 30, 2009
    Date of Patent: December 18, 2012
    Assignee: Fujitsu Limited
    Inventors: Inwoong Kim, Takao Naito
  • Patent number: 8331802
    Abstract: In a synchronous circuit, a synchronizing signal generator combines either an optical BPSK signal or local oscillation light with a phase-shifted signal to produce different optical signals, one of which for use in producing a signal demodulated from the BPSK signal is square-law detected, and calculates the optical signal detected to convert the signal into an electric signal. The generator produces an electric phase-locking signal which will be a demodulated signal from the BPSK signal on the basis of the electric signal. The phase-locking signal is used as a modulating signal by an intensity-modulating circuit to modulate an incident continuous light into an optical intensity-modulated signal, which is optoelectrically converted and square-law detected by an optoelectric converter. The converted signal is used by an optical VCO circuit as a phase error signal to adjust the phase or frequency of the local oscillation light, which is supplied to the signal generator.
    Type: Grant
    Filed: July 6, 2010
    Date of Patent: December 11, 2012
    Assignee: Oki Electric Industry Co., Ltd.
    Inventor: Akihiro Fujii
  • Publication number: 20120308237
    Abstract: A bi-directional optical transceiver includes multiple single mode optical ports and a multi-mode optical port. A multi-mode optical combiner combines single mode optical signals received at the single mode optical ports into a multi-mode optical signal at the multi-mode optical port. Each single mode optical signal has a distinct optical mode that does not interfere with the optical mode of the other single mode optical signals. A photo detector detects a total optical power of the plurality of single mode optical signals in the multi-mode optical signal. An amplifier is coupled to receive an output of the photo detector.
    Type: Application
    Filed: June 1, 2011
    Publication date: December 6, 2012
    Applicant: ARRIS Group Inc.
    Inventors: Venk Mutalik, Marcel F. Schemmann
  • Patent number: 8326160
    Abstract: A dispersion compensation device includes: an optical branching unit to branch an optical signal to be received; a first dispersion compensator to perform dispersion compensation on one part of the optical signal branched by the optical branching unit with a variable compensation amount; a second dispersion compensator to perform dispersion compensation on another part of the optical signal branched by the optical branching unit; a monitoring unit to monitor the communication quality of an output optical signal of the second dispersion compensator; and a controlling unit to determine the direction of variation in chromatic dispersion of the optical signal based on the direction of variation in communication quality monitored by the monitoring unit and control the compensation amount of the first dispersion compensator based on the result of the determination.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: December 4, 2012
    Assignee: Fujitsu Limited
    Inventors: Makoto Murakami, Toshihiro Ohtani
  • Patent number: 8311411
    Abstract: A method of stabilizing the state of polarization of an optical radiation comprises: 1) applying sequentially to the optical radiation a first and a second controllable phase retardation; 2) detecting an optical power of at least a first polarized portion of the optical radiation obtained after step 1; 3) applying sequentially to the optical radiation obtained after step 1 a third and a fourth controllable phase retardation; 4) detecting an optical power of a further polarized portion of the optical radiation obtained after step 3; 5) controlling, responsive to the optical power of said first polarized portion, the second controllable phase retardation so as to maintain the polarization state of the optical radiation obtained after step 1 at a defined great circle r on a Poincare sphere; 6) in case the second controllable phase retardation reaches a first limit value, commuting the first controllable phase retardation between first and second values; 7) controlling, responsive to the optical power of said fur
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: November 13, 2012
    Assignee: Google Inc.
    Inventors: Paolo Martelli, Mario Martinelli, Aldo Righetti
  • Publication number: 20120281990
    Abstract: The present invention provides a simple means of demodulating optical signals, e.g. wideband M-ary orthogonal. The demodulator comprises an optical processor and a comparison module. The optical processor transforms M input optical signals into 2 log2(M) intermediary optical signals and the comparison module determines the logical representation of the input data based on log2(M) binary comparisons of the optical power of the intermediary signals. Example embodiments may be reconfigurable to receive optical signals using M-FSK, M-PPM, M-PolSK, and hybrid M-ary orthogonal modulation formats. Example embodiments also offer small size, weight and power consumption for both free-space and fiber optic environments as well as improved receiver sensitivity and reduced electron bandwidth requirements.
    Type: Application
    Filed: May 2, 2012
    Publication date: November 8, 2012
    Applicant: Massachusetts Institute of Technology
    Inventor: David O. Caplan
  • Patent number: 8306423
    Abstract: A method and an optical network component for data processing in an optical network. A first signal and a second signal are influenced by a tunable element. The first signal is an incoming optical signal, and the second signal is a local oscillator signal generated by a laser. The laser has an optical gain element that is tuned by the tunable element. A communication system is provided with the optical network component.
    Type: Grant
    Filed: December 8, 2008
    Date of Patent: November 6, 2012
    Assignee: Nokia Siemens Networks OY
    Inventors: Erich Gottwald, Harald Rohde, Sylvia Smolorz
  • Patent number: 8306436
    Abstract: A receiver including a fiber optic first input element, through which a signal carrying information circulates, a local laser block, a photo-detection block, and a block of differential demodulation is disclosed. The information-carrying signal of the optical fiber input and the beam of light generated by the local laser block provided in the receiver are coupled and detected in a block of optical detection, which converts the optical signal that carries information into an electrical signal that carries information, which is processed in a block of electrical demodulation, which performs a differential demodulation of its in-phase and quadrature components, combining them later. An optical receiver is obtained, featuring optical homodyne detection, being coincident the wavelengths of the input signal and the tuned beam of light, with a high tolerance to the phase noise, generated by the optical communications lasers, and with no need to use an optical phase-locked loop.
    Type: Grant
    Filed: December 28, 2007
    Date of Patent: November 6, 2012
    Assignee: Universitat Politecnica de Catalunya
    Inventors: Josep Prat Gomà, Josep Maria Fàbrega Sànchez
  • Patent number: 8295712
    Abstract: An optical device comprising an optical device comprising a Mach-Zehnder interferometer having a first 2×2 optical coupler, a second 2×2 optical coupler, a first optical arm, and a second optical arm. The first and second arms connecting corresponding pairs of optical ports of the first and second 2×2 optical couplers. The second optical arm has a longer optical path than the first arm. The device also comprises one or more optical resonators optically coupled to the first optical arm and an optical splitter. The optical splitter is coupled to deliver a portion of an input optical signal to one port of the first 2×2 optical coupler and to deliver a remaining portion of the input optical signal to one port of the second optical coupler.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: October 23, 2012
    Assignee: Alcatel Lucent
    Inventors: Young Kai Chen, Mahmoud Rasras
  • Patent number: 8285153
    Abstract: An optical beam synthesizer formed on a single chip is provided. It allows M-PSK modulation for both beam polarizations. The synthesizer comprises an optical pulse shaper and two M-PSK modulators for each polarization. A single-chip-integrated analyzer is provided to receive a modulated data. Analyzer comprises a pulse shaper operating as an optical sampler and a pair of 90-degrees optical hybrids for each polarization. Each optical hybrids mix incoming portions of the modulated beams with portions of the local oscillator beams. Both the synthesizer and the analyzer include a set of mirrors located on the back and front surfaces of the chips to create compact designs. The output beams from the analyzer are detected by a set of balanced photodiodes, and the data is recovered. It is another object of the invention to provide a communication system for data transmission having the synthesizer and the analyzer.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: October 9, 2012
    Assignee: CeLight, Inc.
    Inventors: Arkady Kaplan, Isaac Shpantzer
  • Patent number: 8270850
    Abstract: A demodulator includes: a splitter that branches a differential phase shift keying optical signal into a first branched optical signal passing through a first optical path and a second branched optical signal passing through a second optical path; a multiplexer that multiplexes the first branched optical signal having passed through the first optical path and the second branched optical signal having passed through the second optical path and makes interference between the first branched optical signal and the second branched optical signal; and a double refraction medium that reduces difference between phase differences between each polarized wave between the first branched optical signal and the second branched optical signal multiplexed by the multiplexer.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: September 18, 2012
    Assignee: Fujitsu Limited
    Inventors: Takashi Shimizu, Koji Terada, Kiyomi Narita, Kazuyuki Mori
  • Publication number: 20120219294
    Abstract: Systems and methods are disclosed for a filter-less coherent receiving system with a filter-less coherent receiver frontend; a signal-signal beat-noise detector coupled to the filter-less coherent receiver frontend; and a real-time processor coupled to the filter-less coherent receiver frontend and the signal-signal beat-noise detector to reject signal-signal interference.
    Type: Application
    Filed: October 10, 2011
    Publication date: August 30, 2012
    Applicant: NEC LABORATORIES AMERICA, INC.
    Inventors: Yue-Kai Huang, Ezra Ip, Dayou Qian, Philip Ji, Yoshiaki Aono, Tsutomu Tajima
  • Patent number: 8254792
    Abstract: A system and computer readable medium for a burst mode optical receiver that enables an optical receiver to receive signals from a plurality of optical network units at different optical power levels. In an exemplary embodiment, the system may include a memory that stores a received signal strength indication, and a media access controller communicably coupled to the memory. The media access controller receives a received signal strength indication of an upcoming data stream to an optical network unit, and asserts a signal control voltage during a guard time to an optical receiver to optimize reception of incoming data streams of the optical network unit based upon the received signal strength indication received from the upcoming data stream.
    Type: Grant
    Filed: July 19, 2010
    Date of Patent: August 28, 2012
    Assignee: Alcatel Lucent
    Inventor: Rodger Dalton
  • Patent number: 8229294
    Abstract: A camera includes a lens and a sensor. A dynamic mask is arranged at an aperture plane between the lens and the sensor, and a static mask is arranged immediately adjacent to the sensor. Angular, temporal or spatial variations in light rays acquired of a scene by the sensor are mapped to individual pixels of the sensor.
    Type: Grant
    Filed: September 18, 2009
    Date of Patent: July 24, 2012
    Assignee: Mitsubishi Electric Research Laboratories, Inc.
    Inventors: Amit Kumar Agrawal, Ashok Veeraraghavan
  • Patent number: 8218976
    Abstract: An optical receiver implemented with a pre-amplifier with an additional trans-impedance able to respond to the input signal in bit-by-bit is disclosed. The optical receiver provides a photodiode to convert an optical signal into a photocurrent, a trans-impedance amplifier to convert the photocurrent to a voltage signal, and an additional trans-impedance circuit able to respond instantaneously to the voltage signal. The additional trans-impedance includes a FET whose gate is fully fixedly biased and the source thereof receives the voltage signal. The FET may bypass the current flowing in the intrinsic trans-impedance instantaneously.
    Type: Grant
    Filed: January 4, 2010
    Date of Patent: July 10, 2012
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventor: Katsumi Uesaka
  • Patent number: 8218977
    Abstract: An optical device includes an interferometer for a received optical differential phase shift keying DPSK signal, and an equalizer integrated with the interferometer in a manner for reducing from optical filtering effects an interference by signal bits of the DPSK signal with signal bits of a contiguous DPSK signal. The interferometer is a Michelson delay interferometer type, but can also be a Mach-Zehnder delay interferometer type on fiber, waveguide or other optical structure. The equalizer is a Fabry-Perot type equalizer, but can be a ring resonator type or a fiber based equalizer.
    Type: Grant
    Filed: March 25, 2010
    Date of Patent: July 10, 2012
    Assignee: NEC Laboratories America, Inc.
    Inventors: Philip Nan Ji, Lei Xu, Ting Wang, Shuji Murakami, Tsutomu Tajima, Yutaka Yano
  • Patent number: 8213802
    Abstract: An optical receiver includes a first substrate including a demultiplexer and a first optical waveguide array. An input of the demultiplexer is configured to receive a wavelength division multiplexed optical input signal having a plurality of channels. Each of the plurality of channels corresponds to one of a plurality of wavelengths. Each of the plurality of outputs is configured to supply a corresponding one of the plurality of channels. The first optical waveguide array has a plurality of inputs. Each of the inputs of the first optical waveguide array is configured to receive a corresponding one of the plurality of channels. A second substrate is in signal communication with the first substrate and includes an optical detector array. The optical detector array has a plurality of inputs, each of which is configured to receive a corresponding one of the plurality of channels and generate an electrical signal in response thereto.
    Type: Grant
    Filed: December 30, 2008
    Date of Patent: July 3, 2012
    Assignee: Infinera Corporation
    Inventors: Brent E. Little, Wei Chen, John V. Hryniewicz, Sai T. Chu, Jeff Rahn, Mehrdad Ziari, Timothy Butrie, Michael Reffle, Fred A. Kish, Jr., Charles H. Joyner