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Небесная энциклопедия

Космические корабли и станции, автоматические КА и методы их проектирования, бортовые комплексы управления, системы и средства жизнеобеспечения, особенности технологии производства ракетно-космических систем

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Мониторинг СМИ

Мониторинг СМИ и социальных сетей. Сканирование интернета, новостных сайтов, специализированных контентных площадок на базе мессенджеров. Гибкие настройки фильтров и первоначальных источников.

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Поддерживает ввод нескольких поисковых фраз (по одной на строку). При поиске обеспечивает поддержку морфологии русского и английского языка
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Применить Всего найдено 3516. Отображено 100.
19-01-2012 дата публикации

Optical amplifier and transmission loss measurement method

Номер: US20120013975A1
Автор: Miki Onaka
Принадлежит: Fujitsu Ltd

An optical amplifier that amplifies signal light with Raman amplification in the Raman amplification medium. The optical amplifier includes a light source that supplies pump light into the Raman amplification medium, a first detector that detects input power of the pump light to be input to the Raman amplification medium, a second detector that detects output power of the pump light output from the Raman amplification medium, and a processor operable to calculate transmission loss of the pump light in the Raman amplification medium by comparing the input power with the output power, and calculate transmission loss of the signal light in the Raman amplification medium based on the transmission loss of pump light corrected based on a wavelength of the signal light and a wavelength of the pump light.

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Номер записи: 1
05-04-2012 дата публикации

Large diameter optical waveguide, grating and laser

Номер: US20120082175A1
Автор: Alan D. Kersey, James M. Sullivan, Martin A. Putnam, Paul E. Sanders, Robert N. Brucato, Timothy J. Bailey
Принадлежит: Individual

A large diameter optical waveguide, grating, and laser includes a waveguide having at least one core surrounded by a cladding, the core propagating light in substantially a few transverse spatial modes; and having an outer waveguide dimension of said waveguide being greater than about 0.3 mm. At least one Bragg grating may be impressed in the waveguide. The waveguide may be axially compressed which causes the length of the waveguide to decrease without buckling. The waveguide may be used for any application where a waveguide needs to be compression tuned. Also, the waveguide exhibits lower mode coupling from the core to the cladding and allows for higher optical power to be used when writing gratings without damaging the waveguide. The waveguide may resemble a short “block” or a longer “cane” type, depending on the application and dimensions used.

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Номер записи: 2
22-11-2012 дата публикации

Novel architecture for undersea repeaterless systems

Номер: US20120294619A1
Автор: Ekaterina A. Golovchenko, Lee John Richardson
Принадлежит: TYCO ELECTRONICS SUBSEA COMMUNICATIONS LLC

An undersea repeaterless optical transmission system is disclosed including first and second stations connected by a communication link which may comprise one or more optical fibers. The system further includes a dedicated Raman pumping path originating from a third intermediate station and interacting with the communication link at an undersea body positioned between the first and second stations. This dedicated Raman pumping path may comprise one or more optical fibers. Communications signals are propagated only between the first and second stations, while the third intermediate station provides only Raman pumping via the pumping path which is used to boost signal power in the communication link between the first and second stations. By limiting this pumping path to Raman pumping only substantially more pumping power can be provided through the path since power is not limited by the equation of a communications signal. The disclosed system architecture facilitates increased capacity (or reach) on the repeaterless link between the first and second stations.

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Номер записи: 3
06-12-2012 дата публикации

Light source apparatus and processing method

Номер: US20120305806A1
Автор: Motoki Kakui, Shinobu Tamaoki
Принадлежит: Sumitomo Electric Industries Ltd

The present invention relates to a light source apparatus. The light source apparatus has an MOPA configuration and comprises a seed light source, a pulse generator, an intermediate optical amplifier, a final stage optical amplifier, a delivery optical fiber, and a light output terminal. The delivery optical fiber is a PBG fiber having a photonic bandgap (PBG) structure in a core-surrounding portion located around the core. Light with a wavelength in a high loss band of the PBG fiber is inputted into the PBG fiber.

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Номер записи: 4
24-01-2013 дата публикации

Frequency Control of Despeckling

Номер: US20130021586A1
Автор: Barret Lippey
Принадлежит: Laser Light Engines Inc

A method and apparatus that reduces laser speckle by using stimulated Raman scattering in an optical fiber. The pulse repetition frequency of the laser is adjusted to control aspects of the laser light such as color or despeckling. In DLP projection systems, an optical monitor may be used to send information to a bit sequence, and the bit sequence may control the pulse repetition frequency of the laser based on the optical monitor signal.

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Номер записи: 5
14-03-2013 дата публикации

Method and Apparatus for Suppression of Stimulated Brillouin Scattering Using Polarization Control with A Birefringent Delay Element

Номер: US20130063808A1
Автор: Joshua E. Rothenberg
Принадлежит: Northrop Grumman Systems Corp

A method and apparatus for suppression of stimulated Brillouin scattering (SBS) includes a master oscillator (MO) that generates a beam; a birefringent element that receives and transmits the beam, wherein the beam is transmitted with a transmission delay between two orthogonal axes; a polarization controller that receives the beam and transmits the beam with a desired polarization; a fiber amplifier that receives the beam, amplifies the beam, and transmits a beam; a compensating birefringent element that receives the beam, approximately removes the transmission delay between the two axes of the beam, and transmits an output beam; and a polarization detector that detects the output beam's polarization and provides feedback to the polarization controller to ensure that the polarization of the output beam is approximately equal to a desired output polarization, so as to reduce SBS.

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Номер записи: 6
21-03-2013 дата публикации

Optical system for signal amplification using a multimode fiber

Номер: US20130070330A1
Автор: Roland Ryf
Принадлежит: Alcatel Lucent USA Inc

An optical coupler for coupling optical-pump power into a multimode fiber configured to transport an optical space-division-multiplexed (SDM) signal, the coupling being performed in a manner that enables amplification of the SDM signal in the multimode fiber via a stimulated-emission process or a stimulated Raman-scattering process. The optical coupler can be a part of an optical transmitter configured for co-directional pumping, an optical receiver configured for contra-directional pumping, or a relay station disposed within an optical communication link and configured for either type of pumping. The optical coupler can advantageously be used, e.g., to offset the different degrees of attenuation to which the SDM-signal components corresponding to different guided modes of the multimode fiber are subjected to therein.

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Номер записи: 7
04-04-2013 дата публикации

Narrow linewidth brillouin laser

Номер: US20130083813A1
Автор: Arthur H. Hartog
Принадлежит: Schlumberger Technology Corp

A Brillouin laser having a narrowed linewidth, reduced relative intensity noise, and increased output power includes a pump laser that provides pump energy to an optical fiber resonant cavity to stimulate Brillouin emission. The output of pump laser is stabilized and its linewidth is narrowed by locking the frequency and phase of the optical signal generated by the pump laser to a longitudinal mode of the optical fiber resonant cavity. In addition, the resonant cavity is temperature and/or strain-tuned so that the Brillouin gain is substantially centered on a longitudinal mode of the cavity, thereby ensuring that the Brillouin frequency shift is substantially equal to an integer number of the free spectral range of the cavity.

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Номер записи: 8
11-04-2013 дата публикации

SINGLE MODE PROPAGATION IN FIBERS AND RODS WITH LARGE LEAKAGE CHANNELS

Номер: US20130089113A1
Автор: Dong Liang, FERMANN Martin E., Wong William
Принадлежит: IMRA AMERICA, INC.

Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprising cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining. 1. (canceled)2. An optical fiber configured to propagate at least one lower order mode having a wavelength , λ , said optical fiber comprising:a core region having a core width; anda cladding region surrounding said core region, said cladding region comprising a plurality of cladding features disposed in a matrix material, said plurality of cladding features having a maximum feature size, d, said plurality of cladding features separated by bridges having a maximum bridge width, a, said bridge comprising matrix material,wherein said core width is greater than about 25 micrometers,wherein said plurality of cladding features are arranged in no more than two layers around said core region, andwherein said maximum bridge width has a value that yields a ratio of a/λ that is at least about 5.3. The optical fiber of claim 2 , wherein said maximum bridge width claim 2 , a claim 2 , has a value that yields a ratio of a/λ that is less than about 100.4. The optical fiber of claim 2 , wherein said core width is less than about 300 micrometers.5. The optical fiber of claim 2 , wherein said maximum feature size claim 2 , d claim 2 , has a value that yields a ratio of d/λ that is in a range from about 5 to 100.6. The optical fiber of claim 2 , wherein said plurality of cladding features have an average center-to-center spacing claim 2 , Λ claim 2 , and wherein d/Λ is greater than about 0.4 and less than about 0.9.7. The optical fiber of claim 2 , wherein said plurality of cladding features are ...

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Номер записи: 9
09-05-2013 дата публикации

LARGE CORE AREA SINGLE MODE OPTICAL FIBER

Номер: US20130114129A1
Автор: Alkeskjold Thomas Tanggaard
Принадлежит: NKT Photonics A/S

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. 163-. (canceled)64. A single-mode optical fiber for guiding an optical signal , said optical fiber having a longitudinal , optical axis and a cross section perpendicular thereto , said optical fiber comprising:{'sub': c', '1, 'a core region being capable of guiding an optical signal in a fundamental core mode with an effective refractive index, n, at an optical signal wavelength, λ;'}{'sub': b', 'r', '1', 'c', '1, 'a cladding region surrounding the core region, the cladding region comprising an inner cladding region and an outer cladding region, said inner cladding region comprising a background material having a refractive index, n, and a plurality of inner cladding features arranged in said background material, wherein at least a plurality of said plurality of inner cladding features are of a first type of feature, said first type of feature comprising an air hole surrounded by a high-index region comprising a high-index material having a refractive index, n, that is larger than the refractive index of the inner cladding background material, said first type of feature supports an optical mode with an effective refractive index, n, which is lower than or equal to the effective refractive index of the fundamental core mode, n, at said optical signal wavelength, ...

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Номер записи: 10
16-05-2013 дата публикации

OPTICAL AMPLIFIERS

Номер: US20130120831A1
Автор: Drake Jonathan Stuart, Flintham Barrie, McClean Ian Peter, Zayer Nadhum Kadhum
Принадлежит:

An optical amplifier system is provided which comprises first and second optical amplifiers () for amplifying optical signals in a fibre optic communications link and a common pump () for optically pumping both the first amplifier () and the second amplifier () to effect such amplification. There is also provided an optical switch () for providing an optical path between the pump and the first amplifier in a first switching state and an optical path between the pump and the second amplifier in a second switching state to enable pumping of the first and second amplifiers by the pump sequentially. Advantageously this arrangement provides high accuracy to the outputs () of the pump () and reduces low power pump noise. 1. An optical amplifier system comprising:(i) first and second optical amplifiers for amplifying optical signals in a fibre optic communications link,(ii) a common pump for optically pumping both the first amplifier and the second amplifier to effect such amplification, and(iii) switching means for providing an optical path between the pump and the first amplifier in a first switching state and an optical path between the pump and the second amplifier in a second switching state to enable optical pumping of the first and second amplifiers by the pump sequentially,wherein the switching means is adapted to independently vary the power supplied to one of the first and second amplifiers from 0% to maximum pump power.2. An optical amplifier system according to claim 1 , wherein the switching means includes an input coupled to the pump and outputs coupled to the first amplifier and the second amplifier.3. An optical amplifier system according to claim 1 , further comprising a grating coupled to an input or an output of the switching means so as to lock the optical path between the pump and the first amplifier in the first switching state and to lock the optical path between the pump and the second amplifier in the second switching state.4. (canceled)5. An ...

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Номер записи: 11
13-06-2013 дата публикации

WAVELENGTH SWEEP CONTROL

Номер: US20130148190A1
Автор: Taverner Domino
Принадлежит: WEATHERFORD/LAMB, INC.

Methods and apparatus for the active control of a wavelength-swept light source used to interrogate optical elements having characteristic wavelengths distributed across a wavelength range are provided. 1. A method comprising:providing light, wherein a wavelength of the light is changed according to a sweep function;interrogating one or more optical elements with the wavelength-swept light to produce optical signals;filtering the optical signals, wherein a bandpass wavelength range is changed based on the sweep function to follow the changes in the light's wavelength; andreceiving the filtered optical signals for processing.2. The method of claim 1 , wherein the optical elements comprise transmissive optical elements.3. The method of claim 1 , wherein the sweep function comprises a constant sweep rate.4. The method of claim 3 , wherein the sweep rate is set to a trip frequency or a harmonic thereof claim 3 , wherein the trip frequency is equal to a speed of light in an optical waveguide for conveying the optical signals divided by a trip distance of the light from a light source to the furthest one of the optical elements and then to a receiver via the optical waveguide.5. The method of claim 1 , wherein filtering the optical signals comprises filtering out Rayleigh scattering and back-reflections from an optical waveguide conveying the optical signals.6. The method of claim 1 , further comprising delaying the sweep function before filtering claim 1 , such that the changing of the bandpass wavelength range is delayed from the changing of the light's wavelength.7. The method of claim 1 , wherein delaying the sweep function comprises delaying the sweep function by a trip distance of the light claim 1 , in an optical waveguide for conveying the optical signals claim 1 , from a light source to one of the optical elements and then to a receiver divided by a speed of light in the optical waveguide.8. The method of claim 1 , wherein filtering the optical signals comprises ...

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Номер записи: 12
13-06-2013 дата публикации

METHOD FOR BEAM COMBINATION BY SEEDING STIMULATED BRILLOUIN SCATTERING IN OPTICAL FIBER

Номер: US20130148673A1
Автор: Creeden Daniel J., Dinndorf Kenneth, Young York E.
Принадлежит: BAE Systems Information and Electronic Systems Integration Inc.

A system and method for efficiently combining multiple laser beams into a single frequency by invoking stimulated Brillouin scattering (SBS) in a dual core optical fiber is disclosed. The method and apparatus essentially becomes a brightness converter for the input laser beams. An SRS seed is generated in a long length of fiber or by a diode and is launched into the back-end of the SBS combining optical fiber. Various single-frequency pump beams are launched into the front-end of the same fiber. The seed acts to lower a threshold for SBS in the fiber, thus invoking the nonlinearity. Provided the various pump beams are close in frequency and seed/pump modes overlap, each acts to amplify the seed through the nonlinear SBS process, providing an output signal which is brighter than the combined pump beams. 1. A method of combining a plurality of pump laser beams comprising:generating said plurality of pump laser beams by utilizing a plurality of pump diodes;launching said plurality of pump laser beams into one end of an optical fiber comprising a dual core Stimulated Brillouin Scattering (SBS) combing optical fiber;generating a seed beam by utilizing a seed generator;launching said seed beam into another end of said optical fiber; andamplifying said seed beam and obtaining an output signal.2. The method of wherein said seed beam is amplified through a nonlinear SBS process in sold optical fiber.3. The method of wherein said output signal is brighter than said combined plurality of laser beams.4. The method of wherein said seed beam acts to lower a threshold for SBS in said optical fiber.5. The method of wherein said seed beam is launched into an inner core of said optical fiber.6. The method of wherein said plurality of laser beams is launched into an outer core of said optical fiber.7. Thee method of wherein said seed generator comprises trapping at least one laser beam from a plurality of laser beams claim 1 , by utilizing a circulator.8. The method of wherein said ...

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Номер записи: 13
12-09-2013 дата публикации

Optical Amplifier and Optical Transmission System

Номер: US20130235449A1
Автор: SUZUKI Mikiya
Принадлежит: FURUKAWA ELECTRIC CO., LTD.

An optical amplifying apparatus that amplifies an optical signal, including an input section whereto the optical signal is inputted, a laser light source that generates laser light, the laser light source including an uncooled semiconductor laser device, an optical fiber that amplifies the optical signal by a stimulated emission based on the laser light from the laser light source, an output section that outputs the optical signal amplified by the optical fiber, and a passive optical component disposed between the optical fiber and the output section. The laser light source is thermally coupled to the optical fiber and/or the passive optical component via a thermally conductive medium. An oscillating wavelength of the laser light source is varied by increasing a temperature of the laser light source with heat generated by the optical fiber and/or the passive optical component. 1. An optical amplifying apparatus that amplifies an optical signal , comprising:an input section whereto the optical signal is inputted;a laser light source that generates laser light, the laser light source including an uncooled semiconductor laser device;an optical fiber that amplifies the optical signal by a stimulated emission based on the laser light from the laser light source;an output section that outputs the optical signal amplified by the optical fiber; anda passive optical component disposed between the optical fiber and the output section,the laser light source being thermally coupled to the optical fiber and/or the passive optical component via a thermally conductive medium,an oscillating wavelength of the laser light source being varied by increasing a temperature of the laser light source with heat generated by the optical fiber and/or the passive optical component.2. The optical amplifying apparatus according to claim 1 , wherein the heat generated by the optical fiber and/or the passive optical component is transferred to the laser light source claim 1 , and a wavelength band ...

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Номер записи: 14
10-10-2013 дата публикации

Raman Amplifiers

Номер: US20130265634A1
Автор: McClean Ian Peter, Wigley Peter
Принадлежит: OCLARO TECHNOLOGY LIMITED

A pump unit () for a Raman amplifier () including an optical fibre () carrying an optical signal () is disclosed. The pump unit includes at least two light sources () for emitting light at different wavelengths into the fibre to induce Raman gain of the optical signal passing along the fibre, and a controller () for providing pulses to each of the light sources to control when they do and do not emit light. The controller is configured to control the width of the pulses to control the total power of the light emitted into the fibre. 1. A pump unit for a Raman amplifier having an optical fibre carrying an optical signal , the pump unit comprising:at least two light sources for emitting light at different wavelengths into the fibre to induce Raman gain of the optical signal passing along the fibre; anda controller for providing pulses to each of the light sources to control when they do and do not emit light, control the width of the pulses to control the total power of the light emitted into the fibre, and', 'optimise overlap times during which the light sources are activated simultaneously so that the overlap time between the light sources is minimised when light from one light source falls near the peak of a Raman gain spectrum produced from light of another light source., 'wherein the controller is configured to2. The pump unit according to claim 1 , wherein the controller comprises a pulse width modulation claim 1 , PWM claim 1 , unit for varying the width of the pulses.3. The pump unit according to claim 1 , wherein the controller is configured to vary the duty cycles of the pulses to each of the light sources in response to changes in gain conditions claim 1 , bandwidth and/or channel allocation in the amplifier.4. The pump unit according to claim 1 , configured to allow a long overlap time between two light sources when light from the two sources does not interact strongly.5. The pump unit according to claim 1 , wherein each of the light sources is configured ...

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Номер записи: 15
17-10-2013 дата публикации

OPTICAL PULSE SOURCE

Номер: US20130271824A1
Автор: Clowes John Redvers, Godfrey Ian Michael, Grudinin Anatoly Borisovich, Vysniauskas Kestutis
Принадлежит:

The invention can include an apparatus for producing optical pulses, comprising an oscillator for producing optical pulses at a first optical pulse repetition frequency, the optical pulses having a first wavelength; a first optical fiber amplifier; a second optical fiber amplifier; a pulse picker located between the first and second optical fiber amplifiers, the pulse picker operable to reduce the optical pulse repetition frequency of optical pulses, wherein the first amplifier amplifies optical pulses at the first optical pulse repetition frequency and the second amplifier amplifies optical pulses at a reduced optical pulse repetition frequency that is less than the first optical pulse repetition frequency; a nonlinear optical fiber receiving amplified optical pulses having the reduced optical pulse repetition frequency and the first wavelength to produce, at the reduced optical pulse frequency, optical pulses that include one or more nonlinearly produced wavelengths different than the first wavelength; and wherein the pulse picker and the first and second optical fiber amplifiers are located between the oscillator and the nonlinear optical fiber. 1. Apparatus for producing optical pulses , comprising:an oscillator for producing optical pulses at a first optical pulse repetition frequency, the optical pulses having a first wavelength;a first optical fiber amplifier;a second optical fiber amplifier;a pulse picker, located between the first and second optical fiber amplifiers, said pulse picker operable to reduce the optical pulse repetition frequency of optical pulses, wherein said first amplifier amplifies optical pulses at the first optical pulse repetition frequency and said second amplifier amplifies optical pulses at a reduced optical pulse repetition frequency that is less than said first optical pulse repetition frequency;a nonlinear optical fiber receiving amplified optical pulses having the reduced optical pulse repetition frequency and the first wavelength ...

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Номер записи: 16
31-10-2013 дата публикации

RAMAN AMPLIFIER, OPTICAL REPEATER, AND RAMAN AMPLIFICATION METHOD

Номер: US20130286468A1
Автор: Akasaka Youichi, Emori Yoshihiro, Namiki Shu
Принадлежит: FURUKAWA ELECTRIC CO., LTD.

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. 1. A Raman amplifier comprising:a pump light source; and a semiconductor laser,', 'an external resonator arranged to maintain a predetermined central wavelength of laser light emitted from said semiconductor laser notwithstanding fluctuation of a driving current of said semiconductor laser,', 'a laser light intensity control unit configured to control a gain profile of the Raman amplifier by controlling the driving current of said semiconductor laser, wherein the predetermined central wavelength of the laser light being maintained substantially constant by the external resonator., 'an amplifying optical fiber configured to transmit a signal light and amplify the signal light by a pumping light supplied from the pump light source, wherein the pump light source comprising2. The Raman amplifier according to claim 1 , wherein said pump light source further comprising:one or more additional semiconductor lasers,one or more additional external resonators corresponding to the one or more additional semiconductor ...

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Номер записи: 17
07-11-2013 дата публикации

SHORTER WAVELENGTH PHOTO-ANNEALING APPARATUS FOR RARE-EARTH-DOPED FIBER AND ITS OPTICAL ASSEMBLIES UNDER IRRADIATION

Номер: US20130293948A1
Автор: Liu Ren-Young, Peng Tz-Shiuan, Wang Lon
Принадлежит:

An optical fiber apparatus is suitable to operate under irradiation, more particularly to mitigating the damage of a rare-earth-doped optical fiber element as part of an optical fiber assembly causes by irradiation. The irradiation mitigation attributes to a photo-annealing apparatus including at least a shorter wavelength photo-annealing spectral content, which is relative to that of a pump light source, for effectively photo-annealing the rare-earth-doped fiber element. Photo-annealing by such shorter wavelength light results in a fast and nearly complete recovery of radiation induced attenuation of the rare-earth-doped optical fiber element in the wavelength range from 900 nm to 1700 nm. 1. An optical fiber apparatus , comprising:an optical fiber assembly including at least a rare-earth-doped fiber element and having a first port and a second port, wherein the first port and the second port can be an input port, an output port or an unused port;a photo-annealing light source coupled to the optical fiber assembly and emitting a light to recover an optical loss induced by irradiation; anda pump laser coupled to the optical fiber assembly and emitting a light to pump the rare-earth-doped fiber element.2. The optical fiber apparatus as claimed in claim 1 , wherein the photo-annealing light source is either a laser or a broadband light source.3. The optical fiber apparatus as claimed in claim 1 , wherein the wavelength range of the photo-annealing light source is less than the wavelength of the pump laser which is used to excite rare-earth-doped fiber elements.4. The optical fiber apparatus as claimed in claim 1 , wherein the photo-annealing light source is able to recover more than 50% claim 1 , preferably at least 75% claim 1 , and most preferably at least 99% of RIA in any wavelength interval from 900 nm to 1700 nm.5. The optical fiber apparatus as claimed in claim 1 , wherein the photo-annealing light source emits light continually or intermittently.6. An optical ...

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Номер записи: 18
14-11-2013 дата публикации

MASTER OSCILLATOR - POWER AMPLIFIER SYSTEMS

Номер: US20130301116A1
Автор: Kliner Dahv, Muendel Martin H.
Принадлежит:

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. 1. An integrated master oscillator and power amplifier (MOPA) system comprising: [ a core doped with active ions along at least a portion thereof,', 'an inner cladding surrounding the core and defining a waveguide for the laser light generated in the core, and', 'an outer cladding surrounding the inner cladding and defining a waveguide for the pump light; and,, 'a first double clad optical fiber (DCF) comprising, 'first and second fiber Bragg grating (FBG) reflectors integrally disposed at opposite ends of the first DCF so as to define an optical cavity of the fiber laser oscillator;, 'a fiber laser oscillator for emitting laser light when pumped by pump light, comprisinga pump source optically coupled to the first DCF for emitting the pump light into the inner cladding of the first DCF; and,a first fiber optic power amplifier comprising a second double clad optical fiber having a core doped with active ions for amplifying the laser light received from the fiber laser oscillator through the second FBG reflector, an inner cladding for guiding the laser radiation, and an outer cladding for guiding the pump radiation received from the fiber laser oscillator through the second FBG reflector; the fiber laser oscillator is optically coupled to the first fiber optic amplifier using one or more optical splices so as to form a monolithic fiber-optic structure,', 'the inner cladding of the first DCF has a circular cross- ...

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Номер записи: 19
28-11-2013 дата публикации

OPTICAL AMPLIFICATION DEVICE AND OPTICAL AMPLIFICATION METHOD

Номер: US20130314769A1
Автор: INAFUNE Kouji, KISHIMOTO Tadashi, MURAI Hitoshi
Принадлежит: OKI ELECTRIC INDUSTRY CO., LTD.

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. 1. An optical amplification device comprising:a first optical amplification portion that generates idler light as wavelength converted light based on wavelengths of signal light and pump light included in input light, and outputs first output light that includes signal light, pump light and idler light;an intermediate portion that generates second output light by exchanging mutually orthogonal polarization components of idler light included in the first output light; anda second optical amplification portion that amplifies an intensity of signal light included in the second output light.2. The optical amplification device according to claim 1 , further comprising:a phase adjustment portion that is capable of changing a relative phase of signal light, pump light and idler light input to the second optical amplification portion,wherein the second optical amplification portion amplifies the intensity of the signal light based on the relative phase.3. The optical amplification device according to claim 2 , ...

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Номер записи: 20
28-11-2013 дата публикации

HIGH POWER PLANAR LASING WAVEGUIDE

Номер: US20130314770A1
Автор: Sfez Bruno
Принадлежит: Soreqnuclear Research Center

A planar optical waveguide amplifier includes an active optical waveguide () containing rare-earth ions embedded in a passive optical waveguide () that guides the pump power. 1. Apparatus characterised by:{'b': 103', '102, 'a waveguide amplifier comprising an active optical waveguide () containing rare-earth ions embedded in a passive optical waveguide () that guides pump power.'}2103. The apparatus according to claim 1 , wherein said active optical waveguide () is single mode.3103102. The apparatus according to claim 1 , wherein an entire length of said active waveguide () is embedded within said pumping waveguide ().4103102. The apparatus according to claim 1 , wherein a refractive index of said active waveguide ( ) is higher than a refractive index of said pumping waveguide ().5201202202103102. The apparatus according to claim 1 , comprising an active waveguide () that is split into a plurality of branches () claim 1 , each of said branches () comprising said active waveguide () embedded within said pumping waveguide ().6202. The apparatus according to claim 5 , wherein light exiting said branches () is recombined in free space.7202201202201. The apparatus according to claim 5 , wherein a high reflectivity mirror (HRM) is deposited on a facet of said branches () and a medium reflectivity mirror (MRM) is deposited on a facet of said active waveguide () claim 5 , and light is reflected back from said branches () and exits through said active waveguide ().8302303302201. The apparatus according to claim 5 , wherein light from said branches () is recombined in a waveguide segment () and reflected back from said branches () and exits through said active waveguide ().9520530501502503504511512513514511512513514520. The apparatus according to claim 1 , wherein said passive optical waveguide comprises a central multimode waveguide () in which said active optical waveguide () is embedded claim 1 , and the apparatus further comprises a plurality of pump diodes ( claim 1 , ...

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Номер записи: 21
12-12-2013 дата публикации

AMPLIFYING APPARATUS AND CONTROL METHOD

Номер: US20130329278A1
Автор: MURO SHINICHIROU, Takeyama Tomoaki
Принадлежит: FUJITSU LIMITED

An amplifying-apparatus that raman-amplifies light transmitted through an optical-fiber-transmission-path, includes: an inputting-unit that inputs pump light to the optical-fiber-transmission-path; a path-switching-unit that is capable of switching between a first state in which the light transmitted through the optical-fiber-transmission-path is output to a first path and a second state in which the light transmitted through the optical-fiber-transmission-path is output to a second path; a splitting-unit that splits the light output to the second path by the path-switching-unit and outputs resulting first light and second light; and a control-circuit that stores information based on a result of reception of the light output to the first path by putting the path-switching-unit into the first state and then controls power of the pump light on a basis of the stored information and a result of reception of the first light output by the splitting-unit by putting the path-switching-unit into the second state. 1. An amplifying apparatus that raman-amplifies light transmitted through an optical-fiber transmission path , the amplifying apparatus comprising:an inputting unit that inputs pump light to the optical-fiber transmission path;a path switching unit that is capable of switching between a first state in which the light transmitted through the optical-fiber transmission path is output to a first path and a second state in which the light transmitted through the optical-fiber transmission path is output to a second path;a splitting unit that splits the light output to the second path by the path switching unit and outputs resulting first light and second light; anda control circuit that stores information based on a result of reception of the light output to the first path by putting the path switching unit into the first state and then controls power of the pump light on a basis of the stored information and a result of reception of the first light output by the ...

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Номер записи: 22
19-12-2013 дата публикации

EFFICIENT EXTENDED SHIFT MONOLITHIC RAMAN FIBER LASER

Номер: US20130335812A1
Автор: Johnson Benjamin R.
Принадлежит: BAE Systems Information and Electronic Systems Integration Inc.

A system and method for producing Stimulated Raman Scattering (SRS) is disclosed. A single optical fiber or Raman oscillator is optically pumped by a pump laser of sufficient power to generate SRS to generate several Stokes shifts of energy. This generates a multi-wavelength output or a single wavelength with several stokes energy shifts from the pump wavelength. A selective, monolithic-coated Raman fiber oscillator laser is utilized to increase the efficiency of frequency shifting by providing frequency-specific feedback at both facets of a free space coupled optical fiber oscillator. Frequencies that lie several bands away from the primary pump frequency may be efficiently achieved in a fiber oscillator by re-circulating the required stokes-shifted frequencies via selective high-reflection coatings. By re-circulating the intra-band stokes frequencies, the required intensities in each respective frequency will be increased, thereby dropping the respective Raman threshold in the optical fiber. 1. A method for producing Stimulated Raman Scattering:pumping a laser beam to a single optical fiber, wherein said optical fiber is coated with a dielectric high reflector at input and a high or partial reflector at output;providing frequency-specific feedback at both facets of a free space coupled optical fiber oscillator; andgenerating a multi-wavelength output or a single wavelength several stokes energy shifts from pump wavelength.2. The method of wherein said optical fiber coating is done at discrete stokes frequencies that lie between pump and desired output wavelength.3. The method of wherein said optical fiber coating prevents feedback into a pump source.4. The method of wherein required stokes-shifted frequencies is re-circulating via selective high-reflection coatings.5. The method of wherein said optical fiber is used in the generation of narrow or broadband light in visible region.6. The method of wherein said optical fiber is pumped with either a narrow or ...

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Номер записи: 23
19-12-2013 дата публикации

Method and apparatus for control of excess pump power in optical amplifiers

Номер: US20130335814A1
Автор: Berendt Martin Ole
Принадлежит:

A method for control of excess pump power in an optical amplifiers is disclosed. In one particular exemplary embodiment the method comprises a state model for the amplifier gain medium ground energy level inversion and a closed loop control tracking a desired degree of excess pump power. 1. An optical amplifier system comprising:a gain medium surrounded by a pump radiation guide;a pump radiation source coupled to the pump guide;a control system acting on the pump radiation power coupled to the pump radiation guide, said control system configured to receive input signal power information, pump rate information and containing;an equivalent circuit model tracking the pump absorption;a decision circuit comparing the model pump absorption with a setpoint and producing a deviation signal used to control the pump radiation power to limit the coupled pump radiation when model pump absorption is low compared to the set-point.3. Fiber laser system comprising:a laser oscillator anda power amplifier receiving as its input the output of the laser oscillator, the laser oscillator operation conditions information transmitted to the pump controller of the power amplifier, said controller using this information ina model to estimate relationship between launched and leaked pump power to regulate the launched pump power maintaining the leaked pump power below or at a setpoint, the controller containing a real time model for the dynamics of the population in the ground energy level of the laser medium active ions.4. A method for controlling excess pumping of a laser medium , the method having the recursive steps of:receiving amplifier input power signal;receiving excess pump power setpoint;model a state variable dependent on input power signal and a model pump, the state variable being representative of instantaneous optical pump power absorption;computing an error signal from the deviation between the setpoint and the state variable;regulating model and optical pump coupled to the ...

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Номер записи: 24
19-12-2013 дата публикации

OPTICAL FIBER, OPTICAL FIBER LASER AND OPTICAL FIBER AMPLIFIER, AND METHOD OF MANUFACTURING OPTICAL FIBER

Номер: US20130336343A1
Автор: Aiso Keiichi, Miyabe Ryo
Принадлежит: FURUKAWA ELECTRIC CO., LTD.

An optical fiber has: a core made of silica glass in which a rare earth element and aluminum have been added; an inner cladding layer that is formed around the core, is made of silica glass in which at least any one of an alkali metal and an alkali earth metal has been added, and has a refractive index lower than a refractive index of the core; and an outer cladding layer that is formed around the inner cladding layer and has a refractive index lower than the refractive index of the inner cladding layer. 1. An optical fiber , comprising:a core made of silica glass in which a rare earth element and aluminum have been added;an inner cladding layer that is formed around the core, is made of silica glass in which at least any one of an alkali metal and an alkali earth metal has been added, and has a refractive index lower than a refractive index of the core; andan outer cladding layer that is formed around the inner cladding layer and has a refractive index lower than the refractive index of the inner cladding layer.2. The optical fiber according to claim 1 , wherein the alkali metal or the alkali earth metal added in the inner cladding layer is at least any one of lithium claim 1 , sodium claim 1 , potassium claim 1 , and calcium.3. The optical fiber according to claim 1 , wherein a doping concentration of the aluminum is 2 wt % or more and 10 wt % or less claim 1 , the rare earth element is ytterbium claim 1 , and a doping concentration of the ytterbium is 0.8 wt % or more.4. The optical fiber according to claim 1 , wherein a relative refractive-index difference of the core with respect to the inner cladding layer is 0.1% to 0.15%.5. The optical fiber according to claim 1 , wherein the core is added with fluorine.6. The optical fiber according to claim 1 , wherein the outer cladding layer is made of a resin.7. The optical fiber according to claim 1 , wherein a relative refractive-index difference of the inner cladding layer with respect to pure silica glass is 0% to 0 ...

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Номер записи: 25
02-01-2014 дата публикации

FIBER AMPLIFIER SYSTEM

Номер: US20140002893A1
Автор: Limpert Jens, Nodop Dirk, Tuennermann Andreas
Принадлежит:

The invention relates to a fiber amplifier system for amplifying and emitting pulsed radiation, having a master source () which emits pulsed output radiation, and at least one amplifier stage (), which is arranged after the master source () in the direction of radiation, and which amplifies the output radiation. The aim of the invention is to provide a fiber amplifier system for amplifying and emitting pulsed radiation which avoids stimulated Brillouin scattering as effectively as possible and at the same time can be produced simply and inexpensively. To this end, the output radiation emitted by the master source () is broadband and is generated substantially by means of spontaneous emission. 1141. A fiber amplifier system for amplifying and emitting pulsed radiation , having a master source () which emits pulsed output radiation , and at least one amplifier stage () , which is arranged after the master source () in the direction of radiation , and which amplifies the output ,wherein{'b': '1', 'the output radiation emitted from the master source () is broadband and generated substantially by means of spontaneous emission.'}218. The fiber amplifier system according to claim 1 , wherein the master source () is an LED claim 1 , namely a super-luminescence diode (SLD) claim 1 , the end facets () of which have an antireflective coating.318. The fiber amplifier system according to claim 1 , wherein the master source () is an LED claim 1 , wherein the surface normal of at least one end facet () has an angle versus the direction of radiation that deviates from 0°.44. The fiber amplifier system according to claim 1 , wherein a filtrating element is arranged upstream to and/or downstream of the amplifier stage ().532. The fiber amplifier system according to claim 4 , wherein the filtrating element is a spectral filter () or a polarization filter ().64. The fiber amplifier system according to claim 1 , wherein the amplifier stage () is several times passed through by the ...

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Номер записи: 26
09-01-2014 дата публикации

RARE EARTH DOPED AND LARGE EFFECTIVE AREA OPTICAL FIBERS FOR FIBER LASERS AND AMPLIFIERS

Номер: US20140009822A1
Автор: Dong Liang, Peng Xiang
Принадлежит: IMRA AMERICA, INC.

Various embodiments described herein include rare earth doped glass compositions that may be used in optical fiber and rods having large core sizes. Such optical fibers and rods may be employed in fiber lasers and amplifiers. The index of refraction of the glass may be substantially uniform and may be close to that of silica in some embodiments. Possible advantages to such features include reduction of formation of additional waveguides within the core, which becomes increasingly a problem with larger core sizes. 1. An optical fiber system for providing optical amplification , said optical fiber system comprising: [{'sub': 'core', 'a core having a core radius ρ and a core index of refraction n, wherein said core comprises a doped region;'}, {'sub': 1', 'c1', 'core', 'c1, 'a first cladding disposed about said core, said first cladding having an outer radius ρand an index of refraction n, said core and said first cladding having a difference in index of refraction Δn=n−n; and'}, {'sub': '1', 'a second cladding disposed about said first cladding, said first cladding and said second cladding having a difference in index of refraction Δn,'}, {'sub': 1', '1, 'wherein the first cladding radius, ρ, is greater than about 1.1ρ and less than about 2ρ, and the refractive index difference between said first cladding and said second cladding, Δn, is greater than about 1.5Δn and less than about 50Δn,'}, 'wherein said large-core optical fiber comprises a combined waveguide formed by said core and said first cladding layer, said combined waveguide configured such that a mode supported in said core has increased gain relative to a mode having substantial power in said first cladding., 'a large-core optical fiber comprising2. The optical fiber system of claim 1 , wherein said second cladding comprises holes that are configured to provide leakage channels such that said large-core optical fiber supports one or a few modes and higher order modes are leaked.3. The optical fiber system of ...

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Номер записи: 27
30-01-2014 дата публикации

AMPLIFICATION OPTICAL FIBER, AND OPTICAL FIBER AMPLIFIER AND RESONATOR USING SAME

Номер: US20140029084A1
Автор: KASHIWAGI Masahiro
Принадлежит: FUJIKURA LTD.

An amplification optical fiber includes a core and a clad which covers the core. The core propagates light having a predetermined wavelength in at least an LP01 mode, an LP02 mode, and LP03 mode and, in the core, when the LP01 mode, the LP02 mode, and the LP03 mode are standardized by a power, in at least a part of a region where an intensity of at least one of the LP02 mode and the LP03 mode is stronger than an intensity of the LP01 mode, an active element which stimulates and emits light having a predetermined wavelength is added with a higher concentration than that in at least a part of a region where the intensity of the LP01 mode is stronger than the intensities of the LP02 mode and the LP03 mode. 1. An amplification optical fiber , comprising:a core and a clad which covers the core,wherein the core propagates light having a predetermined wavelength in at least an LP01 mode, an LP02 mode, and an LP03 mode,in the core, when the LP01 mode, the LP02 mode, and the LP03 mode are standardized by a power, in at least a part of a region where an intensity of at least one of the LP02 mode and the LP03 mode is stronger than an intensity of the LP01 mode, an active element which stimulates and emits the light having the predetermined wavelength is added with a higher concentration than that in at least a part of a region where the intensity of the LP01 mode is stronger than the intensities of the LP02 mode and the LP03 mode, and [{'br': None, 'sub': 0', '02', '01, 'sup': 'b', 'i': n', 'r', 'r', 'I', 'r', 'rdr>O, '∫()×{I()−()}\u2003\u2003(1)'}, {'br': None, 'sub': 0', '03', '01, 'sup': 'b', 'i': n', 'r', 'I', 'r', 'I', 'r', 'rdr>O, '∫()×{()−()}\u2003\u2003(2)'}], 'at least one of the following Formulae (1) and (2) is satisfied.'}{'sub': 01', '03, '(In this case, r is a distance from the center in the radial direction of the core, I(r) is an intensity of the LP01 mode in the distance r from the center in the radial direction of the core, I02(r) is an intensity of the LP02 ...

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Номер записи: 28
06-02-2014 дата публикации

FEW MODE RARE EARTH DOPED OPTICAL FIBERS FOR OPTICAL AMPLIFIERS, AND AMPLIFIERS USING SUCH FIBERS

Номер: US20140036348A1
Автор: Bennett Kevin Wallace, Koreshkov Konstantin Sergeevich, Korolev Andrey Evgenievich, Kuksenkov Dmitri Vladislavovich, Li Ming Jun, Nazarov Vladimir Nikolaevich
Принадлежит: CORNING INCORPORATED

According to some embodiments a few moded optical fiber includes a glass core structured to provide light amplification at an amplification wavelength and a cladding surrounding the core. According to some embodiments the core of the few moded optical fiber includes a portion that has an average concentration of rare earth dopant which is lower by at least 30%, and preferably by at least 50%, than the average concentration of the rare earth dopant at another portion of the core that is situated further from the core center. 2. A rare earth doped fiber comprising a glass core structured to provide light amplification at an amplification wavelength and a cladding surrounding the core , said fiber comprising:{'sub': 1', '1', 'c', '1', 'c', '1, '(i) the glass core having a radius R, said core containing a rare earth dopant such that the average concentration of said rare earth dopant is at least 30% lower in the portion of the core situated within 0Δ'}3. The rare earth optical fiber according to claim 2 , wherein said core has a refractive index profile structured such that the core is capable of supporting the propagation and amplification of optical signals with X number of LP modes at the amplification wavelength claim 2 , wherein X is an integer greater than 1 claim 2 , wherein said rare earth dopant is the rare-earth dopant is at least one of: Yb claim 2 , Er claim 2 , Nd claim 2 , Tm claim 2 , Sm claim ...

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Номер записи: 29
06-02-2014 дата публикации

HIGH POWER PARALLEL FIBER ARRAYS

Номер: US20140036350A1
Автор: Dong Liang, FERMANN Martin, HARTL Ingmar, MARCINKEVICIUS Andrius
Принадлежит: IMRA AMERICA, INC.

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. 1. A high peak power fiber amplifier system , comprising:an array of fiber amplifiers implemented in the form of a multi-core fiber, said fiber amplifiers being spaced such that thermal fluctuations of said fiber amplifiers are matched sufficiently to limit relative phase fluctuations at fiber amplifier outputs to a bandwidth less than 10 kHz, and such that optical energy coupling between any of the fiber amplifiers of said array of fiber amplifiers is negligible;a laser source for seeding said array of fiber amplifiers;a beam distributor disposed between said laser source and said array of fiber amplifiers to distribute a pulse from said laser source into a plurality of beam paths incident on corresponding amplifiers of the array, wherein beams in said path have a spatial distribution substantially similar to the spatial distribution of an output of said laser source;at least one pump source configured for optically pumping said array of fiber amplifiers;a plurality of phase-control elements arranged in a spatial relation and optically connected to fiber amplifiers of said array of fiber amplifiers, said elements modifying an optical phase of at least one fiber amplifier output in response to phase-control signals;a phase control unit for producing said control signals to control the optical phase at the output of a majority of said fiber amplifiers of said array of fiber amplifiers, wherein said control signal and said phase control elements stabilize the ...

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Номер записи: 30
13-02-2014 дата публикации

SINGLE MODE PROPAGATION IN FIBERS AND RODS WITH LARGE LEAKAGE CHANNELS

Номер: US20140044139A1
Автор: Dong Liang, FERMANN Martin E., Wong William
Принадлежит: IMRA AMERICA, INC.

Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprising cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining. 1. A polarization-maintaining (PM) optical fiber for propagating at least one lower order mode having a wavelength , λ , while limiting propagation of higher order modes having a wavelength , λ , by providing said higher order modes with a higher loss than said at least one lower order mode at said wavelength , λ , said optical fiber comprising:a first cladding region comprising one or more cladding features; anda core region surrounded by said first cladding region, said core region having a width of at least about 20 micrometers, said one or more cladding features configured to substantially confine propagation of said at least one lower order mode to said core region,wherein said one or more cladding features are arranged in no more than two layers around core region, andwherein said core region, said first cladding region, or both said core region and said first cladding region have a two dimensional asymmetry that provides birefringence2. The PM optical fiber of claim 1 , wherein said width of said core region is less than about 300 micrometers.3. The PM optical fiber of claim 1 , wherein said one or more cladding features are arranged in no more than one layer around said core region.4. The PM optical fiber of claim 1 , wherein said PM optical fiber comprises at least one stress-producing region.5. The PM optical fiber of claim 1 , wherein said one or more cladding features comprises stress elements.6. The PM optical fiber of claim 1 , wherein said one or more cladding features ...

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Номер записи: 31
01-01-2015 дата публикации

SELF-AUTOMATIC GAIN CONTROL DISTRIBUTED RAMAN FIBER AMPLIFIER AND AUTOMATIC GAIN CONTROL METHOD

Номер: US20150002922A1
Автор: CHAE Woon Byung, CHOI Meong Kyu, KIM Jeong Mee, KIM Sung Jun, YOON Soo Young
Принадлежит:

Disclosed is a self-automatic gain control distributed Raman fiber amplifier, in which a signal is transmitted to a self-AGC monitor and a PD via a pump/signal combiner through a transmission fiber and passes through an RFA control circuit, a self-AGC firmware, and an ASCII communication unit and an Raman pump laser module communicates with the RFA control circuit and transmits the signal to the pump/signal combiner. 1. A self-automatic gain control distributed Raman fiber amplifier , comprising:a Raman pump laser module configured to generate pumping light to compensate for a signal loss generated from a transmission fiber;a pump/signal combiner configured to input the pumping light to the transmission fiber;a self-AGC monitor configured to monitor a self-AGC state and convert an optical signal into an electrical signal to be output;an RFA control circuit configured to generate an electrical signal for controlling the Raman pump laser module using the electrical signal output from the self-AGC monitor;a self-AGC firmware configured to generate a target pump laser value using a monitor signal received through the RFA control circuit and transmit a control signal to the RFA control circuit; andan ASCII communication unit configured to transmit or receive monitor and control information to or from an external user.2. The self-automatic gain control distributed Raman fiber amplifier of claim 1 , wherein the self-AGC monitor includes a first filter claim 1 , a second filter claim 1 , and a tap coupler claim 1 , which are connected to a BPD claim 1 , an RPD claim 1 , and an OPD claim 1 , respectively claim 1 ,the Raman pump laser module includes a B-pump, an R-pump, and a pump combiner,the RFA control circuit includes a pump LD bias & TEC control circuit, a low power monitoring circuit, and a wide dynamic range monitoring circuit, andthe self-AGC firmware includes a pump LD APC algorithm, an EDFA ASE compensate algorithm, and a total power conversion software.3. The self ...

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Номер записи: 32
01-01-2015 дата публикации

Stabilizing apparatus for tremolo system for string instrumen

Номер: US20150003772A1
Автор: Scott Nicholas Dante Lionello
Принадлежит: Individual

A few-moded fiber device has several discrete sections of few-moded fibers that are separated by mode converters, with each mode converter accomplishing mode conversion between one or more pairs of modes. The mode conversions can be accomplished using a sequence, such as a periodic or cyclic sequence that would cause (1) a signal wave launched with any mode to assume every other mode for one or more times; (2) the number of times the signal remains in any modal state is substantially the same; and (3) the net signal gain or loss or group delay of the input signal is substantially the same regardless of the state of input mode. A laser few-mode amplifier is provided. An optical transmission system is also provided.

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Номер записи: 33
03-01-2019 дата публикации

LIFETIME EXTENDING AND PERFORMANCE IMPROVEMENTS OF OPTICAL FIBERS VIA LOADING

Номер: US20190004396A1
Автор: Thomsen Carsten l.
Принадлежит: NKT Photonics A/S

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material. 1. (canceled)2. An optical supercontinuum system comprising an optical fiber and a feeding unit wherein said feeding unit is a pulsed pump light source and is adapted to feed said optical fiber with pulses with a peak power density within said fiber equal to or higher than 10 W/μm , wherein said optical fiber comprises a core and a cladding , comprising a core material and a cladding material , respectively , at least a part of the core comprising silica , and wherein said fiber is a non-linear microstructured optical fiber , wherein said non-linear microstructured optical fiber comprises hydrogen and/or deuterium bound to said core material.3. The optical supercontinuum system of claim 2 , wherein said core material has a Germanium content of less than or equal to 20 at %.4. The optical supercontinuum system of claim 2 , wherein said feeding unit is adapted to feed said fiber with pulses with a peak power density within said fiber of equal to or higher than 50 W/μm.5. The optical supercontinuum system of claim 2 , wherein said fiber is adapted to guide light for at least a range of wavelengths λto λand has a non-linear parameter γ wherein for at least part of said range the product of the wavelength X and the non-linear parameter γ is more than or equal to 4·10W.6. The optical supercontinuum system of claim 2 , wherein said fiber has a lifetime until the absorption of light in the visible has decreased by more than 40% claim 2 , wherein said lifetime is more than 100 ...

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Номер записи: 34
05-01-2017 дата публикации

ADAPTIVE BOOST CONTROL FOR GATING PICOSECOND PULSED FIBER LASERS

Номер: US20170005451A1
Автор: Kutscha Timothy N., Lowder Tyson
Принадлежит: nLIGHT, Inc.

A method includes applying a boost pump signal to a pump laser of a laser system based on a preceding off duration associated with the laser system, and applying a forward pump signal to the pump laser. A laser system includes a seed laser situated to generate seed optical pulses, a pump laser situated to generate pump optical radiation, a fiber amplifier situated to receive the pump optical radiation and the seed optical pulses, and a controller situated to select a pump boost duration or pump boost magnitude based on an off duration associated with the laser system. 1. A method , comprising:applying a boost pump signal to a pump laser of a laser system based on a preceding off duration associated with the laser system; andapplying a forward pump signal to the pump laser.2. The method of claim 1 , further comprising detecting the off duration.3. The method of claim 1 , wherein the off duration is associated with a laser gate signal claim 1 , and the boost pump signal is applied in response to the laser gate signal.4. The method of claim 1 , wherein the off duration is associated with the pump laser.5. The method of claim 1 , further comprising determining a duration of the boost pump signal based on stored pump signal values associated with a plurality of off durations.6. The method of claim 5 , further comprising:applying the boost pump signal in response to a gate signal;wherein the forward pump signal is applied upon completion of the boost pump signal.7. The method of claim 6 , wherein the boost pump signal is selected based on a laser system output pulse rise time and overshoot.8. The method of claim 1 , further comprising determining a magnitude of the boost pump signal based on stored pump signal magnitudes associated with a plurality of off durations.9. The method of claim 8 , wherein a duration of the boost pump signal is common for at least two off durations.10. The method of claim 1 , further comprising determining a duration of the boost pump signal ...

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Номер записи: 35
07-01-2016 дата публикации

Self-automatic gain control distributed raman fiber amplifier and automatic gain control method

Номер: US20160006206A1
Автор: Jeong Mee Kim, Meong Kyu CHOI, Soo Young Yoon, Sung Jun Kim, Woon Byung CHAE
Принадлежит: LICOMM CO Ltd

Disclosed is a self-automatic gain control distributed Raman fiber amplifier, in which a signal is transmitted to a self-AGC monitor and a PD via a pump/signal combiner through a transmission fiber and passes through an RFA control circuit, a self-AGC firmware, and an ASCII communication unit and an Raman pump laser module communicates with the RFA control circuit and transmits the signal to the pump/signal combiner.

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Номер записи: 36
07-01-2016 дата публикации

Pump laser architecture and remotely pumped raman fiber amplifier laser guide star system for telescopes

Номер: US20160006209A1
Автор: Daoping WEI, Vladimir Karpov, Wallace R. L. CLEMENTS
Принадлежит: MPB Communications Inc

There is provided a system for remote pumping of a Raman fiber amplifier comprising a pump laser located remotely from the Raman fiber amplifier and a laserhead and one or more optical fibers to optically couple the high power pump light from the remote pump laser to the Raman fiber amplifier where a seed laser light is amplified wherein the pump laser for producing a high power laser light of a predetermined pump wavelength comprises a first fiber laser emitting light at the predetermined pump wavelength and one (second) or two (third) laser emitting light at a wavelength lower than the predetermined pump wavelength and multiplexed with light from the first laser into an optical fiber providing Raman gain at the predetermined pump wavelength to convert the second (and optionally also the third) laser light to light at the predetermined pump wavelength.

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Номер записи: 37
07-01-2021 дата публикации

Single-Frequency Fiber Amplifier with Distal Cladding Stripper

Номер: US20210006029A1
Автор: Franklin Jose, Kelsey Yee, Steven J. Augst
Принадлежит: Massachusetts Institute of Technology

Stimulated Brillouin scattering (SBS) limits the maximum power in fiber lasers with narrow linewidths. SBS occurs when the power exceeds a threshold proportional to the beam area divided by the effective fiber length. The fiber lasers disclosed here operate with higher SBS power thresholds (and hence higher maximum powers at kilohertz-class linewidths) than other fiber lasers thanks to several techniques. These techniques include using high-absorption gain fibers, operating the laser with low pump absorption (e.g., ≤80%), reducing the length of un-pumped gain fiber at the fiber output, foregoing a delivery fiber at the output, foregoing a cladding light stripper at the output, using free-space dichroic mirrors to separate signal light from unabsorbed pump light, and using cascaded gain fibers with non-overlapping Stokes shifts. The upstream gain fiber has high absorption and a larger diameter for high gain, and subsequent gain fiber has a smaller diameter to improve beam quality.

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Номер записи: 38
02-01-2020 дата публикации

METHOD AND APPARATUS FOR DETERMINING MAXIMUM GAIN OF RAMAN FIBER AMPLIFIER

Номер: US20200007238A1
Автор: Bu Qinlian, Fang Di, Fu Chengpeng, Le Menghui, Liu Fei, Tao Jintao, Yu Chunpin, Zhang Cuihong, Zhang Peng
Принадлежит: ACCELINK TECHNOLOGIES CO., LTD.

The present disclosure relates to a technical field of optical communication, and provides a method and an apparatus for determining maximum gain of Raman fiber amplifier. Wherein the method includes obtaining transmission performance parameters of a current optical fiber transmission line; respectively obtaining impact factors A, A, Aaccording to a distance between a joint and a pump source, a fiber loss coefficient, and a fiber length included in the transmission performance parameters; calculating a joint loss value Attaccording to a distance between a joint and a pump source, a fiber loss coefficient, and looking up impact factor Aaccording to Att; determining an actual maximum gain which may actually be achieved by the Raman fiber amplifier according to A, A, A, A. The actual maximum gain obtained in the present disclosure is the maximum gain that may be achieved over all input power ranges, and the original signal in system is kept to operate at a fixed gain, such that a gain locking effect is realized, and fluctuation of existing transmission signal power caused by signal change in transmission fiber link is avoided. 1. A method for determining a maximum gain of a Raman fiber amplifier , characterized in that a relationship between the maximum Raman gain and a 0 km joint loss Attequivalent to a joint loss at different positions of one or more types of fibers , a relationship between the maximum Raman gain and a 0 km joint loss Attequivalent to a joint loss caused by a loss coefficient of the fibers , a relationship between the maximum Raman gain and a 0 km joint loss Att equivalent to a joint loss caused by a mode field diameter of the fibers , and a relationship between the maximum Raman gain and a fiber length are pre-configured , where i is a distance from a joint to a pump source , j is the loss coefficient of the fibers , and k is the mode field diameter of the fibers , the method comprises:obtaining transmission performance parameters of a current ...

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Номер записи: 39
20-01-2022 дата публикации

Efficient In-Band Pumping of Holmium-Doped Optical Fiber Amplifiers

Номер: US20220021173A1
Автор: Delavaux Jean-Marc, Tench Robert E.
Принадлежит: Cybel, LLC.

A fiber-based optical amplifier for operation at an eye-safe input signal wavelength λwithin the 2 μm region is formed to include a section of Holmium (Ho)-doped optical gain fiber. The pump source for the fiber amplifier is particularly configured to provide pump light at a wavelength where the absorption coefficient of the Ho-doped optical gain fiber exceeds its gain coefficient (referred to as an “absorption-dominant pump wavelength”), and is typically within the range of 1800-1900 nm. The selection of an absorption-dominant pump wavelength limits the spontaneous emission of the pump from affecting the amount of gain achieved at the higher wavelength end of the operating region. The amount of crosstalk between the signal wavelength and pump wavelength is also reduced (in comparison to using the conventional 1940 nm pump wavelength). 1. An optical amplifier for operation at an eye-safe input signal wavelength λwithin the 2 μm region , comprising:a section of Holmium (Ho)-doped optical gain fiber responsive to an input optical signal for generating gain within the input optical signal as it propagates therealong by the presence of Ho ions, providing as an output an amplified optical signal, the section of Ho-doped optical gain fiber exhibiting a gain coefficient G and an absorption coefficient α that both vary as a function of an applied pump wavelength; and{'sub': P', 'P', 'P, 'a pump source coupled to the section of Ho-doped optical gain fiber and configured to provide pump light at a wavelength λwithin an absorption-dominant wavelength region where α(λ)>G(λ).'}2. An optical amplifier as defined in wherein the absorption-dominant wavelength region extends from about 1800 nm to about 1900 nm.3. An optical amplifier as defined in wherein the absorption-dominant pump wavelength λcomprises a value in the range of about 1820 nm to about 1880 nm.4. An optical fiber amplifier as defined in wherein the section of Ho-doped optical gain fiber comprises a section of single- ...

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Номер записи: 40
10-01-2019 дата публикации

Mode Mixing Optical Fibers and Methods and Systems Using the Same

Номер: US20190011637A1
Автор: Abramczyk Jaroslaw, CONROY MICHAEL, FARLEY Kevin, Jollivet Clemence, Tankala Kanishka
Принадлежит: Nufem

The present disclosure relates more to mode mixing optical fibers useful, for example in providing optical fiber laser outputs having a desired beam product parameter and beam profile. In one aspect, the disclosure provides a mode mixing optical fiber for delivering optical radiation having a wavelength, the mode mixing optical fiber having an input end, an output end, a centerline and a refractive index profile, the mode mixing optical fiber comprising: an innermost core, the innermost core having a refractive index profile; and a cladding disposed about the innermost core, wherein the mode mixing optical fiber has at least five modes at the wavelength, and wherein the mode mixing optical fiber is configured to distribute a fraction of the light input at its input end from its lower-order modes to its higher-order modes. 161-. (canceled)62. A mode mixing optical fiber for delivering optical radiation having a wavelength , the mode mixing optical fiber having a input end , an output end , a centerline and a refractive index profile , the mode mixing optical fiber comprising:an innermost core, the innermost core having a refractive index profile; anda cladding disposed about the innermost core,wherein the mode mixing optical fiber has at least five modes at the wavelength, andwherein the mode mixing optical fiber is configured to distribute a fraction of the light input at its input end from its lower-order modes to its higher-order modes.63. The mode mixing optical fiber according to claim 62 , wherein the innermost core has a centerline that is positioned substantially non-collinearly with the centerline of the optical fiber claim 62 , and wherein a lateral offset of the center of the innermost core with respect to the centerline of the fiber is at least 10 microns.6461. The mode mixing optical fiber according to claim claim 62 , wherein there is no substantially down-doped region disposed symmetrically around the centerline of the innermost core.65. The mode ...

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Номер записи: 41
10-01-2019 дата публикации

POLARIZED FIBER-LASER

Номер: US20190013638A1
Автор: CAPRARA Andrea, SHU Qi-Ze
Принадлежит:

A fiber-laser includes a gain-fiber in a laser-resonator. A polarizer is located in the laser-resonator at an end thereof, causing the output of the fiber-laser to be linearly polarized. A wavelength-selective element is also included in the laser-resonator for selecting an output wavelength of the fiber-laser from within a gain-bandwidth of the gain-fiber. 1. Fiber-laser apparatus , comprising:a laser-resonator including a gain-fiber, the laser-resonator terminated at first and second ends thereof by respectively first and second reflectors;a pump-radiation source arranged to provide pump-radiation to the gain-fiber and cause the resonator to deliver laser-radiation;a polarizer located between one of the reflectors and the gain-fiber, the polarizer arranged to cause the laser-radiation delivered from the laser-resonator to be linearly-polarized; anda wavelength-selective device located in the laser-resonator for selecting the wavelength of the delivered radiation from within a gain-bandwidth of the gain-fiber.2. The apparatus of claim 1 , further including a waveplate located between the polarizer and the gain-fiber.3. The apparatus of claim 2 , wherein the waveplate has a retardance greater than or equal to a quarter wave.4. The apparatus of claim 3 , wherein the waveplate is a half-waveplate.5. The apparatus of claim 1 , wherein the polarizer selects an eigen polarization of the resonator.6. The apparatus of claim 1 , wherein the polarizer is a cube-prism polarizer.7. The apparatus of claim 1 , wherein the gain-fiber is not polarization maintaining.8. The apparatus of claim 1 , wherein the gain-fiber is a single-mode gain-fiber.9. The apparatus of claim 1 , wherein the gain-fiber is a ytterbium-doped fiber.10. The apparatus of claim 1 , wherein one of the reflectors is a fiber Bragg grating.1105. The apparatus of claim 10 , wherein the fiber Bragg grating has a reflection bandwidth of about . nm or less.12. The apparatus of claim 1 , further including an ...

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Номер записи: 42
17-01-2019 дата публикации

APPARATUS AND METHOD FOR DIMINISHING MODE LOCK INDUCED ERROR IN STIMULATED BRILLOUIN SCATTERING WAVEGUIDE RING LASER GYROSCOPES

Номер: US20190017824A1
Автор: Puckett Matthew Wade, Qiu Tiequn, Wu Jianfeng
Принадлежит:

In one embodiment, a method is provided. The method comprises transmitting a first laser pump signal to an optical resonator; adjusting a frequency of the first laser pump signal; generating a first order Stokes signal from the first laser pump signal in an optical resonator; measuring a first beat signal frequency; ceasing transmission of the first laser pump signal to the optical resonator; transmitting a second laser pump signal to the optical resonator; adjusting a frequency of the second laser pump signal; generating a first order Stokes signal from the second laser pump signal in the optical resonator; and measuring a second beat signal frequency; ceasing transmission of the second laser pump signal to the optical resonator. 1. A stimulated Brillouin scattering (SBS) ring laser gyroscope , comprising:a first laser configured to generate a first laser pump signal;a second laser configured to generate a second laser pump signal;a first variable optical attenuator coupled to the output of the first laser;a second variable optical attenuator coupled to the output of the second laser;an optical resonator coupled to the first variable optical attenuator and the second variable optical attenuator;an input axis parallel to a center axis of the optical resonator;wherein the first variable optical attenuator and the second variable optical attenuator are configured to alternatively, during different time periods, transmit to the optical resonator the first laser pump signal and the second laser pump signal;wherein the first laser pump signal and the second laser pump signal each generate a first order Stokes signal in the optical resonator that propagates in an opposite direction, around the optical resonator, of the corresponding first laser pump signal and the second laser pump signal;a first photodetector coupled to the optical resonator;a second photodetector coupled to the optical resonator;a third photodetector coupled to the optical resonator;a fourth ...

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Номер записи: 43
18-01-2018 дата публикации

Raman amplifier system and method with integrated optical time domain reflectometer

Номер: US20180019813A1
Автор: Balakrishnan Sridhar, Jean-Luc Archambault, Jun Bao
Принадлежит: Ciena Corp

An optical module includes an optical amplifier configured to amplify Wavelength Division Multiplexing (WDM) channels transmitted on a fiber; and an optical time domain reflectometer (OTDR) configured to transmit an OTDR signal on the fiber and detect a back-scattered signal based thereon to test the fiber, wherein a wavelength of the OTDR signal is one of i) between one or more wavelengths associated with the optical amplifier and one or more wavelengths associated with the WDM channels and ii) greater than the one or more wavelengths associated with the WDM channels, for in-service operation of the OTDR.

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Номер записи: 44
17-01-2019 дата публикации

Ultra-wideband raman amplifier with comb source

Номер: US20190020171A1
Автор: Nitin Kumar Goel, Satyajeet Singh Ahuja
Принадлежит: Facebook Inc

Disclosed are fiber amplifiers with multiple pumping sources including multiple optical sources or an optical comb source with multiple spectral lines. A comb source may include generating a plurality of evenly spaced or nearly evenly spaced spectral lines. The optical comb source may pump a fiber by propagating optical energy at the multiple spectral lines through the fiber. The comb source may cause gain in the fiber at in a band of wavelengths different from the spectral lines of the comb source. A weak signal injected into the fiber that propagates in the fiber will experience optical gain in the fiber producing an amplified signal at the wavelength within a band of wavelengths different from the comb source wavelengths. When the bandwidth of the multiple bands of gain is wide, the amplifier may be referred to as an ultra-wideband amplifier.

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Номер записи: 45
22-01-2015 дата публикации

Compact coherent high brightness light source for the mid-ir and far ir

Номер: US20150023628A1
Автор: Ingmar Hartl, Martin E. Fermann
Принадлежит: IMRA America Inc

Compact laser systems are disclosed which include ultrafast laser sources in combination with nonlinear crystals or waveguides. In some implementations fiber based mid-IR sources producing very short pulses and/or mid-IR sources based on a mode locked fiber lasers are utilized. A difference frequency generator receives outputs from the ultrafast sources, and generates an output including a difference frequency. The output power from the difference frequency generator can further be enhanced via the implementation of large core dispersion shifted fibers. Exemplary applications of the compact, high brightness mid-IR light sources include medical applications, spectroscopy, ranging, sensing and metrology.

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Номер записи: 46
26-01-2017 дата публикации

Raman Pump Laser Control Apparatus And Control Method Therefor

Номер: US20170025814A1
Автор: Bu Qinlian, Fu Chengpeng, Jing Yunyu, Le Menghui, Tao Jintao, Xiong Tao, Yu Chunping
Принадлежит:

A Raman pump laser control apparatus comprises a wavelength division multiplexer, a tap coupler, a photoelectric detector, an analogue amplification processing circuit, an analogue-to-digital converter, a fast Raman pump control unit, an digital-analog converter, and a Raman pump laser. The fast Raman pump control unit, after having known anticipated output light power of the Raman pump laser, based on a direct relationship between a current anticipated output light power of the Raman pump laser and input digital quantity that is needed by the digital-analog converter, uses a feedforward control mechanism so that actual output light power of the Raman pump laser fastly approximates the anticipated output light power thereof, and then synchronously combines with a feedback control mechanism so that the actual output light power of the Raman pump laser is precisely locked on the anticipated output light power, thereby achieving fast and precise control of the Raman pump laser. 1. A control device of Raman pump laser , comprising a wavelength division multiplexer , a tap coupler , a photoelectric detector , an analog amplifier processing circuit , an analog-digital converter , a fast Raman pump control unit , a digital-analog converter , and a Raman pump laser ,wherein the wavelength division multiplexer couples the pump light output from the tap coupler with signal light;the tap coupler splits the pump light, one part of light energy of the split light is coupled into the wavelength division multiplexer, and another part enters into the photoelectric detector,the photoelectric detector detects the split light output from the tap coupler,the analog amplifier processing circuit performs amplification processing on the analog signal detected by the photoelectric detector,the analog-digital converter converts the analog signal processed by the analog amplifier processing circuit into digital signal,the fast Raman pump control unit performs data processing on digital ...

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Номер записи: 47
24-04-2014 дата публикации

Raman Distributed Feedback Fiber Laser and High Power Laser System Using the Same

Номер: US20140112357A1
Автор: Abedin Kazi S., Kremp Tristan, Nicholson Jeffrey W., Porque Jerom C., Westbrook Paul S.
Принадлежит:

A Raman distributed feedback (DFB) fiber laser is disclosed. It includes a pump source and a Raman gain fiber of a length smaller than 20 cm containing a distributed feedback (DFB) grating with a discrete phase structure located within no more than 10% off the center of the grating and wherein the Raman DFB fiber laser generates a laser signal with an optical spectrum, which has an optical bandwidth at half maximum optical intensity of less than 1 gigahertz (GHz) (wherein a maximum intensity frequency is different from the frequency of the pump laser). The Raman laser includes compensation for the nonlinear phase change due to Kerr effect and thermal effect resulting from absorption of the optical field, thus enhancing the conversion efficiency. 1. A Raman laser , comprising:an optical input enabled to receive radiation from a pump source; anda Raman gain fiber less than 20 cm in length, comprising at least one Bragg grating enabled to provide Raman radiation on an optical output.2. The Raman laser of claim 1 , wherein the at least one Bragg grating has a phase shift.3. The Raman laser of claim 1 , wherein the at least one Bragg grating has a longitudinally nonuniform profile in refractive index modulation in strength4. The Raman laser of claim 1 , wherein the at least one Bragg grating has a longitudinally nonuniform profile in phase.5. The Raman laser of claim 1 , wherein the Raman laser generates Raman radiation on the optical output with an optical spectrum having an optical bandwidth at half maximum optical intensity of about or less than 1 gigahertz (GHz).6. The Raman laser of claim 5 , wherein the optical bandwidth is about or less than 100 MHz.7. The Raman laser of claim 5 , wherein the optical bandwidth is between about 6 MHz and 10 MHz.8. The Raman laser of claim 1 , wherein the Raman laser has a threshold power within a range of 0.08-10 W.9. The Raman laser of claim 1 , wherein the Raman laser has a threshold power within a range of 1.28-4.4 W.10. The ...

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Номер записи: 48
10-02-2022 дата публикации

CONTROLLER AND CONTROL METHOD FOR RAMAN AMPLIFIER

Номер: US20220045755A1
Автор: Shukunami Norifumi, Takeyama Tomoaki
Принадлежит: FUJITSU LIMITED

A controller for a front-exciting Raman-amplifier that amplifies an optical signal transmitted from one end of an optical fiber to other end by inputting an excitation light to the one end, the controller includes a memory, and a processor coupled to the memory and configured to acquire communication-related information regarding communication of the optical signal in the optical fiber, when the acquired communication-related information does not indicate the communication of the optical signal, set a Raman gain of the front-exciting Raman amplifier based on a first light intensity of an amplified spontaneous scattered light of the excitation light, and when the acquired communication-related information indicates the communication of the optical signal, set the Raman gain based on a second light intensity of the optical signal output from the optical fiber. 1. A controller for a front-exciting Raman amplifier that amplifies an optical signal transmitted from one end of an optical fiber to other end of the optical fiber by inputting an excitation light to the one end of the optical fiber , the controller comprising:a memory; anda processor coupled to the memory and configured to:acquire communication-related information regarding communication of the optical signal in the optical fiber,when the acquired communication-related information does not indicate the communication of the optical signal,set a Raman gain of the front-exciting Raman amplifier based on a first light intensity of an amplified spontaneous scattered light of the excitation light, andwhen the acquired communication-related information indicates the communication of the optical signal,set the Raman gain based on a second light intensity of the optical signal output from the optical fiber.2. The controller according to claim 1 ,wherein the processor is configured to:when setting the Raman gain based on the first light intensity,calculate the first light intensity when the Raman gain based on the first ...

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Номер записи: 49
24-01-2019 дата публикации

Apparatus and Method For Optical Isolation

Номер: US20190027888A1
Автор: Durkin Michael Kevan
Принадлежит:

Apparatus for optical isolation, which apparatus comprises a laser (), a beam delivery system (), and an output port (), wherein: the beam delivery system () comprises an optical isolator () and an optical fibre (); the laser () is defined by a peak power (); the laser () emits laser radiation () at a signal wavelength (); the laser radiation () is coupled from the laser () to the output port () via the beam delivery system (); and the optical fibre () comprises an optical waveguide () defined by a core (), a cladding (), a mode field area () at the signal wavelength (), a length (), and a Raman wavelength (); and the apparatus being characterised in that: the Raman wavelength () is longer than the signal wavelength (); the beam delivery system () attenuates the laser radiation () at the signal wavelength () such that the power of the laser radiation () emitted by the laser () is more than the power of the laser radiation () at the output port (); the apparatus does not include a pump for pumping the laser radiation () at the signal wavelength () as the laser radiation () propagates along the optical fibre (); the optical isolator () has greater backward optical isolation () and greater forward transmission () at the signal wavelength () compared to the Raman wavelength (); and the optical fibre () comprises a suppressing means () for suppressing stimulated Raman scattering. 2. Apparatus according to wherein the suppressing means is distributed over the length of the optical fibre.3. Apparatus according to wherein the suppressing means comprises high refractive index features which surround the core and which are configured to increase coupling of light into leaky modes at the Raman wavelength compared to coupling of light into leaky modes at the signal wavelength.4. Apparatus according to wherein the suppressing means comprises at least one blazed grating.5. Apparatus according to wherein the suppressing means comprises at least one long-period grating.6. Apparatus ...

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Номер записи: 50
24-01-2019 дата публикации

DEVICE FOR GENERATING A POLYCHROMATIC PHOTON BEAM HAVING SUBSTANTIALLY CONSTANT ENERGY

Номер: US20190027890A1
Автор: Couderc Vincent, KRUPA Katarzyna, LABRUYERE Alexis, LOUOT Christophe, Pagnoux Dominique, SHALABY Badr, TONELLO Alessandro
Принадлежит:

Some embodiments relate to a generation device that includes: a pulsed laser source generating primary photons having at least one wavelength within pulses having time dissymmetry, a forming device(s) controlling the primary photons so as to generate a selective-polarization, focused input beam, and an optical fiber wherein the primary photons induce secondary photons having different wavelengths resulting from a raman conversion cascade and forming a wide-spectrum output beam having substantially constant energy. 1. A device for generating a polychromatic beam of photons , comprising:a pulsed laser source that is able to deliver primary photons having a wavelength, a forming device able to act on the primary photons to deliver a focused input beam having a chosen polarization,an optical fiber that is arranged to produce, from the input beam, a polychromatic output beam including secondary photons having a plurality of wavelengths, wherein the pulsed laser source is able to deliver the primary photons in pulses having a temporal asymmetry such as to induce secondary photons having various wavelengths, resulting from a cascade of Raman conversions, and forming a broad-spectrum output beam having an energy that is distributed substantially constantly.2. The device as claimed in claim 1 , wherein the pulsed laser source is able to deliver a power density per meter of optical fiber that induces a non-linear generation of the secondary photons that is spread over time depending on their respective wavelengths.3. The device as claimed in claim 2 , wherein the power density per meter of optical fiber is higher than 0.2 kW/μm/m.4. The device as claimed in claim 2 , further comprising a filter installed downstream of optical fiber and that are able to let pass only secondary photons having wavelengths included in a predefined interval claim 2 , in order to deliver a filtered output beam taking the form of pulses of a duration equal to their difference in spread over time.5. ...

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Номер записи: 51
24-01-2019 дата публикации

Signal light interruption detection device, optical amplifier, optical wavelength multiplex transmission device, and optical wavelength multiplex transmission system

Номер: US20190028202A1
Автор: Kanehiro MATSUMOTO, Kengo Takata, Shun Chikamori, Toshiyuki Tokura
Принадлежит: Mitsubishi Electric Corp

A signal light interruption detection device includes an optical interleaver to demultiplex wavelength-multiplexed light into light in first frequency ranges corresponding to a first frequency grid including frequencies at regular frequency intervals in which a main signal light component can be arranged and light in second frequency ranges corresponding to a second frequency grid shifted from the first frequency grid by a half cycle of the regular frequency intervals, a first optical detector to detect first light power as total power of the light in the first frequency ranges, a second optical detector to detect second light power as total power of the light in the second frequency ranges, and a judgment unit to output a notification signal based on a difference between the first light power detected by the first optical detector and the second light power detected by the second optical detector.

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Номер записи: 52
28-01-2021 дата публикации

OPTICAL AMPLIFIER, OPTICAL COMMUNICATION SYSTEM AND OPTICAL AMPLIFICATION METHOD

Номер: US20210028590A1
Автор: LE TAILLANDIER DE GABORY Emmanuel, MATSUMOTO Keiichi
Принадлежит: NEC Corporation

An object is to provide an optical amplifier capable of performing Raman amplification while suppressing power consumption and a size. A multicore fiber has a double clad structure. The double clad structure includes a plurality of cores thorough which an optical signal is transmitted and a clad includes the cores. A light source outputs a pump light used for amplifying the optical signal by stimulated Raman scattering in the multicore fiber. The pump light is generated by multiplexing multimode laser lights. A optical coupler couples the pump light into the clad of the multicore fiber. 1. An optical amplifier comprising:a multicore fiber having a double clad structure, the double clad structure including a plurality of cores thorough which an optical signal is transmitted and a clad including the cores;a first light source configured to output a first pump light used for amplifying the optical signal by stimulated Raman scattering in the multicore fiber, the first pump light being generated by multiplexing a plurality of first multimode laser lights, anda first optical coupler configured to couple the first pump light into the clad of the multicore fiber.2. The optical amplifier according to claim 1 , wherein all or a part of spectrums of the first multimode laser lights are overlapped.3. The optical amplifier according to claim 1 , wherein the first multimode laser lights are multiplexed in a wavelength manner or in a modal manner to generate the first pump light.4. The optical amplifier according to claim 1 , whereinthe optical signal is transmitted through the multicore fiber in a first direction, andthe first pump light is transmitted through the multicore fiber in a second direction opposite to the first direction.5. The optical amplifier according to claim 4 , wherein the first optical coupler is disposed at a first end of the multicore fiber claim 4 , the optical signal transmitted and amplified through the multicore fiber is output from the first end of the ...

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Номер записи: 53
28-01-2021 дата публикации

SUBMARINE NETWORK DEVICE

Номер: US20210028591A1
Автор: JIN Ge, LI Yuhe, Ma Liping, Wang Yan, XU Changwu
Принадлежит: Huawei Marine Networks Co., Ltd.

Disclosed is a submarine network device, comprising a fiber set, a pump laser set, an erbium doped fiber amplifier (EDFA) set, a primary fiber coupler (CPL) set and a secondary CPL set, wherein the primary CPL set comprises N primary CPLs, the secondary CPL set comprises N secondary CPLs, with N being an integer greater than or equal to 3. The fiber set is configured to connect the pump laser set, the primary CPL set, the secondary CPL set and the EDFA set. An input port of each primary CPL in the primary CPL set is at least connected with a pump laser. An output port of each secondary CPL in the secondary CPL set is at least connected with an EDFA. Output ports of each primary CPL in the primary CPL set are respectively connected with two different secondary CPLs that are spaced by a secondary CPL, and input ports of each secondary CPL in the secondary CPL set are respectively connected with two different primary CPLs that are spaced by a primary CPL. 1. A submarine network device , comprising a fiber set , a pump laser set , an erbium doped fiber amplifier (EDFA) set , a primary fiber coupler (CPL) set and a secondary CPL set , wherein the primary CPL set comprises N primary CPLs , the secondary CPL set comprises N secondary CPLs , with N being an integer greater than or equal to 3 , the fiber set is configured to connect the pump laser set , the primary CPL set , the secondary CPL set and the EDFA set , and an input port of each primary CPL in the primary CPL set is at least connected with a pump laser , an output port of each secondary CPL in the secondary CPL set is at least connected with an EDFA , each primary CPL in the primary CPL set is adjacent to the other two primary CPLs in the primary CPL set , each secondary CPL in the secondary CPL set is adjacent to the other two secondary CPLs in the secondary CPL set , output ports of each primary CPL in the primary CPL set are respectively connected with two different secondary CPLs that are spaced by a ...

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Номер записи: 54
17-02-2022 дата публикации

DISTRIBUTED BRILLOUIN LASER SENSOR

Номер: US20220050012A1
Автор: Murray Joseph B., Redding Brandon F.
Принадлежит:

Brillouin fiber sensors can provide distributed measurements of parameters of interest over long distances in a fiber by measuring the Brillouin frequency shift as a function of position along the fiber. The Brillouin frequency shift may be determined, to within a small fraction of the Brillouin linewidth, by establishing a series of lasing modes that experience Brillouin amplification at discrete spatial locations in a test fiber. A linewidth narrowing and high intensity associated with the lasing transition enable precise measurements of the lasing frequency associated with each of the lasing modes. The Brillouin frequency may be determined based on the lasing frequency. 1. A system , comprising:a lasing cavity comprising a fiber under test and a feedback fiber that has a length that is based on a length of the fiber under test;a pump generator configured to periodically pump the lasing cavity with a plurality of pump sequences, each pump sequence having a pump sequence period, to excite a plurality of lasing modes that are configured to be amplified by stimulated Brillouin scattering in the fiber under test, the pump sequence period being configured to match a round-trip time in the lasing cavity; anda lasing frequency determiner configured to sample each of the lasing modes and determine a lasing frequency as a function of time relative to each of the pump sequences, the lasing frequency occurring at a frequency with a highest gain to provide a measurement of a Brillouin frequency as a function of position in the fiber under test.2. The system of claim 1 , further comprisinga processing unit configured to determine a change in a parameter of interest based on the Brillouin frequency.3. The system of claim 1 , wherein the pump sequence period is configured to enable each of the lasing modes to experience gain at a same position in the fiber under test each time it circulates through the lasing cavity.4. The system of claim 1 , wherein each of the lasing mode has ...

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Номер записи: 55
05-02-2015 дата публикации

OPTICAL AMPLIFIER DEVICE

Номер: US20150036210A1
Автор: Asobe Masaki, Enbutsu Kouji, Miyamoto Yutaka, TAKARA Hidehiko, Takenouchi Hirokazu, TOKURA Akio, Tomita Isao, Umeki Takeshi
Принадлежит:

The phase sensitive amplifier according to the present invention is a phase sensitive amplifier that uses the optical mixing using a nonlinear optical effect to amplify the signal light. The phase sensitive amplifier according to the present invention includes: the first second-order nonlinear optical element; and the second second-order nonlinear optical element. The first second-order nonlinear optical element causes the fundamental wave light to generate second harmonic light used as pump light and separates only the second harmonic light. The second second-order nonlinear optical element includes a multiplexer to multiplex the signal light with the second harmonic light and spectrally separates only the amplified signal light. The multiplexed signal light and second harmonic light are used subjected to parametric amplification. 1. A phase sensitive amplifier that amplifies signal light based on the optical mixing using nonlinear optical effects , comprising:an optical fiber laser amplifier for amplifying fundamental wave light;a second-order nonlinear optical element that consists of a periodically-poled second-order nonlinear optical material and that includes an optical waveguide for generating a sum frequency light from fundamental wave light;a filter for spectrally separating the sum frequency light from among the fundamental wave light and the sum frequency light;a multiplexer for multiplexing the signal light and the sum frequency light that is pump light;a second-order nonlinear optical element that consists of a periodically-poled second-order nonlinear optical material and that includes an optical waveguide for parametric amplification of the signal light by using pump light;a filter for spectrally separating the amplified signal light from the pump light; anda synchronization system for synchronizing the phase of the signal light with the phase of the pump light.2. The phase sensitive amplifier according to claim 1 , wherein the sum frequency light is ...

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Номер записи: 56
05-02-2015 дата публикации

Single mode propagation in fibers and rods with large leakage channels

Номер: US20150036703A1
Автор: Liang Dong, Martin E. Fermann, William Wong
Принадлежит: IMRA America Inc

Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprise cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining.

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Номер записи: 57
31-01-2019 дата публикации

ULTRA SHORT PULSE FIBER PRE-AMPLIFIER SYSTEM FOR LARGE-CORE FIBERS

Номер: US20190036292A1
Автор: Budnicki Aleksander, JANSEN Florian, Killi Alexander, Sutter Dirk
Принадлежит:

A fiber amplification system is provided for amplifying a laser pulse signal, e.g., an oscillator signal of an oscillator device. The fiber amplification system includes a fiber pre-amplification system having a short, fundamental-mode and step-index fiber configured to pre-amplify the laser pule signal to generate a seed signal and a main amplification system having a large core fiber configured to amplify the seed signal. The short, fundamental-mode step-index fiber can have a length no longer than about 30 cm, and a mode field diameter no less than about 30 μm, e.g., in a range from 30 μm to 60 μm, as well as a high doping concentration needed to provide an absorption length no more than about 30 cm, for providing the seed signal for the large core fiber with low non-linearity. 1. A fiber amplification system comprising:a short, fundamental-mode step-index fiber having a mode field diameter no less than about 30 μm and a length no longer than about 30 cm and being configured for generating a seed signal from a laser pulse signal to be amplified; anda large-core fiber having a mode field diameter no less than 40 μm and configured for amplifying the seed signal and outputting the amplified seed signal.2. The fiber amplification system of claim 1 , wherein the short claim 1 , fundamental-mode step-index fiber is highly doped such that it has a length of less than or equal to 30 cm.3. The fiber amplification system of claim 2 , wherein the length of the short claim 2 , fundamental-mode step-index fiber substantially corresponds to an absorption length of 13 dB absorption with respect to a pumping light used for amplifying the laser pulse signal.5. The fiber amplification system of claim 1 , wherein a beam quality Mat an output of the short claim 1 , fundamental-mode step-index fiber is less than or equal to 1.3.6. The fiber amplification system of claim 1 , wherein the short claim 1 , fundamental-mode step-index fiber comprises a double clad-single mode step-index ...

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Номер записи: 58
30-01-2020 дата публикации

LASER AMPLIFIER SYSTEM

Номер: US20200036152A1
Автор: Budnicki Aleksander, Scelle Raphael
Принадлежит:

A laser amplifier system includes: a fiber-laser pre-amplifier system for pre-amplifying initial laser pulses and outputting pre-amplified laser pulses; an intermediate-compressor for temporally partially compressing the pre-amplified laser pulses; a solid-state post-amplifier for post-amplifying temporally partially compressed pre-amplified laser pulses and for outputting post-amplified laser pulses; and a post-compressor for temporally compressing the post-amplified laser pulses to generate the output laser pulses. 1. A laser amplifier system comprising a two-stage compressor system , the laser amplifier system comprising:a fiber-laser pre-amplifier system to pre-amplify initial laser pulses coupled into the fiber-laser pre-amplifier and to output pre-amplified laser pulses;an intermediate laser pulse compressor to temporally partially compress the pre-amplified laser pulses by at least 30%;a solid-state post-amplifier to post-amplify temporally partially compressed pre-amplified laser pulses from the intermediate laser pulse compressor as and output post-amplified laser pulses; anda post laser pulse compressor to temporally compress the post-amplified laser pulses to generate output laser pulses.2. The laser amplifier system of claim 1 , wherein the fiber-laser pre-amplifier system comprises at least one fiber-laser amplifier with an amplification fiber claim 1 , wherein an amplification process in the amplification fiber requires the pre-amplified laser pulses to have a fiber minimum output laser pulse length claim 1 , T claim 1 , and each of the pre-amplified laser pulses comprises a corresponding first pulse length that is greater than or equal to T claim 1 , and{'sub': min,Fiber out', 'min,FK in, 'the intermediate-compressor stage is configured to compress the first pulse lengths of the pre-amplified laser pulses to second pulse lengths, each second pulse length being shorter than Tand is greater than or equal to a solid-state minimum input pulse length, T, ...

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Номер записи: 59
08-02-2018 дата публикации

Fiber Device and Method for Amplifying Pulses of Laser Light

Номер: US20180039018A1
Автор: KAFKA James, Petersen Alan
Принадлежит: Newport Corporation

The present application discloses a double-clad crystal fiber which includes a Yb-doped CALGO core region, a pump cladding region configured to have the core region positioned therein, and a second cladding region configured to have the core region and pump cladding region positioned therein. 1. A double-clad crystal fiber , comprising:a core region manufactured from at least one non-glass material;a pump cladding region configured to have the core region positioned therein; anda second cladding region configured to have the core region and pump cladding region positioned therein.2. The device of wherein the core region comprises an effectively single mode core.3. The device of wherein the core region has a transverse dimension of 10 μm or more.4. The device of wherein the core region includes at least one doping material selected from the group consisting of Yb claim 1 , Nd claim 1 , Er claim 1 , Pr claim 1 , Ti claim 1 , Ho claim 1 , Tm claim 1 , and Cr.5. The device of wherein the core material is CALGO claim 1 , YAG claim 1 , LuAG claim 1 , YAlO claim 1 , sapphire claim 1 , LiCAF claim 1 , LiSAF claim 1 , and CaFand YLF.6. The device of wherein the core region is manufactured using a laser heated pedestal growth (LHPG) technique.7. The device of where the core region is manufactured using a micro-pulling down technique.8. The device of wherein the core region has a high doping level and substantially no photodarkening.9. The device of wherein the pump cladding region is manufactured from at least one material selected from the group selected from CALGO claim 1 , YAG claim 1 , LuAG claim 1 , YAlO claim 1 , alumina (sapphire) claim 1 , calcium fluoride claim 1 , polyimide claim 1 , silica claim 1 , LiCAF claim 1 , LiSAF claim 1 , spinel claim 1 , MgO claim 1 , LiF claim 1 , BaF claim 1 , MgF claim 1 , and YLF.10. The device of wherein the pump cladding region has a numeric aperture of 0.4 or greater.11. The device of wherein the pump cladding region is applied ...

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Номер записи: 60
08-02-2018 дата публикации

LIFETIME EXTENDING AND PERFORMANCE IMPROVEMENTS OF OPTICAL FIBERS VIA LOADING

Номер: US20180039155A1
Автор: Thomsen Carsten l.
Принадлежит: NKT Photonics A/S

A method of making a microstructured optical fiber comprising loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material. 1. (canceled)2. A method of producing a microstructured optical fiber comprising a core and a cladding comprising a core material and a cladding material , respectively , the method comprising:providing a preform comprising the core material surrounded by the cladding material, wherein at least a part of the core material is silica or doped silica;loading the core material and/or the cladding material with hydrogen and/or deuterium;forming the microstructured optical fiber from the preform;applying a coating to the formed fiber; andwherein the loading with hydrogen and/or deuterium is performed prior to or during the process of forming the fiber and prior to the application of the coating.3. The method of claim 2 , wherein the loading with hydrogen and/or deuterium includes loading at a temperature T claim 2 , wherein T is equal to or higher than 400° C.4. The method of claim 2 , wherein the loading with hydrogen and/or deuterium includes loading at a temperature T claim 2 , wherein T is equal to or higher than 500° C.5. The method of claim 2 , wherein the core material has a Germanium content of less than or equal 20 at %.6. The method of claim 2 , wherein the core material is undoped.7. The method of claim 2 , wherein the method comprises subjecting the microstructured optical fiber is to energy stimulation prior to the application of the coating.8. The method of claim 2 , wherein the method comprises subjecting at least the core material to energy stimulation after ...

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Номер записи: 61
04-02-2021 дата публикации

POLARIZATION-MAINTAINING HIGHLY ELLIPTICAL CORE FIBER WITH STRESS-INDUCED BIREFRINGENCE

Номер: US20210036480A1
Автор: CHANG Junho, Corsi Alessandro, LA ROCHELLE Sophie
Принадлежит:

An optical fiber comprises a core having an elliptical cross section and a cladding having a circular cross section. The core has an ellipticity between 2 and 40. The core and the cladding have a common central axis with the core being enclosed by the cladding. The difference of a refractive index of the cladding to a refractive index of the core is between 1×10and 1.5×10. A trench is located between the core and the cladding. The trench has a uniform width and encircles the core. The refractive index of the trench is lower than the refractive index of the cladding. 1. An optical fiber comprising:a core having an elliptical cross section, the core having an ellipticity between 2 and 40; anda cladding, having a circular cross section, enclosing the core.2. The optical fiber of wherein the core and the cladding have a common central axis.3. The optical fiber of wherein a difference of a refractive index of the cladding to a refractive index of the core is between 1×10and 1.5×10.4. The optical fiber of further comprising a trench located between the core and the cladding claim 3 , the trench having a uniform width and encircling the core claim 3 , a refractive index of the trench being lower than the refractive index of the cladding.5. The optical fiber of wherein a width of the core along a y-axis allows for single mode transmission.6. The optical fiber of wherein a width of the core along an x-axis allows for the transmission of a plurality of mode pairs.7. The optical fiber of wherein each of the plurality of mode pairs is comprised of two orthogonal linear polarizations.8. The optical fiber of wherein the plurality of mode pairs have an effective index separation between adjacent vector modes greater than 1×10.9. The optical fiber of wherein the effective index separation is caused by thermal stress induced during the manufacture of the optical fiber and the elliptical shape of the core.10. The optical fiber of wherein the core is doped with rare earth ions.11. An ...

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Номер записи: 62
12-02-2015 дата публикации

METHOD FOR GENERATING OPTICAL PULSES AND OPTICAL PULSE GENERATOR

Номер: US20150043598A1
Автор: Kashyap Raman, Lambin Iezzi Victor, LORANGER Sébastien
Принадлежит:

The method generally has the steps of propagating a seed wave in an optical fiber; generating a wave of first order by stimulated Brillouin scattering of the seed wave in the optical fiber, the wave of first order having a frequency spectrally shifted from the seed wave and being backscattered from the seed wave; propagating the seed wave and the wave of first order in a feedback cavity thereby generating a plurality of waves of higher order, each wave of higher order being cascadely generated by the wave of previous order, each wave of higher order being backscattered and having a frequency spectrally shifted from its corresponding wave of previous order and forming a frequency comb with the seed wave and the wave of first order; the frequency comb generating optical pulses; and propagating the generated optical pulses out of the feedback cavity. 1. A method for generating optical pulses , the method comprising the steps of:propagating a seed wave in an optical fiber;generating a wave of first order by stimulated Brillouin scattering of the seed wave in the optical fiber, the wave of first order having a frequency spectrally shifted from the seed wave and being backscattered from the seed wave;propagating the seed wave and the wave of first order in a feedback cavity thereby generating a plurality of waves of higher order, each wave of higher order being cascadely generated by the wave of previous order, each wave of higher order being backscattered and having a frequency spectrally shifted from its corresponding wave of previous order and forming a frequency comb with the seed wave and the wave of first order; the frequency comb generating optical pulses; andpropagating the generated optical pulses out of the feedback cavity.2. The method of claim 1 , wherein optical fiber is a single mode fiber.3. The method of claim 2 , wherein the optical fiber has a length of at least 5 m claim 2 , preferably at least about 1 km.4. The method of claim 1 , wherein the optical ...

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Номер записи: 63
11-02-2016 дата публикации

AMPLIFICATION OPTICAL FIBER AND FIBER LASER DEVICE USING THE SAME

Номер: US20160043525A1
Автор: Goto Ryuichiro, Ichige Tomoya, KASHIWAGI Masahiro
Принадлежит: FUJIKURA LTD.

The refractive index of the first core portion is higher than that of a clad , and the refractive index of the second core portion is higher than that of the first core portion . When light of the LP01 mode and light of the LP11 mode are standardized by power, in the core , an active element that stimulates to emit light of the predetermined wavelength is doped at a higher concentration in at least a part of an area where power of light of the LP01 mode is larger than that of light of the LP11 mode than at least a part of an area where the power of light of the LP11 mode is larger than that of light of the LP01 mode. 2. The amplification optical fiber according to claim 1 , wherein the second core portion is formed on an outer peripheral side of a position where the power of light of the LP01 mode and the power of light of the LP11 mode are identical when light of the LP01 mode and light of the LP11 mode are standardized by power.3. The amplification optical fiber according to claim 2 , wherein a peak of the power of light of the LP11 mode is positioned in the second core portion when light of the LP11 mode is standardized by power.4. The amplification optical fiber according to claim 2 , wherein an average concentration of the active element doped in the first core portion is higher than an average concentration of the active element in the second core portion.5. The amplification optical fiber according to claim 4 , wherein the active element is not doped in the second core portion.6. The amplification optical fiber according to claim 5 , wherein the active element is doped in an area from the center of the core to a position where the power of light of the LP01 mode and the power of light of the LP11 mode are identical when light of the LP01 mode and light of the LP11 mode are standardized by power.7. The amplification optical fiber according to claim 6 , wherein the active element is doped at a uniform concentration.8. The amplification optical fiber according ...

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Номер записи: 64
18-02-2021 дата публикации

Multi-Channel Laser

Номер: US20210050704A1
Автор: Haghany Hosain, Heberle Albert P., Jepsen Mary Lou, Keaton Gregory Lee, Newswanger Craig
Принадлежит:

A laser device includes a seed laser, a plurality of optical amplifiers, and an optical distribution assembly. The seed laser is configured to emit seed laser light. The plurality of optical amplifiers is configured to generate amplified laser light by amplifying the seed laser light. The optical distribution assembly is configured to distribute the seed laser light to an input of each of the optical amplifiers in the plurality and each of the optical amplifiers is configured to direct its respective amplified laser light to a common target. 1. An imaging device comprising:an imaging module including a sensor configured to image an interference pattern generated by an infrared reference beam interfering with an infrared exit signal exiting a diffuse medium; and a seed laser configured to emit seed infrared laser light;', 'a plurality of optical amplifiers configured to generate amplified infrared laser light by amplifying the seed infrared laser light; and', 'an optical distribution assembly configured to distribute the seed infrared laser light to inputs of the optical amplifiers in the plurality, each of the optical amplifiers configured to direct its respective amplified infrared laser light to the diffuse medium to generate the infrared exit signal., 'a laser assembly comprising2. The imaging device of further comprising:a reference optical amplifier configured to generate infrared reference light for the imaging module to convert to the infrared reference beam by amplifying the seed infrared laser light, wherein the optical distribution assembly is configured to distribute the seed infrared laser light to a reference input of the reference optical amplifier.3. The imaging device of claim 1 , wherein the optical distribution assembly includes:an optical isolator configured to receive the seed infrared laser light and reduce optical feedback to the seed laser; andan optical system configured to receive the seed infrared laser light that has been isolated by the ...

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Номер записи: 65
06-02-2020 дата публикации

Complementary Optical Fiber-Based Amplifiers With Built-In Gain Flattening

Номер: US20200044408A1
Автор: Zhu Benyuan
Принадлежит: OFS FITEL, LLC

A fiber-based optical amplifying system for use with a multi-wavelength input optical signal operating over a predetermined bandwidth is specifically configured to eliminate the need for a separate gain-flattening filter, improving the power conversion efficiency (PCE) of the system. Both a distributed Raman amplifier (DRA) and an erbium-doped fiber amplifier (EDFA) are used, where the DRA component is configured to use a pump beam with at a power level no greater than 200 mW. The EDFA is configured to exhibit a gain profile the complements that of the DRA, while also providing amplification that is no less than 10dB at any wavelength within the system bandwidth. With these parameters, the combination of the DRA and EDFA is able to maintain an output gain deviation of less than about 2 dB. 1. A fiber-based optical amplifying system for use with a multi-wavelength input optical signal operating over a predetermined bandwidth , the fiber-based optical amplifying system comprising:a distributed Raman amplifier (DRA) including a Raman pump source with an output power no greater than 200 mW, the DRA configured to exhibit a first gain profile over the predetermined bandwidth; andan erbium-doped fiber amplifier (EDFA) disposed at the output of the DRA and configured to exhibit a second gain profile complementing the first gain profile over the predetermined bandwidth, the EDFA generating a gain no less than 10 dB at any wavelength within the predetermined bandwidth, the combination of the DRA and EDFA maintaining an output gain deviation less than about 2 dB across the predetermined bandwidth of the fiber-based optical amplifying system.2. The fiber-based optical amplifying system as defined in wherein the Raman pump source operates with an output power no greater than 100 mW.3. The fiber-based optical amplifying system as defined in wherein the DRA provides optical gain no greater than 4 dB.4. The fiber-based optical amplifying system as defined in wherein the DRA ...

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Номер записи: 66
06-02-2020 дата публикации

EXCITATION LIGHT SOURCE APPARATUS AND OPTICAL TRANSMISSION SYSTEM

Номер: US20200044741A1
Автор: CHIKAMORI Shun, IMANISHI Katsunori, TAKATA Kengo, Tokura Toshiyuki
Принадлежит: Mitsubishi Electric Corporation

An excitation light source apparatus includes: an excitation light source to generate Raman excitation light in a drive state and to stop generating the Raman excitation light in a stop state; a light source controller to control the intensity of the Raman excitation light in the drive state; a light level measuring instrument to measure the light level of signal light; a logarithmic converter to convert at least one measurement result of measuring by the light level measuring instrument to a logarithmic value; and a main controller to decide a correction value based on the logarithmic value of the at least one measurement result in the stop state. The main controller controls the light source controller by using the correction value and a preset gain control target value. 1. An excitation light source apparatus for outputting Raman excitation light for amplifying signal light , to a transmission path through which the signal light is transmitted , the excitation light source apparatus comprising:an excitation light source to generate the Raman excitation light in a drive state and to stop generating the Raman excitation light in a stop state;a light source controller to control intensity of the Raman excitation light in the drive state;a light level measuring instrument to measure a light level of the signal light input into the excitation light source apparatus;a logarithmic converter to convert at least one measurement result of measuring by the light level measuring instrument to a logarithmic value; anda main controller to decide a correction value based on the logarithmic value of the at least one measurement result in the stop state,wherein the main controller controls the light source controller by using the correction value and a preset gain control target value.2. The excitation light source apparatus according to claim 1 , whereinthe main controlleracquires, from the logarithmic converter, the logarithmic value of a first measurement result of the at ...

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Номер записи: 67
08-05-2014 дата публикации

FIBER AMPLIFIERS AND FIBER LASERS WITH REDUCED OUT-OF-BAND GAIN

Номер: US20140126041A1
Автор: BOULA-PICARD REYNALD, MURISON RICHARD, PANARELLO TULLIO, REID BENOIT
Принадлежит: ESI-PyroPhotonics Lasers, Inc.

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. 1. A method of operating an ytterbium-doped fiber amplifier , the method comprising:providing an input signal at a wavelength between 1050 nm and 1090 nm;providing pump radiation at a wavelength between 1010 nm and 1050 nm;coupling the pump radiation to the ytterbium-doped fiber amplifier; andamplifying the input signal to generate an output signal.2. The method of wherein a value of pump power exiting an output end of the ytterbium-doped fiber amplifier is at least greater than or equal to three times a critical power.3. The method of wherein a value of pump power exiting an output end of the ytterbium-doped fiber amplifier is at least greater than or equal to a value of pump power absorbed in the ytterbium-doped fiber amplifier. This application is a continuation of co-pending U.S. patent application Ser. No. 13/081,051 filed 6 Apr. 2011, which application is a division of U.S. patent application Ser. No. 11/834,472, filed Aug. 6, 2007; which claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 60/836,244, filed Aug. 7, 2006, the disclosures of which are incorporated herein by ...

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Номер записи: 68
03-03-2022 дата публикации

LIFETIME EXTENDING AND PERFORMANCE IMPROVEMENTS OF OPTICAL FIBERS VIA LOADING

Номер: US20220066285A1
Автор: Thomsen Carsten l.
Принадлежит: NKT Photonics A/S

A method of making a microstructured optical fiber including loading the core and cladding materials of the fiber with hydrogen and deuterium at a loading temperature; annealing the fiber at a selected temperature T; pumping the fiber with radiation; and reducing the temperature of the fiber and storing the fiber at the reduced temperature before the step of pumping the fiber; and wherein the method allows the hydrogen and the deuterium to become bound to the core material and the cladding material.

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Номер записи: 69
25-02-2016 дата публикации

OPTICAL TRANSMISSION MEDIUM AND OPTICAL AMPLIFIER

Номер: US20160054519A1
Автор: ONAKA Miki
Принадлежит: FUJITSU LIMITED

An optical transmission medium includes: a plurality of cores; a first cladding that covers each of the plurality of cores; a second cladding that covers a plurality of first claddings; and a reflection layer that covers the second cladding and has reflection characteristics with respect to a wavelength band of multimode light. 1. A multimode optical transmission medium , comprising:a plurality of cores;a first cladding that covers each of the plurality of cores;a second cladding that covers a plurality of first claddings; anda reflection layer that covers the second cladding and has reflection characteristics with respect to a wavelength band of multimode light, the reflection layer being a metal film of one of Invar alloy or Kovar alloy.2. The multimode optical transmission medium according to claim 1 ,wherein signal light is introduced to the plurality of cores, andmultimode excitation light that is propagated in the multimode optical transmission medium is introduced to a region inside the reflection layer of the optical transmission medium.3. (canceled)4. The multimode optical transmission medium according to claim 2 ,wherein the multimode excitation light is excitation light for distributed Raman amplification, andthe reflection layer is formed in a length corresponding to at least an effective length of the distributed Raman amplification, in a direction parallel to a direction in which the signal light propagates.5. The multimode optical transmission medium according to claim 1 ,wherein the metal film is formed using electroless plating.6. An optical amplifier claim 1 , comprising:a multimode optical transmission medium includinga plurality of cores,a plurality of separated first claddings, each of the first claddings covering one of the plurality of cores, anda second cladding that covers the plurality of first claddings;a reflection layer that covers the second cladding and has reflection characteristics with respect to a wavelength band of multimode light ...

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Номер записи: 70
03-03-2022 дата публикации

ERBIUM DOPED FIBER ISOLATOR COMPONENTS

Номер: US20220069535A1
Автор: Cryan Colm V.
Принадлежит: Acacia Communications, Inc.

A system including an erbium doped fiber amplifier (EDFA), comprising a length of erbium doped fiber having a first end and a second end, an isolator wavelength division multiplexer (IWDM) comprising an output optically connected at an optical connection with the first end of the erbium doped fiber, wherein the optical connection with the first end of the erbium doped fiber is continuous between the IWDM and the first end of the erbium doped fiber, and an isolator comprising an input optically connected at an optical connection with the second end of the erbium doped fiber.

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Номер записи: 71
03-03-2022 дата публикации

OPTICAL FIBER DEVICES AND METHODS FOR SUPPRESSING STIMULATED RAMAN SCATTERING (SRS)

Номер: US20220069538A1
Автор: Fanning C. Geoffrey, Kliner Dahv A.V., Lowder Tyson L.
Принадлежит: nLIGHT, Inc.

Optical fiber devices, systems, and methods for separating Raman spectrum from signal spectrum Raman spectrum may be suppressed as a result of a reduction in gain and/or through dissipation while the signal spectrum may Raman Components In be propagated in one or more guided modes of a fiber system. A fiber system may Length include a propagation mode coupler to couple a first guided mode into a second guided mode with an efficiency that varies as a function of wavelength of the propagated light. Mode coupling efficiency may be higher for Raman spectrum, and lower for signal spectrum so that Raman spectrum associated with a fundamental mode is preferentially coupled into a higher-order mode. A fiber system may include a mode filter operable to discriminate between first and second guided modes. Within the filter, guiding of the first mode may be superior to that of the second mode with Raman spectrum preferentially rejected. 1. A fiber optic device , comprising:a first length of optical fiber comprising a core and one or more cladding layers, wherein the first length of fiber supports at least a first guided mode for light comprising both signal spectrum and Raman spectrum;a second length of optical fiber comprising a core and one or more cladding layers, wherein the second length of optical fiber supports multiple guided modes; anda propagation mode coupler between the first and second lengths of fiber, the propagation mode coupler to couple at least some of the light propagated in the first guided mode into a second guided mode with a mode coupling efficiency over the Raman spectrum that differs from that over the signal spectrum.2. The fiber optic device of claim 1 , further comprising a propagation mode filter coupled to receive the light from the first or second lengths of fiber claim 1 , and to discriminate between the first and second guided modes.3. The fiber optic device of claim 1 , wherein:the second guided mode is of a higher-order than the first guided ...

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Номер записи: 72
25-02-2021 дата публикации

BARE SINGLE MODE FIBER AMPLIFIER/LASER

Номер: US20210057867A1
Автор: KOTOV Leonid, Peyghambarian Nasser, Temyanko Valery
Принадлежит:

A gain fiber assembly for use in optical fiber amplification systems such as fiber amplifiers and fiber lasers utilizes an active or “bare” fiber that has a single glass cladding with an outer diameter of less is less than 80 μm and preferably less than 60 μm or even 40 μm. A passive double-clad input fiber is stripped of the outer cladding and tapered to match the outer diameter of the bare fiber. A glass-fluid or glass-vacuum interface along the taper provides guidance of the pump into and along the cladding of the bare fiber and a NA>1 for a vacuum or gasses and an NA>0.8 for liquids. This allows for much shorter fiber lengths to reach max signal power and higher pump conversion efficiencies. 1. A fiber optical amplification system , comprising:{'sup': st', 'nd', 'st', 'nd, 'a passive double-clad input fiber including a passive core with diameter D1, a 1glass cladding of diameter D2 and a 2cladding of diameter D3 configured to receive and propagate an optical signal in the passive core and an optical pump in the passive core and 1glass cladding, a tapered end section of the input fiber without the 2cladding having a final diameter D4 Подробнее

Номер записи: 73
25-02-2021 дата публикации

OPTICAL PARAMETRIC CHIRPED-PULSE AMPLIFIER

Номер: US20210057868A1
Автор: HODGSON Norman, SIMANOVSKI Dmitri
Принадлежит: Coherent, Inc.

An optical parametric chirped-pulse amplifier includes first and second optical parametric amplifier stages that successively amplify a stretched signal beam. A pulsed laser provides a fundamental beam. The second amplifier stage is pumped by the full power of a second-harmonic beam that is generated from the fundamental beam. A residual fundamental beam is used to generate another second-harmonic beam that pumps the first amplifier stage. 1. An optical amplifier , comprising:a pulsed laser generating a beam of fundamental laser radiation;a first optically nonlinear crystal partially converting the fundamental beam into a first beam of second-harmonic laser radiation and leaving a residual beam of unconverted fundamental laser radiation;a second optically nonlinear crystal partially converting the residual fundamental beam into a second beam of second-harmonic laser radiation;a first optical parametric amplifier stage optically pumped by the second second-harmonic beam and arranged to amplify a signal beam; anda second optical parametric amplifier stage optically pumped by the first second-harmonic beam and arranged to further amplify the signal beam.2. The optical amplifier of claim 1 , wherein the signal beam amplified in the first amplifier stage is generated by a short-pulse laser and stretched by a pulse stretcher.3. The optical amplifier of claim 2 , wherein pulse generation in the pulsed laser and in the short-pulse laser is synchronized to temporally overlap pulses of the second second-harmonic beam and pulses of the signal beam in the first amplifier stage.4. The optical amplifier of claim 1 , further including an optical delay arranged to temporally overlap pulses of the first second-harmonic beam and pulses of the signal beam in the second amplifier stage.5. The optical amplifier of claim 1 , wherein the amplified signal beam from the second optical amplifier is directed into a pulse compressor that is arranged to temporally compress the amplified signal ...

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Номер записи: 74
25-02-2021 дата публикации

OPTICAL AMPLIFIER AND OPTICAL AMPLIFICATION METHOD

Номер: US20210057869A1
Автор: LE TAILLANDIER DE GABORY Emmanuel, MATSUMOTO Keiichi, TAKESHITA Hitoshi
Принадлежит: NEC Corporation

In optical amplifiers that use a multicore optical fiber, the absorption efficiency of excitation light in an optical amplification medium is low and the amplification efficiency of light intensity becomes lower in the cladding excitation method; therefore, an optical amplification apparatus according to the present invention includes an optical amplification medium, having a gain in a wavelength band of signal light, configured to receive the signal light; excitation light introduction means for introducing, into the optical amplification medium, excitation light to excite the optical amplification medium; and residual excitation light introduction means for introducing, into the optical amplification medium, residual excitation light output from the optical amplification medium, the residual excitation light having a wavelength component of the excitation light. 1. An optical amplification apparatus comprising:an optical amplification medium, having a gain in a wavelength band of signal light, configured to receive the signal light;an excitation light introduction unit configured to introduce, into the optical amplification medium, excitation light to excite the optical amplification medium; anda residual excitation light introduction unit configured to introduce, into the optical amplification medium, residual excitation light output from the optical amplification medium, the residual excitation light having a wavelength component of the excitation light.2. The optical amplification apparatus according to claim 1 , whereinthe residual excitation light introduction unit includes a residual excitation light multiplexing unit configured to multiplex the signal light and the residual excitation light on a side of one end of the optical amplification medium, and a residual excitation light demultiplexing unit configured to wavelength-demultiplex the signal light and the residual excitation light on a side of another end of the optical amplification medium.3. The ...

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Номер записи: 75
25-02-2021 дата публикации

FIBER LASER DEVICE, PRODUCTION METHOD FOR FIBER LASER DEVICE, AND SETTING METHOD

Номер: US20210057873A1
Автор: Sakamoto Shinichi
Принадлежит: FUJIKURA LTD.

A fiber laser device includes: an amplifying fiber; a delivery fiber in which laser light that has been outputted from the amplifying fiber is guided; and a Raman filter that reflects part of Raman scattered light that is generated by stimulated Raman scattering caused to the laser light. 4. The fiber laser device according to claim 1 , wherein the Raman filter further satisfies inequality (d){'br': None, 'sub': 'L1', 'sup': 'L1+L2', 'i': g', 'P', 'z', 'dz−ar−am, '2∫(())<0\u2003\u2003(d)'}where:P(z) represents power of the laser light at a point at which a light path length from the first end to the delivery fiber, wherein the point is z; andg(P(z)) represents gain that the Raman scattered light receives per unit length at the point.6. The fiber laser device according to claim 1 , further comprising:a plurality of amplifying fibers that comprises the amplifying fiber; anda combiner that combines the laser light that has been outputted from each of the plurality of amplifying fibers, wherein delivery fibers in each of which the laser light that has been outputted from a corresponding one of the plurality of-amplifying fibers is guided to the combiner; and', 'a delivery fiber in which the laser light that has been combined by the combiner is guided., 'the delivery fiber comprises The present invention relates to a fiber laser device. The present invention further relates to a production method of producing a fiber laser device. The present invention also relates to a setting method of, in a fiber laser device, setting a reflection attenuation by a processable workpiece.In the field of material processing, fiber laser devices have drawn attention as laser beam machines which are excellent in ease of maintenance and processing ability. However, in a fiber laser device, in a case where a power density of laser light guided in an optical fiber becomes high, a nonlinear optical effect, such as stimulated Raman scattering, becomes likely to be brought about. Further, it is ...

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Номер записи: 76
13-02-2020 дата публикации

HIGH-ENERGY FEMTOSECOND LIGHT PULSES BASED ON A GAIN-SWITCHED LASER DIODE

Номер: US20200052455A1
Автор: Fu Walter, Wise Frank W., Wright Logan
Принадлежит:

This disclosed subject matter allows short pulses with high peak powers to be obtained from seed pulses generated by a gain-switched diode. The gain-switched diode provides a highly stable source for optical systems such as nonlinear microscopy. The disclosed system preserves the ability to generate pulses at arbitrary repetition rates, or even pulses on demand, which can help reduce sample damage in microscopy experiments or control deliberate damage in material processing. 1. A pulsed laser device , comprising:a seed laser including a gain-switched diode laser to produce seed laser pulses;a self-phase modulation device located in a path of the seed laser pulses to produce a self-phase modulation on each of the seed laser pulses to generate spectral fringes in the seed laser pulses as self-phase modulated seed laser pulses;a spectral filter located downstream from the self-phase modulation device that isolates a spectral region of the self-phase modulated seed laser pulses, wherein the spectral filter performs pulse reshaping and compression in the temporal domain;a reshaping device providing self-phase modulation and normal group-velocity dispersion located downstream of the spectral filter to receive the filtered seed laser pulses and to nonlinearly reshape the filtered seed laser pulses into reshaped light pulses having a parabolic waveform;an optical amplifier to amplify the reshaped light pulses out of the reshaping device as amplified light pulses; anda dechirping device located downstream from the optical amplifier to cause dechirping of the amplified light pulse to generate near transform-limit output laser pulses with an amplified peak power.2. The pulsed laser device as in claim 1 , wherein the dechirping device includes a linear dispersive delay line.3. The pulsed laser device as in claim 1 , wherein laser seed pulses are about 10 picoseconds in duration.4. The pulsed laser device as in claim 1 , wherein the output laser pulses are 50-200 femtoseconds in ...

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Номер записи: 77
13-02-2020 дата публикации

LASER APPARATUS

Номер: US20200052456A1
Автор: MIYATA Ryusuke, TAKIGAWA Hiroshi
Принадлежит: FANUC Corporation

A laser apparatus calculates a temperature of a temperature increase portion that is raised in temperature by reflection light, and determines and outputs an emergency optical output command with the aim of ensuring that the calculated temperature does not exceed a first predetermined temperature, which is set at a lower temperature than an upper limit heat resistance temperature, and if necessary, controlling the temperature to or below a second predetermined temperature set at a lower temperature than the first predetermined temperature. When the emergency optical output command is to be output, a control unit switches an optical output command output thereby to the emergency optical output command and outputs the emergency optical output command. 1. A laser apparatus , comprising:at least one laser oscillator;a power supply unit for supplying a driving current to the laser oscillator;a laser optical system that includes a machining head for irradiating a workpiece serving as a laser machining subject with laser light emitted from the laser oscillator through an optical fiber;at least one light detecting unit capable of detecting the laser light emitted from the laser oscillator and reflection light propagating in a substantially opposite direction to the laser light; anda control unit that outputs an optical output command and a current output command corresponding to the optical output command to the power supply unit,the laser apparatus further comprising:a temperature calculation unit that is provided either inside the laser apparatus or outside the laser apparatus and uses a detection result acquired by the light detecting unit to calculate the temperature of at least one of respective temperature increase portions of the laser apparatus, which increase in temperature in response to the reflection light; andan emergency command determination unit that refers to the calculated temperature of the temperature increase portion, calculated by the temperature ...

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Номер записи: 78
13-02-2020 дата публикации

DISTRIBUTED RAMAN AMPLIFIER SYSTEMS

Номер: US20200052457A1
Автор: Hochhalter David
Принадлежит:

A smart spool is configured to be optically coupled between a pumping light source and optical point-loss sources in an optical fiber transmission line. The smart spool comprises a probe signal transmitter that transmits an optical probe signal into the transmission line. An optical detector receives probe signals scattered in the transmission line. A loss-measuring device is coupled to the optical detector and operable to measure aggregate losses in the transmission line and report the aggregate losses to a network manager. The spool comprises a fiber of sufficient length to offset the aggregated losses to enable a distributed Raman amplifier to pump the transmission line. The smart spool prevents the distributed Raman amplifier from shutting down and allows the distributed Raman amplifier to achieve entitled gain by pumping the fiber in the spool. 120-. (canceled)21. A Raman amplifier system comprising:a Raman amplifier configured to detect observed optical losses of a transmission line via a pulse and to pump the transmission line when the observed optical losses satisfy optical threshold criteria; anda length of fiber coupled with the Raman amplifier, wherein the length of fiber is configured to offset aggregated losses from at least one optical point-loss source by causing the observed optical losses observed by the Raman amplifier to satisfy the optical threshold criteria.22. The system of claim 21 , wherein the optical threshold criteria includes a condition that the aggregated losses are no greater than 2 dB.23. The system of claim 22 , wherein the optical threshold criteria includes a condition that a single point-loss has a loss of no greater than 1 dB.24. The system of claim 21 , wherein the aggregated losses comprise multiple point-losses that are at least 2 dB.25. The system of claim 21 , further comprising a set of optical point-loss sources proximate to the Raman amplifier wherein claim 21 , in aggregate claim 21 , the set of optical point-loss ...

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Номер записи: 79
10-03-2022 дата публикации

MULTI-STAGE PROBABILISTIC SIGNAL SHAPING

Номер: US20220075239A1
Автор: CHO Joon Ho
Принадлежит: NOKIA SOLUTIONS AND NETWORKS OY

A shaping encoder capable of improving the performance of PCS in nonlinear optical channels by performing the shaping in two or more stages. In an example embodiment, a first stage employs a shaping code of a relatively short block length, which is typically beneficial for nonlinear optical channels but may cause a significant penalty in the energy efficiency. A second stage then employs a shaping code of a much larger block length, which significantly reduces or erases the penalty associated with the short block length of the first stage while providing an additional benefit of good performance in substantially linear optical channels. In at least some embodiments, the shaping encoder may have relatively low circuit-implementation complexity and/or relatively low cost and provide relatively high energy efficiency and relatively high shaping gain for a variety of optical channels, including but not limited to the legacy dispersion-managed fiber-optic links. 1. An apparatus , comprising:a digital encoder having, at least, first and second digital stages to produce a stream of symbols from a bitstream, the first digital stage being configured to separately encode segments of a same number of bits of the bitstream into first sequences of symbols such that each of the first sequences has a same first length and a respective total energy of the symbols therein lower than a threshold, the second digital stage being configured to encode blocks of the first sequences into second sequences of symbols, each of the blocks having a same number of first sequences therein, each of the second sequences having a same second length; andwherein a total energy of symbols of any of the second sequences divided by the second length is smaller than the threshold divided by the first length.2. The apparatus of claim 1 , wherein the threshold is smaller than an average energy of an unshaped sequence of symbols of the first length.3. The apparatus of claim 1 , wherein the second length is ...

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Номер записи: 80
05-03-2015 дата публикации

Reducing thermal dependence of amplifier gain

Номер: US20150062692A1
Автор: Lijie Qiao
Принадлежит: Individual

Devices and methods for lessening a thermal dependence of gain profile of an optical amplifier are disclosed. An optical beam is split in two sub-beams with a thermally variable power splitting ratio. One sub-beam travels a longer optical path length than the other. When the two sub-beams are recombined, they interfere with each other, causing the throughput to be wavelength dependent. An amplitude of this wavelength dependence is thermally variable due to the thermally variable power splitting ratio. The thermally variable power splitting ratio and the optical path length difference are selected so as to offset a thermal variation of a spectral gain profile of an optical amplifier.

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Номер записи: 81
21-02-2019 дата публикации

SPECTROSCOPY SYSTEM WITH LASER AND PULSED OUTPUT BEAM

Номер: US20190056266A1
Автор: Islam Mohammed N.
Принадлежит:

A spectroscopy system includes a light source having an input light source, including semiconductor diodes generating an input beam with a wavelength shorter than 2.5 microns. Cladding-pumped fiber amplifiers receive the input beam and form an amplified optical beam having a spectral width. A nonlinear element broadens the spectral width of the amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam that is pulsed. A filter is coupled to at least one of a lens and a mirror that receives the output beam and delivers the filtered output beam to a sample. A detection system includes detectors configured to receive the output beam reflected or transmitted from the sample. The detection system is configured to use a lock-in technique with the pulsed output beam and the spectroscopy system is adapted to detect chemicals in the sample. 1. A spectroscopy system , comprising: an input light source, including one or more semiconductor diodes, configured to generate an input beam that comprises a wavelength shorter than 2.5 microns;', 'one or more optical amplifiers configured to receive at least a portion of the input beam and to form an amplified optical beam having a spectral width, wherein at least a portion of the one or more optical amplifiers comprises a cladding-pumped fiber amplifier; and', 'a nonlinear element configured to receive at least a portion of the amplified optical beam and to broaden the spectral width of the received amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam, wherein the output beam is pulsed;, 'a light source comprisinga filter coupled to at least one of a lens and a mirror configured to receive at least a portion of the output beam, and to deliver at least a portion of the received output beam to a sample; anda detection system comprising one or more detectors configured to receive at least a part of the output beam reflected or transmitted from the sample, wherein the ...

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Номер записи: 82
05-03-2015 дата публикации

PUMP ABSORPTION AND EFFICIENCY FOR FIBER LASERS/AMPLIFIERS

Номер: US20150063381A1
Автор: Creeden Daniel J.
Принадлежит:

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. 1. An optical fiber comprising:a fiber core;a first cladding surrounding the core;an outer cladding surrounding the first cladding, wherein the outer cladding has a lower index of refraction than the first cladding; andpartial reflector applied to a fiber-to-free space interface associated with the fiber, wherein the partial reflector is reflective at pump light wavelengths antireflective at core light wavelengths.2. The optical fiber of claim 1 , wherein the partial reflector is configured to double-pass any unabsorbed pump light back through the first cladding.3. The optical fiber of claim 2 , wherein the length of the optical fiber is determined based on optimal double-pass absorption of pump light.4. The optical fiber of claim 1 , wherein the partial reflector is applied to a tip of the optical fiber.5. The optical fiber of claim 1 , wherein a tip of the optical fiber is coated by the partial reflector.6. The optical fiber of claim 1 , wherein the partial reflector is applied to a tip of the optical fiber using a fiber connector claim 1 , and connectorization adhesive does not strip cladding light or intervene between the partial reflector and the tip of the optical fiber.7. ...

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Номер записи: 83
10-03-2022 дата публикации

ULTRAHIGH POWER FIBER LASER SYSTEM WITH CONTROLLABLE OUTPUT BEAM INTENSITY PROFILE

Номер: US20220077648A1
Автор: ABRAMOV Andrey, Abramov Mikhail, Fomin Valentin, Scherbakov Eugene, YAGODKIN Dmitri
Принадлежит:

The disclosed ultra-high power all fiber laser system is configured with multiple spaced apart fiber lasers outputting respective laser beams respective paths, The disclosed system is further configured with a tapered fiber-bundle including at least one central guiding fiber and a plurality of peripheral guiding fibers. The disclosed system further has a multiclad, delivery fiber configured with a double-bottle neck cross-section and provided with at least two concentric and radially spaced apart inner and outer cores. The inner core is coupled to the peripheral guiding fibers while the inner core is spliced to the central guiding fiber so that a system output emitted from the inner core of the delivery fiber has a different beam shape from the system output emitted from the outer core. 2. The laser system of further comprising a plurality of central feeding fibers which are coupled to respective central guiding fibers of the combiner.3. The laser system of claim 2 , wherein the central guiding fibers are butt-spliced to the central core of the delivery fiber claim 2 , and the peripheral guiding fibers are butt-spliced to the second core of the delivery fiber and do not overlap the central core of the delivery fiber.4. The laser system of further comprising multiple second fiber combiners each combining a group of at least two feeding fibers so that the central feeding fibers are combined in a central second fiber combiner while the peripheral feeding fibers are combined in a plurality of peripheral second fiber combiners claim 2 , the second central and peripheral fiber combiners having respective output fibers spliced to the central and peripheral guiding fibers of the combiner.5. The laser system of further comprising a controller coupled to and selectively energizing the fiber laser sources so thatonly the central fiber laser source emits a laser beam propagating along the first fixed path into the central core of the delivery fiber, oronly one of or more ...

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Номер записи: 84
21-02-2019 дата публикации

HIGH POWER SINGLE MODE FIBER LASER

Номер: US20190058300A1
Автор: ABRAMOV Andrey, FERIN Anton, Fomin Valentin
Принадлежит:

A single mode (SM) high power laser system is configured with a laser source outputting a single mode or low mode kW-power light and a passive delivery fiber spliced to an output fiber of the fiber laser source and having a double bottleneck-shaped core. The latter is configured to increase a threshold for nonlinear effects in general and in particular for stimulated Raman scattering (SRS) so that the delivery passive fiber has a fiber length at least twice the length of a delivery passive fiber with a standard uniformly dimensioned core, which may be used with the same laser source, while outputting the kW-power light with an M2 factor less than 2. 1. A high power laser system , comprising:a laser source outputting a single mode (SM) or low mode kW-power light and having at least one fiber gain block which has an active fiber and an output SM passive fiber;{'sup': '2', 'a delivery passive fiber spliced to the output SM passive fiber of the laser source and configured to have a double bottleneck-shaped core which increases a threshold of nonlinear effects so that the delivery passive fiber has a fiber length at least twice the length of a delivery passive fiber with a standard uniformly dimensioned core, which is optionally used with the laser source, while outputting the kW-power light with an Mfactor less than 2.'}2. The high power laser system of claim 1 , wherein the laser source is configured to output the single mode or low mode light in a power range varying between 1 kW and 50 kW.3. The high power laser system of any of the above claims claim 1 , wherein the laser source is configured to output 1 kW-power light coupled into the passive delivery fiber with the double bottleneck-shaped core claim 1 , the passive delivery fiber being configured with the length varying between 10 and 20 meters while emitting the 1 kW light with the M2 factor of about 1.05.4. The high power laser system of or claim 1 , wherein the laser source is configured to output 2 kW-power ...

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Номер записи: 85
21-02-2019 дата публикации

SHARED OPTICAL PUMPS AMONG MULTIPLE FIBER CHANNELS

Номер: US20190058301A1
Автор: Ahuja Satyajeet Singh, Goel Nitin Kumar, Nagarajan Gayathrinath
Принадлежит:

Aspects of an optical communications network are described that include two or more optical fibers arranged to allow communication in the same direction. The optical network includes a first optical amplifier coupled to the first optical fiber, a second optical amplifier coupled to the second optical fiber, a first optical pump to provide optical power to the first optical fiber, and a second pump to provide optical power to both the first and the second optical fibers. By sharing the second pump between the first and the second optical fibers, a need to deploy additional pumps is alleviated. Scaling of the optical network to include additional optical fibers provides further cost savings by allowing more pumps to be shared among the multiple optical fibers. 1. An optical communication network , comprising:a first node coupled to a first optical channel and to a second optical channel, the first optical channel formed as part of a first optical fiber and the second optical channel formed as part of a second optical fiber;a second node coupled to the first optical channel and to the second optical channel and configured to receive optical signals from the first node through both the first and the second optical channels;a first optical amplifier coupled to the first optical fiber;a second optical amplifier coupled to the second optical fiber; an input coupled to a first pump,', 'a first output coupled to the first optical amplifier, and', 'a second output coupled to the second optical amplifier;, 'a coupler includingthe first pump coupled to the coupler to provide optical power to the first optical fiber; anda second pump coupled to the coupler to provide optical power to both the first and the second optical fibers via the first optical amplifier and the second amplifier that are both coupled to the coupler, wherein the first optical fiber powered via the coupler carries the first optical channel between the first node and the second node, the second optical fiber ...

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Номер записи: 86
21-02-2019 дата публикации

Hybrid random fiber laser distributed amplification method based on erbium fiber with low doping concentration

Номер: US20190058524A1
Автор: Jiaqi Li, Yun Fu, Yunjiang Rao, Zinan Wang
Принадлежит: University of Electronic Science and Technology of China

A hybrid distributed amplification method based on a random fiber laser generated within erbium fiber with low doping concentration, i.e. weak erbium-doped fiber (WEDF), which includes: Step 1. constructing a fiber link via WEDF; Step 2. generating the random fiber laser based on the fiber link, the pump source, the wavelength division multiplexer and the strong feedback module; Step 3. constructing the spatial equalized gain based on hybrid gain of the erbium fiber and random fiber laser; Step 4. the signal is amplified by the hybrid spatial equalized gain. The present invention solves the typical problem of high laser threshold and low pump conversion efficiency when conventional fiber is used to generate random fiber laser for distributed amplification.

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Номер записи: 87
04-03-2021 дата публикации

FIBER AMPLIFIER SYSTEM RESISTANCE TO NONLINEAR SPECTRAL BROADENING AND DECOHERENCE

Номер: US20210063635A1
Автор: Goodno Gregory D.
Принадлежит:

A method for reducing nonlinear frequency shifts and suppressing stimulated Brillouin scattering (SBS) in a fiber laser amplifier system. The method includes providing a seed beam having a certain wavelength and frequency modulating the seed beam with an RF waveform to spectrally broadening the seed beam, where the RF waveform is a relatively slow-speed waveform having a large modulation depth. The method also includes amplifying the frequency modulated seed beam with an amplifier having a large nonlinear phase shift and exhibiting frequency modulation (FM) to amplitude modulation (AM) conversion, where the modulation depth is much larger than the nonlinear phase shift of the amplifier. 1. A method for reducing nonlinear frequency shifts and suppressing stimulated Brillouin scattering (SBS) in a fiber laser amplifier system , said method comprising:providing at least one seed beam having a certain wavelength;frequency modulating the at least one seed beam with an RF waveform to spectrally broaden the seed beam, said RF waveform being a relatively slow-speed waveform having a large modulation depth; andamplifying the modulated seed beam with an amplifier having a large nonlinear phase shift and exhibiting frequency modulation (FM) to amplitude modulation (AM) conversion, wherein the modulation depth is much larger than the nonlinear phase shift.2. The method according to wherein frequency modulating the at least one seed beam with an RF waveform includes frequency modulating the at least one seed beam with a piecewise parabolic RF waveform.3. The method according to wherein frequency modulating the at least one seed beam with an RF waveform includes frequency modulating the at least one seed beam with a single tone RF waveform.4. The method according to wherein the frequency of the single tone RF waveform is 100 MHz.5. The method according to further comprising splitting the frequency modulated seed beam into a plurality of split frequency modulated seed beams claim ...

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Номер записи: 88
03-03-2016 дата публикации

OPTICAL PARAMETRIC AMPLIFICATION, OPTICAL PARAMETRIC GENERATION, AND OPTICAL PUMPING IN OPTICAL FIBERS SYSTEMS

Номер: US20160064891A1
Автор: FERMANN Martin E., Imeshev Gennady
Принадлежит:

Embodiments described herein include a system for producing ultrashort tunable pulses based on ultra broadband OPA or OPG in nonlinear materials. The system parameters such as the nonlinear material, pump wavelengths, quasi-phase matching periods, and temperatures can be selected to utilize the intrinsic dispersion relations for such material to produce bandwidth limited or nearly bandwidth limited pulse compression. Compact high average power sources of short optical pulses tunable in the wavelength range of 1800 to 2100 nm and after frequency doubling in the wavelength range of 900 to 1050 nm can be used as a pump for the ultra broadband OPA or OPG. In certain embodiments, these short pump pulses are obtained from an Er fiber oscillator at about 1550 nm, amplified in Er fiber, Raman-shifted to 1800 to 2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber. 1. An optical pulse source comprising:a fiber based laser system comprising a seed laser configured to emit optical seed pulses;a pulse stretcher configured to stretch said seed pulses;a Tm fiber amplifier configured to amplify said stretched optical pulses, said Tm fiber amplifier comprising at least one doped fiber containing Tm;a pulse compressor disposed downstream from said at least one Tm fiber amplifier and arranged to compress pulses produced by said Tm fiber amplifier; andan output port configured to output optical pulses compressed with said pulse compressor.2. The optical pulse source according to claim 1 , wherein said seed laser comprises an Er laser.3. The optical pulse source according to claim 1 , wherein said seed laser comprises a mode-locked Er fiber oscillator.4. The optical pulse source according to claim 3 , wherein said fiber based laser system comprises a Raman shifter configured to generate Raman scattering within said fiber based laser system to shift a wavelength of a pulse generated with said mode-locked Er fiber oscillator to a longer wavelength in a range extending ...

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Номер записи: 89
22-05-2014 дата публикации

Optical Fiber with Multi Section Core

Номер: US20140140361A1
Автор: Jiang Shibin
Принадлежит: AdValue Photonics, Inc.

An optical fiber which includes a core region embedded within a cladding. The core region of the optical fiber further comprises multiple sections, each doped with rare earth ions. 1. A fiber laser , comprising:a laser optical fiber comprising a first single mode core region embedded within a cladding, the first single mode core region having two non-concentric core glass sections, wherein:each of the core glass sections is doped with a rare-earth ion;each core glass section comprises a semi-cylindrical rod having a ground surface; andthe ground surfaces are disposed in direct physical contact with one another such that the two core glass sections form a cylinder, such that each core glass section is in continuous contact with the other core glass section along a length of the fiber.2. The fiber laser of claim 1 , wherein one core glass section is doped with a first rare-earth ion and the other core glass section is doped with a second rare-earth ion claim 1 , the first rare-earth ion being different from the second rare earth ion.3. The fiber laser of claim 1 , wherein one core glass section is doped with a first doping concentration and the other core glass section is doped with a second doping concentration claim 1 , the first doping concentration being different from the second doping concentration.4. The fiber laser of claim 1 , wherein one core glass section is of a first glass host and the other section is of a second glass host claim 1 , the first glass host being different from the second glass host.5. The fiber laser of claim 1 , wherein the laser optical fiber further comprises a second single mode core region claim 1 , the second single mode core region having a plurality of sections claim 1 , wherein each of the plurality of sections is doped with a rare-earth ion.6. An ultra short pulse fiber laser claim 1 , comprising:a laser optical fiber comprising a first single mode core region embedded within a cladding, the first single mode core region having ...

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Номер записи: 90
20-02-2020 дата публикации

MULTI-WAVELENGTH SOURCES BASED ON PARAMETRIC AMPLIFICATION

Номер: US20200059060A1
Автор: Aggarwal Ishwar D., Auxier Jason, Busse Lynda E., Gattass Rafael R., Rhonehouse Daniel L., Sanghera Jasbinder S., Shaw L. Brandon, Thapa Rajesh
Принадлежит:

Fiber optic amplification includes a photonic crystal fiber coupled to a pump laser through a first coupler. The pump laser emits a first electromagnetic radiation wave into the photonic crystal fiber at a first oscillation frequency and a second electromagnetic radiation wave into the photonic crystal fiber at a second oscillation frequency equaling the first oscillation frequency. The first and second electromagnetic radiation waves interact to generate a signal comprising an electromagnetic radiation wave at a third oscillation frequency and an idler comprising a fourth electromagnetic radiation wave at a fourth oscillation frequency to be generated and amplified through parametric amplification. Parametric amplification is achieved by four wave mixing. The photonic crystal fiber emits a parametric output signal based on the four wave mixing. A nonlinear crystal frequency doubles the parametric output signal through second-harmonic generation. 1. A system of parametric generation and amplification , the system comprising:a photonic crystal fiber attached to a first coupler,a pump laser coupled to the first coupler, wherein the pump laser emits a first electromagnetic radiation wave into the photonic crystal fiber at a first oscillation frequency and a second electromagnetic radiation wave into the photonic crystal fiber at a second oscillation frequency, and wherein the first oscillation frequency equals the second oscillation frequency, wherein the first electromagnetic radiation wave and the second electromagnetic radiation wave in the photonic crystal fiber interact to parametrically generate through four wave mixing a signal comprising an electromagnetic radiation wave at a third oscillation frequency and an idler comprising a fourth electromagnetic radiation wave at a fourth oscillation frequency and amplified through parametric amplification,wherein wave dispersion in the photonic crystal fiber causes a first wavelength of the first electromagnetic ...

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Номер записи: 91
20-02-2020 дата публикации

Anti-Stokes-Fluorescence-Cooled Fiber-Based Gain Element

Номер: US20200059063A1
Автор: DIGONNET Michael J., KNALL Jennifer
Принадлежит:

This disclosure enables laser-based gain elements, such as fiber lasers, fiber amplifiers, and the like, that have higher power and better frequency stability than can be achieved in the prior art. Embodiments disclosed herein include a fiber-based gain element having a first portion in which anti-Stokes fluorescence (ASF) reduces its temperature below that of an ambient environment and a second portion whose temperature is not reduced below that of the ambient environment. The fiber-based gain element is arranged such that the first and second portions are thermally coupled so heat can flow from the second portion into the first portion, thereby reducing the average temperature of the gain element. In some embodiments, a core configured to provide optical gain is thermally coupled with a first cladding configured to exhibit ASF cooling via an intervening cladding layer that acts to confine a first pump signal to the core. 1. A fiber-based gain element comprising an optical fiber having a longitudinal axis , a first portion having a first outer surface , and a second portion having a second outer surface , the optical fiber including:a core configured to provide optical gain in response to a first pump signal; anda first cladding that surrounds at least a portion of the core, the first cladding configured to exhibit anti-Stokes fluorescence (ASF) in response to a second pump signal, wherein the ASF removes heat from the first cladding;wherein the optical fiber is arranged such that the first outer surface and the second outer surface are thermally coupled; and (i) the first cladding and core are a thermally coupled such that heat can flow from the core into the first cladding;', '(ii) the first portion has a temperature that is lower than a first temperature and a second portion having a temperature that is higher than the first temperature; and', '(iii) heat can flow from the second portion to the first portion through the first and second surfaces along a ...

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Номер записи: 92
02-03-2017 дата публикации

OPTICAL FIBER LASER DEVICE AND OPTICAL FIBER LASER PROVIDING METHOD

Номер: US20170063019A1
Автор: JUNG Chang Soo, Lee Yeung Lak, NOH Young Chul, Shin Woo Jin, YU Bong Ahn
Принадлежит:

Disclosed herein is an optical fiber laser device including a seed unit for providing at least two seed lights having different wavelengths; and an amplifying unit for amplifying the at least two seed lights. The amplifying unit includes: a preamplifying unit for amplifying the at least two seed lights by using excitation light of which the wavelength is shorter than the wavelengths of the seed lights; and a final amplifying unit to which no separate excitation light source is provided. The final amplifying unit amplifies the seed light having the longest wavelength by using the other seed light as excitation light with respect to the seed light having the longest wavelength among the at least two seed light. 1. An optical fiber laser apparatus comprising:a seed unit for providing at least two seed lights having different wavelengths; andan amplifying unit for amplifying the at least two seed lights, a pre-amplifying unit for amplifying the at least two seed lights by means of excitation light having wavelength shorter than that of the seed lights, and', 'a final amplifying unit for amplifying one seed light having a longest wavelength amongst the at least two seed lights by allowing the other seed light to serve as excitation light without providing a separate excitation light source., 'wherein the amplifying unit comprises'}2. The optical fiber laser apparatus of claim 1 , wherein LMA DCF is used as amplifying optical fiber in the final amplifying unit claim 1 , and the amplifying optical fiber amplifies the seed light having the longest wavelength in a manner of exciting a core.3. The optical fiber laser apparatus of claim 2 , wherein length of the amplifying optical fiber is provided as ½ to 1/400 of length of amplifying optical fiber having clad absorbance of 90%.4. The optical fiber laser apparatus of claim 3 , wherein the number of the seed lights is two claim 3 , Ytterbium (Yb) is doped to the amplifying optical fiber claim 3 , wavelength of one seed light ...

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Номер записи: 93
27-02-2020 дата публикации

DIAGNOSTIC SYSTEM WITH BROADBAND LIGHT SOURCE

Номер: US20200064189A1
Автор: Islam Mohammed N.
Принадлежит:

A diagnostic system is provided with a plurality of semiconductor light emitters, each configured to generate an optical beam, and a beam combiner to generate a multiplexed optical beam. An optical fiber or waveguide communicates at least a portion of the multiplexed optical beam to form an output beam, wherein the output beam is pulsed. A filter, coupled to at least one of a lens and a mirror to receive at least a portion of the output beam, forms an output light. A beam splitter splits the light into a sample arm and a reference arm and directs at least a portion of the sample arm light to a sample. A detection system is configured to receive from the sample at least a portion of reflected sample light, to generate a sample detector output, and to use a lock-in technique with the pulsed output beam. 1. A diagnostic system , comprising: an input light source, including one or more semiconductor diodes, configured to generate an input beam that comprises a wavelength shorter than 2.5 microns, and', 'one or more optical amplifiers configured to receive at least a portion of the input beam and form an amplified optical beam having a spectral width;, 'a light source comprisinga nonlinear element configured to receive at least a portion of the amplified optical beam and to broaden the spectral width of the received amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam, wherein the output beam is pulsed;at least one of a lens and a mirror configured to receive at least a portion of the output beam;a filter coupled to the lens or the mirror and configured to form an output light; receive at least part of the output light,', 'split the received output light into a sample arm and a reference arm, and', 'direct at least a portion of the sample arm light to a sample;, 'a beam splitter configured to receive from the sample at least a portion of reflected sample light,', 'generate a sample detector output, and', 'use a lock-in technique with ...

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Номер записи: 94
17-03-2022 дата публикации

Optical fiber devices and methods for reducing stimulated raman scattering (srs) light emissions from a resonant cavity

Номер: US20220085567A1
Автор: C. Geoffrey Fanning, Dahv A.V. Kliner, Tyson L. Lowder
Принадлежит: NLight Inc

Fiber laser devices, systems, and methods for reducing Raman spectrum in emissions from a resonant cavity. A fiber laser oscillator that is to generate an optical beam may include a Raman reflecting output coupler that strongly reflects a Raman component pumped within the resonant cavity, and partially reflects a signal component to sustain the oscillator and emit a signal that has a reduced Raman component. A Raman filtering output coupler may comprise a superstructure fiber grating, and such a grating may be chirped or otherwise designed to have a desired bandwidth.

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Номер записи: 95
10-03-2016 дата публикации

Optical Amplifier and Optical Transmission System

Номер: US20160072254A1
Автор: SUZUKI Mikiya
Принадлежит:

An optical amplifying apparatus that amplifies an optical signal, including an input section whereto the optical signal is inputted, a laser light source that generates laser light, the laser light source including an uncooled semiconductor laser device, an optical fiber that amplifies the optical signal by a stimulated emission based on the laser light from the laser light source, an output section that outputs the optical signal amplified by the optical fiber, and a passive optical component disposed between the optical fiber and the output section. The laser light source is thermally coupled to the optical fiber and/or the passive optical component via a thermally conductive medium. An oscillating wavelength of the laser light source is varied by increasing a temperature of the laser light source with heat generated by the optical fiber and/or the passive optical component. 1. An optical amplifying apparatus that amplifies an optical signal , comprising:an input section whereto the optical signal is inputted;a laser light source that generates multimode laser light propagating in a multimode, the laser light source including a multimode semiconductor laser device with no electronic cooling element;a double-clad optical fiber that amplifies the optical signal by a stimulated emission based on the multimode laser light from the laser light source;an output section that outputs the optical signal amplified by the double-clad optical fiber;a passive optical component disposed between the double-clad optical fiber and the output section; anda thermally conductive medium,the double-clad optical fiber being mounted on the thermally conductive medium, the double-clad optical fiber being configured to heat the thermally conductive medium by propagation of the multimode laser light,the laser light source being mounted on the thermally conductive medium so as to be heated by the double-clad optical fiber via the thermally conductive medium,an oscillating wavelength of the ...

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Номер записи: 96
08-03-2018 дата публикации

PULSED LASER FOR LIDAR SYSTEM

Номер: US20180069367A1
Автор: Eichenholz Jason M., LaChapelle Joseph G., Villeneuve Alain
Принадлежит:

A lidar system comprising with a light source, an optical link, and a sensor head. The light source can include a seed laser to produce pulses of light and an optical preamplifier to amplify the pulses of light. The optical link can convey amplified pulses of light to the sensor head remotely located from the light source. The sensor head can include an optical booster amplifier, a scanner to scan amplified output pulses of light across a field of regard, and a receiver to detect pulses of light scattered by a target located a distance from the sensor head. 1. A lidar system comprising: a seed laser configured to produce pulses of light; and', 'an optical preamplifier configured to amplify the pulses of light to produce amplified pulses of light;, 'a light source comprisingan optical link configured to convey at least a portion of the amplified pulses of light to a sensor head remotely located from the light source; and an optical booster amplifier configured to receive the portion of the amplified pulses of light and amplify the received pulses of light to produce amplified output pulses of light;', 'a scanner configured to scan the amplified output pulses of light across a field of regard; and', 'a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the sensor head., 'the sensor head, wherein the sensor head comprises2. The lidar system of claim 1 , wherein:the optical link comprises a fiber-optic cable terminated at the sensor head by an output collimator which produces a free-space optical beam directed to the optical booster amplifier; andthe optical booster amplifier comprises a free-space optical amplifier comprising a pump laser and a gain crystal configured to provide gain to the free-space optical beam.3. The lidar system of claim 2 , wherein:the pump laser has an operating wavelength of approximately 908 nm, 915 nm, 940 nm, 960 nm, 976 nm, 980 nm, 1050 nm, 1064 nm, 1450 nm, or 1480 ...

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Номер записи: 97
28-02-2019 дата публикации

HIGH POWER SUB-400 FEMTOSECOND MOPA WITH SOLID-STATE POWER AMPLIFIER

Номер: US20190067897A1
Автор: HODGSON Norman, STARODOUMOV Andrei
Принадлежит:

Laser-apparatus includes a fiber-MOPA arranged to deliver amplified seed optical pulses having a wavelength of about 1043 nanometers to a multi-pass ytterbium-doped yttrium aluminum garnet solid-state optical amplifier for further amplification. 1. Laser apparatus , comprising:a source of optical pulses having a first pulse-duration, the optical pulses having a center-wavelength in a predetermined wavelength-range between first and second wavelengths;a pulse-stretcher arranged to stretch the duration of the optical pulses to a second pulse-duration longer than the first pulse-duration;a solid-state multi-pass amplifier including a crystalline ytterbium-doped gain-element arranged to amplify the stretched optical pulses, the crystalline ytterbium-doped gain-element having a maximum emission cross-section at a wavelength outside of the predetermined wavelength-range of the optical pulses; anda pulse-compressor arranged to reduce the duration of the amplified optical pulses from the solid-state multi-pass amplifier to a duration of less than about 400 femtoseconds.2. The apparatus of claim 1 , wherein the crystalline ytterbium-doped gain-element of the solid-state multi-pass amplifier is made of ytterbium-doped yttrium aluminum garnet.3. The apparatus of claim 1 , wherein the crystalline ytterbium-doped gain-element of the solid-state multi-pass amplifier is made of a material selected from the group comprising ytterbium-doped lutetium aluminum garnet claim 1 , ytterbium-doped lutetium scandium oxide claim 1 , ytterbium-doped lutetium oxide claim 1 , and ytterbium-doped scandium oxide.4. The apparatus of claim 1 , wherein the first wavelength is about 1038 nanometers and the second wavelength is about 1052 nanometers.5. The apparatus of claim 4 , wherein the center wavelength of the optical pulses from the source thereof is about 1043 nanometers.6. The apparatus of claim 4 , wherein the center wavelength of the optical pulses from the source thereof is about 1048 ...

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Номер записи: 98
08-03-2018 дата публикации

Optical transmission system and related remote optically pumped amplifier (ropa) and method

Номер: US20180069637A1
Автор: Do-Il Chang, Herve A. Fevrier, Philippe Andre Perrier
Принадлежит: Neptune Subsea IP Ltd

An apparatus includes a remote optically pumped amplifier (ROPA). The ROPA includes a bypass filter configured to receive an optical signal and first pump power and to separate the optical signal and the first pump power. The ROPA also includes an amplifier configured to receive the optical signal from the bypass filter and to amplify the optical signal. The ROPA further includes an optical combiner/multiplexer configured to receive the first pump power from the bypass filter, receive at least second and third pump powers, combine at least two of the first, second and third pump powers, and provide different pump powers or combinations of pump powers to different locations within the ROPA to feed the amplifier.

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Номер записи: 99
05-03-2020 дата публикации

ADAPTIVE ILLUMINATION APPARATUS, METHOD, AND APPLICATIONS

Номер: US20200069233A1
Автор: Buttolph Michael, Charan Kriti, Li Bo, Xu Chris
Принадлежит: CORNELL UNIVERSITY

A system and method for adaptive illumination, the imaging system comprising an excitation source having a modulator, which generates a pulse intensity pattern having a first wavelength when the excitation source receives a modulation pattern. The modulation pattern is a data sequence of a structural image of a sample. An amplifier of the imaging system is configured to receive and amplify the pulse intensity pattern from the modulator. A frequency shift mechanism of the imaging system shifts the first wavelength of the pulse intensity pattern to a second wavelength. A laser scanning microscope of the imaging system receives the pulse intensity pattern having the second wavelength. 1. An imaging system for adaptive illumination , comprising:an excitation source having a modulator, which generates a pulse intensity pattern having a first wavelength when the excitation source receives a modulation pattern;wherein the modulation pattern is a data sequence of a structural image of a sample;an amplifier configured to receive and amplify the pulse intensity pattern from the modulator;a frequency shift mechanism which shifts the first wavelength of the pulse intensity pattern to a second wavelength; anda laser scanning microscope, which receives the pulse intensity pattern having the second wavelength.2. The imaging system of claim 1 , wherein the frequency shift mechanism a SSFS.3. The imaging system of claim 2 , wherein the SSFS is in a photonic crystal rod.4. The imaging system of claim 1 , further comprising:5. The imaging system of claim 1 , wherein the sample is a neuron.6. The imaging system of claim 1 , wherein the excitation source is an all-fiber chirped pulse amplifier.7. The imaging system of claim 1 , wherein the modulator is an electro-optic modulator.8. A method for adaptive illuminating claim 1 , comprising the steps of:generating a high-resolution structural image of a sample;processing the high-resolution structural image to determine one or more regions ...

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Номер записи: 100