Correction Of Deleterious Effects Patents (Class 359/337)
  • Patent number: 10374708
    Abstract: An optical communication device and related method are provided for reducing power variations among wavelength division multiplexing (WDM) signals. The device includes a dynamic gain equalizer (DGE) coupled to an optical communication path carrying WDM optical signals. The DGE is controlled in response to signals generated by an optical channel monitor (OCM). The OCM monitors signals coming into the DGE and monitors the signals leaving the DGE to thus monitor the WDM spectrum for optical signal power variations and adjust the DGE to reduce the signal power variations.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: August 6, 2019
    Assignee: Molex, LLC
    Inventors: Yi Liao, Gongjian Hu, Tian Zhu, Guijun Ji, Lifu Gong
  • Patent number: 10320513
    Abstract: A distributed Automatic Power Optimization (APO) system and method are provided. The distributed APO system includes: one or more APO modules and a network management system. The one or more APO modules belong to one or more pre-divided APO links. Each APO module in the one or more APO modules belongs to only one APO link. The APO module is configured to, when the APO link to which the APO module belongs is triggered to perform power regulation, regulate a power attenuation or a gain between the two adjacent stations corresponding to the APO module and report a regulation result. The network management system is configured to, when learning that all of one or more APO modules in one APO link are successful in regulation, if there is a next APO link of the APO link, trigger the next APO link of the APO link to perform power regulation.
    Type: Grant
    Filed: April 1, 2016
    Date of Patent: June 11, 2019
    Assignee: ZTE CORPORATION
    Inventors: Lijun Zhang, Mingchao Zhang
  • Patent number: 10298317
    Abstract: A method is described in which a loss of spectrum in an optical signal having an optical signal spectrum is detected. The optical signal is transmitted from a first node to a second node. In response to detecting the loss of spectrum in the optical signal, at least one idler carrier without data imposed is supplied into the optical signal spectrum transmitted from the first node to the second node, the optical signal spectrum encompassing a frequency band including a plurality of optical channels, the idler carrier being amplified stimulated emission light having a frequency corresponding to a first optical channel of the plurality of optical channels.
    Type: Grant
    Filed: December 21, 2017
    Date of Patent: May 21, 2019
    Assignee: Infinera Corporation
    Inventors: Pierre Mertz, Omer Faruk Yilmaz
  • Patent number: 10263383
    Abstract: An optical gain fiber for use in high power (e.g., greater than 500 W pump power) is proposed that is configured to exhibit a minimum bend radius such that the bend loss for the propagating LP01 mode is greater than about 0.03 dB/m. It has been discovered that this bend radius criteria, which is less stringent than that typically suggested in the art (e.g., bend loss less than about 0.03 dB/m), meets the modal stability requirements at high power operation, since the increase in operating temperature of the fiber laser or amplifier has been found to somewhat relax the bend radius requirement (which was heretofore only measured at “room temperature”, not “operating temperature”). Modal stability is defined in terms of a reduced presence of unwanted higher-order modes (such as the LP11 mode) in the amplified output signal.
    Type: Grant
    Filed: January 18, 2018
    Date of Patent: April 16, 2019
    Assignee: OFS FITEL, LLC
    Inventor: Clifford E Headley
  • Patent number: 10256938
    Abstract: An optical receiver includes a demultiplexer configured to demultiplex, for each channel, optical signals input through a plurality of channels, a photoelectric converter having a number of light receivers corresponding to the plurality of channels, the photoelectric converter being configured to convert an optical signal into an electric signal for each channel, a monitor circuit configured to monitor, for each channel, an amplitude characteristic of the optical signal converted into the electric signal by the photoelectric converter, and a control circuit configured to control, based on a monitored result of the monitor circuit, a bias voltage to be applied to the light receiver such that an amount of variability in the amplitude characteristic between the channels is minimum or falls within a predetermined range.
    Type: Grant
    Filed: June 28, 2017
    Date of Patent: April 9, 2019
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventor: Toshio Ishii
  • Patent number: 10250331
    Abstract: A subscriber device includes a demultiplexer configured to demultiplex input wavelength-multiplexed light into a plurality of light signals for each wavelength, a plurality of light receivers configured to receive each of the plurality of light signals obtained through demultiplexing by the demultiplexer and to convert the light signals into electrical signals, a plurality of limiting amplifiers configured to amplify each of the plurality of electrical signals output from the plurality of light receivers, and a plurality of signal selection units configured to select a plurality of signals to be received from among a plurality of amplified signals output from the plurality of limiting amplifiers.
    Type: Grant
    Filed: May 19, 2016
    Date of Patent: April 2, 2019
    Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
    Inventors: Katsuhisa Taguchi, Kota Asaka
  • Patent number: 10236656
    Abstract: Aspects of an optical communications network are described that include two or more optical fibers arranged to allow communication in the same direction. The optical network includes a first optical amplifier coupled to the first optical fiber, a second optical amplifier coupled to the second optical fiber, a first optical pump to provide optical power to the first optical fiber, and a second pump to provide optical power to both the first and the second optical fibers. By sharing the second pump between the first and the second optical fibers, a need to deploy additional pumps is alleviated. Scaling of the optical network to include additional optical fibers provides further cost savings by allowing more pumps to be shared among the multiple optical fibers.
    Type: Grant
    Filed: August 18, 2017
    Date of Patent: March 19, 2019
    Assignee: Facebook, Inc.
    Inventors: Nitin Kumar Goel, Satyajeet Singh Ahuja, Gayathrinath Nagarajan
  • Patent number: 10211593
    Abstract: In one embodiment, an optical amplifier includes a first pump laser diode and a second pump laser diode. The first pump laser diode is configured to produce pump light that includes a first amount of optical power at a first wavelength, and the second pump laser diode is configured to produce pump light that includes a second amount of optical power at a second wavelength different from the first wavelength. The optical amplifier also includes an optical gain fiber configured to receive the pump light from the first and second pump laser diodes and provide optical gain for an optical signal propagating through the optical gain fiber. The optical amplifier further includes a controller configured to adjust the first amount of optical power produced by the first pump laser diode and the second amount of optical power produced by the second pump laser diode.
    Type: Grant
    Filed: November 30, 2017
    Date of Patent: February 19, 2019
    Assignee: LUMINAR TECHNOLOGIES, INC.
    Inventors: Laurance S. Lingvay, Alain Villeneuve, Jason M. Eichenholz
  • Patent number: 10177523
    Abstract: An optical fiber apparatus and a method of recovering radiation-induced-attenuation (RIA) onto a rare-earth-doped optical fiber under irradiation are provided in this disclosure. A light source is coupled to a rare-earth doped optical fiber. The light source emits a combination of mode locked pulsed light and non-mode locked quasi-continuous-wave light. The mode locked pulsed light are used to recover RIA onto the rare-earth doped optical fiber in real time, and the non-mode locked light are used to pump the rare-earth doped optical fiber as a gain medium. Each pulsed duration of the mode locked pulsed light is much shorter than operation duration of the non-mode locked light, such that an instantaneous power of the mode locked pulsed light exceeds a saturated pumping power required for the rare-earth doped optical fiber, so as to effectively elevate the core temperature of rare-earth doped fiber to achieve a confined photo-annealed recovery of RIA onto rare-earth doped fibers.
    Type: Grant
    Filed: September 14, 2015
    Date of Patent: January 8, 2019
    Assignee: NATIONAL APPLIED RESEARCH LABORATORIES
    Inventors: Sheng Hsiung Chang, Ren-Young Liu, Chii-Chang Chen, Chao-Yi Tai
  • Patent number: 10158208
    Abstract: Provided is a method of measuring a phase noise of a repetition rate of a femtosecond laser including generating a combined signal using a first wavelength element and a second wavelength element of an optical pulse train generated by the femtosecond laser, which is mode-locked, guiding the combined signal to a first path and a second path, allowing a signal of the second path to interfere with the signal of the first path, and outputting an interfering combined signal, dividing the interfering combined signal into a first interference signal and a second interference signal, converting the interference signals to radio frequency signals, and detecting a baseband signal including a frequency noise of the repetition rate from the radio frequency signals using a mixer.
    Type: Grant
    Filed: November 20, 2015
    Date of Patent: December 18, 2018
    Assignee: KOREA ADVANCED INSTITUE OF SCIENCE AND TECHNOLOGY
    Inventors: Jung Won Kim, Kwang Yun Jung
  • Patent number: 10080070
    Abstract: Implementing a laser into a system that uses a remote powered combiner or an aggregating combiner (AC) with one or more in-range contributing combiners may provide power to the downstream contributing combiners (CC). The power may be provided on the same fiber that downstream signals and the upstream signals traverse.
    Type: Grant
    Filed: September 29, 2016
    Date of Patent: September 18, 2018
    Assignee: ARRIS Enterprises LLC
    Inventors: Venkatesh G. Mutalik, Marcel F. Schemmann
  • Patent number: 10056971
    Abstract: An amplifier receives an optical signal including a number of labeled channels via a fiber. The amplifier determines a count of the labeled channels and a spectral distribution of the labeled channels. The amplifier adjusts a parameter of the amplifier based on the count of the labeled channels and the spectral distribution of the labeled channels. The amplifier amplifies the optical signal at an adjusted output gain resulting from adjusting the parameter of the amplifier.
    Type: Grant
    Filed: February 22, 2016
    Date of Patent: August 21, 2018
    Assignee: AT&T Intellectual Property I, L.P.
    Inventors: Martin Birk, Mark David Feuer, Kathleen A. Tse
  • Patent number: 10044444
    Abstract: A novel and simple photonic vector signal generation scheme at radio frequency (RF) bands enabled by a single-drive Mach-Zehnder modulator (MZM)-based optical carrier suppression (OCS) without precoding techniques and optical filter, which can reduce the complexity of transmitter digital signal processing (DSP), is described. The generation and reception of 16/20/22-Gbaud quadrature-phase-shift-keying (QPSK) vector signals at 16/20/22 GHz are experimentally demonstrated, respectively. The measured bit-error ratio for 16G-baud QPSK vector signals after transmitting over 10-km standard single mode fiber (SSMF) can be under 7% hard-decision forward-error-correction (HD-FEC) threshold of 3.8×10?3. Moreover, compared to the conventional precoding scheme, the receiver sensitivity can be enhanced by 4 dB at both back-to-back (BTB) and after 10-km SSMF transmission cases, which demonstrates the feasibility of this technique, and show its potential promising application in radio over fiber (RoF) system.
    Type: Grant
    Filed: July 29, 2016
    Date of Patent: August 7, 2018
    Assignee: ZTE Corporation
    Inventors: Jianjun Yu, Yuanquan Wang, Xinying Li
  • Patent number: 9954610
    Abstract: There are provided methods and devices for determining a quality parameter characterizing an optical communication signal, the methods being performed by signal detection devices. At the transmitting end, there are obtained a signal power P1 of a first optical signal, a signal power P2 of a second optical signal, a signal power P3 of a third optical signal, optionally a signal power P4 of a fourth optical signal, and a total signal power Ps of a channel where the first, second, third and optional fourth optical signals are located. At a detection point, there are further obtained a signal power P1? of the first optical signal, a signal power P2? of the second optical signal, a signal power P3? of the third optical signal and optionally a signal power P4? of the fourth optical signal. There are then determined a signal deformation factor SDF and/or an optical signal to ASE noise ratio OSNR from the obtained signal powers.
    Type: Grant
    Filed: November 4, 2015
    Date of Patent: April 24, 2018
    Assignee: EXFO Inc.
    Inventors: Gang He, Daniel Gariepy
  • Patent number: 9948057
    Abstract: An optical amplifier includes: an optical amplifying fiber; and a pump light source that supplies pump light to the optical amplifying fiber, the pump light being used for parametrically amplifying signal light input to the optical amplifying fiber by using a non-linear optical effect of the optical amplifying fiber. The fluctuation of the zero-dispersion wavelength of the optical amplifying fiber in the longitudinal direction is within the limit of 0.5 nm/100 m.
    Type: Grant
    Filed: February 24, 2016
    Date of Patent: April 17, 2018
    Assignee: FURUKAWA ELECTRIC CO., LTD.
    Inventor: Shigehiro Takasaka
  • Patent number: 9941956
    Abstract: A first photodetector is interconnected with a control unit equipped with a communication interface and powered by a power supply module. An output of a first optical filter is connected to an input of a first photodetector via a second optical filter, while a second output of the second optical filter is connected to an input of a second photodetector. An output of the second photodetector is connected to a control unit. A split branch of a third directional coupler is connected to the input of a third photodetector, the output of which is connected to the control unit. A split branch of a fourth directional coupler is connected to the input of a fourth photodetector, the output of which is connected to the control unit.
    Type: Grant
    Filed: June 17, 2016
    Date of Patent: April 10, 2018
    Assignee: Cesnet, zajmove sdruzeni pravnickych osob
    Inventors: Radan Slavik, Josef Vojtech, Vladimir Smotlacha, Jan Radil
  • Patent number: 9929533
    Abstract: The present disclosure relates to the field of optical communication, particularly to an optical module. An optical module according to embodiments of the disclosure includes: a laser device including an emission region, and a modulation region to which light emitted by the emission region is transmitted; a bias circuit connected with the emission region, configured to drive the emission region to emit light at stable optical power; a modulation circuit connected with the modulation region, configured to drive the modulation region, so that the modulation region varies the optical power of the light emitted from the emission region; and a semiconductor optical amplifier configured to receive the light from the modulation region, and to vary the optical power of the light.
    Type: Grant
    Filed: December 22, 2016
    Date of Patent: March 27, 2018
    Assignees: Hisense Broadband Multimedia Technologies Co., Ltd., Hisense USA Corporation, Hisense International Co., Ltd.
    Inventors: Shihai Yang, Qiang Zhang, Qisheng Zhao
  • Patent number: 9921354
    Abstract: Disclosed herein is an optical fiber assembly comprising a launching fiber having a receiving end and a transmitting end; an illuminating fiber having a receiving end and a transmitting end; where the receiving end of the launching fiber is operative to receive light from a light source and the transmitting end of the launching fiber is operative to transmit light to the receiving end of the illuminating fiber; where the launching fiber contacts the illuminating fiber in a manner so as to be offset from a center of a cross-sectional area of the illuminating fiber; and where the launching fiber has a diameter that is ? to ½ of a diameter of the illuminating fiber; and a lens that is operative to contact the transmitting end of the illuminating fiber.
    Type: Grant
    Filed: September 22, 2017
    Date of Patent: March 20, 2018
    Assignee: OFS FITEL, LLC
    Inventor: Xiaoguang Sun
  • Patent number: 9917412
    Abstract: An optical amplifier may comprise a first gain stage and a second gain stage. Each of the first and second gain stages may comprise a laser pump and an active fiber. A liquid crystal device may be coupled between an output of the first gain stage and an input of the second gain stage. A control unit may be coupled to the first and second gain stages, liquid crystal device and configured to control the first and second gain stages, and the liquid crystal device to provide a switchable gain. Light may pass through the first and second gain stages and be amplified by the first and second gain stages. The light amplified by the first gain stage may pass through the liquid crystal device and may be filtered by the liquid crystal device.
    Type: Grant
    Filed: November 4, 2016
    Date of Patent: March 13, 2018
    Assignee: Cisco Technology, Inc.
    Inventors: Stefano Piciaccia, Lorenzo Ghioni, Walid Wakim
  • Patent number: 9917410
    Abstract: Fiber amplifier and/or mode filter including a linearly birefringent LMA fiber coiled at a radius of curvature over a bend length to differentiate a fundamental optical mode from supported higher-order modes through bending losses. The LMA fiber may be a polarization-maintaining (PM) fiber having a variety of geometrical core shapes and cladding configurations. In some embodiments, the birefringent LMA fiber includes a radially asymmetric core that is angularly rotated over a length of the coiled fiber to ensure bending losses are experienced in orthogonally oriented higher-order modes associated with some orientation relative to the core orientation. In some embodiments, the fiber coiling is two-dimensional with bending occurring only about one axis. In some embodiments, an asymmetric core is pre-spun to a predetermined axial spin profile. In some embodiments, angular rotation of the core is achieved through mechanically twisting an un-spun fiber over a length of the coil.
    Type: Grant
    Filed: November 28, 2016
    Date of Patent: March 13, 2018
    Assignee: nLIGHT, Inc.
    Inventors: Matthieu Saracco, David N. Logan, Timothy S. McComb, Roger L. Farrow
  • Patent number: 9899792
    Abstract: An array of optical amplifiers that recycles the unused pump power of some or all constituent amplifiers thereof, thereby beneficially improving pump-power utilization therein compared to that of conventional optical amplifiers. In an example embodiment, different amplifiers of the array can be configured to receive approximately equal pump power and be used to independently amplify different respective optical signals. In various embodiments, the unused pump power can be recycled using one or more optical couplers and/or optical paths that appropriately interconnect different amplifiers of the array. Some embodiments have one or more optical loops configured to operate as a ring laser that regenerates pump light in response to the unused pump power being coupled thereto. Some embodiments provide a spectral gain profile suitable for amplifying WDM signals in at least some of the constituent amplifiers of the array.
    Type: Grant
    Filed: August 19, 2016
    Date of Patent: February 20, 2018
    Assignee: Alcatel-Lucent USA Inc.
    Inventors: Peter J. Winzer, Alan H. Gnauck
  • Patent number: 9887512
    Abstract: The invention concerns a laser amplification system comprising a pumping device and at least one thick amplifier disc having a first face, which is reflective at the wavelengths of a pulsed laser beam of the laser amplification system and of a pump beam of the pumping device, as well as at least one heat-dissipation component to which this first face of the amplifier disc is firmly secured, the saturation fluence of the active medium of the amplifier disc being equal to or less than 3 J·cm?2.
    Type: Grant
    Filed: May 20, 2014
    Date of Patent: February 6, 2018
    Assignees: COMPAGNIE INDUSTRIELLE DES LASERS CILAS, AIRBUS DEFENCE AND SPACE SAS
    Inventors: Jean-Eucher Montagne, Sandrine Auroux, Bruno Esmiller
  • Patent number: 9851510
    Abstract: The inventive configurable optical fiber polarization mode coupler is capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array is configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing, and that are preferably optimized for use with photonic integrated circuits, such as coupling to dense optical input/output interfaces, wafer-level testing, etc.
    Type: Grant
    Filed: July 7, 2016
    Date of Patent: December 26, 2017
    Assignee: Chiral Photonics, Inc.
    Inventor: Victor Il'ich Kopp
  • Patent number: 9843153
    Abstract: A beam reverser module for an optical power amplifier of a laser arrangement comprises at least one reflecting surface for receiving an incoming laser beam propagating in a first direction and reflecting the incoming laser beam into a second direction different from the first direction, wherein the at least one reflecting surface is a highly reflecting surface of at least one mirror.
    Type: Grant
    Filed: August 3, 2015
    Date of Patent: December 12, 2017
    Assignee: Carl Zeiss SMT GmbH
    Inventors: Michael Schall, Johannes Kraus, Holger Muenz, Ingrid Schuster, Willi Anderl, Ulrich Weber, Markus Bauer, Jeffrey Erxmeyer, Michel Le Maire
  • Patent number: 9841654
    Abstract: An optical crystal can be mounted to a mounting block configured to receive the crystal. A base portion on the mounting block utilizes two walls forming a corner and a single biasing spring clip to secure the crystal. The spring clip applies forces in two different directions substantially orthogonal to the two walls. The spring clip is based off a symmetrical geometry which applies nearly the same force application in both directions. The spring also features bend regions that contact the crystal in such a way as to reduce the presence of point loads or stress risers. The length of contact along the crystal is maximized, allowing for proper force distribution and a sufficient surface are contact for static holding capabilities.
    Type: Grant
    Filed: June 3, 2016
    Date of Patent: December 12, 2017
    Assignee: IPG PHOTONICS CORPORATION
    Inventors: Daniel Swanbeck, Mark W. Byer, Manuel Martinez
  • Patent number: 9806488
    Abstract: A method includes applying a boost pump signal to a pump laser of a laser system based on a preceding off duration associated with the laser system, and applying a forward pump signal to the pump laser. A laser system includes a seed laser situated to generate seed optical pulses, a pump laser situated to generate pump optical radiation, a fiber amplifier situated to receive the pump optical radiation and the seed optical pulses, and a controller situated to select a pump boost duration or pump boost magnitude based on an off duration associated with the laser system.
    Type: Grant
    Filed: June 29, 2016
    Date of Patent: October 31, 2017
    Assignee: nLIGHT, Inc.
    Inventors: Tyson Lowder, Timothy N. Kutscha
  • Patent number: 9693420
    Abstract: Systems and methods for operating one or more light emitting devices are disclosed. In one example, a negative temperature coefficient control parameter is applied to an amplifier to adjust a gain of the amplifier so as to provide a substantially constant level of irradiance output from one or more light emitting devices.
    Type: Grant
    Filed: May 17, 2016
    Date of Patent: June 27, 2017
    Assignee: Phoseon Technology, Inc.
    Inventor: Salvatore T. Battaglia
  • Patent number: 9680284
    Abstract: Devices and methods for lessening a thermal dependence of gain profile of an optical amplifier are disclosed. An optical beam is split in a plurality of sub-beams with a thermally variable power splitting ratio, e.g. one sub-beam may travel a longer optical path length than another. When the sub-beams are recombined, they interfere with each other, causing the throughput to be wavelength dependent. An amplitude of this wavelength dependence is thermally variable due to the thermally variable power splitting ratio. The thermally variable power splitting ratio and the optical path length difference are selected so as to offset a thermal variation of a spectral gain profile of an optical amplifier.
    Type: Grant
    Filed: October 13, 2015
    Date of Patent: June 13, 2017
    Inventor: Lijie Qiao
  • Patent number: 9647789
    Abstract: An optical transmission device includes a splitter configured to have at least a first port, a second port, and a third port that output branched input light, branching ratios of the first port and the second port being variable, and a controller configured to reduce an optical level of output light from the first port to be monitored and increase an optical level of output light from the second port according to the reduced optical level of output light from the first port by controlling the branching ratios.
    Type: Grant
    Filed: April 29, 2014
    Date of Patent: May 9, 2017
    Assignee: FUJITSU LIMITED
    Inventor: Satoshi Miyazaki
  • Patent number: 9641438
    Abstract: A regenerator system is provided for dynamic and asymmetric bandwidth capacity adjustment when exchanging data between a first remote network device and a second remote network device. The regenerator includes first and second couplers in communication with the first and second remote network devices, respectively, using a first communication medium that provides multiple communication channels, and at least one redirecting device operable to selectively configure at least one of the channels for either transmission of a signal from the first remote network device to the second remote network device, or transmission of the signal from the second remote network device to the first remote network device.
    Type: Grant
    Filed: February 11, 2014
    Date of Patent: May 2, 2017
    Assignee: Level 3 Communications, LLC
    Inventor: Peter Brennan Doerr
  • Patent number: 9634453
    Abstract: An apparatus includes a controllable optical interferometer having first and second external optical ports and a traveling-wave modulation electrode. The apparatus also includes an electrical driver configured and connected to apply a voltage with a periodic modulation to the traveling-wave modulation electrode such that the controllable optical interferometer operates as an optical isolator over a wavelength range.
    Type: Grant
    Filed: December 16, 2014
    Date of Patent: April 25, 2017
    Assignee: Alcatel Lucent
    Inventor: Po Dong
  • Patent number: 9608398
    Abstract: The present application is directed to an optical apparatus including an optical waveguide configured to receive an optical signal at an input wavelength. The apparatus also includes one or more optical pump sources connected to transmit pump light to the optical gain medium for the optical gain medium to amplify the optical signal. The apparatus also includes an optical feedback loop for a protection wavelength that includes the optical gain medium and at least a portion of the optical waveguide. A round-trip optical gain of the optical feedback loop is higher at an optical wavelength of the pump light than at the input wavelength less than unity in the presence of the optical signal. In addition, the round-trip gain of the optical feedback loop is greater than or equal to unity in the absence of the optical signal.
    Type: Grant
    Filed: February 20, 2014
    Date of Patent: March 28, 2017
    Assignee: LGS INNOVATIONS LLC
    Inventor: Albin L. Kasper
  • Patent number: 9596027
    Abstract: There is provided a method and an apparatus for determining quality parameters on a polarization-multiplexed optical signal based on an analysis of the power spectral density of the Signal-Under-Test (SUT). The method is predicated upon knowledge of the spectral shape of the signal in the absence of significant noise or spectral deformation. This knowledge is provided by a reference optical spectrum trace. Based on this knowledge and under the assumption that ASE noise level is approximately constant in wavelength over a given spectral range, the spectral deformation of the signal contribution of the SUT may be estimated using a comparison of the spectral variations of the optical spectrum trace of the SUT with that of the reference optical spectrum trace.
    Type: Grant
    Filed: May 2, 2014
    Date of Patent: March 14, 2017
    Assignee: Exfo Inc.
    Inventors: Gang He, Daniel Gariepy, Mats Skold
  • Patent number: 9525339
    Abstract: According to various embodiments, a circuit includes a charge pump and a feedback circuit. The charge pump includes a first input, a second input configured to receive an offset signal, and an output terminal configured to provide a charge pump signal based on the first and second inputs. The feedback circuit includes a first input coupled to the output of the charge pump, a second input configured to be coupled to a reference signal, an enable input configured to enable and disable the feedback circuit, and a feedback output coupled to the first input of the charge pump.
    Type: Grant
    Filed: November 13, 2015
    Date of Patent: December 20, 2016
    Assignee: Infineon Technologies AG
    Inventors: Christian Jenkner, Richard Gaggl
  • Patent number: 9507238
    Abstract: The invention provides a new linearized electro-optic modulator in which linearization is achieved by modulating the index of a Bragg grating reflector placed in the arm(s) of a Michelson Interferometer. This grating-assisted Michelson Interferometer (GAMI) modulator operates as either an intensity or amplitude modulator, and is shown to significantly improve the linearity of microwave photonics links. Furthermore, this modulator improves the performance of optical communication systems using advanced modulation formats.
    Type: Grant
    Filed: August 20, 2015
    Date of Patent: November 29, 2016
    Assignee: Morton Photonics
    Inventors: Jacob Khurgin, Paul A. Morton
  • Patent number: 9509370
    Abstract: An optical transmission system includes: a first optical transmission device configured to perform bidirectional optical transmission with a second optical transmission device via an optical transmission line, wherein the first optical transmission device includes a transmitted light power adjusting section configured to transmit, to the second optical transmission device, a first light power which is set based on a measurement result, the second transmission device measuring a fluctuating light power transmitted from the first transmission device and informing the first transmission device of the measurement result.
    Type: Grant
    Filed: September 10, 2014
    Date of Patent: November 29, 2016
    Assignee: FUJITSU LIMITED
    Inventor: Tomoaki Takeyama
  • Patent number: 9503181
    Abstract: A doped fiber amplifier (e.g., an erbium-doped fiber amplifier—EDFA) module is configured to include metrology functionality for performing real-time measurements of the fiber spans connected to the EDFA. In one embodiment, a separate component utilized to perform optical time domain reflectometry (OTDR) measurements is embedded with the EDFA module. The OTDR measurement component includes its own laser source and detector, which are used to analyze the input and output fiber spans associated with the EDFA. In another embodiment, the pump laser of the EDFA is also used as the optical probe light source for the OTDR component, where the source is either “switched” or “shared” between performing amplification and providing OTDR measurements. In yet another embodiment, a “dual pump” source is included with the OTDR component itself and modified to utilize one laser for amplification and the other for OTDR purposes.
    Type: Grant
    Filed: January 6, 2015
    Date of Patent: November 22, 2016
    Assignee: II-VI Incorporated
    Inventors: Ian Peter McClean, Aravanan Gurusami
  • Patent number: 9485551
    Abstract: Embodiments of the disclosure are directed to optimizing routing and wavelength assignment in a network. An embodiment determines a routing assignment for a network, wherein the routing assignment is determined using a decongestion cost-based function; and determines a wavelength assignment for the network based on vector difference. The determination of the wavelength assignment comprises spanning the network for a path; calculating a weighted correlation function for at least one length in the network; storing the weighted correlation; and determining if a next path exists. If a next path is found, spanning for a next path in the network, and if a next path is not found, returning the stored correlation.
    Type: Grant
    Filed: November 6, 2013
    Date of Patent: November 1, 2016
    Assignee: Ciena Corporation
    Inventors: Anurag Prakash, Mohit Chhillar
  • Patent number: 9362716
    Abstract: An optical crystal can be mounted to a mounting block configured to receive the crystal. A base portion on the mounting block utilizes two walls forming a corner and a single biasing spring clip to secure the crystal. The spring clip applies forces in two different directions substantially orthogonal to the two walls. The spring clip is based off a symmetrical geometry which applies nearly the same force application in both directions. The spring also features rounded bend regions that contact the crystal in such a way as to reduce the presence of point loads or stress risers. The length of contact along the crystal is maximized, allowing for proper force distribution and a sufficient surface are contact for static holding capabilities.
    Type: Grant
    Filed: September 19, 2014
    Date of Patent: June 7, 2016
    Assignee: IPG PHOTONICS CORPORATION
    Inventors: Daniel Swanbeck, Mark W. Byer, Manuel Martinez
  • Patent number: 9356417
    Abstract: A fiber laser includes: an amplification optical fiber; a pumping light source configured to emit pumping light to pump the active element of the amplification optical fiber; a first mirror provided on one side of the amplification optical fiber; and a second mirror provided on the other side of the amplification optical fiber. When an optical loss between the first mirror and the second mirror is equal to an optical gain in the amplification optical fiber, a difference between a gain of light having a wavelength at which a gain becomes maximum and a gain of light having a wavelength reflected off the first mirror and the second mirror is 35 dB or less in the amplification optical fiber.
    Type: Grant
    Filed: May 14, 2014
    Date of Patent: May 31, 2016
    Assignee: FUJIKURA LTD.
    Inventor: Tomoharu Kitabayashi
  • Patent number: 9310487
    Abstract: A lidar includes CW laser light sources that oscillate CW laser light rays with wavelengths different from each other; an optical multiplexing coupler that mixes the CW laser light rays oscillated by the CW laser light sources; an optical branching coupler that splits the CW laser light passing through the mixing by the optical multiplexing coupler; a light modulator that modulates first CW laser light split by the optical branching coupler; and an optical fiber amplifier that amplifies the laser light modulated by the light modulator, in which a transmit-receive optical system irradiates a target with the laser light amplified by the optical fiber amplifier, and receives scattered light of the laser light by the target.
    Type: Grant
    Filed: December 7, 2012
    Date of Patent: April 12, 2016
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takeshi Sakimura, Takayuki Yanagisawa, Shumpei Kameyama, Toshiyuki Ando, Yoshihito Hirano
  • Patent number: 9294194
    Abstract: A network monitoring system for a multimode optical data network includes a filter based splitter and an avalanche photodiode detector-based detection subsystem. The system takes a very small amount of the energy from the main data stream to use as monitoring data signal. The filter based splitter operates in a manner that is fairly uniform among modes and permits very low energy levels to be diverted for monitoring without disrupting either the main or monitor data streams for any modes.
    Type: Grant
    Filed: August 19, 2013
    Date of Patent: March 22, 2016
    Assignee: Virtual Instruments Corporation
    Inventors: Rama Vuppuladhadium, Chi-Luen Wang, John Marcolina, Jeff Chung
  • Patent number: 9287992
    Abstract: A transmitter to be added or reduced turns ON/OFF an optical output. A relay station and a receiving terminal station acquire the amount of fluctuation of the optical output of the received signal light when the optical output of the added transmitter is turned ON and OFF. From the amount of fluctuation of the optical output, the number of wavelengths after the addition or reduction is acquired. Without an OSC signal, each station may be informed of the number of wavelengths. Therefore, the configuration for transmitting and receiving the OSC signal is not requested, thereby reducing the total cost, appropriately controlling the gain of the optical amplifier, and successfully maintaining transmission quality.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: March 15, 2016
    Assignee: FUJITSU LIMITED
    Inventors: Takehiro Fujita, Toshiki Honda
  • Patent number: 9287970
    Abstract: An optical transmission device includes: a switching configured to be capable of switching a transmission path to which light is input from a first transmission path to a second transmission path; a first calculation unit configured to calculate, based on a difference between a first light level of the first transmission path and a second light level of the second transmission path, a first control amount for the second light level; and a control unit configured to perform a first control in which the second light level is decreased or increased based on the first control amount upon switching of the transmission path.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: March 15, 2016
    Assignee: FUJITSU LIMITED
    Inventor: Ayumu Nonaka
  • Patent number: 9231695
    Abstract: An optical transmission device includes: a switching configured to be capable of switching a transmission path to which light is input from a first transmission path to a second transmission path; a first calculation unit configured to calculate, based on a difference between a first light level of the first transmission path and a second light level of the second transmission path, a first control amount for the second light level; and a control unit configured to perform a first control in which the second light level is decreased or increased based on the first control amount upon switching of the transmission path.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: January 5, 2016
    Assignee: FUJITSU LIMITED
    Inventor: Ayumu Nonaka
  • Patent number: 9225456
    Abstract: Methods and systems for post-transient gain control of optical amplifiers may include using a gain offset control module in an optical amplifier to generate a gain offset cancelling signal. The gain offset cancelling signal may be output to a gain control module in the optical amplifier to generate at least one of a pump signal and an attenuation control signal. In this manner, a gain offset may be cancelled for a plurality of wavelengths in an optical signal transmitted by an optical network.
    Type: Grant
    Filed: November 18, 2013
    Date of Patent: December 29, 2015
    Assignee: Fujitsu Limited
    Inventors: Idan Mandelbaum, Dogan Atlas
  • Patent number: 9184554
    Abstract: Devices and methods for lessening a thermal dependence of gain profile of an optical amplifier are disclosed. An optical beam is split in two sub-beams with a thermally variable power splitting ratio. One sub-beam travels a longer optical path length than the other. When the two sub-beams are recombined, they interfere with each other, causing the throughput to be wavelength dependent. An amplitude of this wavelength dependence is thermally variable due to the thermally variable power splitting ratio. The thermally variable power splitting ratio and the optical path length difference are selected so as to offset a thermal variation of a spectral gain profile of an optical amplifier.
    Type: Grant
    Filed: August 27, 2014
    Date of Patent: November 10, 2015
    Inventor: Lijie Qiao
  • Patent number: 9170437
    Abstract: The invention relates to a method and device for controlling a physical parameter of an optical signal. According to the invention, a portion of the initial optical signal (SE) having passed through an optical waveguide from the input (24.1) to the output (24.2) thereof, is returned into said optical waveguide (24) using a sequential circulator (25) and an optical amplifier (28), in order to at least partially form the optical control signal (SE2), which counter-propagates relative to said initial optical signal (SE), so as to stabilize, or at the very least control, the physical parameter of said initial optical signal when the latter exits said optical waveguide (24) via the output (24.2) thereof.
    Type: Grant
    Filed: August 2, 2012
    Date of Patent: October 27, 2015
    Assignees: CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE—CNRS, UNIVERSITÉ DE BOURGOGNE
    Inventors: Stéphane Pitois, Julien Fatome, Philippe Morin, Guy Millot
  • Patent number: 9065250
    Abstract: There is provided an optical amplifier including a diffusing unit configured to be driven by a first current density and to increase a beam diameter of an incident laser beam that passes through a first waveguide that guides the laser beam, and an amplifying unit configured to be driven by a second current density that is higher than the first current density and to amplify intensity of the laser beam that passes through a second waveguide that guides the laser beam whose beam diameter has been increased by the diffusing unit. The first waveguide of the diffusing unit has a tapered shape in which a cross-sectional area of the first waveguide is gradually increased toward a travelling direction of the laser beam.
    Type: Grant
    Filed: March 13, 2014
    Date of Patent: June 23, 2015
    Assignee: SONY CORPORATION
    Inventor: Hiroshi Yoshida
  • Patent number: 9059799
    Abstract: An apparatus comprising a processor configured to calculate a noise figure of an optical amplifier for a plurality of selected wavelength channels in a partial-fill scenario that accounts for channel loading. The noise figure is calculated using a plurality of corresponding noise figure correction values at a plurality of wavelengths based on an effective number of channels.
    Type: Grant
    Filed: April 21, 2011
    Date of Patent: June 16, 2015
    Assignee: Futurewei Technologies, Inc.
    Inventors: Zhiping Jiang, Jian Zhong, Yan Cui