Specific Optical Elements Patents (Class 398/180)
  • Patent number: 11838061
    Abstract: Described is a method of setting up a plurality of quantum communications links, forming a quantum network providing provably secure communications and internet services over intercontinental distances without requiring direct line of sight communication or the intermediate use of the entanglement resource of satellites. Also described is a quantum communicator device for use in this method. Two or more quantum memory units are disposed at a first location, an entangled link is set up between at least two of the quantum memory units, at least one of the quantum memory units sharing in the entangled link is physically transported to a second location. The quantum communicator device comprises communications nodes, an optical interface to set up entanglement to other devices and storage nodes, each node in the form of a quantum memory unit capable of storing quantum information for a desired length of time, i.e. weeks or longer.
    Type: Grant
    Filed: February 9, 2021
    Date of Patent: December 5, 2023
    Inventor: Michele Reilly
  • Patent number: 11599429
    Abstract: A quantum failsafe service (QFS) is disclosed herein. In one example, a first quantum computing device executes a QFS that receives a system stress indicator from a system monitor that tracks a status of the first quantum computing device and/or a status of qubits maintained by the first quantum computing device. The QFS determines, based on the system stress indicator, that a quantum service backup is to be performed for a quantum service running on the first quantum computing device, and obtains a profile snapshot representing a current state of the quantum service. The QFS service then performs superdense encoding of the profile snapshot using a first set of qubits entangled with a second set of qubits of a second quantum computing device, and the first set of qubits are sent to the second quantum computing device (e.g., for storage in a classical data repository, according to some examples).
    Type: Grant
    Filed: March 29, 2021
    Date of Patent: March 7, 2023
    Assignee: Red Hat, Inc.
    Inventors: Stephen Coady, Leigh Griffin
  • Patent number: 11387991
    Abstract: Aspects of the subject disclosure may include, for example, determining that quantum entanglement be established between first and second nodes of a service provider network including a software defined network (SDN) that facilitates delivery of a service to a subscriber and identifying a path between the first node and the second node based on pre-provisioned information supplied by the SDN. A path length of the path is estimated based on the pre-provisioned information supplied by the SDN, and a repeater node is selected responsive to the path length exceeding a threshold, wherein the path includes a first segment having a segment length that does not exceed the threshold. A quantum entanglement state is shared between the first and second nodes based on transportation of a first photon of a first entangled pair of photons via the first segment. Other embodiments are disclosed.
    Type: Grant
    Filed: December 6, 2019
    Date of Patent: July 12, 2022
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Moshiur Rahman, Robert D. Boudreau, Jr.
  • Patent number: 9496684
    Abstract: A system to control an optical signal may include a semiconductor laser diode. The system may also include an optical amplifier to receive an optical signal from the semiconductor laser diode. The optical amplifier may be configured to spectrally filter the optical signal.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: November 15, 2016
    Assignee: International Business Machines Corporation
    Inventors: Harry H. Bagheri, Casimer M. DeCusatis
  • Patent number: 9030730
    Abstract: A method for amplifying optical signals includes determining a source optical signal, generating a first resultant signal including a pump signal and the source optical signal, sending the first resultant signal through a non-linear element to generate a second resultant signal including the first resultant signal and an idler signal, and sending the second resultant signal through a non-linear element to perform phase-sensitive amplification. The phase-sensitive amplification results in a third resultant signal including an amplified source optical signal, the pump signal, and the idler signal. The method also includes filtering the third resultant signal to remove the pump signal and the idler signal and outputting the amplified source optical signal.
    Type: Grant
    Filed: January 14, 2013
    Date of Patent: May 12, 2015
    Assignee: Fujitsu Limited
    Inventors: Jeng-Yuan Yang, Motoyoshi Sekiya, Yoichi Akasaka
  • Patent number: 8989576
    Abstract: A method of processing optical signal (TE) whose power (PE) varies in a random manner in a range of variation of power (?PE) around a mean power (PE?), the processing of the optical signal (TE) generating processing noise (GELECTRONIC), characterized in that the relative variation of power (GE) of at least a temporal part at said optical signal (TE) is optically amplified.
    Type: Grant
    Filed: March 24, 2011
    Date of Patent: March 24, 2015
    Assignees: Universite de Bourgogne, CNRS—Centre National de Recherche Scientifique
    Inventors: Christophe Finot, Julien Fatome
  • Patent number: 8948606
    Abstract: A semiconductor optical amplifier includes an n-type semiconductor layer, a p-type semiconductor layer an active layer provided between the n-type semiconductor layer and the p-type semiconductor layer, the active layer transmitting an optical signal and a current-injection part that injects current into the active layer via the n-type semiconductor layer and the p-type semiconductor layer, the active layer including a first active layer that includes AlGaInAs, and a second active layer that includes GaInAsP, the second active layer provided closer to an output side than the first active layer, and the first active layer and the second active layer being butt-jointed.
    Type: Grant
    Filed: August 29, 2011
    Date of Patent: February 3, 2015
    Assignee: Fujitsu Limited
    Inventors: Shinsuke Tanaka, Tsuyoshi Yamamoto
  • Patent number: 8923697
    Abstract: The present invention provides a long reach optical amplification device, a passive optical network and an optical signal transmission method in the communication field.
    Type: Grant
    Filed: December 30, 2010
    Date of Patent: December 30, 2014
    Assignee: ZTE Corporation
    Inventors: Jidong Xu, Dezhi Zhang
  • Patent number: 8909055
    Abstract: A relay device includes: a housing including: a first surface; and a second surface which is different from the first surface; a light signal receiving element operable to receive a light signal from outside, the light signal receiving element provided at the first surface of the housing; a light emission element operable to emit light responsive to the light signal received by the light signal receiving element; and a longitudinally elongated light guide member provided at the second surface of the housing, the light guide member to which the light emitted from the light emission element is incident, the light guide member including an emission part which causes the incident light to be emitted to outside from a lateral surface of the light guide member, the lateral surface which extends along a longitudinal direction of the light guide member.
    Type: Grant
    Filed: May 21, 2012
    Date of Patent: December 9, 2014
    Assignee: Yamaha Corporation
    Inventors: Yoshiaki Kawaida, Koji Suzuki, Takamori Shimazu, Masaki Yamamoto
  • Patent number: 8909063
    Abstract: A method for regenerating and amplifying optical signals includes determining a source optical signal, adding a first pump optical signal and a second pump optical signal to the source optical signal to yield an intermediate optical signal, duplicating the intermediate optical signal to yield a first duplicate signal and a second duplicate signal, phase-shifting the first duplicate signal, passing the phase-shifted first duplicate signal and the second duplicate signal bi-directionally through a nonlinear optical element, and performing degenerate phase-sensitive amplification on the phase-shifted first duplicate signal and the second duplicate signal.
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: December 9, 2014
    Assignee: Fujitsu Limited
    Inventors: Jeng-Yuan Yang, Youichi Akasaka, Motoyoshi Sekiya, Inwoong Kim
  • Publication number: 20140199083
    Abstract: A repeater amplifier assembly that includes at least two chassis containing optics and electronics. The chassis are connected with a size-adjustment mechanism that can adjust a size of the repeater amplifier assembly by reversibly adjusting the positions of the chassis with respect to each other. To insert the repeater amplifier assembly into a repeater housing, the repeater amplifier assembly is accessed in a contracted position. The amplifier is inserted into the housing, and then a control of the size adjustment mechanism is actuated to urge the chassis outwards until the chassis push against the repeater housing. To remove the repeater amplifier assembly from the repeater housing, the control is actuated to cause the size adjustment mechanism to pull the chassis inwards with respect to each other until the chassis no longer push against the repeater housing. The repeater amplifier assembly may then be freely removed from the repeater housing.
    Type: Application
    Filed: January 15, 2013
    Publication date: July 17, 2014
    Applicant: XTERA COMMUNICATIONS, INC.
    Inventors: Kevin Willoughby, John Durban, Adam Arnold
  • Patent number: 8781334
    Abstract: An iterative method is provided for progressively building an end-to-end entanglement between qubits in first and second end nodes (91, 92) of a chain of nodes whose intermediate nodes (90) are quantum repeaters. At each iteration, a current operative repeater (90) of the chain merges an entanglement existing between qubits in the first end node (91) and the operative repeater, with a local entanglement formed between qubits in the operative repeater and its neighbor node towards the second end node (92). For the first iteration, the operative repeater is the neighbor of the first end node (91); thereafter, for each new iteration the operative repeater shifts one node further along the chain toward the second end node (92). A quantum repeater adapted for implementing this method is also provided.
    Type: Grant
    Filed: October 26, 2009
    Date of Patent: July 15, 2014
    Inventors: William Munro, Keith Harrison, Timothy Spiller, Kae Nemoto
  • Patent number: 8718475
    Abstract: A system and method for sizing transponder pools in a dynamic wavelength division multiplexing optical network having selected nodes designated to have a shared transponder pool is presented.
    Type: Grant
    Filed: March 16, 2011
    Date of Patent: May 6, 2014
    Assignee: Telcordia Technologies, Inc.
    Inventors: Ronald A. Skoog, Brian J. Wilson
  • Patent number: 8699881
    Abstract: A method and apparatus for providing passive optical networks with extended reach and/or splitting ratio are disclosed. For example, the optical network comprises a first optical line termination (OLT) device having a transceiver for sending and receiving optical signals. The optical network further comprises an optical extender box comprising at least one hybrid SOA-Raman amplifier, wherein the optical extender box is coupled to the first optical line termination device via a first standard single mode fiber section. Finally, the optical network further comprises an optical splitter coupled to the optical extender box via a second standard single mode fiber section.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: April 15, 2014
    Assignee: AT&T Intellectual Property II, L.P.
    Inventors: Patrick Paul Iannone, Han Hyub Lee, Kenneth Charles Reichmann, Xiang Zhou
  • Patent number: 8682161
    Abstract: An optical data transmission system for transmitting optical data in a flight vehicle, including a head end, optical splitter, N units of terminals that process optical data received from the optical splitter to display such as video, plural optical cables connected between the head end and the optical splitter and between the optical splitter and the terminals, and a seat group including N sets of passenger seats that transmit two-way optical data and are placed close to one another. The N units of terminals are placed in association with the respective N sets of seats. The optical splitter is placed in association with the seat group; sends optical data from the head end to the N units of terminals; and reversely unifies N-series optical data, different from one another, from the N units of terminals into one series and sends it to the head end.
    Type: Grant
    Filed: April 21, 2011
    Date of Patent: March 25, 2014
    Assignee: Panasonic Corporation
    Inventors: Masaaki Higashida, Satoshi Ohyama
  • Patent number: 8676059
    Abstract: In an optical signal processing apparatus, carrier light propagates through a nonlinear optical medium. An optical combiner optically combines output control light for generating idler light of the carrier light with the carrier light. An optical splitter splits the idler light from the carrier light. A receiver acquires a signal multiplexed on the carrier light from the idler light split by the optical splitter.
    Type: Grant
    Filed: April 13, 2012
    Date of Patent: March 18, 2014
    Assignee: Fujitsu Limited
    Inventor: Shigeki Watanabe
  • Publication number: 20130338804
    Abstract: Systems, methods, apparatus, and articles of manufacture to provide an infrared signal are disclosed. An example apparatus includes an infrared provider to receive a first signal from a first device. The first signal is analog and representative of a command. The example infrared provider is to linearly manipulate the first signal in analog form, wherein the manipulated signal remains analog. The example infrared provider is to relay the manipulated signal to a second device. The relayed manipulated signal is representative of the command and is indistinguishable from the first signal.
    Type: Application
    Filed: June 19, 2012
    Publication date: December 19, 2013
    Inventor: Timothy W. Sheen
  • Patent number: 8576480
    Abstract: An optical amplifier using the evanescent light to control the optical output level is provided. The optical amplifier includes: a waveguide path transmitting an optical signal; an optical amplification unit formed on the waveguide path and amplifying the optical signal by an excitation light; an irradiation unit irradiating the excitation light to the optical amplification unit; an optical detection unit generating an electric signal which corresponds to a detected light; a branching unit branching an evanescent light being the optical signal outputted from the optical amplification unit and leaked outside the waveguide path, and focusing the evanescent light on the optical detection unit; a wavelength detection unit detecting a wavelength multiplicity of the optical signal based on the detected evanescent light; and a light amount adjustment unit adjusting a light amount of the excitation light irradiated by the irradiation unit based on the wavelength multiplicity.
    Type: Grant
    Filed: June 7, 2012
    Date of Patent: November 5, 2013
    Assignee: NEC Corporation
    Inventor: Hideshi Yoshida
  • Patent number: 8543013
    Abstract: Technology for detecting an optical data signal carried in a combined optical signal that comprises a carrier optical signal modulated by the optical data signal and also comprises ASE noise. The proposed optical data detector/receiver is provided with an SHG device adapted to generate a second harmonic optical signal of the carrier optical signal modulated by the data signal. In the signal, generated by the SHG, the ASE noise will be essentially reduced.
    Type: Grant
    Filed: April 5, 2009
    Date of Patent: September 24, 2013
    Assignee: ECI Telecom Ltd.
    Inventors: Uri Mahlab, Michael Gutin
  • Patent number: 8452185
    Abstract: The present invention, in one embodiment contemplates a polarization insensitive optical circuit constructed of an input/output signal separator, such as an optical circulator or a 1Ă—2 or 2Ă—2 coupler or NĂ—M coupler, a polarization sensitive operator, and a polarization rotator reflector. In an alternate embodiment, the invention contemplates a polarization insensitive optical circuit comprising a polarization rotator reflector, and a polarization sensitive operator which may comprise for example a first polarization rotator, an operator/coupler, and a polarization beam combiner. Preferably at least one of the components in the optical circuit is constructed integrally from the substrate upon which the optical circuit is based. For example the polarization rotator and/or polarization sensitive operator of the present invention may be monolithic.
    Type: Grant
    Filed: December 21, 2007
    Date of Patent: May 28, 2013
    Assignee: Infinera Corporation
    Inventors: Brent E. Little, Sai T. Chu
  • Patent number: 8428470
    Abstract: A waveform shaping apparatus includes a quantum dot optical amplifier in which an amplification factor of input signal beams saturates if the optical power of the signal beams is equal to or greater than a predetermined value; and a quantum dot saturable absorber in which an absorption factor of the input signal beams saturates if the optical power of the signal beams is under a predetermined value. The quantum dot optical amplifier and the quantum dot saturable absorber are connected in series with a transmission path of the signal beams, and shape the waveform of the signal beams. Voltages applied to the quantum dot optical amplifier and the quantum dot saturable absorber, respectively, are adjusted based on the optical power of the signal beams.
    Type: Grant
    Filed: February 28, 2008
    Date of Patent: April 23, 2013
    Assignee: Fujitsu Limited
    Inventors: Fumio Futami, Shigeki Watanabe
  • Patent number: 8340526
    Abstract: Systems and methods for a reconfigurable, long-range, underwater data-communication network are described. The network provides a low cost, low power, lightweight, and easy to deploy underwater communication system capable of being operated at long distances. The network may include a cabled ocean observatory, which may be deployed underwater and connected to a surface buoy. The cabled ocean observatory may be connected to one or more removable underwater sensors via fiber optic cables. The underwater sensors may be disposed at underwater locations at long distances from the cabled ocean observatory. Fiber optic extension modules may be permanently connected to each end of the fiber optic cables. Each fiber optic extension module may include an optical transceiver, a power supply, and an inductive element for removably coupling an underwater sensor or the cabled ocean observatory to the fiber optic cable.
    Type: Grant
    Filed: July 8, 2010
    Date of Patent: December 25, 2012
    Assignee: Woods Hole Oceanographic Institution
    Inventors: Richard Camilli, Frederick Sonnichsen, Albert M. Bradley, Steven A. Lerner
  • Patent number: 8311410
    Abstract: The polarization direction of an optical signal is changed by a polarization controller so as to be orthogonal to a main axis of a polarizer. A control pulse generator generates control pulses from control beam with a wavelength which is different from the wavelength of the optical signal. The optical signal and the control pulse are input to a nonlinear optical fiber. In the nonlinear optical fiber, the optical signal, during a time period in which the optical signal and the control pulse coincide, is amplified with optical parametric amplification around a polarization direction of the control pulse. The optical signal, during the time period in which the optical signal and the control pulse coincide, passes through the polarizer.
    Type: Grant
    Filed: October 29, 2010
    Date of Patent: November 13, 2012
    Assignee: Fujitsu Limited
    Inventor: Shigeki Watanabe
  • Patent number: 8290365
    Abstract: An optical communication apparatus that includes multiple optically communicative components positioned optically in series. Some of the optically communicative components may be optical fiber segments of perhaps different types. The optical channel represented by the series of optically communicative components and approximates a transfer function of an optical channel of a longer optical fiber. Accordingly, rather than deal with a lengthy optical fiber, an apparatus having a shorter optical channel may be used instead. The construction of the optical communicative components may be calculating an input transfer function. The construction would include an ordering of discrete optically communicative components that, when placed optically in series, simulates an estimation of a particular transfer function. Testing may then occur by actually passing an optical signal through the series construction of optically communicative components, rather than through the longer optical fiber.
    Type: Grant
    Filed: August 20, 2008
    Date of Patent: October 16, 2012
    Assignee: Finisar Corporation
    Inventors: Gayle L. Noble, Lucy G. Hosking, Luke M. Ekkizogloy
  • Patent number: 8275010
    Abstract: The pulse light source according to the present invention comprises: a seed pulse generator 1 for outputting an input pulse 10 as a seed pulse; a pulse amplifier 2; and a dispersion compensator 3 for dispersion compensating a light pulse output from the pulse amplifier 2. Moreover, the pulse amplifier 2 comprises a normal dispersion medium (DCF 4) and an amplification medium (EDF 5) that are multistage-connected alternately, for changing the input pulse 10 to a light pulse having a linear chirp and outputting the light pulse. Furthermore, an absolute value of the dispersion of the DCF 4 becomes to be larger than the absolute value of the dispersion of the EDF 5.
    Type: Grant
    Filed: June 10, 2008
    Date of Patent: September 25, 2012
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Atsushi Oguri, Shunichi Matsushita
  • Patent number: 8270845
    Abstract: A device for processing data being optically transmitted via a LRM connection includes an optical splitter for splitting an input signal into a first output signal and a second output signal, the optical splitter having an operating wavelength with a value that is between 1260 nm and 1355 nm, wherein the optical splitter has an input end for receiving the input signal, a first output end for outputting the first output signal, and a second output end for outputting the second output signal.
    Type: Grant
    Filed: February 17, 2009
    Date of Patent: September 18, 2012
    Assignee: Gigamon LLC
    Inventors: Thomas K. Cheung, King L. Won, Patrick P. Leong
  • Patent number: 8270837
    Abstract: A device capable of equalizing optical powers of optical signals in a passive optical network, the device comprising a first optical coupler for receiving optical signals having different optical power levels, an optical circulator capable of directing the optical signals from the first optical circulator, a laser diode capable of generating equalized optical signals having a predetermined range of optical power levels in response to the optical signals directed from the optical circulator, and a second optical coupler for receiving the equalized optical signals.
    Type: Grant
    Filed: November 28, 2006
    Date of Patent: September 18, 2012
    Assignee: Industrial Technology Research Institute
    Inventors: Chien-Hung Yeh, Dar-Zu Hsu, Sien Chi
  • Patent number: 8265485
    Abstract: An optical transmission system including an optical transmission path for transmitting WDM signals multiplexed different wavelength optical signals, the WDM signals including different bit rate optical signals or different modulation format optical signals; a repeater arranged in the optical transmission path, the repeater including a chromatic dispersion compensation unit for compensating chromatic dispersion compensation for the WDM signals; and a network management system including processes of determining a dispersion compensation ratio indicating the ratio with respect to the dispersion compensation amount at which the residual dispersion of the WDM signals are zero after transmission via the optical transmission path, on the bases of the mixture ratio of different optical signals included in the WDM signals, and variably setting the dispersion compensation amount for the in-line repeater according to the dispersion compensation ratio.
    Type: Grant
    Filed: March 17, 2009
    Date of Patent: September 11, 2012
    Assignee: Fujitsu Limited
    Inventors: Kantaro Nakamura, Hiroki Ooi, George Ishikawa
  • Patent number: 8233807
    Abstract: A method and apparatus for producing a series of amplified optical pulses from a series of input optical pulses. The method includes creating a set of local optical pulses from a series of input optical pulses, the set of local optical pulses being applied to the input of an optical amplifier and having different amplitudes arranged in a graded order. The set of local optical pulses are amplified by an optical amplifier to have a significantly amplified first local optical pulse that is removed from the set of local optical pulses and output as a part of the series of amplified optical pulses. After removing the significantly amplified first local optical pulse, the set of local optical pulses is recreated by adding a new optical pulse from the series of input optical pulses to the end of the set of local optical pulses; and the recreated set of local optical pulses is routed back to be applied to the input of the optical amplifier to continue producing the series of amplified optical pulses.
    Type: Grant
    Filed: July 25, 2011
    Date of Patent: July 31, 2012
    Assignee: International Business Machines Corporation
    Inventor: Yuanmin Cai
  • Patent number: 8213804
    Abstract: In one embodiment, a gain medium for an external cavity diode laser (ECDL) includes a gain section to provide a gain operation on optical energy in the ECDL that is controlled by a first electrical signal, a semiconductor optical amplifier (SOA) section disposed adjacent to the gain section to amplify the gained optical energy responsive to a second electrical signal, and a trench disposed between the gain section and the SOA section to act as an integrated mirror. Other embodiments are described and claimed.
    Type: Grant
    Filed: June 5, 2007
    Date of Patent: July 3, 2012
    Assignee: Intel Corporation
    Inventor: Sergei Sochava
  • Publication number: 20120163830
    Abstract: Disclosed is an optical amplifier which includes an upward optical amplifier configured to amplify an input upward optical signal of an input optical signal; and a control circuit configured to control an operation of the upward optical amplifier according to whether an upward stream is detected from the input upward optical signal.
    Type: Application
    Filed: August 30, 2011
    Publication date: June 28, 2012
    Applicant: Electronics and Telecommunications Research Institute
    Inventors: Mun Seob LEE, Jong Deog KIM, Dongsoo LEE, Sung Chang KIM, Hark YOO, Geun Yong KIM, Youngsuk LEE, Sim-Kwon YOON
  • Publication number: 20120148237
    Abstract: A method is provided of creating an end-to-end entanglement (87) between qubits in first and second end nodes (81, 82) of a chain of optically-coupled nodes whose intermediate nodes (80) are quantum repeaters. Local entanglements (85) are created on an on-going basis between qubits in neighbouring pairs in the chain through interaction of the qubits with light fields transmitted between the nodes. The quantum repeaters (80) are cyclically operated with their top-level operating cycles being synchronized. Once every top-level operating cycle, each repeater (80) initiates a merging of two entanglements involving respective repeater qubits that are at least expected to be entangled with qubits in nodes disposed in opposite directions along the chain from the repeater. A quantum repeater (80) adapted for implementing this method is also provided.
    Type: Application
    Filed: October 26, 2009
    Publication date: June 14, 2012
    Inventors: Keith Harrison, William Munro, Kae Nemoto
  • Publication number: 20120141121
    Abstract: Optical transmission equipment includes: a first optical amplifier to amplify an input optical signal; a second optical amplifier provided at an output side of the first optical amplifier; an optical module having a first relay port to receive an optical signal from the first optical amplifier, a second relay port to output an optical signal to the second optical amplifier, an optical device provided between the first relay port and the second relay port, and a first output port optically couplable to the optical device; and a second output port to output the optical signal amplified by the second optical amplifier.
    Type: Application
    Filed: December 2, 2011
    Publication date: June 7, 2012
    Applicant: FUJITSU LIMITED
    Inventors: Hiroyuki ITOH, Kazuo Takatsu
  • Patent number: 8135276
    Abstract: A quantum repeater includes a transmitter portion including a source, a set of matter systems, and an optical system. The source produces a probe pulse in a probe state having components with different photon numbers, and each matter system has at least one state that interacts with photons in the probe pulse to introduce a change in a phase space location of the probe state. The optical system can direct the probe pulse for interaction with one of the matter systems and direct light from the matter system for transmission on a first channel.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: March 13, 2012
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: William J. Munro, Kae Nemoto, Peter Van Loock, Yoshihisa Yamamoto
  • Patent number: 8130443
    Abstract: An optical waveform reshaping device, including a semiconductor optical waveguide which has an active layer, wherein: optical amplification regions and optical absorption regions are installed alternately along the semiconductor optical waveguide; one optical amplification region is set longer than the other optical amplification regions so that a desired amplification factor can be obtained when power of an input optical signal is at an ON level; a power level is maintained by the other optical amplification regions excluding the one optical amplification region and by the optical absorption regions when the power of the input optical signal is at the ON level; and when the power of the input optical signal is at an OFF level, the input optical signal is absorbed by the optical absorption regions so that a power level of an output optical signal will not be higher than the power level of the input optical signal.
    Type: Grant
    Filed: February 19, 2008
    Date of Patent: March 6, 2012
    Assignee: Fujitsu Limited
    Inventor: Koji Otsubo
  • Patent number: 8068735
    Abstract: An optically amplified wavelength division multiplexing network has the functionality to add/drop channels at the optical add/drop multiplexing (OADM) nodes. The OADM node includes a receiver amplifier, an OADM module, and a transmitter amplifier. Once the OADM node detects a loss of signal (LOS) due to a fiber cut or network element failure upstream, the receiver amplifier is kept in operation as a noise source. The output of the receiver amplifier is immediately raised by increasing pump power to compensate for the LOS. The noise power received at the transmitter amplifier from the receiver amplifier is substantially equal to the signal power expected before LOS. The transient effect of downstream optical amplifiers is therefore completely suppressed and the inter-channel stimulated Raman scattering (SRS) induced spectrum tilt does not change. After the noise power is raised, the receiver amplifier may be shut down at a speed much slower than the speed of downstream amplifier control circuitry.
    Type: Grant
    Filed: October 8, 2010
    Date of Patent: November 29, 2011
    Assignee: AT&T Intellectual Property II, LP
    Inventors: Joseph T. Stango, Guodong Zhang
  • Patent number: 8059966
    Abstract: An optical regeneration system for regenerating a degenerated signal light, comprising a regeneration device having at least one of a soliton converter, a pulse roller, a Kerr-shutter and a soliton purifier. The solilton converter uses an anomalous-dispersion fiber (ADF) having a fiber length up to three times the soliton frequency, and the pulse roller is provided with a pulse roller fiber having high non-linear characteristics. The Kerr-shutter comprises an optical LO (local oscillation) generator for generating an optical LO on an OPLL (optical phase locked loop), a phase comparator for detecting the phase difference between an externally-input signal light and an optical LO, and a control unit for regulating the repeated frequency of an optical LO based on the phase difference. The soliton purifier has a soliton fiber disposed between two optical fibers.
    Type: Grant
    Filed: June 11, 2003
    Date of Patent: November 15, 2011
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Koji Igarashi, Shunichi Matsushita, Shu Namiki, Shigehiro Takasaka, Takashi Inoue, Hideaki Tobioka, Jiro Hiroishi
  • Patent number: 8055127
    Abstract: A wavelength division multiplex optical ring network comprises optical fibre (1-4) arranged in a ring configuration and a plurality of doped fibre optical amplifiers (17-20) arranged in the ring. The spectral response in the ring is configured such in use amplified spontaneous emission (ASE) noise circulates around the ring in a lasing mode to clamp the gain of each doped fibre optical amplifier. Each optical amplifier (17-20) includes respective control means (28) which in use control the optical amplifier to produce a substantially constant output power or to maintain a substantially constant pump power. In the event of loss of the lasing peak, detection means switches the doped fibre optical amplifiers to a different mode of gain control, for example, a mode to produce constant gain at the value before the loss of the lasing peak. Optionally, after a predetermined delay, the optical amplifiers may revert to constant output power or pump power mode.
    Type: Grant
    Filed: November 22, 2004
    Date of Patent: November 8, 2011
    Assignee: Ericsson AB
    Inventors: Roberto Magri, Cornelius Furst
  • Patent number: 8036526
    Abstract: A method and apparatus for restoration of operating conditions of a WDM optical ring network comprising a plurality of amplifiers linked together in a ring after a break or fault has occurred in the network. The method comprises in response to repair of the break or other fault, increasing output power or/and pump power of an amplifier in the network such that the output power or/and pump power increases substantially in accordance with a ramp function.
    Type: Grant
    Filed: May 26, 2006
    Date of Patent: October 11, 2011
    Assignee: Ericsson AB
    Inventors: Antonella Bogoni, Roberto Magri, Riccardo Ceccatelli
  • Patent number: 8036537
    Abstract: A method and apparatus for producing a series of amplified optical pulses from a series of input optical pulses including creating a set of local optical pulses from a series of input optical pulses, the set of local optical pulses having different amplitudes arranged in a graded order. The set of local optical pulses are amplified by an optical amplifier to form a significantly amplified first local optical pulse that is removed from the set of local optical pulses and output. The method successively removes the significantly amplified first local optical pulse, re-creates the set of local optical pulses by adding a new optical pulse to the end of the set of local optical pulses; and routes the recreated set of local optical pulses back to the input of the optical amplifier to continue producing the series of amplified optical pulses.
    Type: Grant
    Filed: June 13, 2007
    Date of Patent: October 11, 2011
    Assignee: International Business Machines Corporation
    Inventor: Yuanmin Cai
  • Patent number: 8032021
    Abstract: A robust and redundant status link is established by a first multi-channel optoelectronic device with a second multi-channel optoelectronic device in a multi-channel communication link. Transmitter bias currents are effectively modulated with a status link modulation signal representative of status data and subsequently modulated with primary data modulation signals. The resulting signals are transformed into optical signals and transmitted over the link as main communication links combined with a status link. At the second device, the optical signals are received and converted to electrical signals. The receipt of the optical signals creates multiple receiver bias currents, which may be monitored to detect the status link modulation signal. The second device may adjust various operating parameters in response to the information conveyed by the status link.
    Type: Grant
    Filed: February 28, 2008
    Date of Patent: October 4, 2011
    Assignee: Finisar Corporation
    Inventors: Christopher R. Cole, Lewis B. Aronson, Darin James Douma
  • Patent number: 7974002
    Abstract: An optical communication system is operable to communicate a plurality of wavelength signals at a bit rate of at least 9.5 gigabits per second over a multiple span communication link spanning at least 400 kilometers without optical regenerators. The plurality of wavelength signals include a bandwidth of more than 32 nanometers separated into at least 160 optical channels. The system includes a plurality of optical transmitters implementing a forward error correction (FEC) coding technique. The FEC encoded wavelength signals comprise a bit error rate of 10?09 or better after FEC decoding. The system also includes at least five (5) optical add/drop multiplexers (OADMs), each coupled to one or more spans of the multiple span communication link. The system further includes a plurality of amplifiers each coupled to one or more spans of the communication link, at least a majority of the amplifiers comprise a distributed Raman amplification stage.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: July 5, 2011
    Assignee: Xtera Communication, Inc.
    Inventors: Mohammed N. Islam, Carl A. DeWilde
  • Patent number: 7941048
    Abstract: An apparatus and a method for accurately detecting Loss of Optical Power (LOS) by noise power cancellation effect and optical power is measured at two output ports of an athermal periodic filter, wherein one output port in the optical frequency domain, is aligned with the signal channels of an input WDM signal (on-grid port), whereas the second output port is aligned complementary to the first output port (off-grid port). In a preferred embodiment, the apparatus computes the ratio of the measured optical powers at the two output ports of the periodic filter, and comparing them to a threshold value that is determined from the overall common-mode rejection ratio (CMRR) of the detection apparatus. In an alternative embodiment, the apparatus additionally compares the optical power measured at the on-grid port to a threshold power that is determined from system design parameters.
    Type: Grant
    Filed: June 29, 2007
    Date of Patent: May 10, 2011
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Daniel Fishman, Alan Gnauck, Yuan-Hua Kao, Xiang Liu
  • Patent number: 7902526
    Abstract: An imaging system is provided that includes a optical pulse generator for providing an optical pulse having a spectral bandwidth and includes monochromatic waves having different wavelengths. A dispersive element receives a second optical pulse associated with the optical pulse and disperses the second optical pulse at different angles on the surface of the dispersive element depending on wavelength. One or more focal elements receives the dispersed second optical pulse produced on the dispersive element. The one or more focal element recombine the dispersed second optical pulse at a focal plane on a specimen where the width of the optical pulse is restored at the focal plane.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: March 8, 2011
    Assignee: Massachusetts Institute of Technology
    Inventors: Daekeun Kim, Peter T. C. So
  • Patent number: 7853146
    Abstract: An optical transmission apparatus that improves the reliability of system operation by efficiently limiting the line speed of a signal sent from a user with a guard mechanism. An optical branching section makes an optical signal branch in two directions. A through branching line passes an optical signal in its original condition and sends the optical signal as a through optical branch signal. A delay branching line delays an optical signal by a delay amount set and sends the optical signal as a delayed optical branch signal. An optical multiplexing section combines the through optical branch signal and the delayed optical branch signal.
    Type: Grant
    Filed: August 1, 2006
    Date of Patent: December 14, 2010
    Assignee: Fujitsu Limited
    Inventors: Makoto Takakuwa, Futoshi Izumi, Masahiro Yoshimoto, Takahiro Hosokawa
  • Patent number: 7848647
    Abstract: The polarization direction of an optical signal is changed by a polarization controller so as to be orthogonal to a main axis of a polarizer. A control pulse generator generates control pulses from control beam with a wavelength which is different from the wavelength of the optical signal. The optical signal and the control pulse are input to a nonlinear optical fiber. In the nonlinear optical fiber, the optical signal, during a time period in which the optical signal and the control pulse coincide, is amplified with optical parametric amplification around a polarization direction of the control pulse. The optical signal, during the time period in which the optical signal and the control pulse coincide, passes through the polarizer.
    Type: Grant
    Filed: September 1, 2005
    Date of Patent: December 7, 2010
    Assignee: Fujitsu Limited
    Inventor: Shigeki Watanabe
  • Patent number: 7826746
    Abstract: An optically amplified wavelength division multiplexing network has the functionality to add/drop channels at the optical add/drop multiplexing (OADM) nodes. The OADM node includes a receiver amplifier, an OADM module, and a transmitter amplifier. Once the OADM node detects a loss of signal (LOS) due to a fiber cut or network element failure upstream, the receiver amplifier is kept in operation as a noise source. The output of the receiver amplifier is immediately raised by increasing pump power to compensate for the LOS. The noise power received at the transmitter amplifier from the receiver amplifier is substantially equal to the signal power expected before LOS. The transient effect of downstream optical amplifiers is therefore completely suppressed and the inter-channel stimulated Raman scattering (SRS) induced spectrum tilt does not change. After the noise power is raised, the receiver amplifier may be shut down at a speed much slower than the speed of downstream amplifier control circuitry.
    Type: Grant
    Filed: October 28, 2008
    Date of Patent: November 2, 2010
    Assignee: AT&T Intellectual Property II, L.P.
    Inventors: Joseph T. Stango, Guodong Zhang
  • Publication number: 20100266293
    Abstract: A relay apparatus including: a first interface 11 that branches an optical signal that is input in a first direction from one side of the optical transmission line, and directs the optical signal to a first path and a second path, the first path being a processing path of an optical signal having a first transmission speed, the second path being a processing path of an optical signal having a second transmission speed that is different from the first transmission speed; a processing section 12 that executes processing on an optical signal propagating through each of the paths in accordance with a corresponding transmission speed; and a second interface 13 that binds the first path and the second path of the optical signal on which the processing is executed by the processing section, by means of wavelength multiplexing and directs to the other end of the optical transmission line.
    Type: Application
    Filed: April 5, 2010
    Publication date: October 21, 2010
    Applicant: Fujitsu Limited
    Inventors: Kyosuke Sone, Yutaka Kai, George Ishikawa, Susumu Kinoshita
  • Patent number: 7805072
    Abstract: Wavelength division multiplex ring communication network equipment comprises a first multiplexer connected to a first optical fiber portion dedicated to transporting multiplexed signals and a second multiplexer connected to a second optical fiber portion. The equipment comprises signal protection circuitry connected to the first and second multiplexers and to a terminal which, in the event of local detection of interruption of signal transmission at a first wavelength on the first optical fiber portion, send the signals coming from the terminal to the second multiplexer at a second wavelength so that it communicates them to the second optical fiber portion, and sends to the terminal the signals that are addressed to it and that come from the second optical fiber portion at the second wavelength.
    Type: Grant
    Filed: June 24, 2004
    Date of Patent: September 28, 2010
    Assignee: Alcatel
    Inventors: Stéphane Lovisa, Fabio Tassara, Francesco Shiavoni
  • Patent number: 7787777
    Abstract: An optical packet network system of a ring type, capable of preventing degradation of an optical signal, can be implemented by providing a mechanism relatively simple in structure, capable of erasing light noise if the optical packet signal does not exists. In the optical packet network system made up by interconnecting respective nodes adjacent to each other, and connecting a sending source of an optical packet signal to a ring, a light noise removal function block is provided between the respective nodes adjacent to each other.
    Type: Grant
    Filed: August 11, 2006
    Date of Patent: August 31, 2010
    Assignee: Yokogawa Electric Corporation
    Inventors: Shinji Iio, Masayuki Suehiro, Katsuya Ikezawa, Akira Miura, Sadaharu Oka, Chie Sato, Mamoru Hihara, Tsuyoshi Yakihara, Shin-ichi Nakajima, Morio Wada, Daisuke Hayashi, Shinji Kobayashi, Yoshiyuki Asano