Optical Fiber Patents (Class 359/341.1)
  • Patent number: 9077150
    Abstract: A high power fiber laser system consisting of multiple fiber amplifier or laser systems amplifying the input signal in parallel is configured with a high power splitter such as to share some of the gain stages. The high power splitting component consists of high power fiber couplers and splitter(s). The splitter is a holographic optical element, a dielectric coated plate, a diffraction grating, or a volume Bragg grating. The resultant fiber laser configuration reduces the total number of amplifying stages including optical isolators and active fiber assemblies for the system and thus reduces the total volume and weight.
    Type: Grant
    Filed: August 7, 2013
    Date of Patent: July 7, 2015
    Assignee: IPG PHOTONICS CORPORATION
    Inventors: Alex Yusim, Roman Yagodkin
  • Patent number: 9054480
    Abstract: A tunable laser configured in a small package coupled to a printed circuit board. The tunable laser includes a housing with a volume formed by exterior walls. An electrical input interface is positioned at the first end of the housing. An optical output interface is positioned at the second end of the housing and configured to transmit a continuous wave optical beam. A semiconductor optical amplifier or gain chip produces an optical output beam, and an optical isolator is positioned directly downstream of the gain chip to prevent the incoming light from the downstream optics from reflecting back though the isolator and into the cavity of the laser. A beam splitter directs a portion of the light transmitted through the isolator back into the other end of the gain chip.
    Type: Grant
    Filed: October 20, 2014
    Date of Patent: June 9, 2015
    Assignee: NeoPhotonics Corporation
    Inventor: Andrew John Daiber
  • Patent number: 9042006
    Abstract: An exemplary illumination source for an inspection system includes a pulsed seed laser having a wavelength of approximately 1104 nm and a continuous wave, Raman seed laser having a wavelength of approximately 1160 nm. An optical coupler can combine outputs of the pulsed seed laser and the continuous wave, Raman seed laser. Pre-amplification stages can receive an output of the optical coupler. A power amplifier can receive an output of the pre-amplification stages. A sixth harmonic can be generated using the amplified, combined wavelength. Systems for inspecting a specimen such as a reticle, photomask or wafer can include one of the illumination sources described herein.
    Type: Grant
    Filed: September 9, 2013
    Date of Patent: May 26, 2015
    Assignee: KLA-Tencor Corporation
    Inventor: J. Joseph Armstrong
  • Patent number: 9025239
    Abstract: A double-clad (DC) multicore (MC) Erbium-doped fiber amplifier (EDFA) for dense-wavelength-division multiplexing (DWDM) is disclosed. The DC-MC-EDFA comprises a length of DC-MC Erbium-doped fiber (EDF) that is core-matched spliced to a MC tapered signal-pump fiber combiner (TFC). For some embodiments, the optical signals are coupled into the DC-MC-EDF by the MC-TFC, and the pump energy is also coupled into the DC-MC-EDF by the MC-TFC. For some embodiments, the optical signals are also transmitted out of the DC-MC-EDF through the MC-TFC.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: May 5, 2015
    Assignee: OFS Fitel, LLC
    Inventor: Benyuan Zhu
  • Patent number: 9013786
    Abstract: High power parallel fiber arrays for the amplification of high peak power pulses are described. Fiber arrays based on individual fiber amplifiers as well as fiber arrays based on multi-core fibers can be implemented. The optical phase between the individual fiber amplifier elements of the fiber array is measured and controlled using a variety of phase detection and compensation techniques. High power fiber array amplifiers can be used for EUV and X-ray generation as well as pumping of parametric amplifiers.
    Type: Grant
    Filed: October 8, 2013
    Date of Patent: April 21, 2015
    Assignee: IMRA America, Inc.
    Inventors: Martin Fermann, Ingmar Hartl, Andrius Marcinkevicius, Liang Dong
  • Patent number: 9007681
    Abstract: A double-clad (DC) multicore (MC) Erbium-doped fiber amplifier (EDFA) for dense-wavelength-division multiplexing (DWDM) is disclosed. The DC-MC-EDFA comprises a length of DC-MC Erbium-doped fiber (EDF) that is core-matched spliced to a MC tapered signal-pump fiber combiner (TFC). For some embodiments, the optical signals are coupled into the DC-MC-EDF by the MC-TFC, and the pump energy is also coupled into the DC-MC-EDF by the MC-TFC. For some embodiments, the optical signals are also transmitted out of the DC-MC-EDF through the MC-TFC.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: April 14, 2015
    Assignee: OFS Fitel, LLC
    Inventor: Benyuan Zhu
  • Patent number: 9001416
    Abstract: The invention relates to a pulsed light source capable of effectively utilizing optical power and selecting the pulse width of output pulsed light. A pulsed light source has a MOPA structure, and comprises a seed light source and an optical fiber amplifier. The seed light source includes a semiconductor laser outputting pulsed light. In the optical fiber amplifier, an optical filter branches pulsed light amplified by a YbDF into a first wavelength component including the peak wavelength and the remaining second wavelength component. An optical switch outputs one of the pulsed light of the first wavelength component and the pulsed light of the second wavelength component which are inputted. Another YbDF amplifies the pulsed light outputted from the optical switch.
    Type: Grant
    Filed: May 22, 2012
    Date of Patent: April 7, 2015
    Assignee: Megaopto Co., Ltd.
    Inventor: Motoki Kakui
  • Patent number: 8995051
    Abstract: Embodiments of optical fiber may include cladding features that include a material (e.g., fluorine-doped silica glass) that may produce a very low relative refractive index difference with respect to cladding material in which the cladding features are disposed. This relative refractive index difference may be characterized by (n1?n2)/n1, where n1 is the index of refraction of the cladding material in which the cladding features are included, and n2 is the index of refraction of the cladding features. In certain embodiments, the relative refractive index difference may be less than about 4.5×10?3. In various embodiments, the configuration of the cladding features including, for example, the size and spacing of the cladding features, can be selected to provide for confinement of the fundamental mode yet leakage for the second mode and higher modes, which may provide mode filtering, single mode propagation, and/or low bend loss.
    Type: Grant
    Filed: April 5, 2012
    Date of Patent: March 31, 2015
    Assignee: IMRA America, Inc.
    Inventors: Liang Dong, Jun Li, Hugh McKay, Libin Fu, Andrius Marcinkevicius
  • Patent number: 8995048
    Abstract: A change in loading conditions of fiber amplifiers in an optical communications network causes rapid variations in the gain profile of the amplifiers due to spectral hole burning and stimulated Raman scattering. An apparatus for reducing such gain profile variations is described which monitors optical signal perturbations and reacts by adjusting pump powers of the amplifiers and, or fast variable optical attenuator according to a pre-determined function stored in the form of constants in controller's memory. The optical signal is monitored as total power, and the power of light after passing through one or more optical filters. The light detection is relatively fast, whereby the gain profile variations are compensated by fast controlled variable optical attenuator and pump power adjustment upon the change in loading conditions.
    Type: Grant
    Filed: May 22, 2011
    Date of Patent: March 31, 2015
    Assignee: JDS Uniphase Corporation
    Inventors: Maxim Bolshtyansky, Gregory Cowle
  • Publication number: 20150086199
    Abstract: Various exemplary embodiments relate to an optical amplifier, including: a multicore rare-earth doped optical fiber with a first plurality of cores associated with a first stage of the optical amplifier and a second plurality of cores associated with a second stage of the optical amplifier; a three dimensional (3D) waveguide configured to couple input space division multiplexed (SDM) channels into the first plurality of cores at a first end of the multicore rare-earth doped optical fiber and to couple channels from the second plurality of cores to output SDM channels; a reflector configured to optically interconnect the first plurality of cores to the second plurality of cores; and pump laser coupled to the multicore rare-earth doped optical fiber configured to produce laser pump light to pump the multicore rare-earth doped optical fiber.
    Type: Application
    Filed: September 20, 2013
    Publication date: March 26, 2015
    Applicant: ALCATEL -LUCENT USA, INC.
    Inventors: Roland Ryf, Nicolas K. Fontaine, David Neilson
  • 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: 8982452
    Abstract: A low-power “all-in-one” Yb/Raman optical fiber laser system includes a pump input, and a Yb/Raman resonator including a segment of integrated Yb/Raman fiber configured to provide both a ionic gain and Raman gain. A set of input gratings and output gratings define a series of reflector pairs that, together with the integrated Yb/Raman fiber, create a nested series of cavities that provide a stepwise transition from the input wavelength to a selected target output wavelength.
    Type: Grant
    Filed: July 11, 2012
    Date of Patent: March 17, 2015
    Assignee: OFS Fitel, LLC
    Inventors: Jeffrey W. Nicholson, Thierry F. Taunay
  • Patent number: 8982453
    Abstract: The invention relates to a laser device (1) for amplifying and/or transporting electromagnetic radiation, comprising a radiation source (2) for generating the electromagnetic radiation and an amplifier (4) for amplifying or a medium for transporting the generated electromagnetic radiation. In order to make available a device (1) for amplifying or transporting electromagnetic radiation that provides a very easy to implement possibility for reducing the influence of non-linear effects, the electromagnetic radiation propagating in the amplifier (4) or medium is largely non-linearly polarized.
    Type: Grant
    Filed: July 9, 2010
    Date of Patent: March 17, 2015
    Assignees: Fraunhofer-Gesellschaft zur Foerderung der Angewandten Forschung E.V., Friedrich-Schiller-Universitaet Jena
    Inventors: Jens Limpert, Andreas Tuennermann, Damian Schimpf, Tino Eidam, Enrico Seise, Fabian Roeser
  • Publication number: 20150063381
    Abstract: Techniques are disclosed for improving pump absorption and efficiency for fiber lasers and amplifiers, for instance. In some embodiments, the techniques are implemented by applying a partially reflective coating on a fiber end-face to double-pass any unabsorbed or otherwise excess pump light in the cladding of a fiber. While being reflective to pump wavelengths, the coating can be non-reflective at the lasing wavelength, so as to avoid unwanted feedback into the system. The benefits of this approach include that excess pump power can be effectively utilized to add more power to the laser output. In addition, the double-pass technique allows for the use of a shorter fiber length, which in turn allows for more compact system designs, saves on material costs, and facilitates manufacturability.
    Type: Application
    Filed: November 6, 2014
    Publication date: March 5, 2015
    Inventor: Daniel J. Creeden
  • Publication number: 20150062693
    Abstract: Embodiments of the present invention are generally related to a high-power liquid-cooled pump and signal combiner and methods thereof for fiber optic applications. More specifically, embodiments of the present invention relate to a pump and signal combiner capable of conveying several kilowatts of pump laser power for kilowatt class rare-earth doped fiber amplifiers without suffering thermal damage. In one embodiment of the present invention, a high-power, heat dissipating optical fiber device comprises a section of optical fiber configured to propagate light, a cooling chamber, substantially encapsulating the optical fiber, and a fluid within the cooling chamber having a refractive index selected to control the interaction and propagation of the light in the fluid.
    Type: Application
    Filed: August 28, 2013
    Publication date: March 5, 2015
    Inventors: Michael Fishteyn, Marc Mermelstein
  • Patent number: 8970947
    Abstract: Embodiments of auto-cladded optical fibers are described. The fibers may have a refractive index profile having a small relative refractive index change. For example, the fiber may include an auto-cladded structure having, e.g., a trough or gradient in the refractive index profile. A beam of light propagating in the fiber may be guided, at least in part, with the auto-cladded structure. In some embodiments, the optical fiber may be all glass. In some embodiments, the optical fiber may include a large-core or an ultra large-core.
    Type: Grant
    Filed: December 14, 2010
    Date of Patent: March 3, 2015
    Assignee: IMRA America, Inc.
    Inventors: Martin E. Fermann, Liang Dong, Libin Fu, Hugh A. McKay
  • Patent number: 8958145
    Abstract: A fiber laser amplifier system including a beam splitter that splits a feedback beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier for amplifying the fiber beam. A tapered fiber bundle couples the output ends of all of the fiber amplifiers into a combined fiber providing a combined output beam. A beam sampler samples a portion of the output beam from the tapered fiber bundle and provides a sample beam. A single mode fiber receives the sample beam from the beam sampler and provides the feedback beam.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: February 17, 2015
    Assignee: Northrop Grumman Systems Corporation
    Inventor: Joshua Elliott Rothenberg
  • Patent number: 8953240
    Abstract: A chirped diode laser (ChDL) is employed for seeding optical amplifiers and/or dissimilar optical paths, which simultaneously suppresses stimulated Brillouin scattering (SBS) and enables coherent combination. The seed spectrum will appear broadband to suppress the SBS, but the well-defined chirp will have the coherence and duration to allow the active phasing of multiple amplifiers and/or dissimilar optical paths. The phasing is accomplished without optical path-length matching by interfering each amplifier output with a reference, processing the resulting signal with a phase lock loop, and using the error signal to drive an acousto-optic frequency shifter at the front end of each optical amplifier and/or optical path.
    Type: Grant
    Filed: August 3, 2012
    Date of Patent: February 10, 2015
    Assignee: Telaris, Inc.
    Inventor: George Rakuljic
  • Patent number: 8947768
    Abstract: The invention provides fiber-optic light sources such as cladding-pumped master oscillator—power amplifier (MOPA) systems which use double-clad optical fibers (DCF). The inner cladding of the first DCF used in the master oscillator section has a circular cross-section in order to enable the formation of low loss optical splices in the integrated MOPA structure. The inner cladding of the second DCF in the output amplifier section has a shaped non-circular cross-section in order to enhance the absorption of the pump light in the doped core of the second DCF.
    Type: Grant
    Filed: May 13, 2013
    Date of Patent: February 3, 2015
    Assignee: JDS Uniphase Corporation
    Inventors: Dahv Kliner, Martin H. Muendel
  • Publication number: 20150029580
    Abstract: In a fiber amplifier including a third optical fiber made of a double clad fiber for amplifying light and a fifth optical fiber made of a single clad fiber for transmitting the light amplified by the double clad fiber, a fourth optical fiber made of a triple clad fiber is inserted between the third optical fiber and the fifth optical fiber.
    Type: Application
    Filed: September 12, 2014
    Publication date: January 29, 2015
    Applicant: FUJIKURA LTD.
    Inventor: Hiroyuki Taya
  • Patent number: 8941912
    Abstract: An ytterbium-doped optical fiber includes: a core which contains at least ytterbium, aluminum, and phosphorus; and a cladding which encircles the core, wherein an aluminum oxide equivalent concentration of the aluminum in the core is 0.2 mol % or more, a diphosphorus pentaoxide equivalent concentration of the phosphorus is higher than the aluminum oxide equivalent concentration, and the core either does not contain germanium or contains less than 1.1 mol % of germanium in a germanium dioxide equivalent concentration.
    Type: Grant
    Filed: February 3, 2011
    Date of Patent: January 27, 2015
    Assignee: Fujikura Ltd.
    Inventors: Shoji Tanigawa, Teruno Nakaguma, Tomofumi Arai, Kentaro Ichii
  • Patent number: 8922874
    Abstract: An optical amplification device includes a first optical amplification portion, an intermediate portion and a second optical amplification portion. The first optical amplification portion receives input light including signal light and pump light, generates idler light as wavelength converted light based on wavelengths of the signal light and the pump light, and outputs first output light including signal light, pump light and idler light. The intermediate portion outputs second output light, and includes a demultiplexing portion that demultiplexes the first output light into signal light, pump light and idler light, a multiplexing portion that generates the second output light by multiplexing signal light, pump light and idler light, and a polarization plane adjustment portion that exchanges mutually orthogonal polarization components of idler light. The second optical amplification portion amplifies an intensity of signal light included in the second output light.
    Type: Grant
    Filed: May 20, 2013
    Date of Patent: December 30, 2014
    Assignee: Oki Electric Industry Co., Ltd.
    Inventors: Kouji Inafune, Hitoshi Murai, Tadashi Kishimoto
  • Patent number: 8922877
    Abstract: A system and method for controlling polarization in a fiber amplifier is disclosed. A polarization dither waveform is applied to a polarization controller so that dithering does not trigger PI-HOMI (Polarization-Induced High Order Mode Instability). The dither waveform may have a period that is much less than the thermal diffusion time across the fiber amplifier core. The dither waveform may also have a slew rate (defined in degrees/second on the Poincaré sphere) that is much slower than the thermal diffusion time across the fiber amplifier core.
    Type: Grant
    Filed: August 5, 2013
    Date of Patent: December 30, 2014
    Assignee: Northrop Grumman Systems Corporation
    Inventors: Gregory D. Goodno, Stuart McNaught, Peter Thielen, Joshua Rothenberg, Marty Wacks
  • Patent number: 8922881
    Abstract: A fiber laser amplifier system including a beam splitter that splits a feedback beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier for amplifying the fiber beam. A tapered fiber bundle couples all of the output ends of all of the fiber amplifiers into a combined fiber providing a combined output beam. A beam sampler samples a portion of the output beam from the tapered fiber bundle and provides a sample beam. A single mode fiber receives the sample beam from the beam sampler and provides the feedback beam.
    Type: Grant
    Filed: February 1, 2013
    Date of Patent: December 30, 2014
    Assignee: Northrop Grumman Systems Corporation
    Inventor: Joshua Elliot Rothenberg
  • Publication number: 20140376083
    Abstract: A polarization reducing apparatus includes a separating unit configured to separate input light into components having polarization directions orthogonal to each other; a winding waveguide of silicon formed on a silicon substrate in a winding manner, the winding waveguide transmitting a first component among the components separated by the separating unit; an optical path configured to have a shorter optical path length than the winding waveguide, the optical path transmitting a second component among the components separated by the separating unit; a combining unit configured to combine the first component and the second component; and an output unit configured to output light consisting of the first component and the second component combined by the combining unit.
    Type: Application
    Filed: September 8, 2014
    Publication date: December 25, 2014
    Inventor: Miki ONAKA
  • Patent number: 8908263
    Abstract: A very large more area active double clad optical waveguide doped with Nd3+ at a concentration of at least 0.1% by weight can be used to effectively amplify light at a wavelength of between 1050 nm and 1120 nm. At a doping concentration sufficient to provide a net optical absorption of at least 3 dB/m for the pump light at the wavelength of 795 to 815 nm or 883 to 887 nm, Nd3+ operates under much lower inversion levels than Yb3+. Due to the lower inversion levels, the Nd3+ doped waveguide is subject to reduced pump bleaching or photodarkening.
    Type: Grant
    Filed: June 13, 2012
    Date of Patent: December 9, 2014
    Assignee: JDS Uniphase Corporation
    Inventor: Martin H. Muendel
  • Patent number: 8909017
    Abstract: A mode filter for eliminating the propagation of higher-order modes along a section of optical multimode fiber comprises a graded index (GRIN) lens, preferably of a quarter-pitch length, and a pinhole element in the form of a small core fiber. This configuration creates a Fourier spatial filter assembly that removes higher order modes propagating along an optical fiber while capturing the fundamental mode of the optical signal. A section of GRIN fiber is preferably used as the lens, with the small core fiber disposed at the output of the GRIN fiber lens to collect substantially only the on-axis fundamental mode of the optical signal. Since the higher order modes are shifted away from the origin by the GRIN fiber lens, only the fundamental mode signal is captured by the small core fiber.
    Type: Grant
    Filed: May 30, 2012
    Date of Patent: December 9, 2014
    Assignee: OFS Fitel, LLC
    Inventor: Jayesh C. Jasapara
  • Patent number: 8903214
    Abstract: A single-mode optical fiber for guiding an optical signal, wherein the core region is capable of guiding an optical signal in a fundamental core mode at an optical signal wavelength. A cladding region is arranged to surround the core region and includes an inner cladding region and an outer cladding region. The inner cladding region includes a background material and a plurality of inner cladding features arranged in the background material, wherein a plurality of the plurality of inner cladding features are of a first type of feature that includes an air hole surrounded by a high-index region comprising a high-index material that is larger than the refractive index of the inner cladding background material.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: December 2, 2014
    Assignee: NKT Photonics A/S
    Inventor: Thomas Tanggaard Alkeskjold
  • Publication number: 20140340739
    Abstract: An optical amplification device includes: an optical module that outputs an amplified light; and a controller that makes the optical module emit a light when an emission command is input into the controller, wherein the controller cancels an inputting of the emission command until a predetermined time passes, when a protection for forbidding a light emission of the optical module is canceled.
    Type: Application
    Filed: April 21, 2014
    Publication date: November 20, 2014
    Applicants: FUJITSU LIMITED, FUJITSU TELECOM NETWORKS LIMITED
    Inventors: Mitsuya Kawashita, Jinlin Zhang, Eiji Maeda, Shota Mori
  • Patent number: 8873134
    Abstract: Hybrid laser systems include fiber amplifiers using tapered waveguides and solid-state amplifiers. Typically, such systems represent a technically simple and low cost approach to high peak power pulsed laser systems. The tapered waveguides generally are provided with an active dopant such as a rare earth element that is pumped with one or more semiconductor lasers. The active waveguide taper is selected to taper from a single or few mode section to a multimode section. A seed beam in a fundamental mode is provided to a section of the waveguide taper associated with a smaller optical mode, and an amplified beam exits the waveguide taper at a section associated with a larger optical mode. The waveguide taper permits amplification to higher peak power values than comparable small mode area fibers. The fiber amplified beam is then directed to a solid state amplifier, such as a thin disk or rod-type laser amplifier.
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: October 28, 2014
    Assignee: nLight Photonics Corporation
    Inventors: R. Kirk Price, Joseph G. LaChapelle, Matthieu Saracco, Timothy S. McComb, Jason N. Farmer
  • Patent number: 8873132
    Abstract: Methods and systems are provided for generation and detection of rogue waves, including hydrodynamic rogue waves and optical rogue waves. A method for generating an optical rogue wave comprises the steps of generating an input pulse into a nonlinear optical medium, and perturbing the input pulse by directing a narrow-band seed radiation into the input pulse. The seed radiation has a frequency and timing to generate broadband radiation within the nonlinear optical medium.
    Type: Grant
    Filed: December 4, 2012
    Date of Patent: October 28, 2014
    Assignee: The Regents of the University of California
    Inventors: Daniel R. Solli, Bahram Jalali, Claus Ropers
  • Patent number: 8867125
    Abstract: An apparatus includes a multi-core optical fiber and first, second, and third optical couplers. The multi-core optical fiber is rare-earth doped to provide optical amplification in response to optical pumping thereof. The first optical coupler is configured to end-couple a first multi-mode optical fiber to an end of the multi-core optical fiber. The second optical coupler is configured to end-couple a second multi-mode optical fiber to an end of the multi-core optical fiber. The third optical coupler is configured to optically couple a pump light source to the multi-core optical fiber.
    Type: Grant
    Filed: September 30, 2012
    Date of Patent: October 21, 2014
    Assignee: Alcatel Lucent
    Inventors: Roland Ryf, Nicolas K. Fontaine
  • Patent number: 8861913
    Abstract: Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.
    Type: Grant
    Filed: September 11, 2012
    Date of Patent: October 14, 2014
    Assignee: IMRA America, Inc.
    Inventors: Liang Dong, Donald J. Harter, William Wong
  • Patent number: 8854728
    Abstract: A method and apparatus use a photonic-crystal fiber having a very large core while maintaining a single transverse mode. In some fiber lasers and amplifiers having large cores problems exist related to energy being generated at multiple-modes (i.e., polygamy), and of mode hopping (i.e., promiscuity) due to limited control of energy levels and fluctuations. The problems of multiple-modes and mode hopping result from the use of large-diameter waveguides, and are addressed by the invention. This is especially true in lasers using large amounts of energy (i.e., lasers in the one-megawatt or more range). By using multiple small waveguides in parallel, large amounts of energy can be passed through a laser, but with better control such that the aforementioned problems can be reduced. An additional advantage is that the polarization of the light can be maintained better than by using a single fiber core.
    Type: Grant
    Filed: June 25, 2013
    Date of Patent: October 7, 2014
    Assignee: Lockheed Martin Corporation
    Inventors: Christopher D. Brooks, Fabio Di Teodoro
  • Patent number: 8849080
    Abstract: An optical fiber coupler includes a clad optical fiber core having a coupling window formed therein. A laser source is joined to emit light into the core through the coupling window. The core has an output coupler for partially reflecting a portion of light and transmitting a portion as output. A Bragg grating is formed in the core having a pitch and being positioned to reflect light from said laser source toward the output coupler. The pitch is variable in response to a temperature change. A thermal control device is joined to the core for adjusting its temperature and the Bragg grating pitch. In other embodiments a mode convertor is provided to reduce the output modes to selected modes.
    Type: Grant
    Filed: January 14, 2013
    Date of Patent: September 30, 2014
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Tariq Manzur
  • Publication number: 20140285875
    Abstract: A downhole optical system can include an optical fiber disposed in a subterranean well, and an optical fiber amplifier which amplifies optical power in a core of the optical fiber in the well, the amplifier being optically pumped with optical power in another core of the optical fiber in the well. Another downhole optical system can include an optical fiber disposed in a subterranean well, the optical fiber comprising multiple cores, and an optical fiber amplifier comprising multiple cores optically coupled respectively to the optical fiber multiple cores in the well.
    Type: Application
    Filed: March 19, 2013
    Publication date: September 25, 2014
    Applicant: Halliburton Energy Services, Inc.
    Inventors: Mikko JAASKELAINEN, Ian B. MITCHELL
  • Patent number: 8842362
    Abstract: A method of operating a fiber amplifier characterized by a spectral gain curve includes providing an input signal at a signal wavelength. The signal wavelength lies within an in-band portion of the spectral gain curve extending from a first in-band wavelength to a second in-band wavelength, the in-band portion being characterized by a first amplitude range. The method also includes providing pump radiation at a pump wavelength. The pump wavelength is less than the signal wavelength. The method further includes coupling the pump radiation to the fiber amplifier and amplifying the input signal to generate an output signal. All portions of the spectral gain curve at wavelengths less than the first in-band wavelength and greater than the pump wavelength are characterized by a second amplitude less than or equal to 10 dB greater than the first amplitude range.
    Type: Grant
    Filed: January 9, 2014
    Date of Patent: September 23, 2014
    Assignee: ESI-Pyrophotonics Lasers, Inc.
    Inventors: Richard Murison, Tullio Panarello, Benoit Reid, Reynald Boula-Picard
  • Publication number: 20140268309
    Abstract: Described herein are devices and techniques for suppressing parasitic modes in planar waveguide amplifier structures. One or more of the side and end facets of a planar waveguide amplifier are angled with respect to a fast axis defined in a transverse plane perpendicular to a core region. A relationship between glancing in-plane angles of incidence and threshold bevel angles ?T can be used to select side bevel angles ?S to suppress parasitics by redirecting amplified spontaneous emission (ASE) from the core. It is possible to select the one or more bevel angles ?S to be great enough to substantially redirect all but ballistic photons of any guided modes, effectively narrowing a numerical aperture of the planar waveguide amplifier along a slow axis, defined in a transverse plane perpendicular to the fast axis. Beneficially, such improvements can be realized for three part waveguide structures (e.g., cladding-core-cladding), with substantially smooth edge facets.
    Type: Application
    Filed: March 12, 2013
    Publication date: September 18, 2014
    Inventor: Friedrich Strohkendl
  • Publication number: 20140268310
    Abstract: Optical fibers are provided for modal discrimination which include a central core and a cladding disposed about the central core. The central core has a non-circular and non-elliptical cross-section, and it is rotated about a central axis of the optical fiber along the length of the optical fiber at a selected pitch resulting in the capability of a fundamental mode beam output for large core sizes. An optical system includes a seed optical source configured to provide a seed beam and an optical amplifier configured to receive and amplify the seed beam. The optical amplifier also includes an active optical fiber having a large mode area non-circular and non-elliptical core rotated about a central axis of said active optical fiber to provide modal discrimination and fundamental mode output.
    Type: Application
    Filed: March 18, 2014
    Publication date: September 18, 2014
    Applicant: nLIGHT Photonics Corporation
    Inventors: Changgeng Ye, Joona Koponen, Thomas S. Sosnowski
  • Patent number: 8836523
    Abstract: A fault gas alarm system is disclosed. In one embodiment, the fault gas alarm system includes: a gas sensor configured to fluidly connect with an oil valve in an oil-filled vacuum-type on-load tap changer (OLTC), the gas sensor for monitoring a gas level in an oil within the oil valve; and a bi-level alarm system electrically connected with the gas sensor, the bi-level alarm system including a visual alarm indicator configured to provide a visual alarm in response to receiving an indication the gas level in the oil exceeds a threshold.
    Type: Grant
    Filed: May 20, 2011
    Date of Patent: September 16, 2014
    Assignee: General Electric Company
    Inventors: Anik Roy Trudel, Mariana Barbulescu, Yong Ng Tong
  • Patent number: 8837038
    Abstract: Methods and systems for managing pulse energy scaling are disclosed, including generating electromagnetic radiation; coupling the electromagnetic radiation to a fiber geometrical management system comprising: a tapered fiber comprising: an elliptical or rectangular core centrally positioned within a single or double cladding shell, wherein the core comprises a fiber material and a doped gain medium; an input face wherein the doped core comprises a major axis and a minor axis, wherein the ratio of the major to minor axis at the input face ranges from about 1 to about 100; an output face wherein the doped core comprises a major axis and a minor axis, wherein the ratio of the major to minor axis at the output face ranges from about 1 to about 100; and wherein the major (minor) axis is adiabatically or linearly tapered from the input face to the output face. Other embodiments are described and claimed.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: September 16, 2014
    Assignee: PolarOnyx, Inc.
    Inventor: Jian Liu
  • Patent number: 8837885
    Abstract: The inventive concept provides optic couplers, optical fiber laser devices, and active optical modules using the same. The optic coupler may include a first optical fiber having a first core and a first cladding surrounding the first core, a second optical fiber having a second core transmitting a signal light to the first optical fiber and a third cladding surrounding the second core, third optical fibers transmitting pump-light to the first optical fiber in a direction parallel to the second optical fiber; and a connector connected between the first optical fiber and the second optical fiber, the connector extending the third optical fibers disposed around the second optical fiber toward the first optical fiber, the connector comprising a third core connected between the first core and the second core and a fifth cladding surrounding the third core.
    Type: Grant
    Filed: September 13, 2012
    Date of Patent: September 16, 2014
    Assignee: Electronics and Telecommunications Research Institute
    Inventors: Hong Seok Seo, Bong Je Park, Joon Tae Ahn, Jung-Ho Song
  • Patent number: 8830567
    Abstract: A chirped-pulsed amplification laser device includes a fiber laser driver, a laser head, and a delivery fiber that guides amplified stretched laser pulses from the laser driver to the laser head. The fiber laser driver includes a seed pulsed laser, a pulse stretcher, and an optical power amplifier. A chirped fiber Bragg grating compressor in the laser head includes a fiber terminal section configured to minimize broadening of the amplified stretched laser pulses, a chirped fiber Bragg grating section connected to the fiber terminal section and configured to compress and reflect amplified stretched laser pulses to produce reflected laser pulses with compressed pulse durations, and a collimator housing configured to fixedly hold a collimator lens and a ferrule. The ferrule holds the fiber terminal section tilted relative to an optical axis of the collimator lens.
    Type: Grant
    Filed: May 2, 2012
    Date of Patent: September 9, 2014
    Assignee: Calmar Optcom, Inc.
    Inventor: Anthoney Hong Lin
  • Patent number: 8830566
    Abstract: A fiber laser amplifier system including a plurality of master oscillators each generating a signal beam at a different wavelength. A splitter for each master oscillator splits the signal beam into a plurality of fiber beams to be separately amplified. A separate tapered fiber bundle receives the amplified beam for each master oscillator, where each tapered fiber bundle includes a plurality of input end fibers, a plurality of output end fibers and a center bundle portion, where each input end fiber is coupled to a separate one of the fiber amplifiers, where the bundle portion combines all of the fiber beams received by the input end fibers into a single combined beam and each output end fiber is capable of receiving the combined beam separately from the other output end fibers. A separate optical output channel receives one of the output end fibers from each tapered fiber bundle.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: September 9, 2014
    Assignee: Northrop Grumman Systems Corporation
    Inventors: Joshua Elliott Rothenberg, Eric Chiu Tat Cheung
  • Publication number: 20140247477
    Abstract: An integrated optical structure includes at least one optical isolator, having a magneto-optical layer, associated with at least one SOA optical amplifier having a waveguide having an n-doped semiconductor layer, a p-doped semiconductor layer, and an active area disposed between the n-doped semiconductor layer and the p-doped semiconductor layer. The optical isolator is disposed between an SOI base and the SOA optical amplifier's waveguide. The optical isolator's magneto-optical layer is disposed between a lower insulating layer and an upper insulating layer. The optical isolator's magneto-optical layer may be a layer of ferromagnetic metallic material, such as a Fe—Co metallic alloy, or a magnetic oxide layer. An optical device includes at least one integrated optical structure.
    Type: Application
    Filed: October 17, 2012
    Publication date: September 4, 2014
    Inventors: Guang-Hua Duan, Francois Brillouet, Jean-Louis Gentner
  • Publication number: 20140247841
    Abstract: Optical pump modules comprising VCSEL and VCSEL array devices provide high optical power for configuring fiber optic gain systems such as fiber laser and fiber amplifier particularly suited for high power operation. Pump modules may be constructed using two reflector or three reflector VCSEL devices optionally integrated with microlens arrays and other optical components, to couple high power pump beams to a fiber output port. The pump module having a fiber output port is particularly suited to couple light to an inner cladding of a double-clad fiber, often used to configure high power fiber laser and fiber amplifier. The pump modules may be operated in CW, QCW and pulse modes to configure fiber lasers and amplifiers using single end, dual end, and regenerative optical pumping modes. Multiple-pumps may be combined to increase pump power in a modular fashion without significant distortion to signal, particularly for short pulse operation.
    Type: Application
    Filed: March 1, 2013
    Publication date: September 4, 2014
    Applicant: Princeton Optronics Inc
    Inventors: Jean-Francois Seurin, Qing Wang, Laurence Watkins, Chuni Lal Ghosh
  • Publication number: 20140240818
    Abstract: An optical amplification component 1 includes a heat dissipation plate 10 and an amplification optical fiber 20 arranged on the heat dissipation plate 10. A first fiber portion 20A extending from a reference position RP between a first end E1 and a second end E2 of the amplification optical fiber 20 toward the first end E1 and a second fiber portion 20B extending from the reference position RP toward the second end E2 are wound in a spiral around the reference position RP so as to be along each other as well as not to overlap with each other, and the distance between the first fiber portion 20A and the second fiber portion 20B increases toward the ends thereof.
    Type: Application
    Filed: February 25, 2014
    Publication date: August 28, 2014
    Applicant: FUJIKURA LTD.
    Inventor: Hiroyuki Taya
  • Patent number: 8818151
    Abstract: An novel fiber pump signal combiner is disclosed in which a fiber bundle array is coupled to a double-clad fiber with a taper section that is formed by etching a tapered outer surface into the cladding of a fiber rod to produce a high quality tapered outer surface free of defects with an inner core that has a constant diameter.
    Type: Grant
    Filed: April 15, 2010
    Date of Patent: August 26, 2014
    Assignee: United States of America as represented by the Secretary of the Air Force
    Inventor: Benjamin G. Ward
  • Publication number: 20140233091
    Abstract: A supercontinuum optical pulse source provides a combined supercontinuum. The supercontinuum optical pulse source comprises one or more seed pulse sources, and first and second optical amplifiers arranged along first and second respective optical paths. The first and second optical amplifiers are configured to amplify one or more optical signals generated by said one or more seed pulse sources. The supercontinuum optical pulse source further comprises a first microstructured light-guiding member arranged along the first optical path and configured to generate supercontinuum light responsive to an optical signal propagating along said first optical path, and a second microstructured light-guiding member arranged along the second optical path and configured to generate supercontinuum light responsive to an optical signal propagating along said second optical path.
    Type: Application
    Filed: February 19, 2014
    Publication date: August 21, 2014
    Applicant: Fianium Ltd.
    Inventors: John Redvers Clowes, Anatoly Borisovich Grudinin, Adam Devine
  • Patent number: 8797642
    Abstract: A large-mode-area (LMA) optical fiber (10) that operates as a single-mode optical fiber. The optical fiber includes a core region (20) surrounded by an inner cladding (32), which in turn is surrounded by an outer cladding (40). The inner cladding includes at least one up-doped ring region (32R1). The ring region is configured to form a large attenuation differential between the higher-order modes and the fundamental mode so only that the fundamental mode remains traveling in the optical fiber. If necessary, the optical fiber can include a bend (10B) having a select “resonant” bend diameter (DB) that increases the relative attenuation of the fundamental and higher-order modes. The optical fiber supports an effective mode field diameter (MFD) of up to 40 ?m to 50 ?m. As a result, detrimental non-linear effects are suppressed, which allows the optical fiber to carry substantially more optical power than conventional LMA optical fibers.
    Type: Grant
    Filed: July 16, 2008
    Date of Patent: August 5, 2014
    Assignee: Corning Incorporated
    Inventors: Xin Chen, Joohyun Koh, Ming-Jun Li, Anping Liu