With Multiple Systems Patents (Class 359/341.33)
  • Patent number: 11303094
    Abstract: An optical amplifier includes two amplifier stages, a circulator and an output stage. The first amplifier stage amplifies an input optical signal, and provides a first-stage amplified optical signal that is to be outputted via the circulator to the second amplifier stage. The second amplifier stage amplifies the first-stage amplified optical signal, and outputs a second-stage amplified optical signal to the output stage. The output stage outputs a returned optical signal to the second amplifier stage, so that the second amplifier stage amplifies the returned optical signal, and provides a third-stage amplified optical signal that is to be outputted via the circulator and the output stage to serve as an output optical signal.
    Type: Grant
    Filed: August 16, 2019
    Date of Patent: April 12, 2022
    Assignee: AOC Technologies (Wuhan) Co., Ltd.
    Inventors: Jiyu Peng, Lei Hu, Lijie Qiao
  • Patent number: 11245242
    Abstract: The present invention relates to the field of optical communication, and particularly to a balanced pumping L-band optical fiber amplifier comprising a first erbium-doped optical fiber, a second erbium-doped optical fiber, an absorbing erbium-doped optical fiber and at least two pumping lasers, the first erbium-doped optical fiber, the second erbium-doped optical fiber and the absorbing erbium-doped optical fiber being sequentially arranged in this order, and the at least two pumping lasers providing pumping light; wherein the first erbium-doped optical fiber and the second erbium-doped optical fiber both are injected with forward pumping light and backward pumping light, and the absorbing erbium-doped fiber is arranged downstream of the second erbium-doped optical fiber to absorb amplified spontaneous emission (ASE) generated in the amplifier.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: February 8, 2022
    Assignee: Accelink Technologies Co., Ltd.
    Inventors: Chengpeng Fu, Zhenyu Yu, Qing Liu, Menghui Le, Chunping Yu
  • Patent number: 11201676
    Abstract: The invention discloses a method of amplifying an optical signal, in particular a data signal, transmitted from a first location (A) to a second location (B) via a first transmission link (10a), wherein said optical signal is amplified by means of a transmitter side remote optically pumped amplifiers (ROPA) (18) comprising a gain medium (24), wherein the gain medium (24) of said transmitter side ROPA (18) is pumped by means of transmitter side pump power (20) provided from said first location (A), characterized in that at least a part of said transmitter side pump power (20) is provided by means of light supplied from said first location (A) to said transmitter side ROPA (18) via a portion of a second transmission link (10b) provided for transmitting optical signals from said second location (B) to said first location (A).
    Type: Grant
    Filed: April 13, 2017
    Date of Patent: December 14, 2021
    Assignee: XIEON NETWORKS S.a.r.l.
    Inventors: Lutz Rapp, Nelson Costa
  • Patent number: 10958370
    Abstract: In order to provide a compact and low power consumption optical repeater capable of amplifying a plurality of wavelength ranges, the optical repeater is provided with: an excitation means which generates excitation light in a single wavelength range; a first light amplification means which is excited by the excitation light and the amplification band of which is a first wavelength range; and a second light amplification means which is excited by the excitation light and the amplification band of which is a second wavelength range different from the first wavelength range.
    Type: Grant
    Filed: January 3, 2020
    Date of Patent: March 23, 2021
    Assignee: NEC CORPORATION
    Inventor: Satoshi Mikami
  • Patent number: 10447004
    Abstract: A laser diode system includes plurality of laser pumps, each of the plurality of laser pumps including a plurality of laser diode drivers and a plurality of laser diode elements, wherein each of the plurality of laser diode drivers is electrically coupled to power at least two of the plurality of laser diode elements. A combiner electrically is coupled to the plurality of laser diode elements to combine an output of each of the plurality of laser pumps to generate a combined output light. A controller identifies a failed laser pump or a failed laser diode element, receives an encoded key to gain access to the controller, and disables the failed laser pump or the failed laser diode element based at least in part on authenticating the encoded key.
    Type: Grant
    Filed: November 18, 2016
    Date of Patent: October 15, 2019
    Assignee: NLIGHT, INC.
    Inventor: Robert Joseph Foley
  • Patent number: 10396525
    Abstract: A laser diode system includes plurality of laser pumps, each of the plurality of laser pumps including a plurality of laser diode drivers and a plurality of laser diode elements, wherein each of the plurality of laser diode drivers is electrically coupled to power at least two of the plurality of laser diode elements. A combiner electrically is coupled to the plurality of laser diode elements to combine an output of each of the plurality of laser pumps to generate a combined output light. A controller identifies a failed laser pump or a failed laser diode element, receives an encoded key to gain access to the controller, and disables the failed laser pump or the failed laser diode element based at least in part on authenticating the encoded key.
    Type: Grant
    Filed: November 18, 2016
    Date of Patent: August 27, 2019
    Assignee: NLIGHT, INC.
    Inventor: Robert Joseph Foley
  • Patent number: 10374379
    Abstract: A fiber amplifier includes an isolator, a gain fiber to amplify an input laser signal, and an optical filter disposed between the isolator and the gain fiber. The optical filter transmits the laser signal and reflects amplified spontaneous emission (ASE) propagating from the gain fiber toward the isolator. The reflected ASE reenters the gain fiber and is absorbed by the gain fiber for amplifying the input laser signal. The optical filter in the amplifier can protect the usually expensive isolator and reduce potential damage to the gain fiber induced by fluctuation of the input laser signal power, as well as reduce potential photodarkening at the input of the gain fiber.
    Type: Grant
    Filed: September 9, 2016
    Date of Patent: August 6, 2019
    Assignee: Massachusetts Institute of Technology
    Inventor: Steven J. Augst
  • Patent number: 10298331
    Abstract: An optical transmission system is configured to optically transmit data from an optical transmitter to an optical receiver using a plurality of subcarriers. The optical transmitter includes a control unit configured to transmit a measurement signal using a subcarrier included in a band used for optical transmission when a signal is communicated to the optical receiver, the control unit being configured to calculate transmission characteristics obtained between the optical transmitter and the optical receiver based on the measurement signal returned from the optical receiver, and the control unit being configured to allocate, based on the transmission characteristics, a communication link to a subcarrier excellent in the transmission characteristics and least affecting transmission capacity. The optical receiver is configured to return the measurement signal received thereby to the optical transmitter.
    Type: Grant
    Filed: July 13, 2017
    Date of Patent: May 21, 2019
    Assignee: FUJITSU OPTICAL COMPONENTS LIMITED
    Inventor: Yasushi Koiwai
  • Patent number: 10299020
    Abstract: A method and apparatus for signal processing by light waveform shaping are provided to process an uplink signal generated by a digital-to-analog converter (DAC) and/or process a downlink signal to be transmitted to an analog-to-digital converter (ADC). The method includes adjusting the waveform of the uplink signal and/or the waveform of the downlink signal with a light waveform shaping module so that, even if the DAC and/or ADC has a low sampling rate and a narrow bandwidth, a high-frequency signal portion of the uplink signal and/or a high-frequency signal portion of the downlink signal can be preserved.
    Type: Grant
    Filed: June 28, 2018
    Date of Patent: May 21, 2019
    Assignee: National Sun Yat-Sen University
    Inventor: Chia-Chien Wei
  • Patent number: 9948422
    Abstract: A communication system includes a first optical system and a second optical system optically connected to a clamping laser and a pump laser. The first optical system includes first and second optical splitters. The first optical splitter is configured to receive a clamping laser signal from the clamping laser and split the signal into split clamping laser signals. The second optical splitter is configured to receive a pump laser signal from the pump laser and split signal into split pump laser signals. The second optical system is optically connected to the first optical system and includes amplifier systems. Each amplifier system is configured to receive a multiplexed signal. The second optical system includes first and second combiners optically connected to an erbium-doped fiber. The first combiner is optically connected to the first splitter, and the second combiner is optically connected to the second splitter.
    Type: Grant
    Filed: February 9, 2017
    Date of Patent: April 17, 2018
    Assignee: Google LLC
    Inventors: Xiangjun Zhao, Chiachi Wang, Daoyi Wang, Cedric Fung Lam, Liang Du, Changhong Joy Jiang
  • Patent number: 9502860
    Abstract: A tunable swept multi-laser system comprising a first laser source, a second laser source, a first wavelength blocking component, and a second wavelength blocking component. The first laser source has a first wavelength working range and the second laser source has a second wavelength working range. The first wavelength working range begins at a first start wavelength and ends at a first end wavelength. The second wavelength working range begins at a second start wavelength, ends at a second end wavelength, and overlaps with the first wavelength working range. The first wavelength blocking component has a first wavelength blocking range including the first end wavelength. The second wavelength blocking component has a second wavelength blocking range including the second start wavelength. The first wavelength blocking component is optically coupled with the first laser source and the second wavelength blocking component is optically coupled with the second laser source.
    Type: Grant
    Filed: March 14, 2014
    Date of Patent: November 22, 2016
    Assignee: Insight Photonic Solutions, Inc.
    Inventor: Michael Minneman
  • Patent number: 9450371
    Abstract: A laser utilizes a cavity design which allows the stable generation of high peak power pulses from mode-locked multi-mode fiber lasers, greatly extending the peak power limits of conventional mode-locked single-mode fiber lasers. Mode-locking may be induced by insertion of a saturable absorber into the cavity and by inserting one or more mode-filters to ensure the oscillation of the fundamental mode in the multi-mode fiber. The probability of damage of the absorber may be minimized by the insertion of an additional semiconductor optical power limiter into the cavity.
    Type: Grant
    Filed: September 14, 2015
    Date of Patent: September 20, 2016
    Assignee: IMRA AMERICA, INC.
    Inventor: Martin E. Fermann
  • Patent number: 9413462
    Abstract: An optical amplification repeater includes a first rare-earth-doped optical amplification medium which amplifies a first signal light to be transmitted to a downstream, a second rare-earth-doped optical amplification medium which amplifies a second signal light to be transmitted to an upstream, and a pump light split and guide unit configured to split a pump light transmitted together with any of the first and second signal lights and to guide the split pump light to each of the first and second rare-earth-doped optical amplification mediums.
    Type: Grant
    Filed: February 2, 2015
    Date of Patent: August 9, 2016
    Assignee: FUJITSU LIMITED
    Inventor: Miki Onaka
  • Publication number: 20150098125
    Abstract: A multiple-output laser component is described with a plurality of diode lasers in a common package, each of the diode lasers having distinct electrical control and optically coupled to a distinct output fiber, the component configured such that up to a maximum total output power can be selectively and dynamically partitioned among said diode lasers. The dynamic allocation can be based on demand for laser power in a fiber optic coupled to each diode laser. The multi-output laser component can be used to drive amplifiers associated with a multicast switch in some embodiments.
    Type: Application
    Filed: October 6, 2014
    Publication date: April 9, 2015
    Inventors: Ilya Vorobeichik, Edward C. Vail, Anthony J. Ticknor
  • Patent number: 9001414
    Abstract: The invention relates to a high power amplifier waveguide for amplifying an optical signal wherein photo darkening due to high optical flux is reduced considerably. This is achieved by providing a cladding pumped amplifier waveguide wherein the optical mode overlap to the active material of the waveguide is low and/or wherein the active material is distributed over a large cross sectional region of the waveguide.
    Type: Grant
    Filed: November 30, 2009
    Date of Patent: April 7, 2015
    Assignee: NKT Photonics A/S
    Inventors: Kent Mattsson, Kim Per Hansen
  • Publication number: 20150085352
    Abstract: In an example embodiment, an optical amplifier comprises a doped multi-core optical fiber and two optical couplers placed at the ends of the doped multi-core fiber, with each optical coupler having a respective plurality of optical waveguide cores optically coupled to the optical waveguide cores of the doped multi-core fiber. The spatial arrangement of the cores at the input end of the first optical coupler is configured for low-loss intake of the optical energy from the input transmission line. The spatial arrangement of the cores at the output end of the first optical coupler and the spatial arrangement of the cores at the input end of the second optical coupler match the spatial arrangement of the cores in the doped multi-core fiber. The spatial arrangement of the cores at the output end of the second optical coupler is configured for low-loss transfer of the optical energy into the output transmission line.
    Type: Application
    Filed: September 20, 2013
    Publication date: March 26, 2015
    Applicant: ALCATEL-LUCENT USA INC.
    Inventors: Roland Ryf, Nicolas K. Fontaine, Rene-Jean Essiambre, David Neilson
  • Patent number: 8941911
    Abstract: Doped fiber amplifiers (DFA) using rare-earth doping materials with linear and non-linear interactions between the optical signal to be amplified and the pump laser have become a standard element of optical telecommunications systems for multiple applications including for example extending the reach of optical links before opto-electronic conversion is required or support increased fanout. However, in many applications wherein multiple DFAs are employed the electrical power budget wherein the pump laser diode (LD) represents approximately 25% of the module power consumption directly, and closer to approximately 40-50% once the control and drive electronics for the thermoelectric cooler and LD are included. Accordingly, it would be beneficial to reduce the overall power consumption of a DFA by exploiting unused optical pump power such that multiple gain stages, within the same or different DFAs, may be driven from a single pump LD.
    Type: Grant
    Filed: November 15, 2013
    Date of Patent: January 27, 2015
    Assignee: Viscore Technologies Inc.
    Inventors: Yunqu Liu, Kin-Wai Leong
  • Patent number: 8837948
    Abstract: In the method for processing a signal light from free-space by amplifying said signal for free-space optical communications, wherein the improvement includes the steps of (a) pre-amplifying said signal light with low noise; and (b) coupling said signal light into a multimode filter which reduces coupling losses compared to single mode filters.
    Type: Grant
    Filed: June 24, 2010
    Date of Patent: September 16, 2014
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventors: Robert T. Carlson, Daniel J. Creeden
  • Patent number: 8830568
    Abstract: In some embodiments, the present invention provides an apparatus, method and use for improving and merging two existing techniques (core pumping and cladding pumping) to enable high-power fiber-laser systems having excellent beam quality while using large-core (LMA) step-index gain fibers at very high optical power, wherein the core pumping includes mixing a laser seed optical signal (having a signal wavelength) with optical core-pump light (having a core-pump wavelength that is near the signal wavelength) in a manner that matches the modes of the seed optical signal and the pump light. The combined core light is mode matched to the LMA gain fiber. The core-pump light is substantially all absorbed within a short distance from the entry end of the gain fiber and provides a strong pre-amplified signal for later cladding-pumped amplification. In some embodiments, the signal wavelength and the core-pump wavelength are within a single multiplet of a rare-earth dopant.
    Type: Grant
    Filed: April 12, 2011
    Date of Patent: September 9, 2014
    Assignee: Lockheed Martin Corporation
    Inventors: Matthias P. Savage-Leuchs, Christian E. Dilley
  • Publication number: 20140240819
    Abstract: A multi-core amplification optical fiber includes a plurality of rare-earth-doped core portions and a cladding portion positioned at an outer periphery of the core portions and having refractive index lower than those of the core portions. When a doping concentration of the rare-earth of each of the core portions is 250 ppm to 2000 ppm, a relative refractive index difference of each of the core portions relative to the cladding portion is 0.5% to 2% at a wavelength of 1550 nm, and a core diameter of each of the core portions is 1 ?m to 5 ?m, a separation distance between each of the core portions and adjacent one of the core portions is set at equal to or larger than 30 ?m and at equal to or smaller than 60 ?m so that a light-crosstalk between the adjacent core portions is equal to or lower than ?30 dB.
    Type: Application
    Filed: April 4, 2014
    Publication date: August 28, 2014
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventors: Yukihiro TSUCHIDA, Koichi Maeda, Yu Mimura, Hiroshi Matsuura, Kengo Watanabe, Tsunetoshi Saito, Ryo Miyabe, Shigeto Matsumoto, Keiichi Aiso, Ryuichi Sugizaki
  • Patent number: 8767288
    Abstract: Systems and methods for amplification are shown that include a pump preparation module configured to provide a pump output that includes a plurality of pump modes; an amplification module configured to accept a multimode signal input and the pump output, such that the pump output causes an amplification of a plurality of modes in the signal input to produce an amplified signal output; and a gain control module configured to adjust a balance of the plurality of pump modes in the pump output to produce a predetermined amplified signal output.
    Type: Grant
    Filed: April 11, 2012
    Date of Patent: July 1, 2014
    Assignee: NEC Laboratories America, Inc.
    Inventors: Neng Bai, Ezra Ip
  • Publication number: 20140139909
    Abstract: An optical amplification device includes: a plurality of semiconductor optical amplifiers to which an optical burst signal is input at a different timing; an optical coupler that combines output signals output from the plurality of semiconductor optical amplifiers; a detection unit that detects an optical inputting to the plurality of semiconductor optical amplifiers; and a control unit that activates one of the semiconductor optical amplifiers where the optical inputting is detected, inactivates the other semiconductor optical amplifier, and remains the activation until another optical inputting is detected in the other semiconductor optical amplifier.
    Type: Application
    Filed: November 6, 2013
    Publication date: May 22, 2014
    Applicant: FUJITSU LIMITED
    Inventors: Susumu KINOSHITA, Setsuo YOSHIDA
  • Publication number: 20130286468
    Abstract: A Raman amplifier using semiconductor lasers of Fabry-Perot, DFB, or DBR type or MOPAs, to output pumping lights having different central wavelengths, an interval between adjacent central wavelengths greater than 6 nm and smaller than 35 nm. An optical repeater is adapted to compensate loss in an optical fibre transmission line by the Raman amplifier. A Raman amplification method wherein the shorter the central wavelength of the pumping light, the higher light power of the pumping light. In the Raman amplifier, a certain pumping 1 wavelength being a first channel, and second to n-th channels are arranged with an interval of about 1 THz toward a longer wavelength side, pumping lights having wavelengths corresponding to the first to n-th channels are multiplexed, and pumping light having a wavelength spaced apart from the n-th channel by 2 THz or more toward the longer wavelength side is combined with the multiplexed light, thereby forming the pumping light source.
    Type: Application
    Filed: April 9, 2013
    Publication date: October 31, 2013
    Applicant: FURUKAWA ELECTRIC CO., LTD.
    Inventor: FURUKAWA ELECTRIC CO., LTD.
  • Publication number: 20130250402
    Abstract: A laser beam amplifier with high optical axis stability is provided. The laser beam amplifier includes: a container for accommodating a laser medium; a pair of electrodes for performing discharge in the laser medium to form an amplification region for a laser beam in the laser medium; and an optical system for forming an optical path between a first point, upon which the laser beam is incident, and a second point, from which the laser beam is outputted, such that the amplification region is located in the optical path between the first point and the second point, wherein the first point and the second point are conjugate to each other, and the laser beam incident upon the first point is amplified while passing through the amplification region at least twice and then transferred to the second point.
    Type: Application
    Filed: May 15, 2013
    Publication date: September 26, 2013
    Applicant: GIGAPHOTON INC.
    Inventors: Krzysztof NOWAK, Masato MORIYA, Osamu WAKABAYASHI
  • Patent number: 8493652
    Abstract: The invention refers to a method for operating an amplifier with a first amplifier stage (A1) and a second amplifier stage (A2), pumped by a single pump light source (11) generating a primary pump signal (SPUMP), which is split into first pump signal (S1) and a second pump signal (S2) according to a variable splitting factor (?) for pumping the first amplifier stage (A1) and the second amplifier stage (A2) respectively. The splitting factor (?) is varied to achieve an optimized noise figure.
    Type: Grant
    Filed: March 11, 2009
    Date of Patent: July 23, 2013
    Assignee: Nokia Siemens Networks Oy
    Inventors: Lutz Rapp, Dario Setti
  • Patent number: 8482849
    Abstract: A Raman amplifier, at the time of start up or the like, drives a predetermined number of pump light sources among a plurality of pump light sources, in a stable region, and judges a Raman gain in the transmission line, and based on the judgment result, specifies a pump light source to switch on and a pump light source to switch off, among the plurality of pump light sources, and controls the drive state of the pump light sources that are switched on. As a result, the plurality of pump light sources are appropriately driven corresponding to the system requirements so that stable behavior is possible, and constant control of Raman gain can be realized at a high accuracy.
    Type: Grant
    Filed: September 1, 2009
    Date of Patent: July 9, 2013
    Assignee: Fujitsu Limited
    Inventor: Miki Onaka
  • Patent number: 8379299
    Abstract: An optical amplifier includes a first excitation light source that outputs a first excitation light; a second excitation light source that outputs a second excitation light; a first amplifying optical fiber doped with a rare-earth element and excited by the first excitation light to amplify light input to the first amplifying optical fiber; and a second amplifying optical fiber doped with a rare-earth element and excited by the second excitation light to amplify the light from the first amplifying optical fiber. A ratio between the intensity of the first excitation light and the intensity of the second excitation light is controlled according to the number of signal lights wavelength-multiplexed in the light input.
    Type: Grant
    Filed: January 23, 2010
    Date of Patent: February 19, 2013
    Assignee: Fujitsu Limited
    Inventors: Tomoaki Takeyama, Keiko Sasaki, Shinichirou Muro
  • Patent number: 8379298
    Abstract: A high power short optical pulse source 10 can include a master oscillator 12, preamplifier 14, and pump laser 16 provided within a first enclosure 28 at a first location. The high power short optical pulse source can further include a high power fiber amplifier 20 provided within an optical head 18, which is located at a second location, remote from the first location. The optical head 18 can have a small footprint and can be positioned at the intended target of optical pulses output from the high power short optical pulse source. The large, noisy elements of the high power short optical pulse source 10 are thereby provided away from the application site of the pulses.
    Type: Grant
    Filed: January 18, 2007
    Date of Patent: February 19, 2013
    Assignee: Fianium Ltd
    Inventors: John Redvers Clowes, Anatoly Borisovich Grudinin, Ian Michael Godfrey, Kestutis Vysniauskas
  • Patent number: 8363311
    Abstract: An optical amplifier has a pump and an “anti-pump” for reducing a variation of the amplifier gain with the input optical power. The wavelength of “anti-pump” light is longer than the wavelength of the optical signal being amplified, so that the optical signal serves as a pump for the “anti-pump” light, whereby an optical loss variation with the signal power at the signal wavelength is created, which reduces optical gain variation with the signal power. To compensate for gain loss due to the anti-pump light, two and three stages of amplification can be used.
    Type: Grant
    Filed: December 23, 2009
    Date of Patent: January 29, 2013
    Inventor: Lijie Qiao
  • Patent number: 8351110
    Abstract: An optical-signal processing apparatus includes a polarizer that is provided at an output terminal of an optical fiber, and polarization control units that adjust a first excitation light and a second excitation light input to the optical fiber. The polarization control units adjust polarization states of the first excitation light and the second excitation light so that, when the first excitation light and the second excitation light are input to the polarizer, polarization directions of the first excitation light and the second excitation light are orthogonal to each other, and angular difference between the polarization direction of the first excitation light and the polarization direction of the second excitation light, measured against the polarization main axis of the polarizer, is equal to or smaller than a threshold value.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: January 8, 2013
    Assignee: Fujitsu Limited
    Inventor: Shigeki Watanabe
  • Patent number: 8300306
    Abstract: A Raman amplifier includes at least a first and a second optical Raman-active fiber disposed in series with each other. A first pump source is connected to the first Raman-active fiber, and is adapted for emitting and coupling into the first Raman-active fiber a first pump radiation including a first group of frequencies. A second pump source is connected to the second Raman-active fiber, and is adapted for emitting and coupling into the second Raman-active fiber a second pump radiation including a second group of frequencies. The whole of said first and second group of frequencies extends over a pump frequency range having a width of at least the 40% of the Raman shift. The minimum and the maximum frequency in each of said first and second group of frequencies differ with each other of at most the 70% of said Raman shift.
    Type: Grant
    Filed: October 4, 2010
    Date of Patent: October 30, 2012
    Assignee: Google Inc.
    Inventors: Attilio Bragheri, Giulia Pietra, Raffaele Corsini, Danilo Caccioli
  • Patent number: 8284479
    Abstract: A system for optical communication including an optical amplifier card configured to receive a plurality of pump laser modules. The optical amplifier card includes a receptacle configured to receive the pump laser module, a connector configured to couple the pump laser module to the optical amplifier card, a monitor configured to measure at least the optical output power of the pump laser module, and a pump combiner communicatively coupled to the monitor. The pump combiner is configured to receive a signal from the monitor indicating a drop in the output power of a first pump laser module below a threshold level, and, in response to the signal, switch the optical amplifier card from using the optical power of the first pump laser module to using the optical power of a second pump laser module without substantially affecting normal operation of the optical amplifier card.
    Type: Grant
    Filed: August 18, 2009
    Date of Patent: October 9, 2012
    Assignee: Fujitsu Limited
    Inventors: Youichi Akasaka, Takao Naito
  • Publication number: 20120170111
    Abstract: One aspect provides an optical device. The optical device includes a first and a second array of optical couplers, a plurality of waveguides and a plurality of pump couplers located over a surface of a substrate. The optical couplers of the first array are able to end-couple in a one-to-one manner to the optical cores of a first multi-core fiber having an end facing and adjacent to the first array and the surface. The optical couplers of the second array are able to end-couple in a one-to-one manner to optical cores having ends facing and adjacent to the second array. The plurality of optical waveguides connects in a one-to-one manner the optical couplers of the first array to the optical couplers of the second array. Each optical waveguide has a pump coupler connected thereto between the ends of the waveguide.
    Type: Application
    Filed: January 24, 2011
    Publication date: July 5, 2012
    Inventors: Christopher Doerr, Peter Winzer
  • Patent number: 8189258
    Abstract: An optical amplifier configuration for WDM (wavelength division multiplex) systems uses a common pump source connected to an input of an optical splitter deploying pump light via variable optical attenuators to a plurality of optical amplifiers. Control circuits determine individually the output powers of the amplifiers by varying the attenuations of the variable optical attenuators. Amplifier units based on PLC technology are implemented to reduce the size.
    Type: Grant
    Filed: June 4, 2009
    Date of Patent: May 29, 2012
    Assignee: Nokia Siemens Network Oy
    Inventors: Lutz Rapp, Dario Setti
  • Publication number: 20120062984
    Abstract: Techniques and devices for producing short laser pulses based on chirped pulse amplification.
    Type: Application
    Filed: September 13, 2010
    Publication date: March 15, 2012
    Applicant: Calmar Optcom, Inc. dba Calmar Laser, Inc.
    Inventors: Sha Tong, Jerry Prawiharjo, Hong Cong, Daniel Beom Soo Soh, Lawrence C. West, Anthony Hong Lin
  • Patent number: 8111454
    Abstract: Cross-distribution of the output pump power from optical pump units amongst multiple amplifier gain stages even in a single direction of an optical link in an optical communications system. For example, an optical pump unit may output optical pump power that is shared amongst a discrete optical amplification unit and a distributed optical amplification unit (such as a forward and/or backward Raman amplifier). Such sharing has the potential to increase reliability and/or efficiency of the optical communications system.
    Type: Grant
    Filed: February 13, 2009
    Date of Patent: February 7, 2012
    Assignee: Xtera Communications, Inc.
    Inventors: Do-Il Chang, Wayne S. Pelouch
  • Patent number: 8089690
    Abstract: The invention relates to a multistage fiber amplifier having a first amplifying fiber, at least one further amplifying fiber connected in series with the first amplifying fiber, a pump source, a first pump signal fed to the first amplifying fiber, and a further pump signal fed to the further amplifying fiber. The multistage fiber amplifier is distinguished by the fact that a further pump signal is fed to a further amplifying fiber via a power-dependent attenuation element. The attenuation element is formed in such a way that, as the pump power increases, small further pump signals are attenuated to a greater extent than large further pump signals. The power-dependent attenuation of the further pump signal that is fed to the further amplifying fiber and therefore the increased pump signal that is fed to the first amplifying fiber result in improvements in the noise figure of the multistage amplifier.
    Type: Grant
    Filed: July 3, 2006
    Date of Patent: January 3, 2012
    Assignee: GM Global Technology Operations, Inc.
    Inventor: Lutz Rapp
  • Patent number: 8081376
    Abstract: The invention relates to a light source apparatus having a structure for effectively suppressing a negative effect due to a nonlinear effect generated in propagation of an amplifying light, and realizing a stable operation. In the light source apparatus, light amplified in an optical amplifier fiber is emitted to the outside of the apparatus through an optical output fiber whose one end is connected to an output connecter. At this time, a part of Raman scattered light, generated in the optical output fiber, propagates toward an pumping light source through the optical amplifier fiber from the optical output fiber. An optical component having an insertion loss spectrum that attenuates the Raman scattered light but allows pumping light or light to be amplified to transmit therethrough, is provided on a propagation path of the Raman scattered light, due to the light component, the intensity of the Roman scattered light reaching the pumping light source is effectively reduced.
    Type: Grant
    Filed: May 27, 2008
    Date of Patent: December 20, 2011
    Assignee: Sumitomo Electric Industries, Ltd.
    Inventors: Motoki Kakui, Shinobu Tamaoki
  • Patent number: 8059334
    Abstract: An optical fiber amplifier system is described and comprises a first optical fiber having a doped core with a first gain spectral profile upon being pumped. The first optical fiber is adapted to receive an optical signal from a light source. A second optical fiber has a doped core with a second gain spectral profile upon being pumped. The second optical fiber is optically coupled to the first optical fiber. A continuous wave pump light system is optically coupled to the fibers so as to store energy in the fibers for a subsequent amplification of the optical signal from the light source. An overlapping configuration is provided between the first gain spectral profile and the second gain spectral profile so as to reduce energy depletion in one of the optical fibers from amplification of spontaneous emission generated by another of the optical fibers.
    Type: Grant
    Filed: January 16, 2009
    Date of Patent: November 15, 2011
    Assignee: Institut National d'Optique
    Inventors: François Brunet, Pascal Deladurantaye, Yves Taillon
  • Publication number: 20110255153
    Abstract: An optical amplifier comprises at least two gain regions, an intermediate region situated between the gain regions, and a transition region situated between the intermediate region and each gain region. The aforesaid regions have claddings that collectively form a path for pump radiation propagating from at least one of the gain regions to the other gain region, and cores that collectively form a path for signal radiation propagating from at least one of the gain regions to the other gain region. The cores in the gain regions support multiple propagating optical modes, including at least one signal mode and at least one non-signal mode. The intermediate region, however, supports fewer propagating core modes than are supported by the gain regions. The transition regions are conformed such that when radiation in propagating non-signal core modes passes from the gain regions into the intermediate region, it is at least partly coupled into cladding modes of the intermediate region.
    Type: Application
    Filed: April 16, 2010
    Publication date: October 20, 2011
    Inventors: Douglas P. Holcomb, Thomas Huntington Wood, Paul Wysocki
  • Patent number: 8031395
    Abstract: The optical transmission system modulates backward Raman pump light provided to an optical transmission line on one link side of an uplink and downlink, to thereby transmit a pilot signal for confirming a connection state of the optical transmission line to a node on an upstream side. When the pilot signal is received by the node on the upstream side, the backward Raman pump light provided to the optical transmission link on the opposite link side is modulated to thereby send back a response signal to an own node. Then by confirming receipt of the response signal at the own node, the backward Raman pump light provided to the optical transmission line on the one link side is changed over from a low output state to a high output state.
    Type: Grant
    Filed: September 8, 2008
    Date of Patent: October 4, 2011
    Assignee: Fujitsu Limited
    Inventor: Futoshi Izumi
  • Publication number: 20110085231
    Abstract: A reconfigurable optical amplifier is formed of a plurality of optical switches and a plurality of fiber amplifier sections to provide a switchable amplifying network. A variable pump splitter provides pump light from an optical pump source to two or more fiber amplifier sections. The optical switches and variable pump splitters are formed in a planar lightwave circuit, which may further include pump WDM combiners, variable optical attenuators, tap couplers and other optical components, and to which monitoring photodiodes and the fiber amplifier sections are coupled. A same PLC can be used for a wide variety of reconfigurable optical amplifiers.
    Type: Application
    Filed: October 6, 2010
    Publication date: April 14, 2011
    Inventors: Maxim BOLSHTYANSKY, Gregory Cowle
  • Patent number: 7916386
    Abstract: Optical apparatus includes a multimode, gain-producing fiber for providing gain to signal light propagating in the core of the fiber, and a pump source for providing pump light that is absorbed in the core, characterized in that (i) the pump source illustratively comprises a low brightness array of laser diodes and a converter for increasing the brightness of the pump light, (ii) the pump light is coupled directly into the core, and (iii) the area of the core exceeds approximately 350 ?m2. In one embodiment, the signal light propagates in a single mode, and the pump light co-propagates in at least the same, single mode, both in a standard input fiber before entering the gain-producing fiber, and a mode expander is disposed between the input fiber and the gain-producing fiber. In another embodiment, multiple pumps are coupled into the core of the gain-producing fiber. The pumps may generate light of the same wavelength or of different wavelengths.
    Type: Grant
    Filed: January 26, 2007
    Date of Patent: March 29, 2011
    Assignee: OFS Fitel, LLC
    Inventors: David John DiGiovanni, Clifford Everill Headley
  • Patent number: 7894128
    Abstract: A terahertz imaging system and method of use including a compact Yb-doped fiber laser-pumped ZGP crystal as a THz source and an uncooled microbolometer array as a detector. According to the present invention, semiconductor lasers are also drive current modulated to produce desired laser pulsewidth, repetition rate and wavelengths needed for DFG THz generation in various non-linear crystals. The fiber-coupled semiconductor lasers provide at least two wavelengths that will produce THz radiation by DFG in non-linear converter. These two wavelengths are combined and amplified in a single Yb fiber amplifier chain. Yb amplifier is staged in continually increasing core diameters to provide significant signal amplification while suppressing deleterious non-linear effects.
    Type: Grant
    Filed: February 1, 2008
    Date of Patent: February 22, 2011
    Assignee: BAE Systems Information and Electronic Systems Integration Inc.
    Inventors: John C. McCarthy, Daniel Creeden, Peter A. Ketteridge
  • Patent number: 7876497
    Abstract: There is provided a long-band rare-earth-doped optical amplifier and method for amplifying an optical signal. The optical amplifier has a pre-, a mid- and a post-amplification stage. Only the mid-amplification stage is pumped with a pump light source. The other two are pumped using Amplified Spontaneous Emission (ASE) generated in the mid-amplification stage. An optical coupling device is used to couple the three amplification stages together and to split the ASE generated in the mid-amplification stage and available at one end of the mid-amplification stage. One part of the split ASE is used to pump the pre-amplification stage while the other part is used to pump the post-amplification stage.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: January 25, 2011
    Assignee: Institut National D'Optique
    Inventor: Louis Desbiens
  • Publication number: 20100315702
    Abstract: An optical transmission node including an optical preamplifier to amplify input light and an optical postamplifier to amplify light output from the optical preamplifier, includes the optical postamplifier configured to generate amplified spontaneous emission light without signals input, the optical preamplifier configured to amplify the amplified spontaneous emission light from the optical postamplifier, a loopback switch configured to discouple a path of the light output from the optical preamplifier to the optical postamplifier, and couple a path of the light output from the optical postamplifier to the optical preamplifier.
    Type: Application
    Filed: June 15, 2010
    Publication date: December 16, 2010
    Applicant: FUJITSU LIMITED
    Inventors: Hiroyuki ITOH, Takuji Maeda
  • Patent number: 7813034
    Abstract: A Raman amplifier comprises at least a first and a second optical Raman-active fiber disposed in series with each other. A first pump source is connected to the first Raman-active fiber, and is adapted for emitting and coupling into the first Raman-active fiber a first pump radiation including a first group of frequencies. A second pump source is connected to the second Raman-active fiber, and is adapted for emitting and coupling into the second Raman-active fiber a second pump radiation including a second group of frequencies. The whole of said first and second group of frequencies extends over a pump frequency range having a width of at least the 40% of the Raman shift. The minimum and the maximum frequency in each of said first and second group of frequencies differ with each other of at most the 70% of said Raman shift.
    Type: Grant
    Filed: May 18, 2007
    Date of Patent: October 12, 2010
    Assignee: PGT Photonics S.p.A.
    Inventors: Attilio Bragheri, Giulia Pietra, Raffaele Corsini, Danilo Caccioli
  • Publication number: 20100157417
    Abstract: An optical-signal processing apparatus includes a polarizer that is provided at an output terminal of an optical fiber, and polarization control units that adjust a first excitation light and a second excitation light input to the optical fiber. The polarization control units adjust polarization states of the first excitation light and the second excitation light so that, when the first excitation light and the second excitation light are input to the polarizer, polarization directions of the first excitation light and the second excitation light are orthogonal to each other, and angular difference between the polarization direction of the first excitation light and the polarization direction of the second excitation light, measured against the polarization main axis of the polarizer, is equal to or smaller than a threshold value.
    Type: Application
    Filed: February 26, 2010
    Publication date: June 24, 2010
    Applicant: FUJITSU LIMITED
    Inventor: Shigeki Watanabe
  • Patent number: 7729046
    Abstract: In a laser device, a crystal array includes a laser gain crystal and an optically non-linear frequency conversion crystal. A pump source couples at least two mutually spatially separated pump beams into the crystal array. Between two pump beams, a saw kerf of the crystal array extends parallel to the pump beams.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: June 1, 2010
    Assignee: Osram Opto Semiconductors GmbH
    Inventors: Michael Kühnelt, Thomas Schwarz, Ulrich Steegmüller, Frank Singer
  • Publication number: 20100067099
    Abstract: A Raman amplifier according to the present invention comprises a plurality of pumping means using semiconductor lasers of Fabry-Perot, DFB, or DBR type or MOPAs, and pumping lights outputted from the pumping means have different central wavelengths, and interval between the adjacent central wavelength is greater than 6 nm and smaller than 35 nm. An optical repeater according to the present invention comprises the above-mentioned Raman amplifier and adapted to compensate loss in an optical fiber transmission line by the Raman amplifier. In a Raman amplification method according to the present invention, the shorter the central wavelength of the pumping light the higher light power of said pumping light.
    Type: Application
    Filed: November 16, 2009
    Publication date: March 18, 2010
    Applicant: The Furukawa Electric Co., Ltd.
    Inventors: Youichi AKASAKA, Yoshihiro Emori, Shu Namiki