Including Compensation Patents (Class 398/136)
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Patent number: 8909064Abstract: Aspects of the invention provide transmitters and receivers for managing multiple optical signals. High order modulation, such as phase and/or amplitude modulation, is used to achieve multiple bits per symbol by transporting multiple asynchronous data streams in an optical transport system. One or more supplemental multiplexing techniques such as time division multiplexing, polarization multiplexing and sub-carrier multiplexing may be used in conjunction with the high order modulation processing. This may be done in various combinations to realize a highly spectrally efficient multi-data stream transport mechanism. The system receives a number of asynchronous signals which are unframed and synchronized, and then reframed and tagged prior to the high order modulation. Differential encoding may also be performed. Upon reception of the multiplexed optical signal, the receiver circuitry may employ either direct detection without a local oscillator or coherent detection with a local oscillator.Type: GrantFiled: April 11, 2014Date of Patent: December 9, 2014Assignee: Google Inc.Inventors: Bikash Koley, Vijayanand Vusirikala, Hong Liu
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Patent number: 8903247Abstract: A bidirectional interface for multimode optical fiber includes a receive/transmit optical fiber port operable to connect to a multimode optical fiber, a wavelength separating module in communication with the receive/transmit optical fiber port, an optical receiver module in communication with the wavelength separating module and configured to receive optical signals at a first wavelength via the wavelength separating module and the receive/transmit optical fiber port, and an optical transmit module in communication with the wavelength separating module and configured to transmit at a second wavelength via the wavelength separating module and the receive/transmit optical fiber port.Type: GrantFiled: October 30, 2009Date of Patent: December 2, 2014Assignee: Cisco Technology, Inc.Inventors: Marco Mazzini, Cristiana Muzio, Alessandro Sguazzotti, Federico Fontanella
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Patent number: 8903254Abstract: The present disclosure relates to an optical transceiver for use in optical fiber communications and/or telecommunications systems and, more specifically, a low power consumption, long range pluggable transceiver. The transceiver generally comprises a photodiode with a transimpedance amplifier (PIN-TIA); an electro-absorption modulated laser (EML); an optical detector; and a directly modulated laser (DML) driving module connected between the PIN-TIA and EML laser configured to drive the EML laser. A low power-consumption DML driving module is utilized to drive the EML laser, so as to further reduce power consumption. An impedance matching circuit can be applied to modulate an electro-absorption (EA) modulator of the EML laser with maximum efficiency.Type: GrantFiled: May 24, 2011Date of Patent: December 2, 2014Assignee: Source Photonics, Inc.Inventors: Zhaoyang Hu, Lingqiong Zeng, Thomas Liljeberg
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Publication number: 20140348511Abstract: 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: ApplicationFiled: August 8, 2014Publication date: November 27, 2014Inventors: Venkatesh G. Mutalik, Marcel F. Schemmann
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Patent number: 8891980Abstract: Methods, systems, and devices are described for a digital demodulator device for processing received optical signals. The device may include a quadrature error filter that receives a digitized version of an optical signal, and removes quadrature errors to generate a filtered series of data samples. The device may also include a frequency offset removal module for performing frequency rotation on the filtered series of data samples. The device may include a chromatic dispersion compensation module which removes chromatic dispersion from horizontal and vertical polarization channels. The device may include a polarization mode dispersion (PMD)/polarization dependent loss (PDL) compensation module which compensates for interference caused by PMD and PDL. The device may also include a phase recovery module configured to track and correct phase.Type: GrantFiled: February 10, 2014Date of Patent: November 18, 2014Assignee: ViaSat, Inc.Inventors: Fan Mo, William Thesling, Matthew Nimon, Sameep Dave
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Patent number: 8891960Abstract: A method of communicating data between a network device and a data network to which the device is connected via an optical fiber data link in which the device is connected to the optical fiber data link and the connection is monitored to detect data communication at a first standard. If data communication is detected at the first standard, data communication is established using the first standard. If not, the connection is monitored at the second standard. If data communication is detected at the second standard, data communication is established using the second standard.Type: GrantFiled: October 10, 2008Date of Patent: November 18, 2014Assignee: PacketFront Systems ABInventor: Charles Foster
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Patent number: 8885992Abstract: At the time of assembly of an optical transmission/reception module, a test variable wavelength light source 22 for outputting a test light signal is connected to a connector 8 of an optical fiber 7, and a large-diameter PD 23 measures a transmission loss in a light wavelength band limiting filter 12 while a rotational position determining unit 24 rotates a fiber ferrule 5, so that the rotational position determining unit 24 determines the rotational position ?loss-min of the fiber ferrule 5 which minimizes the transmission loss in the light wavelength band limiting filter 12, and aligns the fiber ferrule 5 at the rotational position ?loss-min.Type: GrantFiled: July 9, 2009Date of Patent: November 11, 2014Assignee: Mitsubishi Electric CorporationInventors: Tamon Omura, Nobuo Ohata, Masatoshi Katayama
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Patent number: 8886051Abstract: Compensation for in-phase (I) and quadrature (Q) timing skew and offset in an optical signal may be achieved based on the correlation between derivatives of I and Q samples in the optical signal. The magnitude of the correlation between derivatives is measured to determine the presence of skew. Correlation between derivatives may be coupled with frequency offset information and/or with trials having additional positive and negative skew to determine presence of skew. Correlations are determined according to pre-defined time periods to provide for continued tracking and compensation for timing skew that may result from, for example, thermal drift.Type: GrantFiled: February 12, 2014Date of Patent: November 11, 2014Assignee: ViaSat, Inc.Inventors: Yuri Zelensky, Fan Mo
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Publication number: 20140328600Abstract: A multi-channel or bidirectional optoelectronic device comprises a two or more optoelectronic components, e.g., a photodetector and a light source. A protective encapsulant can be applied to the optoelectronic device that includes hollow dielectric microspheres to reduce electrical cross-talk, and that can further include an optical absorber to reduce optical cross-talk.Type: ApplicationFiled: May 19, 2014Publication date: November 6, 2014Applicant: HOYA Corporation USAInventors: Araceli Ruiz, Peter C. Sercel, Joel S. Paslaski, Rolf A. Wyss
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Publication number: 20140321861Abstract: A digital burst mode communication system operates at a fixed wavelength for transmission and reception of burst mode signals using a pair of transceivers and a single optical cable. The stray noise level in the system is significantly reduced by use of angled plate absorbers that receive scattered transmission burst signal from a 45 degree partially reflecting mirror. Use of transparent glass ferrule with or without a front surface anti-reflection coating instead of an opaque ceramic ferrule to support optical fiber at a selected location within the transreceiver reduces optical detector signal noise. Isolation of received burst signal from transmitted burst signal is increased to better than 30 dB. The system operates by sending only data bits across the single optical cable without scrambling or encoding preambles, significantly improving the efficiency of high speed communication.Type: ApplicationFiled: April 25, 2013Publication date: October 30, 2014Inventors: Yusuke Ota, Kenichiro Takeuchi
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Patent number: 8867921Abstract: Techniques, apparatus and systems to provide carrier signal transmission in reciprocal transmission architecture networks for optical communications.Type: GrantFiled: September 29, 2009Date of Patent: October 21, 2014Assignee: Ziva CorporationInventors: David F. Smith, Anis Husan
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Patent number: 8855484Abstract: The present invention is to provide a method applicable to a fiber-optic transceiver including a transmitter optical subassembly (TOSA) provided therein with a laser diode, but without a monitoring photodiode, a laser driver controlled by a controller IC for driving the laser diode to generate a laser beam, and a thermal sensor for sensing temperature of the laser diode. The method includes executing an approximation process to characteristic data, i.e.Type: GrantFiled: August 14, 2012Date of Patent: October 7, 2014Assignee: Alpha Networks Inc.Inventor: Wei-Hung Tsai
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Optical clock rate negotiation for supporting asymmetric clock rates for visible light communication
Patent number: 8855496Abstract: A method and apparatus conduct an optical clock rate negotiation to support asymmetric clock rates for visible light communication (VLC) in a VLC device. A first frame that includes a receiver clock rate supported by a first VLC device is transmitted at a predetermined clock rate. A response frame that includes a receiver clock rate supported by a second VLC device is received from the second VLC device. A transmission clock rate of the first VLC device is selected based on the response frame from the second VLC device. Subsequent frames for data communication are transmitted to the second VLC device at the selected transmission clock rate of the first device. Alternatively, when conducting optical clock negotiation in the PHY layer, multiple clock rates are supported within a single frame.Type: GrantFiled: December 21, 2010Date of Patent: October 7, 2014Assignee: Samsung Electronics Co., Ltd.Inventors: Sridhar Rajagopal, Eran Pisek, Farooq Khan, Ying Li -
Patent number: 8842985Abstract: Reliable data transmission is secured without inviting large design changes by means of configuring an optical data transmission device in a manner so as to be provided with: data conversion units and optical communication control units that transmit to each of a first communication unit and a second communication unit disposed movably relative to one another an optical signal modulated in response to wired-line data input from a wired line, and that output wired-line data demodulated from the received optical signal to the wired line; a bit data input unit that receives input of bit data for emergency stops; a bit data output unit that outputs bit data for emergency stops; and bit data communication control units that control in a manner so as to transmit/receive input bit data via the optical communication control units using optical signals that are isolated from the optical signal corresponding to the wired-line data.Type: GrantFiled: June 29, 2011Date of Patent: September 23, 2014Inventors: Masanori Hino, Yoji Maejima
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Patent number: 8837934Abstract: Monitoring signals associated with operating parameters of an optical transceiver are ascertained by using a comparator arrangement external to a micro-controller unit. Monitoring signals associated with these operating parameter are provided as inputs to a discrete arrangement of comparators and then evaluated against a known reference voltage source. The reference source is swept across a known range of values, and when the output of the comparator changes state, the value of the reference input associated with this transition is defined as the value of the specific monitoring input signal and stored within the proper memory location within the microcontroller portion of the transceiver monitor circuit. The digital output signal of the comparator is applied as an input to the microcontroller, which recognizes this digital signal as defining the specific value of the reference signal to use and equate with the value of the monitored signal.Type: GrantFiled: August 22, 2012Date of Patent: September 16, 2014Assignee: Avago Technologies General IP (Singapore) Pte. Ltd.Inventor: Tien-Tsorng Shih
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Publication number: 20140255042Abstract: An optical receiver is disclosed having a dielectric non-conductive substrate. A ground plane is positioned on the dielectric non-conductive substrate. An optical signal converting photodiode is also positioned on the dielectric non-conductive substrate, and has an optical signal receiver and an electrical signal output. An electrical signal amplifier is provided having an input connected to the electrical signal output of the optical signal converting photodiode. A first opening is positioned in the ground plane and surrounds the optical signal converting photodiode. The first opening has a resonance frequency higher than a fundamental frequency such that crosstalk is reducible at the input of the electrical signal amplifier.Type: ApplicationFiled: March 7, 2014Publication date: September 11, 2014Applicant: TYCO ELECTRONICS SVENSKA HOLDINGS ABInventors: Andrei Kaikkonen, Lennart Per Olof Lundqvist, Lars-Goete Svensson, Peter Lindberg
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Publication number: 20140255037Abstract: A transceiver includes a transmitter and a receiver. The transmitter includes a precoder stage, an encoder stage and a first converter stage. The precoder stage receives an input binary signal and a previously processed binary signal. The encoder stage is electrically coupled to the precoder stage and the first converter stage and includes a feed forward equalizer (FFE). The first converter stage generates a modulated signal. The receiver includes a second converter stage, an amplifier stage, a first equalizer stage and a second equalizer stage. The second converter stage receives the modulated signal. The first equalizer stage is electrically coupled to the amplifier stage. The second equalizer stage is electrically coupled to the first equalizer stage. The second equalizer stage includes a decision feedback equalizer (DFE) that converts the modulated signal into an output binary signal.Type: ApplicationFiled: March 11, 2013Publication date: September 11, 2014Applicant: SEMTECH CORPORATIONInventor: Song Quan Shang
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Publication number: 20140248059Abstract: Techniques are provided for sending and receiving data communications between an enhanced Quad Small Form-Factor Pluggable (QSFP+) transceiver module and an enhanced Small Form-Factor Pluggable (SFP+) transceiver module. An adapter device is provided that has a first set of signal pins configured to interface with an SFP+ transceiver module and a second set of signal pins is provided that is configured to interface with a QSFP+ host port. A retimer unit is also provided that is configured to modify a 10G signal of a first electrical signal standard associated with the SFP+ transceiver module to a 10G signal of a second electrical standard associated with a QSFP+ transceiver module and to enhance a 10G signal of the second electrical signal standard to a 10G signal of the first electrical signal standard.Type: ApplicationFiled: March 1, 2013Publication date: September 4, 2014Applicant: CISCO TECHNOLOGY, INC.Inventors: Norman Tang, Liang Ping Peng, David Lai, Anthony Nguyen, Steven A. Hanssen
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Patent number: 8824898Abstract: For providing circuit arrangement and method for transmitting signals from a data source to a data sink, the signals being TMDS encoded, the driver circuit is supplied by a connection interface, connected upstream, assigned to data source, with supply voltage, electrical TMDS encoded signals are electro-optically converted by an LED connected downstream of the driver circuit and coupled into an optical fiber as light supplied with TMDS encoded signals, the direct current portion supplied from TMDS transmitter to connection interface, to data source, is converted by driver circuit to a modulated signal current for controlling LED.Type: GrantFiled: April 8, 2011Date of Patent: September 2, 2014Assignee: SILICON LINE GmbHInventors: Martin Groepl, Holger Hoeltke
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Patent number: 8824897Abstract: A system for transmitting data packets over a network. The system includes a plurality of first nodes, wherein each first node has a first transceiver configured to transmit a data packet at at least one of a plurality of first wavelengths and receive a data packet at an assigned first wavelength, wherein each first node is configured to pass incoming data packets not transmitted at the assigned first wavelength, a plurality of second nodes, wherein each second node has a second transceiver configured to transmit a data packet at least one of a plurality of second wavelengths and receive a data packet at an assigned second wavelength, wherein each second node is configured to pass incoming data packets not transmitted at the assigned second wavelength, and at least one optical fiber operably connecting the transceivers.Type: GrantFiled: June 3, 2009Date of Patent: September 2, 2014Assignee: Accipiter Systems, Inc.Inventor: David Markham Drury
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Patent number: 8818206Abstract: The present disclosure provides electrical domain suppression of linear crosstalk in optical communication systems using single-carrier implementations. This electrical domain suppression applies spectral shaping in the electronic radio frequency (RF) domain. Advantageously, spectral shaping in the electronic RF domain transfers system complexity from the bulk optical domain into the highly integrated CMOS (or equivalent) domain. The spectral shaping can include electronic circuitry including an electrical filtering block and a signal linearization block prior to optical modulation. The electrical filtering block suppresses coherent interference terms and can include an RF-domain low pass filter. The signal linearization block linearizes modulator response to compensate spectral regrowth due to nonlinear mixing in the modulator.Type: GrantFiled: June 24, 2009Date of Patent: August 26, 2014Assignee: Ciena CorporationInventor: Michael Y. Frankel
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Patent number: 8818193Abstract: An embodiment of the invention includes a tunable optical dispersion compensator (TODC) comprising a first beam displacer on an optical path, wherein the first beam displacer separates an optical signal into a first beam and a second beam, and one or more polarizing beam splitters on the optical path, wherein the one or more polarizing beam splitters keep the first beam and the second beam on the optical path. The TODC also comprises one or more etalons on the optical path, wherein the one or more etalons are tunable to introduce a group delay in the first beam and the second beam, and a reflecting mirror on the optical path, wherein the reflecting mirror returns the optical signal back along the optical path. The TODC further comprises a second beam displacer, wherein the second beam displacer combines the first beam and the second beam into an output optical signal.Type: GrantFiled: September 29, 2009Date of Patent: August 26, 2014Assignee: Finisar CorporationInventors: Fan Chen, Yongkang Hu, Zhenli Wen, Dongshen Han, Fahua Lan, Kevin Dapeng Zhang
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Patent number: 8805194Abstract: An optical transmission device includes a signal generator configured to generate a first signal corresponding to an amount of residual chromatic dispersion that occurs in a light signal transmitted from the optical transmission device to a downstream device, and a superimposer configured to superimpose the first signal on the light signal transmitted from the optical transmission device and transmit the light signal superimposed by the first signal to the downstream device.Type: GrantFiled: March 26, 2012Date of Patent: August 12, 2014Assignee: Fujitsu LimitedInventor: Takashi Toyomaki
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Patent number: 8792792Abstract: [PROBLEM] Providing an optical source that outputs optical frequency modulated light having a constant output optical intensity. [MEANS FOR SOLVING THE PROBLEM] Provided is a light source apparatus that outputs an optical signal having an optical frequency corresponding to a frequency control signal, the light source apparatus including a laser light source section that outputs laser light having an optical frequency corresponding to the frequency control signal; and an optical intensity adjusting section that compensates for intensity change of the laser light to output laser light in which the intensity change caused by a change in the optical frequency is restricted.Type: GrantFiled: October 18, 2011Date of Patent: July 29, 2014Assignee: Advantest CorporationInventors: Shin Masuda, Kazunori Shiota
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Patent number: 8781332Abstract: An optical transceiver module adapted to a link device includes a connection unit, a driving unit and optical transmitting and receiving units. The connection unit, to be coupled with the link device, includes an indicating element for generating an indicating signal when the connection unit is coupled with the link device. The driving unit, coupled with the connection unit, receives the indicating signal and outputs a control signal according to the indicating signal. The optical transmitting unit, coupled with the driving unit, receives the control signal for driving the optical transmitting unit to output a first optical signal. The optical receiving unit, coupled with the driving unit, transmits a received second optical signal to the driving unit. An optical transmission device using the optical transceiver module, and an optical transmission method are also disclosed. A link training sequence can be initiated after the connection unit is actually coupled with the link device.Type: GrantFiled: February 1, 2011Date of Patent: July 15, 2014Assignee: Via Technologies, Inc.Inventors: Jin-Kuan Tang, Jiin Lai
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Publication number: 20140193160Abstract: An optical module includes: a first circuit board on which a connector socket is mounted, an optical transceiver module that is electrically connected to the first circuit board via the connector socket; a heat sink; and a heat dissipating sheet. The optical transceiver module includes: a second circuit board on which an E/O converter, a drive circuit for the E/O converter, an O/E converter, and a current-to-voltage conversion circuit for the O/E converter are mounted; and an optical waveguide that guides an optical signal generated by the E/O converter to an output end of the optical transceiver module, and that guides an input optical signal to the O/E converter. The heat sink is thermally coupled to the E/O converter, the drive circuit, the O/E converter, and the current-to-voltage conversion circuit via the heat dissipating sheet, and presses the optical transceiver module onto the first circuit board.Type: ApplicationFiled: February 27, 2014Publication date: July 10, 2014Applicant: FUJITSU LIMITEDInventors: Takatoshi YAGISAWA, Takashi SHIRAISHI
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Patent number: 8774568Abstract: Provided is an optical module. The optical module includes: an optical bench having a first trench of a first depth and a second trench of a second depth that is less than the first depth; a lens in the first trench of the optical bench; at least one semiconductor chip in the second trench of the optical bench; and a flexible printed circuit board covering an upper surface of the optical bench except for the first and second trenches, wherein the optical bench is a metal optical bench or a silicon optical bench.Type: GrantFiled: June 7, 2011Date of Patent: July 8, 2014Assignee: Electronics and Telecommunications Research InstituteInventors: Young-Tak Han, Jang Uk Shin, Sang-Pil Han, Sang Ho Park, Yongsoon Baek
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Patent number: 8768181Abstract: A differential code optical transmission and reception device including: a digital signal processing optical transceiver that converts information data into an optical signal and transmits it to a communication channel, a reception front end part that receives the optical signal from the communication channel, an O/E conversion part that converts the optical signal received from the communication channel into an electrical signal, a skew correction part that regulates or correct a skew between lanes contained in the electrical signal, a differential decoder that decodes a differential code of the skew corrected electrical signal, and a lane exchange/rotation part that rearranges the electrical signal having passed through the differential decoder into a lane state thereof at the time of transmission in cases where lane exchange has occurred in the communication channel.Type: GrantFiled: October 6, 2010Date of Patent: July 1, 2014Assignee: Mitsubishi Electric CorporationInventors: Kiyoshi Onohara, Hideo Yoshida, Takashi Sugihara
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Patent number: 8755695Abstract: A burst transmission method and a receiver resetting method and apparatus in a Passive Optical Network (PON) are provided. A burst receiver resetting method in a PON includes: receiving a preamble sequence and synchronizing data; after synchronizing the data, continuing to receive the data, and matching a Burst Terminator (BT); and resetting a receiver after successfully matching the BT. Meanwhile, an apparatus for implementing the method and a corresponding burst data transmission method are provided. By using the burst receiver resetting method and apparatus in the PON and the corresponding burst transmission method at an Optical Network Unit (ONU) burst transmission end, a Reach Extender (RE) does not need to unpack upstream burst bandwidth allocation information carried in downstream data.Type: GrantFiled: September 25, 2013Date of Patent: June 17, 2014Assignee: Huawei Technologies Co., Ltd.Inventors: Jing Li, Dongning Feng, Dongyu Geng, Frank Effenberger
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Publication number: 20140161467Abstract: An optical link power management scheme takes the best advantage of a dynamic connection environment, where ports may be connected and disconnected at any time, and where data flows may start and stop as needed by the applications using the high speed data links Power consumption is optimized, eye safety standards are met, and robust connection detection is preserved.Type: ApplicationFiled: February 18, 2014Publication date: June 12, 2014Inventors: Klaus D. Giessler, Christine M. Krause
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Patent number: 8750713Abstract: The disclosure relates to optical fiber transmission systems, and in particular, pertains to the transceiver cards in an optical fiber transport system. In particular the disclosure teaches an improved transceiver card architecture that allows high density, flexibility and interchangeability of functionality.Type: GrantFiled: February 27, 2012Date of Patent: June 10, 2014Assignee: Pivotal Decisions LLCInventors: Samir Satish Sheth, Marvin R. Young, Jeffrey Lloyd Cox, John W. Ayres, III
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Patent number: 8744279Abstract: Polarization mode dispersion (PMD) in a dual-pole optical communications network is compensated for using an adaptive PMD equalizer. The PMD equalizer may include a number of substantially identical filter modules that provide partial outputs which may be combined to form a PMD compensated output. A constant modulus algorithm (CMA)-based equalizer may track PMD across both poles and generates an error signal. The CMA-based equalizer includes a filter bank, and uses an update algorithm and tap/output adjustments based on a difference between combined tap energies and an index, and feedback from a forward error correction code frame synchronizer.Type: GrantFiled: August 8, 2011Date of Patent: June 3, 2014Assignee: ViaSat, Inc.Inventors: Fan Mo, Sameep Dave, Lawrence W. Esker
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Patent number: 8721190Abstract: An optoelectrical connector is composed of a plug to which a wire and an optical fiber are assembled and a receptacle to which the plug is inserted and connected. A receptacle includes insulation sleeves and conductive contacts in openings of receptacle housings, and plugs include a ferrule assembled bodies which are composed of an insulation ferrule which holds an optical fiber and a conductive cylindrical member which holds the ferrule and to which a wire is assembled, in an opening of the plug housing. When the plugs are inserted into the receptacle, the contacts and the cylindrical member contact with each other and the ferrules are inserted into the sleeves. Parts which serve electrical connection are not exposed.Type: GrantFiled: March 31, 2011Date of Patent: May 13, 2014Assignee: Japan Aviation Electronics Industry LimitedInventors: Yuichi Koreeda, Osamu Hashiguchi
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Patent number: 8725005Abstract: A photodetector receiver circuit for an optical communication system includes an optical photodetector which receives optical signals and converts them into an electrical current. In one illustrative embodiment, a dynamic impedance module which switches the receiver circuit between a high impedance state and a low impedance state and a buffer stage which receives the electrical current and converts the electrical current into a voltage signal compatible with a digital circuit. A method for receiving an optical signal includes, receiving the optical signal and converting it into an electrical pulse train, switching a dynamic impedance module between a high impedance state and a low impedance state, transforming the electrical pulse train into an output voltage signal using a buffer stage, and receiving the output voltage signal by a digital circuit.Type: GrantFiled: February 23, 2009Date of Patent: May 13, 2014Assignee: Hewlett-Packard Development Company, L.P.Inventors: Kyung Hoae Koo, Marco Fiorentino, David A. Fattal
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Patent number: 8718398Abstract: A method to process an image acquired through an optical-fiber guide includes acquiring a first reference image through the optical-fiber guide, acquiring a second calibration image through the optical-fiber guide, spatially identifying each fiber of the optical-fiber guide of the second calibration image in a first detection map, acquiring a recalibration image through the optical-fiber guide, determining a geometrical transformation to make the recalibration image coincide with the first reference image, deriving a new detection map spatially identifying each fiber of the optical-fiber guide of the recalibration image, wherein the new detection map is derived using the geometrical transformation and the first detection map, and individually processing zones of an acquired image corresponding to each fiber of the optical-fiber guide using the new detection map.Type: GrantFiled: December 28, 2009Date of Patent: May 6, 2014Assignee: Mauna Kea TechnologiesInventors: Aymeric Perchant, Nicolas Savoire
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Patent number: 8712252Abstract: To efficiently apply jitter to an optical signal using a simple configuration, provided is an optical signal output apparatus that outputs an optical pulse pattern signal including jitter, the optical signal generating apparatus comprising a light source section that outputs an optical signal having an optical frequency corresponding to a frequency control signal; an optical modulation section that modulates the optical signal output by the light source section, according to a designated pulse pattern; and an optical jitter generating section that delays an optical signal passed by the optical modulation section according to the optical frequency, to apply jitter to the optical signal.Type: GrantFiled: October 18, 2011Date of Patent: April 29, 2014Assignee: Advantest CorporationInventors: Shin Masuda, Kazunori Shiota
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Patent number: 8712251Abstract: Aspects of the invention provide transmitters and receivers for managing multiple optical signals. High order modulation, such as phase and/or amplitude modulation, is used to achieve multiple bits per symbol by transporting multiple asynchronous data streams in an optical transport system. One or more supplemental multiplexing techniques such as time division multiplexing, polarization multiplexing and sub-carrier multiplexing may be used in conjunction with the high order modulation processing. This may be done in various combinations to realize a highly spectrally efficient multi-data stream transport mechanism. The system receives a number of asynchronous signals which are unframed and synchronized, and then reframed and tagged prior to the high order modulation. Differential encoding may also be performed. Upon reception of the multiplexed optical signal, the receiver circuitry may employ either direct detection without a local oscillator or coherent detection with a local oscillator.Type: GrantFiled: April 19, 2011Date of Patent: April 29, 2014Assignee: Google Inc.Inventors: Bikash Koley, Vijayanand Vusirikala, Hong Liu
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Patent number: 8705974Abstract: An optical transmission system transmits an optical signal of multi-level modulation. In a transmitter module, a data string in a specified frame is rearranged into a plurality of logical lanes. A lane ID, which specifies in what logical lane out of the plurality of logical lanes a start of the data string is arranged, is assigned to a non-scrambled area in an overhead portion of the frame. The lane ID corresponding to one of the plurality of logical lanes is different from the lane IDs corresponding to the other remaining logical lanes. The optical signal is generated using the data string rearranged into the plurality of logical lanes. In a receiver, the lane ID is detected according to a majority method. The inversion of bits and the swapping of lanes are detected using the lane ID and compensated.Type: GrantFiled: March 5, 2012Date of Patent: April 22, 2014Assignee: Fujitsu LimitedInventors: Yohei Koganei, Masahiro Shioda, Osamu Takeuchi, Hayato Furukawa, Yasuhiko Aoki
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Patent number: 8699640Abstract: A method by an optical OFDM receiver includes converting a received optical signal to an electrical signal, deriving a digital signal from the electrical signal, and emulating, with an iterative OFDM demodulator responsive to the digital signal, a transmitter effect in the received signal of lower peak clipping and top peak distortion and applying the transmitter effect to the received signal and a decision-made signal for estimating an error function to be applied to a demodulation of the received optical signal.Type: GrantFiled: December 3, 2009Date of Patent: April 15, 2014Assignee: NEC Laboratories America, Inc.Inventors: Junqiang Hu, Dung-Huy Han, Ting Wang
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Patent number: 8693882Abstract: An electronic dispersion compensation module may perform one or more electronic dispersion compensation solutions. The electronic dispersion compensation module may include a solution control module. The solution control module may configure the electronic dispersion compensation module to perform an electronic dispersion compensation solution using data indicating a bit error rate. A bit error rate module may create the data indicating a bit error rate. The bit error rate module may form part of a clock and data recovery module. The electronic dispersion compensation module may be configured to receive a signal from a backplane and may also be configured to apply any of a plurality of electronic dispersion compensation solutions to the signal received from the backplane.Type: GrantFiled: May 30, 2007Date of Patent: April 8, 2014Assignee: Finisar CorporationInventors: James D. McVey, Charles Steven Joiner
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Patent number: 8693897Abstract: Methods, systems, and devices are described for a digital demodulator device for processing received optical signals. The device may include a quadrature error filter that receives a digitized version of an optical signal, and removes quadrature errors to generate a filtered series of data samples. The device may also include a frequency offset removal module for performing frequency rotation on the filtered series of data samples. The device may include a chromatic dispersion compensation module which removes chromatic dispersion from horizontal and vertical polarization channels. The device may include a polarization mode dispersion (PMD)/polarization dependent loss (PDL) compensation module which compensates for interference caused by PMD and PDL. The device may also include a phase recovery module configured to track and correct phase.Type: GrantFiled: August 8, 2011Date of Patent: April 8, 2014Assignee: ViaSat, Inc.Inventors: Fan Mo, William Thesling, Matthew Nimon, Sameep Dave
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Patent number: 8693898Abstract: An adaptive equalizer includes a finite impulse response filter with a predetermined number of taps; and a tap coefficient adaptive controller having a register to hold tap coefficients for the filter, a weighted center calculator to calculate a weighted center of the tap coefficients, and a tap coefficient shifter to shift the tap coefficients based on a calculation result of the weighted center. During an initial training period, the tap coefficient shifter shifts the tap coefficients on a symbol data basis such that a difference between the calculated weighted center of the tap coefficients and a tap center defined by the number of taps is minimized.Type: GrantFiled: October 14, 2011Date of Patent: April 8, 2014Assignee: Fujitsu LimitedInventors: Nobukazu Koizumi, Kazuhiko Hatae, Noriyasu Nakayama, Koji Nakamuta, Hisao Nakashima, Kosuke Komaki
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Patent number: 8687973Abstract: A voltage generator (400) includes a resistor ladder including resistors (4000-4008) which divide a supplied voltage to generate a plurality of reference voltages, a resistor (4009) provided between a power supply voltage (VCC) and one terminal of the resistor ladder, and a resistor (4010) provided between a power supply voltage (VEE) and the other terminal of the resistor ladder.Type: GrantFiled: August 12, 2009Date of Patent: April 1, 2014Assignee: Nippon Telegraph and Telephone CorporationInventors: Hideyuki Nosaka, Munehiko Nagatani, Shogo Yamanaka, Kimikazu Sano, Koichi Murata, Kiyomitsu Onodera, Takatomo Enoki
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Patent number: 8687974Abstract: Compensation for in-phase (I) and quadrature (Q) timing skew and offset in an optical signal may be achieved based on the correlation between derivatives of I and Q samples in the optical signal. The magnitude of the correlation between derivatives is measured to determine the presence of skew. Correlation between derivatives may be coupled with frequency offset information and/or with trials having additional positive and negative skew to determine presence of skew. Correlations are determined according to pre-defined time periods to provide for continued tracking and compensation for timing skew that may result from, for example, thermal drift.Type: GrantFiled: August 8, 2011Date of Patent: April 1, 2014Assignee: ViaSat, Inc.Inventors: Yuri Zelensky, Fan Mo
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Patent number: 8687968Abstract: A vector sum phase shifter includes a 90° phase shifter (1) which generates an in-phase signal (VINI) and a quadrature signal (VINQ) from an input signal (VIN), a four-quadrant multiplier (2I) which changes the amplitude of the in-phase signal (VINI) based on a control signal (CI), a four-quadrant multiplier (2Q) which changes the amplitude of the quadrature signal (VINQ) based on a control signal (CQ), a combiner (3) which combines the in-phase signal (VINI) and the quadrature signal (VINQ), and a control circuit (4). The control circuit (4) includes a voltage generator which generates a reference voltage, and a differential amplifier which outputs the difference signal between a control voltage (VC) and the reference voltage as the control signal (CI, CQ). The differential amplifier performs an analog operation of converting the control voltage (VC) into the control signal (CI, CQ) similar to a sine wave or a cosine wave.Type: GrantFiled: August 12, 2009Date of Patent: April 1, 2014Assignee: Nippon Telegraph and Telephone CorporationInventors: Hideyuki Nosaka, Munehiko Nagatani, Shogo Yamanaka, Kimikazu Sano, Koichi Murata, Kiyomitsu Onodera, Takatomo Enoki
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Patent number: 8670678Abstract: A digital coherent receiver converts signals and local light respectively detected, as detection results, in signal light from an optical transmission line, into digital signals and that further applies digital processing to the digital signals. The receiver includes a skew detecting unit that detects skew between the digital signals; a skew control unit controls the skew of each of the signals so that the skew to be detected by the skew detecting unit will be reduced; and a demodulating unit that demodulates each signal controlled for skew by the skew control unit.Type: GrantFiled: February 24, 2011Date of Patent: March 11, 2014Assignee: Fujitsu LimitedInventors: Yuichirou Sakamoto, Kosuke Komaki
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Patent number: 8666256Abstract: An optical receiving apparatus with frame synchronization technology which makes it easy to activate a frame synchronization established state even if bit errors are produced over a transmission link. The apparatus includes: an optoelectrical converting circuit; a pre-stage synchronizing word detecting circuit; a decoder; a post-stage frame synchronization detecting circuit; and a receiver frame synchronization display output circuit.Type: GrantFiled: March 21, 2012Date of Patent: March 4, 2014Assignee: NEC CorporationInventor: Tsugio Takahashi
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Publication number: 20140056594Abstract: Integrated performance monitoring (PM); optical layer operations, administration, maintenance, and provisioning (OAM&P); alarming; amplification, or the like is described in optical transceivers, such as multi-source agreement (MSA)-defined modules. An optical transceiver defined by an MSA agreement can include advanced integrated functions for carrier-grade operation which preserves the existing MSA specifications allowing the optical transceiver to operate with any compliant MSA host device with advanced features and functionality.Type: ApplicationFiled: November 4, 2013Publication date: February 27, 2014Applicant: MENARA NETWORKS, INC.Inventors: Ming DING, Fredrick MUYA, Siraj Nour ELAHMADI, Salam ELAHMADI, Adam R. HOTCHKISS, Gabriel E. CARDONA
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Patent number: 8660431Abstract: A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a liquid lens are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where a liquid lens is deployed with each of the one or more detectors. The method determines, for each of the detected signals, if the detected signal is out of focus, and applies a corrective voltage to each liquid lens that corresponds to a detected terahertz signal that is out of focus, wherein the corrective voltage adjusts a focus of the detected signal. The method measures a signal-to-noise ratio of the detected signals, and establishing a terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio.Type: GrantFiled: April 8, 2013Date of Patent: February 25, 2014Assignee: AT&T Intellectual Property I, L.P.Inventors: David Michael Britz, Robert Raymond Miller
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Patent number: 8660437Abstract: A fiber optic network reduces distortion present in modulated optical signals received at an optical receiver from an optical transmitter via a fiber optic link. The optical receiver analyzes a received modulated optical signal, where the wavelength of the received signal is periodically varied at the transmitter around a center wavelength over a wavelength range. Based on the analysis, the receiver generates a link transmission curve indicative of the optical power of the received signal over the wavelength range. The network disclosed herein subsequently uses the link transmission curve to reduce the distortion caused by misalignment between the operating wavelength of a transmitter laser and a peak power wavelength at the peak power of the link transmission curve. For example, the transmitter may adjust the laser operating wavelength based on a control signal received from the receiver and generated at the receiver based on the link transmission curve.Type: GrantFiled: February 25, 2011Date of Patent: February 25, 2014Assignee: Emcore CorporationInventor: Henry A. Blauvelt