УСИЛИВАЮЩЕЕ ОПТИЧЕСКОЕ ВОЛОКНО, А ТАКЖЕ ОПТИЧЕСКИЙ ВОЛОКОННЫЙ УСИЛИТЕЛЬ И РЕЗОНАТОР, ИСПОЛЬЗУЮЩИЙ УКАЗАННЫЙ УСИЛИТЕЛЬ

Изобретение относится к усиливающему оптическому волокну, оптическому волоконному усилителю и резонатору с его использованием. Усиливающее оптическое волокно содержит: сердцевину; оболочку, покрывающую сердцевину; и наружную оболочку, покрывающую оболочку. Сердцевина позволяет свету с предварительно определенной длиной волны распространяться в моде LP01 и моде LP02 и имеет более высокий показатель преломления, чем оболочка. Сердцевину легируют активным элементом, который стимулирует испускание света предварительно определенной длины волны. При этом положение, где интенсивность моды LP02 становится равна нулю, легируют в более высокой концентрации, чем центр сердцевины. Технический результат - обеспечение луча света высокого качества, даже когда мода высшего порядка, которая является осесимметричной, возбуждается в дополнение к моде LP01. 6 н. и 27 з.п. ф-лы, 10 ил.

VERBESSERTER OPTISCHER FASERLASER.

OPTICAL FIBER WITH FLUORESZENTEM ADDITIVE

Optical amplifier and light source

Heat treatment of silica based glasses

AMPLIFIERS AND LIGHT SOURCES EMPLOYING S-BAND ERBIUM-DOPED FIBER AND L-BAND THULIUM-DOPED FIBER WITH DISTRIBUTED SUPPRESSION OF AMPLIFIED SPONTANEOUS EMISSION (ASE)

The present invention provides an Erbium-Doped Fiber Amplifier (EDFA) and a source that employs the EDFA for generating light in an S-band of wavelengths. A fiber amplifier (10) in a depressed cladding or W-profile fiber has a core (12) doped with the active material (18) and defined by a core cross-section and a refractive index no. A depressed cladding (14) of index n1 surrounds the core (12) and a secondary cladding (16) of index n2 surrounding the depressed cladding (14). The fiber amplifier is pumped a level of high relative inversion D, such that the active material exhibits positive gains in a short wavelength band and high gains in a long wavelength band. In one embodiment, the core cross-section, the depressed cladding cross-section and the refractive indices no, n1, and n2 are selected to provide distributed ASE suppression at wavelengths longer than cutoff wavelength .lambda.c over the length of fiber amplifier (10). In another embodiment, such selection provides a roll-off loss ...

Pumping in a higher-order mode that is different from a signal mode

FIBEROPTIC DUAL-CORE WITH RING DOPES RARE EARTH

OPTICAL SOURCE IMPLEMENTING a FIBRE DOPEE, FIBRE FOR SUCH a SOURCE OPTICAL AND MANUFACTORING PROCESS Of SUCH a FIBRE

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

FIBER OPTIC POWER LASER DEVICE

The invention relates to a fiber optic power laser device comprising a power laser diode (1) emitting a pump wave, an optical resonator (12) comprising a totally reflecting end (6) and a partially reflecting end (9), an amplifying multimode optic fiber (7) and optical means (3, 11) coupling said pump wave in the multimode optical fiber (7). According to the invention, the optical resonator (12) comprises at least one optical sub-module (25, 26) consisting of a spatial filtering means and comprising optical means (2, 8) having a specific position in the optical sub-module (25, 26) so as to make the optical sub-module able to reproduce in amplitude and phase, after a round trip of the laser beam in said sub-module, the fundamental mode of the multimode optical fiber (7) on the input or output face (23, 24) of said multimode optical fiber (7), minimizing the losses of the fundamental mode, and so as to make the optical sub-module capable of filtering the other modes by producing in the optical ...

ARRANGEMENT FOR THE TRANSMISSION OF ELECTROMAGNETIC RADIATION, PREFERABLY FOR SUPPLYING LUMINOUS ENERGY TO BIOLOGICAL STRUCTURES

The invention relates to an arrangement for supplying luminous energy to biological structures, comprising a pumping light source and/or a laser source (41), an optical beam forming system (43), and an optical waveguide (45) which is coupled to the beam forming system to create a light intensity profile dependent on the full length of the waveguide and/or a change in shape and which comprises a core (46) and a cladding surrounding the core, a distal fiber end being free. The arrangement is characterized by a depressed refractive index structure which extends across the core and the cladding and consists of a succession of concentric zones that are designed, in at least some sections in the radial direction, as an alternating succession of regions having a relatively low refractive index and a relatively high refractive index. In a method for producing an optical waveguide for an arrangement for supplying luminous energy in a targeted manner to biological structures, a diffractive index ...

CASCADE LASER

Disclosed is an optical fiber that includes an inner core having a concentration of at least one laser active material, the inner core being adapted to operate in a single mode manner; and an outer core disposed about the inner core having a concentration of at least one laser active material. The outer core being adapted to operate in a multimode manner, a cladding disposed about the outer core; and an outer cladding is disposed about the cladding adapted to substantially confine pump light within the cladding.

Article comprising an optical fiber laser

An article, such as an optical communication system, which includes a laser formed in an optical waveguide or optical fiber having a rare-earth-doped core or core portion. In one embodiment, the optical resonant cavity of the laser is at least partially defined by a distributed Bragg reflector (10, 20) formed in a portion of the core. In contrast to the prior art, the length of the optical resonant cavity is about 5 cm or less. ...

3-УРОВНЕВЫЙ ВОЛОКОННЫЙ ЛАЗЕР/УСИЛИТЕЛЬ С НАКАЧКОЙ ЧЕРЕЗ ОБОЛОЧКУ ВОЛОКНА

... 1. Оптически активное волокно, формирующее волоконный лазер или усилитель, содержащее сердцевину, легированную оптически возбуждаемым ионом, с трехуровневым переходом, причем сердцевина имеет показатель преломления и площадь поперечного сечения, внутреннюю оболочку, окружающую сердцевину, причем внутренняя оболочка имеет показатель преломления внутренней оболочки, который меньше показателя преломления сердцевины, площадь поперечного сечения внутренней оболочки, превышающую площадь поперечного сечения сердцевины в 2-25 раз, и коэффициент формы свыше 1,5:1, и наружную оболочку, окружающую внутреннюю оболочку, причем наружная оболочка имеет показатель преломления, который меньше показателя преломления внутренней оболочки. 2. Оптически активное волокно по п.1, отличающееся тем, что размер сердцевины достаточно мал, в результате чего сердцевина поддерживает единственную поперечную моду на длине волны выходного сигнала, и единственная поперечная мода имеет такой же диаметр поля моды, как у стандартного ...

SINGLE-APERTURE CORE FIBER

OPTICAL FIBER WITH FLUORESZENTEM ADDITIVE.

TRANSVERSE ELECTROMAGNETIC WAVE STRUCTURE WITH LASER CHARACTERISTICS

FIBRE LASER WITH PLATE SHAPED ACTIVE MEDIUM FIBRE GRATINGS

GERMANIUM-FREE SILICATE WAVEGUIDE COMPOSITIONS FOR ENHANCED L-BAND AND S-BAND EMISSION AND METHOD FOR ITS MANUFACTURE

Amplifiers and light sources employing s-band erbium-doped fiber and l-band thulium-doped fiber with distributed suppression of amplified spontaneous emission (ase)

Sequentially increasing effective area in higher-order mode (HOM) signal propagation

Disclosed are multi-stage optical amplifiers that propagate higher-order mode (HOM) signals. One embodiment, among others, comprises a first segment of optical fiber in which a first HOM signal propagates, a second segment of optical fiber in which a second HOM signal propagates, and a mode converter that converts the first HOM signal into the second HOM signal.

OPTICAL FIBRE WITH FLUORESCENT ADDITIVE

An optical fibre for use in fibre lasers has the lasing additive, eg Er3+, concentrated in centre of the core. Preferably the core has an inner region which contains the additive and an outer region which is dopant free. The concentration of the dopant reduces the pump threshold for a laser and improves the gain performance for a given pump power. The fibre is conveniently made by MCVD. The use of Al2O3 in the inner zone appears to reduce loss of dopant during tube collapse.

MULTIPORT OPTICAL AMPLIFIER AND METHOD AMPLIFYING OPTICAL SIGNALS

An amplifier for optical signals is disclosed. The amplifier includes a source of optical pump power and a containment body for substantially containing the pump power at a predetermined power intensity. At least one guided signal path passes through the containment body, the signal path being capable of carrying at least one optical signal component. The source of optical pump power is coupled to the containment body. In one embodiment the containment body is a transparent material surrounded by a material having a lower index of a fraction. Pump power is contained within the containment body by means of total internal reflection (TIR). In another embodiment the containment body is formed from a metallic reflective material which surrounds the guided signal paths passing through the containment body.

LASER DEVICE HAS FIBEROPTIC OF POWER

OPTICAL ELEMENT AND ASSOCIATED MANUFACTURING METHOD

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

Amplification optical fiber and optical fiber amplifier and resonator using the same

The invention provides an amplification optical fiber, which can output light with a good beam quality even when a higher-order mode is excited, and an optical fiber amplifier using the amplification optical fiber. An amplification optical fiber 50 has a core 51 and a clad 52 covering the core 51. The core 51 propagates light with a predetermined wavelength in at least an LP01 mode, and an LP02 mode, and an LP03 mode. When the LP01 mode, the LP02 mode, and the LP03 mode are standardized by power, in at least a part of a region where the intensity of the LP01 mode is larger than at least one of the intensities of the LP02 mode and the LP03 mode, the active element is added to the core 51 at a higher concentration than the central portion of the core.

Composite laser gain medium

A composite laser gain medium is comprised of a first rare-earth element doped core; and a second rare-earth element doped cladding, at least partially, adjacent to the core. A portion of the lasing by the cladding at one wavelength within the composite laser gain medium is absorbed by the core so as to cause lasing of the core at a different wavelength. At least two distinct rare earth element pairs may be used in embodiments: (1) thulium (Tm) as a cladding rare-earth dopant and holmium (Ho) as the core rare-earth dopant; and (2) ytterbium (Yb) as a cladding rare-earth dopant and erbium (Er) as the core rare-earth dopant. Other rare earth element pairs are also believed possible. The laser composite gain medium may be configured to have a slab, or a cylindrical geometry.

Optical amplifier for collectively amplifying optical signals having a plurality of multiplexed wavelengths

Disclosed is an optical amplifier for collectively amplifying optical signals having multiplexed wavelengths. The optical amplifier enables a gain control in a range as wide as 1 dBm or larger, and employs a fiber that is doped with a rare-earth metal, such as erbium. The erbium-doped fiber in cross section is formed of a plurality of glass materials that are doped with erbium, and excitation light wavelength bands relative to the erbium-doped fiber are provided in a number equivalent to the count of the glass materials.

Large mode area fiber amplifiers with reduced stimulated brillouin scattering

A large mode area fiber amplifier suitable for high power applications includes a core region specifically configured to allow for high power operation while also limiting the amount of SBS that is generated. The composition of the core region is selected to include a dopant (such as aluminum) in selected areas to reduce the acoustic refractive index of the core and limit the spatial overlap between the acoustic and optical fields. The acoustic refractive index is also structured so that the acoustic field is refracted away from the central core area. In one embodiment, the core may comprise a depressed index center portion and surrounding ring core area, with the center portion including the aluminum doping and the ring formed to have a diameter less that the phonon decay length for the operating wavelength(s).

Selectively pumping a gain-doped region of an optical fiber

The present disclosure provides an approach to more efficiently amplify signals by matching either the gain materials or the pump profile with the signal profile for a higher-order mode (HOM) signal. By doing so, more efficient energy extraction is achieved.

TANDEM PUMPED FIBER AMPLIFIER

In an example, a tandem pumped fiber amplifier may include a seed laser, one or more diode pumps, and a single or plural active core fiber. The single or plural active core fiber may include a first section to operate as an oscillator and a second different section to operate as a power amplifier. The one or more diode pumps may be optically coupled to the first section of the single or plural active core fiber, and the seed laser may be optically coupled to the single active core or an innermost core of the plural active core fiber. 1. A tandem pumped fiber amplifier for high energy laser (HEL) applications , the tandem pumped fiber amplifier comprising:an optical fiber including at least one core, wherein a seed laser is optically coupled to the at least one core;the optical fiber including a first section to operate as an oscillator and a second different section to operate as a power amplifier; andone or more diode pumps optically coupled to the first section of the optical fiber,wherein the at least one core of the first section is doped to convert the one or more diode pumps into a tandem pump, wherein the one or more diode pumps and the tandem pump bi-chromatically pump the power amplifier;wherein a selected wavelength associated with the oscillator is less than a center wavelength of the seed laser, wherein the at least one core is dimensioned to suppress modal instability at 2 kW or greater output power when a difference between the selected wavelength and the center wavelength is in a range of 0.1-8% and a single active core is employed.2. The tandem pumped fiber amplifier of claim 1 , wherein a center wavelength of the seed laser is in a range of 1020-1080 nm.3. The tandem pumped fiber amplifier of claim 1 , wherein the selected wavelength is in the range of 1010-1045 nm.4. The tandem pumped fiber amplifier of claim 1 , wherein the oscillator comprises a single mode or multi mode oscillator.5. The tandem pumped fiber amplifier of claim 1 , wherein the one ...

RING CORE FIBER

The invention relates to fibers, such as fiber lasers, fiber amplifiers, and systems containing such fibers. In one aspect, the invention features a fiber that includes a first region (12), a core (14) and a cladding (16). The core (14) surrounds the first region (12), and the cladding (16) surrounds the core (14). Typically, the core (14) includes an active material. In a further aspect, the invention features a system that includes two fibers (10, 48). One of the fibers has a first region, a first core (e.g., a multimode core) surrounding the first region, and a cladding surrounding the core. The other fiber has a core (e.g., a single mode core). The fibers are connected so that energy can propagate between the cores of the two fibers. Typically, the core includes an active material.

Optical fibre with fluorescent additive

An optical fibre for use in fibre lasers contains Er3+ as the lasing additive, together with Al2O3 to reduce loss of the lasing additive during fibre preparation. Preferably the core has an inner region (13) which contains the Er3+ and Al2O3 and an outer region (12) which contains no Er3+. ...

OPTICAL FIBER FOR REINFORCEMENT OR LASER RADIATION

Cascade laser

P-si er fiber profile

Multiport optical amplifier and method of amplifying optical signals

HEAT TREATMENT OF SILICA BASED GLASSES

A sintered dense glass, alumina-doped optical fiber preform is stretched and is then heated to a temperature of 1490-1495.degree.C to remove bubbles without causing crystallization. Thereafter, the stretched glass body is either drawn directly into an optical fiber or overclad and then drawn into a fiber.

OPTICAL FIBER FOR OPTICAL AMPLIFIER AND FIBER OPTIC AMPLIFIER

An optical fiber for optical amplification used for 1.58 .mu.m band signal light amplification, at least a core region thereof being doped with Er, wherein at least a part of the core region is made of silica glass co-doped with Ge and A1 together with Er, and an average Er atomic concentration in the core region is from 950 wt-ppm to 3000 wt-ppm inclusive.

OPTICAL FIBER PUMPING APPARATUS AND METHOD FOR THE USE IN PUMPED OPTICAL FIBER AMPLIFIER AND LASER SYSTEMS

An optical fiber pumping apparatus for use with a double-cladding fiber in a n optical amplifier or laser configuration comprises a plurality of laser diodes used as pump sources disposed in a spatial configuration for radiating pump energy along an optic al axis through a surrounding generally annular area, leaving an available middle area. The apparatus further comprises an optical coupling device having an optical input portion general ly aligned with the optical axis to collect the pump energy and having an optical output portion aligned with the pumping input portion for transferring the pump energy to the inner cladding surrounding the doped core of the fiber. The apparatus exhibits high pump power rating and allows efficient input signal coupling in optical fiber amplifier applications. According to the different preferred embodiments, the apparatus can act either simultaneously or independently as a pump combiner, multiple pump injector, signal coupler or pump/signal multiplexer ...

Pumping in a higher-order mode that is different from a signal mode

The present disclosure provides an approach to more efficiently amplify signals by matching either the gain materials or the pump profile with the signal profile for a higher-order mode (HOM) signal. By doing so, more efficient energy extraction is achieved.

FIBEROPTIC DOPEE RARE EARTH RESISTANT TO RADIATIONS AND PROCESS OF HARDENING TO RADIATIONS Of a FIBEROPTIC DOPEE RARE EARTH

La présente invention concerne une fibre optique résistante aux radiations comprenant au moins un cœur et au moins une première gaine entourant ledit cœur. Selon l'invention, ledit cœur comprend une matrice de phosphosilicate, ledit cœur étant dopé terre-rare choisi parmi l'erbium, l'ytterbium, le néodyme, le thulium ou codopé erbium-ytterbium ou thulium-holmium et ledit cœur est codopé au cérium. L'invention concerne également un procédé de durcissement aux radiations d'une fibre optique comprenant un cœur à matrice de phospho-silicate , ledit cœur étant dopé terre-rare choisi parmi l'erbium, l'ytterbium, le néodyme, le thulium ou codopé erbium-ytterbium ou thulium-holmium, et comprenant une étape de codopage au cerium du cœur de ladite fibre.

IMPROVEMENTS IN OR RELATING TO ELECTRO-MAGNETIC WAVE TRANSMISSION LINES

OPTICAL AMPLIFIER, AND TOGETHER COMPRISING IT

L'invention concerne un amplificateur optique. Elle se rapporte à un amplificateur optique qui comprend une fibre (1) dopée par un métal des terres rares, possédant plusieurs couches de matériaux vitreux en coupe, ces matériaux étant dopés par un élément des terres rares, afin que des signaux optiques à plusieurs longueurs d'onde soient amplifiés collectivement, et des sources lumineuses (23, 25) destinées à créer des lumières d'excitation dans plusieurs bandes de longueurs d'onde qui correspondent au nombre de matériaux vitreux qui forment la fibre dopée par un métal des terres rares, les sources étant destinées à émettre des lumières d'excitation vers la fibre dopée par un métal des terres rares. Application aux communications optiques.

LASER PUMPS AND LASER MEDIUM OPTIMIZES

Laser pompé longitudinalement comprenant un ou plusieurs milieux actifs lasers disposés dans une cavité optique et au moins un moyen de pompage (4) émettant au moins un faisceau de pompe vers le ou les milieux actifs lasers (3), des moyens de couplage (5) du ou des faisceaux de pompe avec le milieu actif caractérisé en ce que au moins un des milieux actifs lasers comporte une ou plusieurs zones (8) dopées de façon non homogène et en ce que la dimension desdites zones (8) dopées et/ ou la répartition des dopants est choisie en fonction du mode transversal souhaité. Utilisation du laser comme amplificateur.

OPTICAL AMPLIFIER, AND TOGETHER COMPRISING IT

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

Rare-earth doped optical fiber, method of producing the same, and fiber laser

A rare-earth doped optical fiber that includes a core and one or more clad layers surrounding the core, in which the core has a rare earth dopant, and a relationship of Equation (1) is satisfied: 0 < r 0 r c ⁢ D ⁡ ( r ) · P p 2 ⁡ ( r ) · P s 2 ⁡ ( r ) ⁢ r ⁢ ⁢ ⅆ r r 0 r c ⁢ D ⁡ ( r ) · P p 2 ⁡ ( r ) ⁢ r ⁢ ⁢ ⅆ r 0.35 ( 1 ) where Pp(r) represents an electric field distribution in an exciting wavelength, Ps(r) represents an electric field distribution in wavelengths of spontaneous emission and/or stimulated emission carried in the core, D(r) (mass %) represents a rare-earth dopant distribution, ro represents a core center, and rc represents a core radius.

OPTICAL FIBER FOR OPTICAL FIBER LASER, METHOD OF MANUFACTURING THE SAME AND OPTICAL FIBER LASER

PROBLEM TO BE SOLVED: To provide an optical fiber for an optical fiber laser, its manufacturing method and the optical fiber laser which suppress a temperature rise of the optical fiber in the optical fiber laser and increase an output of laser beams. SOLUTION: The optical fiber for the optical fiber laser 1 includes: a rare earth adding core 2 to which a rare earth element is added; and a clad 3 formed surrounding the rare earth adding core. In the optical fiber for the optical fiber laser 1, an excited light Le enters from an end of the clad 3, and the rare earth element is excited to output laser oscillation beams L of a high output. The rare earth adding core 2 is divided into a plurality of core areas 2a, 2b, ..., 2n-1, 2n along a longitudinal direction thereof, and an addition concentration of the rare earth element added to the respective core areas 2a, 2b, ..., 2n-1, 2n is different. COPYRIGHT: (C)2009,JPO&INPIT ...

СПОСОБ УМЕНЬШЕНИЯ КОЛИЧЕСТВА ПУЗЫРЬКОВ В СТЕКЛЯННОМ ИЗДЕЛИИ (ВАРИАНТЫ) И СТЕКЛЯННОЕ ИЗДЕЛИЕ

Заготовку оптического волокна из спеченного плотного стекла с добавкой оксида алюминия вытягивают, а затем нагревают до температуры 1490-1495oС для удаления пузырьков при отсутствии протекания кристаллизации. После этого вытянутое стеклянное изделие либо непосредственно вытягивают в оптическое волокно, либо на изделие наносят покрытие, а затем вытягивают в волокно. Стеклянное изделие с добавкой оксида алюминия имеет первый максимум концентрации оксида алюминия в сердцевине около 1,3 мас.% и второй максимум - на радиальном расстоянии около 2,35 мас.%. Технический результат изобретения - снижение содержания пузырьков в заготовках для вытяжки оптического волокна и снижение вероятности кристаллизации заготовок, что позволяет получать волокна большой длины. 3 с. и 8 з.п. ф-лы, 10 ил. 1 табл.

Faseroptischer Verstärker

IMPROVED OPTICAL FIBRE LASER

BLUE LASER ON THE BASIS OF RECIPROCAL EFFECTS IN A FIBER

IMPROVED OPTICAL FIBER LASER.

STRENGTHENING OPTICAL FIBER WITH CIRCULAR ONE ANORDUNG THE DOPING AND AMPLIFIER WITH A SUCH FIBER

Germanium-free silicate waveguide compositions for enhanced l-band and s-band emission and method for its manufacture

Amplifying optical fiber, and optical fiber amplifier and oscillator using same

LASER PUMPS AND LASER MEDIUM OPTIMIZES

FIBEROPTIC FOR AMPLIFICATION OR LASER EMISSION

MULTIMODE OPTICAL AMPLIFICATION DEVICE

L'invention concerne un dispositif d'amplification optique multimode (1), notamment pour un système de télécommunications par fibres, comprenant une fibre amplificatrice (11) présentant un cœur central non dopé et un cœur annulaire dopé. Ce dispositif comprend en outre : - au moins un premier (20) et un second (22) réseaux à période longue asymétrique configurés pour transformer respectivement un premier et un second groupes de modes optiques de cœur central en entrée (3) en des premier et second modes optiques annulaires et orthogonaux, - une pompe optique (24), couplée à la fibre amplificatrice (11), - au moins un troisième (26) et un quatrième (28) réseaux à période longue asymétrique, associés respectivement au premier (20) et au second (22) réseaux à période longue et configurés pour transformer respectivement des premier et second groupes de modes optiques annulaires orthogonaux en des premier et second groupes de modes optiques de cœur central en sortie (7).

FIBEROPTIC FOR AMPLIFICATION OR LASER EMISSION

L'invention concerne le domaine des fibres optiques amplificatrices ou émettrices. C'est une fibre optique amplificatrice, dopée avec une terre rare, comprenant successivement plusieurs tranches (1, 2, 3, 4, 5), présentant un coeur monomode et un coeur multimode, présentant à la périphérie du coeur multimode une tranche périphérique (4) d'indice faible afin d'augmenter l'ouverture numérique de la fibre optique, une gaine (5) extérieure étant située à la périphérie de la tranche périphérique (4) à faible indice, le coeur multimode étant au moins en partie au-dessus de la gaine (5) extérieure, la tranche périphérique (2) présentant une forme en gradient décroissant.

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

AMPLIFYING OPTICAL FIBER RING DOPING AND AMPLIFIER USING [...]

PUMPING IN A HIGHER-ORDER MODE THAT IS DIFFERENT FROM A SIGNAL MODE

The present disclosure provides an approach to more efficiently amplify signals by matching either the gain materials or the pump profile with the signal profile for a higher-order mode (HOM) signal. By doing so, more efficient energy extraction is achieved.

BURST MODE RARE EARTH-DOPED FIBER AMPLIFIER

... [PROBLEMS] To provide a rare earth-doped fiber the transient response of which is suppressed and an optical packet communication optical amplifier which has a good characteristic even if traffic is low. [MEANS FOR SOLVING PROBLEMS] An optical packet communication optical amplifier comprises a first rare earth-doped fiber (EDFA) having an active region the diameter of which ranges from 3.4 μm to 10 μm, an intermediate gain flattening filter, and a second EDFA. The first EDFA is shorter than the second EDFA. The intensities of the wavelength channels of the intermediate gain flattening filter are regulated so that the light intensities of the wavelength channels transmitted through the second EDFA may be equal to one another.

COMMUNICATION SYSTEM AND SPLIT-BAND AMPLIFYING APPARATUS USING A DEPRESSED-PROFILE FIBER AMPLIFIER

An optical communication system (200) and a split-band amplifying apparatus (212) that amplifies optical signals whose short wavelength band includes at least a portion of the S-band and whose long wavelength band includes at least a portion of the C- and/or L-band. The amplifying apparatus (212) has a first (212A) and second section (212B) for respectively amplifying the long and short wavelength bands. The second section (212B) comprises a short-pass fiber (10) with a core (12) doped with an active material (18) such as Erbium. A pump source pumps the Erbium to a level of high relative inversion D such that the Erbium exhibits positive gains in the S-band and high gains in a long wavelength band longer than the S-band, i.e., in the C- and L-Bands. The core (12) is surrounded by a depressed cladding (14), which is surrounded by a secondary cladding (16). The core (12) has a core cross-section and a refractive index no, the depressed cladding (14) has a depressed cladding cross-section ...

Article comprising an optical waveguide containing a fluorescent dopant

Optical waveguide amplifiers and lasers having a novel fluorescent dopant distribution are disclosed. Exemplarily, in a Si-based optical fiber the fluorescent dopant (e.g., Er) has an annular distribution, with the concentration maximum not at the center of the core but typically between the center and the core/cladding interface. The novel waveguides can be relatively insensitive to variations in cut-off wavelength and/or modal distribution of pump power.

Optical module and processing method

The present invention relates to an optical module which is capable of amplifying light to be amplified to high power and which has a structure for effectively reducing influences of damage to other optical parts, and heat generation. The optical module includes a fiber unit constituted by an optical coupler, an amplification optical fiber, and an absorption optical fiber. Each of the amplification optical fiber and the absorption optical fiber has a core, a first cladding, a second cladding, and a third cladding. Further, each of the fibers allows the light to be amplified to propagate in a single mode in each of the cores, and allows pumping light to propagate in a multimode in the core, the first cladding, and the second cladding. The core of the amplification optical fiber is doped with an amplification dopant for amplifying the light to be amplified. The second cladding of the absorption optical fiber is doped with an absorption dopant for absorbing the pumping light.

DOPED-RING AMPLIFYING OPTICAL FIBER, AND AN AMPLIFIER CONTAINING SUCH A FIBER

The amplifying optical fiber comprises a single-mode core and a multimode core surrounding the single-mode core, the multimode core containing a doped layer referred to as a "doped ring" and having a certain concentration of active rare earth ions to perform amplification by active rare earth ions on at least one optical signal for injection into the amplifying fiber. The fiber is dimensioned so that the product of its length multiplied by its Raman efficiency is greater than or equal to 0.5 W^-1. In addition, the fiber presents absorption defined by an absorption coefficient expressed in dB/m, which absorption presents, at a certain wavelength, a maximum value referred to as the "absorption maximum", the fiber presents accumulated absorption, corresponding to the product of its length multiplied by the absorption maximum, that is greater than or equal to 100 dB. The invention also provides an amplifier including such a fiber, a single-mode pump, and a multimode pump.

Optical fiber for an optical fiber laser, method for fabricating the same, and optical fiber laser

The optical fiber 1 for an optical fiber laser is provided with a rare earth element doped core 2 doped with a rare earth element, and a cladding 3 formed at an outer periphery of the rare earth element doped core 2. In the optical fiber 1 for an optical fiber laser, the rare earth element doped core 2 is divided into a plurality of core regions 2a, 2b, . . . , 2n1, 2n along a longitudinal direction of the optical fiber 1 and dopant concentrations of the rare earth element in respective core regions 2a, 2b, . . . , 2n1, 2n are different from each other, in order to flatten a temperature distribution of the optical fiber 1 along the longitudinal direction.

Optical source implementing a doped fiber, fiber for such an optical source and method for manufacturing such a fiber

An optical source having a fiber emitting controlled single-transverse mode radiation at a wavelength of less than 1030 nm, includes at least one laser diode suitable for emitting a pumping wave; and a section of sheathed amplifying optical fiber having two ends, the amplifying optical fiber comprising a core and a pumping sheath, the fiber being doped with a rare earth dopant; a device for coupling the pumping source in the sheath of the doped fiber, characterized in that the core of the doped fiber includes a cylindrical portion doped with a rare earth element selected among ytterbium, neodymium, and thulium, in order to obtain a refractive index of the core that is higher than the refractive index of the sheath; the excitation wavelength of the laser diode is between 750 nm and 960 nm; the diameter of the sheath is greater than 50 microns, and the surface ratio of the doped core to the pumping sheath is between 8 and 50.

SEGMENTED GAIN-DOPING OF AN OPTICAL FIBER

Erbium-doped fiber amplifier

LMA FIBERS FOR SUPPRESSION OF THERMAL MODE INSTABILITY

Hermetisch dicht beschichtete, dotierte Glasfaser

Optische Faser mit fluoreszentem Additiv

Data transmission system

Optical amplifier for wavelength division multiplexed signals

OPTICAL FIBER FOR OPTICAL AMPLIFIER AND FIBER OPTIC AMPLIFIER

An optical fiber for optical amplification used for 1.58 .mu.m band signal light amplification, at least a core region thereof being doped with Er, wherein at least a part of the core region is made of silica glass co-doped with Ge and Al together with Er, and an average Er atomic concentration in the core region is from 950 wt-ppm to 3000 wt-ppm inclusive.

Large diameter optical waveguide, grating and laser

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.

Thulium and/or Holmium Doped Germanosilicate Glasses for Two Micron Lasers

A laser glass fiber with a core of the fiber comprising a germanosilicate glass host, one or more glass network modifiers, one or more glass network intermediators, and Thulium ions, Holmium ions, or a combination of Thulium ions and Holmium ions. The fiber emits laser light from 1.7 micron to 2.2 micron.

Method and apparatus for generation and amplification of light in a semi-guiding high aspect ratio core fiber

A planar laser gain medium and laser system. The novel laser gain medium includes an active core having a high aspect ratio cross-section with a fast-axis dimension and a slow-axis dimension, signal claddings adapted to form reflective boundaries at fast-axis boundaries of the core, and a material adapted to minimize reflections at slow-axis boundaries of the core. In an illustrative embodiment, the laser gain medium is an optical fiber. The core and claddings form a waveguide adapted to control modes propagating in the fast-axis direction. When the laser gain medium is employed as a laser oscillator, a high reflectivity mirror and an outcoupler are positioned at opposite ends of the core to form a laser resonator adapted to control modes in the slow-axis direction.

Compact optical frequency comb systems

Compact optical frequency sources are described. The comb source may include an intra-cavity optical element having a multi-material integrated structure with an electrically controllable active region. The active region may comprise a thin film. By way of example, the thin film and an insulating dielectric material disposed between two electrodes can provide for rapid loss modulation. In some embodiments the thin film may comprise graphene. In various embodiments of a frequency comb laser, rapid modulation of the CEO frequency can be implemented via electric modulation of the transmission or reflection loss of an additional optical element, which can be the saturable absorber itself. In another embodiment, the thin film can also be used as a saturable absorber in order to facilitate passive modelocking. In some implementations the optical element may be formed on a cleaved or polished end of an optical fiber.

Mode-locked fiber laser based on narrowband optical spectral filtering and amplifier similaritons

Implementations and examples of mode-locked fiber lasers based on fiber laser cavity designs that produce self-similar pulses (“similaritons”) with parabolic pulse profiles with respect to time at the output of the fiber gain media to effectuate the desired mode locking operation. An intra-cavity narrowband optical spectral filter is included in such fiber lasers to ensure the proper similariton conditions.

Large core holey fibers

Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers.

Fiber amplifier system including tapered fiber bundle and combined lens and sampling grating

A fiber laser amplifier system including a beam splitter that splits a feedback beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier for amplifying the fiber beam. A tapered fiber bundle couples the output ends of all of the fiber amplifiers into a combined fiber providing a combined output beam. A beam sampler samples a portion of the output beam from the tapered fiber bundle and provides a sample beam. A single mode fiber receives the sample beam from the beam sampler and provides the feedback beam.

METHOD AND DEVICE FOR AMPLIFYING AN OPTICAL SIGNAL

According to the invention, the optical signal (SE) is spatially divided into N elementary optical signals (SE., SE., . . . , SE.N), the spectral ranges thereof being adjacent in pairs and forming, substantially by juxtaposition, the spectral range of the optical signal; these N elementary signals are amplified respectively by means of N elementary amplifiers (.N), the spectral ranges thereof respectively comprising the spectral ranges of said N elementary signals; the N amplified elementary signals (Ss., Ss., . . . , Ss.N) are assembled to form an amplified optical signal (Ss), the spectral range thereof substantially coinciding with a predetermined spectral range, and finally the spectral phases of the N initial elementary signals (Ss., Ss., . . . , Ss.N) are adjusted before amplification on the basis of the spectral phase of said amplified signal (Ss). 111-. (canceled)12. Method for amplifying an optical signal (S) , wherein:{'sub': E', 'E', 'E', 'E', 'E', 'E', 'E', 'E', 'E, 'b': 1', '2', '1', '2, 'the optical signal (S) is spatially divided into N elementary optical signals (S., S., . . . , S.N), the spectral ranges (Δλ., Δλ., . . . , Δλ.N) of which are adjacent in pairs and form, substantially by juxtaposition, the spectral range (Δλ) of the optical signal (S), N being an integer at least equal to 2;'}{'sub': E', 'E', 'E', 'G', 'G', 'G', 'E', 'E', 'E, 'b': 1', '2', '4', '1', '4', '2', '4', '1', '2', '1', '2, 'the N elementary optical signals (S., S., . . . , S.N) are amplified respectively by means of N elementary amplifiers (., ., . . . , .N), the spectral ranges of amplification (Δλ., Δλ., . . . , Δλ.N) of which respectively comprise substantially the spectral ranges (Δλ., Δλ., . . . , Δλ.N) of said N elementary optical signals;'}{'sub': S', 'S', 'S', 'S', 'S, 'b': 1', '2, 'the N amplified elementary optical signals (S., S., . . . , S.N) are assembled to form an amplified optical signal (S), the spectral range (Δλ) of which substantially coincides with a ...

High Power Single Mode Ytterbium Fiber Laser System with Single Mode Neodymium Fiber Pump Source

A high power fiber laser system emitting a substantially diffraction limited beam with a Gaussian intensity profile includes a single mode (“SM”) neodymium fiber pump source outputting a SM pump light; a seed laser operative to emit a SM signal light at a wavelength greater than that of the pump light; a SM DWM receiving and multiplexing the SM pump and signal lights. The disclosed system further includes a booster fiber amplifier which is configured with a frustoconically-shaped ytterbium (“Yb”) doped core receiving the pump and signal lights and configured with a small diameter input end which supports only a SM and a large diameter output end which is capable of supporting the SM and high order modes (:HOM”). The booster further has a cladding surrounding and coextending with the core, the core being configured for having intensity profiles of respective SMs of pump and signal lights overlap one another so that an overlap integral substantially equals to one (1) along an entire length of the core. The SM of the light signal extracts substantially the entire energy from the pump mode leaving the HOMs without amplification necessary to affect a quality of the diffraction limited beam of the system in a MW peak power range and hundreds of watt average power range.

Fiber Geometrical Management for TEM00 Mode Pulse Energy Scaling of Fiber Lasers and Amplifiers

Methods and systems for managing pulse energy scaling are disclosed, including generating electromagnetic radiation; coupling the electromagnetic radiation to a fiber geometrical management system comprising: a tapered fiber comprising: an elliptical or rectangular core centrally positioned within a single or double cladding shell, wherein the core comprises a fiber material and a doped gain medium; an input face wherein the doped core comprises a major axis and a minor axis, wherein the ratio of the major to minor axis at the input face ranges from about 1 to about 100; an output face wherein the doped core comprises a major axis and a minor axis, wherein the ratio of the major to minor axis at the output face ranges from about 1 to about 100; and wherein the major (minor) axis is adiabatically or linearly tapered from the input face to the output face. Other embodiments are described and claimed.

SHORT PULSE WAVELENGTH TUNING VIA TIMED SOLITON-DISPERSIVE WAVE INTERACTION

When a soliton and a dispersive pulse propagate in an optical fiber, they can interact via cross-phase modulation, which occurs when one pulse modulates the refractive index experienced by the other pulse. Cross-phase modulation causes each pulse to shift in wavelength by an amount proportional to the time delay between the pulses. Changing the time delay between the pulses changes the wavelength shift of each pulse. This make it possible to produce pulses whose output wavelengths can be tuned over large ranges, e.g. hundreds of nm, in a time as short as the pulse repetition period of the laser (e.g., at rates of megahertz or gigahertz). Such a laser requires no moving parts, providing high reliability. The laser's optical path can be made entirely of optical fiber, providing high efficiency with low size, weight, and power consumption. 1. A laser system comprising:a first laser source to emit a first pulse at a first wavelength;a second laser source to emit a second pulse at a second wavelength different than the first wavelength;a controller, operably coupled to at least one of the first laser source or the second laser source, to vary a time delay between the first pulse and the second pulse; andan optical waveguide in optical communication with the first laser source and the second laser source and having a zero-dispersion wavelength between the first wavelength and the second wavelength, to guide the first pulse and the second pulse, cross-phase modulation in the optical waveguide causing the first pulse to shift the second wavelength by a first wavelength shift and the second pulse to shift the first wavelength by a second wavelength shift, the first wavelength shift and the second wavelength shift depending on the time delay.2. The laser system of claim 1 , wherein the first laser source is incoherent with respect to the second laser source.3. The laser system of claim 1 , wherein:the first laser source comprises a first mode-locked laser;the second laser ...

High Power Chirally Coupled Core Optical Amplification Systems and Methods

An optical amplification system is disclosed which includes a seed source providing a seed beam, and a chirally coupled core fiber amplifier optically coupled to the seed beam and configured to convert the coupled seed beam into an amplifier output beam, wherein the polarization of the seed beam is controllably launched into the chirally coupled core fiber in order to reduce nonlinearities in the amplifier output beam. Peak output powers in excess of 500 kW can be realized for short-pulsed single-mode beams having mode field diameters greater than 30 μm.

Optical fiber for a fiber laser, fiber laser, and production method for optical fiber for a fiber laser

An optical fiber for a fiber laser includes a core to which a rare-earth element is added, a first cladding formed around the core; and a second cladding formed around the first cladding, and excitation light is guided from at least one end of the first cladding to excite the rare-earth element to output a laser oscillation light. An addition concentration of the rare-earth element to the core is different in a longitudinal direction of the optical fiber for a fiber laser, and a core diameter and a numerical aperture of the optical fiber for a fiber laser are constant in the longitudinal direction of the optical fiber for a fiber laser.

SINGLE OPTICAL FIBER-BASED MULTI-RING LASER BEAM DEVICE, AND MANUFACTURING METHOD THEREFOR

The present invention relates to a single optical fiber-based multi-ring laser beam device, and a manufacturing method therefor. The present invention enables a laser beam to be emitted in a single optical fiber through at least two stair-type processing methods by allowing the laser beam to be radially spread out in a lengthwise direction of the optical fiber in two or more ring forms. Therefore, if two ring-form light profiles are used instead of one ring-form light profile, an energy burden on a glass tube is reduced because of an energy dispersion effect such that a safe treatment effect can be provided without the risk of damage to the glass tube. In addition, according to one embodiment of the present invention, an unnecessary process is removed by forming two rings in one optical fiber instead of using two optical fibers, such that advantages of simple manufacturing and cost reduction are provided. Furthermore, according to another embodiment of the present invention, two or more ring-form light profiles are provided in one optical fiber such that an effect of enabling a glass tube size to be reduced is provided. 1. A single optical fiber-based multi-ring laser beam device is characterized in that a laser beam is emitted in a single optical fiber in a lengthwise direction of an optical fiber through a two-or-more-stair-type process in two or more ring forms so as to be radially spread out.2. The single optical fiber-based multi-ring laser beam device according to claim 1 , comprising:{'b': '110', 'an optical-fiber outer cover () which is configured to cover an optical fiber;'}{'b': 120', '110', '110, 'an multi-ring optical fiber () which is a part of the optical fiber covered by the optical-fiber outer cover () and is formed through a two-or-more-stair-type process at a section that is not covered by the optical-fiber outer cover (); and'}{'b': 130', '1', '131', '2', '132', '110', '131, 'a glass tube () which has an inner diameter (D) of a mouth () thereof ...

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

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.

SHORT-PULSE LASER SYSTEM

A short-pulse laser system includes a first and a second resonator, and an amplification means for amplifying the electromagnetic pulses both in the first and in the second resonator. The first resonator supports precisely one first linear polarization state, and the second resonator supports precisely one second linear polarization state perpendicular to the first polarization state. The short-pulse laser system has first and second birefringent material sections. The first birefringent material section and/or the second birefringent material section is designed in such a way that a difference between the sum of the optical path length of the first resonator in the first birefringent material section and the optical path length of the first resonator in the second birefringent material section and the sum of the optical path length of the second resonator in the first birefringent material section and the optical path length of the second resonator in the second birefringent material section can be changed in an adjustable manner.

SINGLE-MODE PROPAGATION IN MICROSTRUCTURED OPTICAL FIBERS

The invention relates to an optical fiber as an optical waveguide for the single-mode operation. The present invention proposes a fiber having a microstructure, by which the propagation of modes of a higher order are selectively suppressed in the optical waveguide. At the same time, the propagation of transversal modes of a higher order is dampened more strongly than the propagation of the fundamental modes of the optical waveguide. 1. An optical fiber as an optical waveguide for single-mode operation , wherein the fiber has a structuring by means of which propagation of higher order modes in the optical waveguide is selectively suppressed , wherein the structuring comprises channels that run along the longitudinal expanse of the fiber , whereby a fiber core is formed by a region of the fiber in which no channels run , and wherein the channels , viewed in the cross-section of the fiber , form groups composed of at least two channels , in such a manner that the distances between the center axes of the channels within a group are less than the distances between the center axes of the channels of different groups , whereby the distance of the centroidal axes of the groups is greater than twenty times the wavelength of the radiation guided in the optical waveguide.2. The optical fiber according to claim wherein the groups are disposed hexagonally. This application is a divisional of and Applicants claim priority under 35 U.S.C. §§120 and 121 of U.S. application Ser. No. 13/138,618 filed on Nov. 22, 2011, which application is a national stage application under 35 U.S.C. §371 of PCT Application No. PCT/EP2010/001586 filed on Mar. 12, 2010, which claims priority under 35 U.S.C. §119 from German Patent Application No. 10 2009 012 662.7 filed on Mar. 13, 2009 and under 35 U.S.C. §119 from German Patent Application No. 10 2009 060 711.0 filed on Dec. 29, 2009, the disclosures of each of which are hereby incorporated by reference. The international application under PCT ...

SINGLE PASS AMPLIFICATION OF DISSIPATIVE SOLITON-LIKE SEED PULSES

A system for single pass amplification of dissipative soliton-like seed pulses of 1-20 ps to produce output pulses of 50-200 fs, without requiring a stretcher. Such an amplifier relies on the inherent chirp of the seed pulse out of the oscillator instead of pulse stretching. 1. The method of amplifying dissipative soliton-like seed pulses to produce output pulse comprising the steps of:(a) providing dissipative soliton-shaped seed pulses of 1-20 ps from an oscillator tuned to produce inherently chirped pulses of appropriate spectral shape and phase;(b) providing a pump beam;(c) combining the seed pulses and the pump beam and providing them to an amplifier;(d) amplifying the combined seed pulses and pump beam using two stages of gain fiber to generate amplified pulses; and(c) temporally compressing the amplified pulses and generating output pulses of 50-200 fs;2. An amplifier comprising:a seed source;a pump source;a pump combiner that combines the pump light and seed light and provides them to a first gain fiber;a first gain fiber doped with rare earth ions with one core size and doping level, with the seed amplified by a factor of 10-1000, and the majority of the pump light being transmitted; The first gain fiber can include single mode (SM) fiber, large mode area (LMA) fiber, or photonic crystal fiber (PCF), and can be single or double clad;a second gain fiber with a second core size and doping level, where both the seed and the pump light from the first gain fiber are coupled in sequence into the second fiber, wherein additional gain in the second gain fiber is from 10-1000; The second gain fiber can include single mode (SM) fiber, large mode area (LMA) fiber or photonic crystal fiber (PCF), including rod type fibers, and can be single or double clad; anda compressor.3. The apparatus of wherein the pump source is a single co-propagating pump that is used to provide energy for both gain segments. U.S. Pat. No. 8,416,817 is incorporated herein by reference.Field of ...

Bright Few-Cycle Fiber Source using Resonant Dispersive Wave Emission in an Optical Fiber

Methods and apparatus for generating ultrashort optical pulses. Pulses of an infrared source are launched into an optical fiber characterized by a zero-dispersion wavelength (ZDW), where the wavelength of the infrared source exceeds the ZDW of the optical fiber by at least 100 nm. A resonant dispersion wave (RDW) is generated in the optical fiber that has a central wavelength blue-shifted by more than 500 nm relative to the pump wavelength, and, in some cases, by more than 700 nm. The optical fiber has a core of a diameter exceeding the central wavelength of the RDW by at least a factor of five. In a preferred embodiment, the infrared source includes a master-oscillator-power-amplifier, embodied entirely in optical fiber, and may include an Erbium:fiber oscillator, in particular. 2. A method in accordance with claim 1 , wherein the RDW emission is characterized by a central wavelength blue-shifted by more than 700 nm relative to the pump wavelength.3. A method in accordance with claim 1 , further comprising temporally compressing the RDW emission.4. A method in accordance with claim 1 , wherein the pump pulse energy exceeds 40 nJ.5. A method in accordance with claim 1 , wherein the RDW emission exceeds 1 nJ per pulse.6. A method in accordance with claim 1 , wherein the infrared source includes a master-oscillator-power-amplifier.7. A method in accordance with claim 1 , wherein the infrared source is based upon an Erbium-doped fiber mode-locked oscillator.8. An apparatus for generating ultrashort optical pulses characterized by a central wavelength claim 1 , the apparatus comprising:a. a source of infrared pulses characterized by a wavelength;b. an optical fiber characterized by a core diameter and a zero-dispersion wavelength (ZDW),wherein the wavelength of the infrared pulses exceeds the ZDW of the optical fiber by at least 100 nm, andwherein the core diameter of the optical fiber exceeds the central wavelength of the ultrashort optical pulses by at least a factor ...

Fiber-Optic Laser Oscillator

The invention relates to a laser oscillator comprising an amplifying optical fibre (MA) inserted in a resonant cavity so as to act as an active medium, and pumping means (DL, CP) causing a population inversion in said amplifying optical fibre, characterized in that said amplifying optical fibre comprises at least two cores (C1, C2) optically coupled to each other in a common cladding (G), and in that the shapes, sizes, refractive indices and the relative arrangement of said cores are chosen so that super-modes are supported, at least one (SMI) of which super-modes has, in an emission spectral band of said laser oscillator, a normal chromatic dispersion.

SUPPRESSING STIMULATED BRILLOUIN SCATTERING (SBS)

An optical system comprising an optical conduit (e.g., gain fiber or rare-earth-doped fiber) with a bend having a bend radius (R). The bend induces a tension and a compression in the fiber core, which results in a corresponding strain (ε). The corresponding bend-induced strain impacts the signal properties in the core of the fiber. 1. An optical system comprising:a signal fiber for receiving a narrowband signal;a pump fiber for pumping the narrowband signal; and a bend having a bend radius (R);', 'a tension section induced by the bend, the tension section having a positive strain (+ε);', 'a compression section induced by the bend, the compression section having a negative strain (−ε); and, 'a rare-earth-doped fiber coupled to the signal fiber, the rare-earth-doped fiber comprising the positive strain (+ε) and the negative strain (−ε) alter the narrowband signal;', {'sub': 'max', '|ε|≤ε; and'}, {'sub': 'max', 'ε>0.001.'}], 'wherein2. The system of claim 1 , wherein ε>0.003.3. The system of claim 1 , wherein the rare-earth-doped fiber comprises a dopant selected from the group consisting of:erbium (Er);ytterbium (Yb);{'sub': '2', 'germanium oxide (GeO);'}lanthanum (La); andaluminum (Al).4. The system of claim 1 , further comprising a bend structure for forming the bend claim 1 , the bend structure being one selected from the group consisting of:a cylindrical spool;a variable shaped spool; anda corrugated surface.5. An optical fiber for propagating a narrowband signal claim 1 , the optical fiber comprising:an average stimulated Brillouin scattering (SBS) gain;a bend having a bend radius;tension sections induced by the bend, the tension sections having a positive strain (+ε);compression sections induced by the bend, the compression sections having a negative strain (−ε); andwherein the tension sections and the compression sections alter the average SBS gain by at least three (3) decibels (dB).6. The optical fiber of claim 5 , wherein the tension sections and the ...

BROADBAND SHORT PULSE FIBER LASERS CAPABLE OF GENERATING OUTPUT SPECTRA BROADER THAN GAIN BANDWIDTH

Implementations and examples of fiber lasers based on fiber laser cavity designs that produce self-similar pulses (“similaritons”) to achieve a pulse spectral bandwidth greater than a gain spectral bandwidth based on a spectral broadening fiber segment and a spectral filter to ensure the proper similariton conditions. 1. A method for operating a fiber laser to generate broadband laser pulses with a spectral bandwidth greater than a gain spectral bandwidth of a gain fiber segment in the fiber laser , comprising:providing a ring laser cavity to include a gain fiber segment having a gain spectral bandwidth, a spectral broadening fiber segment coupled to receive output light from the gain fiber segment, and an optical spectral filter coupled to receive light from the spectral broadening fiber segment to circulate laser pulses in a closed optical loop to, sequentially, pass through the gain fiber segment, the spectral broadening fiber segment and the optical spectral filter;operating the optical spectral filter to output filtered light to the gain fiber segment downstream in the closed optical loop to selectively transmit light in a narrow spectral band while rejecting light outside the narrow spectral band and to have a bandwidth for the narrowband that is sufficiently narrow to cause each laser pulse to be self similar after propagating through the gain fiber segment; anddirecting amplified laser pulses out of the gain fiber segment into the spectral broadening fiber segment to produce chirped self-similar laser pulses circulating in the fiber laser to have a pulse spectral bandwidth in each laser pulse output by the spectral broadening fiber segment to be greater than the gain spectral bandwidth of the gain fiber segment, wherein the spectral broadening fiber segment and the optical spectral filter collected to cause each laser pulse to have a varying spectral width in the closed optical loop that reaches a maximum spectral width value at the exit of the spectral ...

Laser cavity repetition rate tuning and high-bandwidth stabilization

The disclosure describes aspects of laser cavity repetition rate tuning and high-bandwidth stabilization of pulsed lasers. In one aspect, an output optical coupler is described that includes a cavity output coupler mirror, a piezoelectric actuator coupled to the cavity output coupler mirror, a locking assembly within which the cavity output coupler mirror and the piezoelectric actuator are positioned, and one or more components coupled to the locking assembly. The components are configured to provide multiple positional degrees of freedom for tuning a frequency comb spectrum of the pulsed laser (e.g., tuning a repetition rate) by adjusting at least one position of the locking assembly with the cavity output coupler mirror. A method of adjusting an output optical coupler in a pulsed laser is also described. These techniques may be used in different applications, including quantum information processing.

AMPLIFICATION OPTICAL FIBER, FIBER LASER DEVICE, AND OPTICAL RESONATOR

An amplification optical fiber includes: a core; an inner cladding having a refractive index lower than a refractive index of the core, wherein an active element pumped by pumping light is entirely doped to the core, and a relative effective refractive index difference of light in an LP01 mode is greater than or equal to 0.05% and a relative effective refractive index difference of light in an LP21 mode is less than 0.05% in light propagating through the core. 1. An amplification optical fiber comprising:a core;a cladding having a refractive index lower than a refractive index of the core, whereinan active element pumped by pumping light is entirely doped to the core, anda relative effective refractive index difference of light in an LP01 mode is greater than or equal to 0.05% and a relative effective refractive index difference of light in an LP21 mode is less than 0.05% in light propagating through the core.2. The amplification optical fiber according to claim 1 , wherein a relative effective refractive index difference of light in an LP11 mode is less than 0.05% in light propagating through the core.3. The amplification optical fiber according to claim 1 , wherein a relative effective refractive index difference of light in an LP11 mode is greater than or equal to 0.05% in light propagating through the core.4. The amplification optical fiber according to claim 1 , wherein a refractive index profile of the core corresponds to a concentration profile of the active element.5. The amplification optical fiber according to claim 1 , wherein an effective area of light in the LP01 mode propagating through the core is greater than or equal to 200 μm.6. The amplification optical fiber according to claim 5 , wherein the effective area of light in the LP01 mode propagating through the core is less than or equal to 400 μm.7. The amplification optical fiber according to claim 1 , wherein a relative refractive index difference of the core is greater than or equal to 0.08%.8. ...

SYSTEM AND METHOD FOR PLASMONIC CONTROL OF SHORT PULSES IN OPTICAL FIBERS

The present disclosure relates to an optical waveguide system. The system may include a first waveguide having a core-guide and a material portion surrounding and encasing the core-guide. The core-guide enables a core-guide mode for an optical signal travelling through the core-guide. A second waveguide forms a lossy waveguide on an outer surface of the first waveguide. The construction of the second waveguide is such as to achieve a desired coupling between the core-guide mode and the lossy waveguide to control an energy level of the optical signal travelling through the core-guide. 1. An optical waveguide system including:a first waveguide having a core-guide and a material portion surrounding and encasing the core-guide, the core-guide enabling a core-guide mode for an optical signal travelling through the core-guide;a second waveguide forming a lossy waveguide on an outer surface of the first waveguide;the construction of the second waveguide being such as to achieve a desired coupling between the core-guide mode and the lossy waveguide to control an energy level of the optical signal travelling through the core-guide; andan optical pump source configured to inject optical energy into the first waveguide from an angle non-parallel to the core-guide, using the coupling between the core-guide mode and the lossy waveguide.2. The system of claim 1 , wherein the second waveguide comprises metal which forms a plasmonic device claim 1 , and which implements a plasmonic mode waveguide.3. The system of claim 2 , wherein the cladding material portion surrounding the core-guide includes a flat surface portion claim 2 , and the plasmonic device is disposed on the flat surface portion.4. The system of claim 3 , wherein the first wave-guide has a D-shaped construction when viewed in cross section.5. The system of claim 2 , wherein a plurality of plasmonic devices are disposed along a length of the optical fiber.6. The system of claim 2 , wherein the plasmonic device comprises ...

LARGE CORE HOLEY FIBERS

Holey fibers provide optical propagation. In various embodiments, a large core holey fiber comprises a cladding region formed by large holes arranged in few layers. The number of layers or rows of holes about the large core can be used to coarse tune the leakage losses of the fundamental and higher modes of a signal, thereby allowing the non-fundamental modes to be substantially eliminated by leakage over a given length of fiber. Fine tuning of leakage losses can be performed by adjusting the hole dimension and/or spacing to yield a desired operation with a desired leakage loss of the fundamental mode. Resulting holey fibers have a large hole dimension and spacing, and thus a large core, when compared to traditional fibers and conventional fibers that propagate a single mode. Other loss mechanisms, such as bend loss and modal spacing can be utilized for selected modes of operation of holey fibers. 1. An optical fiber for propagating a single optical mode , said optical fiber comprising:a cladding region comprising a plurality of cladding features disposed in a matrix, said plurality of cladding features having an average spacing, Λ, and an average size, d, said plurality of cladding features being substantially arranged in a plurality of layers, N; anda core region surrounded by said cladding region, said plurality of cladding features substantially confining propagation of said single optical mode to said core region, said plurality of cladding features having (i) sufficient average spacing, Λ, to provide an increased effective core size, 2ρ, and (ii) a sufficient average size, d, to provide substantial confinement of light having a wavelength, λ, within said core region,wherein said average size, d, and said average spacing, Λ, have values at least about 20 micrometers to provide an effective core size of at least about 20 micrometers;wherein d/Λ is at least about 0.6, and said optical fiber is configured to propagate said single optical mode in said core region ...

Single mode propagation in fibers and rods with large leakage channels

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.

Optical system and method for ultrashort laser pulse characterization

The optical system comprises: means for introducing a controlled negative or positive chirp to an incoming ultrashort laser pulse to be characterized; a nonlinear optical medium through which said chirped ultrashort laser pulse is propagated, wherein as a result of said propagation: different chirp values are introduced in the ultrashort laser pulse at different propagation distances along the nonlinear optical medium, and a transverse nonlinear signal is generated in a direction perpendicular to the propagation axis; analyzing means configured for recording a single-shot spectral image of said generated transverse nonlinear signal; and a processing module comprising one or more processors configured to execute a numerical iterative algorithm to said single-shot spectral image to retrieve the electric field, amplitude and phase, of the ultrashort laser pulse. 1. An optical system for ultrashort laser pulse characterization , comprising:means for introducing a controlled chirp, negative or positive, to an incoming ultrashort laser pulse to be characterized; different chirp values are introduced by the dispersion of the nonlinear optical medium itself in the ultrashort laser pulse at different propagation distances along the nonlinear optical medium, and', 'a transverse nonlinear signal is generated in a direction perpendicular to the propagation axis from said ultrashort laser pulse having different chirp values introduced by the corresponding propagation distance within the nonlinear optical medium said transverse nonlinear signal being a transverse second harmonic generation signal,, 'a nonlinear optical medium, with normal or anomalous dispersion, through which said chirped ultrashort laser pulse is propagated, said nonlinear optical medium having the property of generating a nonlinear signal from the ultrashort laser pulse and emitting the generated nonlinear signal transversally to the propagation direction, wherein as a result of said propagation analyzing ...

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

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 ...

AMPLIFICATION OPTICAL FIBER AND FIBER LASER DEVICE USING THE SAME

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 ...

ABLATED END FIBERS AND METHODS FOR ABLATING OPTICAL FIBERS

A method for ablating an optical fiber includes generating a laser beam for a plurality of discrete time periods. The laser beam impacts and ablates the optical fiber during each discrete time period. Each discrete impact of the laser beam during one of the plurality of discrete time periods is at a different location on a surface of the cladding. The ablation of the optical fiber during the plurality of discrete time periods forms a plurality of discrete craters. The plurality of discrete craters are spaced apart from each other in an array which extends along a longitudinal axis of the optical fiber and about a circumference of the optical fiber. An ablated end fiber includes a core, a cladding surrounding the core, and a plurality of discrete craters defined in the ablated end fiber. 1. A method for ablating an optical fiber , the optical fiber comprising a core and a cladding , the method comprising:generating a laser beam for a plurality of discrete time periods, wherein the laser beam impacts and ablates the optical fiber during each discrete time period and wherein each discrete impact of the laser beam during one of the plurality of discrete time periods is at a different location on a surface of the cladding;wherein the ablation of the optical fiber during the plurality of discrete time periods forms a plurality of discrete craters, the plurality of discrete craters spaced apart from each other in an array which extends along a longitudinal axis of the optical fiber and about a circumference of the optical fiber.2. The method of claim 1 , wherein each of the plurality of discrete craters extends only into the cladding and does not extend into the core.3. The method of claim 1 , wherein each of the plurality of discrete craters has a maximum diameter of greater than 20 microns.4. The method of claim 1 , wherein each of the plurality of discrete craters has a maximum depth of between 10 and 300 microns.5. The method of claim 1 , wherein the optical fiber is a ...

HOMOGENEOUS PUMP STRUCTURE OF LASER, AND DESIGN METHOD FOR STRUCTURE

A homogeneous pump structure of laser, and a design method for the homogeneous pump structure of laser. The homogeneous pump structure of laser is used in a fiber laser or a fiber laser amplifier, and comprises a gain fiber (). The gain fiber () comprises a pump light input end and a pump light output end. The pump area of the gain fiber () gradually decreases from the pump light input end to the pump light output end, so that a change rate between a pump light absorption capacity of each of segments, with equal lengths, of the gain fiber () and a pump light absorption capacity of a neighboring segment is smaller than b %, b being an empirical value. 1. A homogeneous pump structure of a laser used in a fiber laser or a fiber laser amplifier , comprising:a gain fiber having a pump light input end and a pump light output end, wherein a pump area of the gain fiber gradually decreases from the pump light input end to the pump light output end, such that a change rate of a pump light absorption capacity between each segment with an equal length and an adjacent segment of the gain fiber is less than b %, wherein b is an empirical value.2. The homogeneous pump structure of the laser according to claim 1 , wherein the homogeneous pump structure adopts a tapered fiber coupling pump method claim 1 , the gain fiber comprises a fiber core and an inner cladding which is in contact with and closely surrounds the fiber core claim 1 , when a cross section area of the gain fiber is equivalent to a circular claim 1 , a ratio of a diameter of the fiber core to a diameter of the inner cladding gradually increases from the pump light input end to the pump light output end.3. The homogeneous pump structure of the laser according to claim 1 , wherein the homogeneous pump structure adopts an end pumped method claim 1 , the gain fiber comprises a fiber core and an inner cladding which is contact with and closely surrounds the fiber core claim 1 , when a cross section area of the gain fiber ...

SUPERCONTINUUM LIGHT SOURCE COMPRISING TAPERED MICROSTRUCTURED OPTICAL FIBER

The invention relates to a supercontinuum light source comprising a microstructured optical fiber and a pump light source. The microstructured optical fiber comprises a core and a cladding region surrounding the core, as well as a first fiber length section, a second fiber length section and an intermediate fiber length section between said first and second fiber length sections. The first fiber length section comprises a core with a first characteristic core diameter. The second fiber length section comprises a core with a second characteristic core diameter, smaller than said first characteristic core diameter, where said second characteristic core diameter is substantially constant along said second fiber length section. The intermediate length section of the optical fiber comprises a core which is tapered from said first characteristic core diameter to said second characteristic core diameter over a tapered length. 128-. (canceled)29. A microstructured optical fiber for generating supercontinuum light upon feeding of light having a first wavelength λ , the optical fiber having a length and a longitudinal axis along its length and comprising a core region for guiding light along the length of said optical fiber , and a first cladding region surrounding said core region , wherein:said optical fiber, along its length, comprises a first fiber length section, a second fiber length section, and an intermediate fiber length section between said first and second fiber length sections;{'sub': '1', 'said first fiber length section has a core region with a first characteristic core diameter Win a cross-section through the microstructured optical fiber perpendicularly to the longitudinal axis;'}{'sub': 2', '2', '1, 'said second fiber length section has a core region with a second characteristic core diameter Win a cross-section through the microstructured optical fiber perpendicularly to the longitudinal axis, where said second characteristic core diameter Wis smaller than ...

SYSTEM AND METHOD FOR PLASMONIC CONTROL OF SHORT PULSES IN OPTICAL FIBERS

The present disclosure relates to an optical waveguide system. The system has a first waveguide having a core-guide and a cladding material portion surrounding and encasing the core-guide to form a substantially D-shaped cross sectional profile with an exposed flat section running along a length thereof. The core-guide enables a core-guide mode for an optical pulse signal having a first characteristic, travelling through the core-guide. A material layer of non-linear material is used which forms a second waveguide. The material layer is disposed on the exposed flat section of the cladding material portion. The material layer forms a plasmonic device to achieve a desired coupling with the core-guide to couple optical energy travelling through the core-guide into the material layer to modify the optical energy travelling through the core-guide such that the optical energy travelling through the core-guide has a second characteristic different from the first characteristic. 1. An optical waveguide system including:a first waveguide having a core-guide and a cladding material portion surrounding and encasing the core-guide to form a substantially D-shaped cross sectional profile with an exposed flat section running along a length thereof, the core-guide enabling a core-guide mode for an optical pulse signal having a first characteristic, travelling through the core-guide; anda material layer of non-linear material forming a second waveguide, the material layer being disposed on the exposed flat section of the cladding material portion, the material layer forming a plasmonic device to achieve a desired coupling with the core-guide to couple optical energy travelling through the core-guide into the material layer, which modifies the optical energy travelling through the core-guide to cause the optical energy travelling through the core-guide to have a second characteristic different from the first characteristic.2. The system of claim 1 , wherein the first predetermined ...

AMPLIFICATION OPTICAL FIBER AND OPTICAL FIBER AMPLIFIER

An amplification optical fiber operable to propagate light beams in a plurality of modes in a predetermined wavelength range through a core doped with a rare earth element, wherein Expression (1) is satisfied, where a cutoff wavelength of a propagated highest mode light beam is defined as λmax, under conditions in which the cutoff wavelength of the highest mode light beam is defined as λc, a shortest wavelength of the wavelength range is defined as λmin, and a cutoff wavelength of a second-highest mode light beam to the highest mode light beam is λmin. 1. An amplification optical fiber operable to propagate light beams in a plurality of modes in a predetermined wavelength range through a core doped with a rare earth element , , whereinExpression (1) is satisfied, {'br': None, 'i': 'c', 'λ>0.5 λmin+0.5 λmax\u2003\u2003(1)'}, 'where a cutoff wavelength of a propagated highest mode light beam is defined as λmax, under conditions in which the cutoff wavelength of the highest mode light beam is defined as λc, a shortest, wavelength of the wavelength range is defined as λmin, and a cutoff wavelength of a second-highest mode light beam to the highest, mode light beam is λmin.'}2. The amplification optical fiber according to claim 1 , wherein {'br': None, 'i': 'λc', '>0.25 λmin+0.7 λmax\u2003\u2003(2)'}, 'Expression (2) is satisfied.'}3. The amplification optical fiber according to claim 1 , whereinthe predetermined wavelength range is a range of 1,530 to 1,565 nm, inclusive.4. The amplification optical fiber according to claim 1 , wherein:the core has an inner core doped with no rare earth element and an outer core surrounding an outer circumferential surface of the inner core and doped with a rare earth element; anda relative refractive index difference between the inner core and a cladding is smaller than a relative refractive index difference between the outer core and the cladding.5. The amplification optical fiber according to claim 1 , wherein{'sub': 01', '11, 'the ...

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

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 ...

SPECTROSCOPY SYSTEM WITH LASER AND PULSED OUTPUT BEAM

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 ...

Fiber stretcher module for use in the 1550 nm wavelength range

Embodiments of the present invention are generally related to embodiments of the present invention relate to a fiber stretchers module for use in the 1550 nm wavelength range. In one embodiment of the present invention, a fiber stretcher module for use in the 1550 nm wavelength range comprises a first fiber comprising a relative dispersion curve value of greater than about 0.0002 nm −2 and a dispersion value of less than about −60 ps/(nm·km) at about 1550 nm, and a second fiber comprising a relative dispersion curve value of about zero and a relative dispersion slope value of about 0.003 nm −1 at about 1550 nm, wherein the fiber stretcher module comprises a collective relative dispersion slope of about 0.0413 nm −1 and a relative dispersion curve of about 0.00286 nm −2 at 1550 nm.

Q-switched fiber laser

A fiber laser, null coupler acoustic Q-switch, fiber amplifier and feedback system is described for generation of high power laser pulses.

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

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.

MULTI-WAVELENGTH ADJUSTABLE-RADIAL-MODE FIBER LASER

A high-power fiber laser produces a compound output beam having a center beam and an annular beam. The center beam and the annular beam are independently adjustable in power and wavelength. The output beam is delivered from an output optical fiber having a center core and a concentric annular core. A fundamental beam generated by a seed laser is amplified by a fiber amplifier and partially converted to a second-harmonic beam by a second-harmonic generator. The residual fundamental beam and second-harmonic beam are separated, attenuated, and selectively coupled into the cores of the output optical fiber. 1. A fiber laser , comprising:a seed laser providing a laser beam having a fundamental wavelength;a fiber amplifier arranged to receive and amplify the fundamental beam, the amplified fundamental beam being linearly polarized;a harmonic generator arranged to receive the amplified fundamental beam and partially convert the amplified fundamental beam into a laser beam having a harmonic wavelength corresponding to a harmonic of the fundamental wavelength, the partial conversion leaving a residual laser beam having the fundamental wavelength;a dichroic mirror arranged to intercept and spatially separate the residual fundamental beam and the harmonic beam;a first polarization modulator and a first polarizer arranged to receive the residual fundamental beam and to regulate power by passing at least portion thereof;a second polarization modulator and a second polarizer arranged to receive the harmonic beam and to regulate power by passing at least a portion thereof;an output optical fiber having a center core and an annular core; anda fiber combiner arranged to receive the regulated fundamental beam and the regulated harmonic beam, the fiber combiner configured to couple at least a portion of the regulated fundamental beam into a first one of the cores of the output optical fiber and to couple at least a portion of the regulated harmonic beam into a second one of the cores ...

Gain-Equalized Few-Mode Fiber Amplifier

A few-mode rare-earth-doped amplifier fiber has equalized gain for the supported signal transmission modes. The fiber has a raised-index core surrounded by a lower-index cladding region. The core has a radius a 1 and an index difference Δn 1 relative to the surrounding cladding region and is configured to support, at a selected signal wavelength, a set of lower-order fiber modes having an optical field with a diameter greater than 2·a 1 . The fiber further includes an active region, doped with a rare-earth dopant, comprising an inner portion that is coextensive with the core and an outer portion that surrounds the inner portion and extends into the cladding. The active region has an outer radius a 2 greater than a 1 that encompasses the optical field of the set of lower-order fiber modes at the selected signal wavelength.

INEXPENSIVE VARIABLE REP-RATE SOURCE FOR HIGH-ENERGY, ULTRAFAST LASERS

System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective. 1. A system comprising:a pulse source outputting pulses which are less than or equal to approximately 10 ns at a variable repetition rate in a range from about 1 kHz to less than about 10 MHz, said pulse source comprising:a light source; anda fiber amplifier with positive group-velocity dispersion (GVD) at an emission wavelength of said light source, said fiber amplifier receiving an output of said light source, and causing spectral generation by self-phase modulation in said fiber amplifier,wherein said fiber amplifier is one of a multimode fiber or a holey fiber,wherein said positive GVD has a negative value of dispersion when expressed in units of ps/nm/km, andwherein said light source comprises a q-switched microchip laser outputting pulses having a pulse energy equal to or greater than 500 nJ.2. The system as claimed in claim 1 , wherein said microchip laser outputs pulses greater than 1 ps.3. The system as claimed in claim 1 , wherein said microchip laser outputs pulses in a range from about 50 ps to about 10 ns.4. The system as claimed in claim 1 , wherein said fiber is a multimode fiber operably arranged for single mode operation and to generate self-phase modulation claim 1 , wherein said fiber comprises a coreless end cap claim 1 , wherein a mode is expanded before a surface of said fiber.5. The system as claimed in claim 1 , wherein pulse energies are greater than 1 μJ and said pulses are stretched at an output of the fiber amplifier.6. The system as claimed in claim 1 , further comprising: a pulse compressor ...

OPTICAL FIBER DEVICES AND METHODS FOR DIRECTING STIMULATED RAMAN SCATTERING (SRS) LIGHT OUT OF A FIBER CORE & INTO A CLADDING

Optical fiber devices, systems, and methods for separating Raman spectrum from signal spectrum. Once separated, the Raman spectrum may be suppressed (e.g., as a result of a reduction in gain from the signal spectrum, and/or through dissipation of the Raman spectrum energy), while the signal spectrum may be propagated in one or more guided modes of a fiber system. In some embodiments, a fiber system may include a chirped fiber Bragg grating (CFBG) or a long period fiber grating (LPFG), each configured to couple a core propagation mode into a cladding propagation mode with an efficiency that is higher for Raman spectrum than for signal spectrum. A fiber system further may include a cladding light stripper (CLS) configured to preferentially remove cladding modes containing the Raman component. 1. An optical fiber device , comprising:a first and a second length of optical fiber, each of the lengths of optical fiber comprising a core and two or more cladding layers, wherein the core supports at least a first propagation mode for light comprising both signal spectrum and Raman spectrum; anda chirped fiber Bragg grating (CFBG) between the first and second lengths of fiber, the CFBG to couple at least some of the light propagated in the first propagation mode into one or more cladding modes of the first or second length of fiber with a greater coupling efficiency over the Raman spectrum than over the signal spectrum.2. The optical fiber device of claim 1 , wherein:the Raman spectrum comprises one or more first wavelengths that are longer than one or more second wavelengths of the signal spectrum;the two or more cladding layers of at least the second length of fiber further comprise an inner cladding layer, and an outer cladding layer in contact with the inner cladding layer;the CFBG comprises a third length of fiber further comprising a core, an inner cladding layer, and an outer cladding layer in contact with the inner cladding layer, wherein a refractive index of the core ...

Active element-added optical fiber, resonator, and fiber laser device

An active element-doped optical fiber includes a core that includes a first region and a second region. The first region satisfies 0≤r≤0.65d, and the second region surrounds the first region and satisfies 0.65d<r≤d, where d is a radius of the core and r is a distance from a central axis of the core in a radial direction. At least a part of the first region is doped with an active element excited by excitation light, the second region is not doped with the active element, and a shape index is 0.99 or more and less than 1.

PULSE CONFIGURABLE FIBER LASER UNIT

A pulse configurable laser unit is an environmentally stable, mechanically robust, and maintenance-free ultrafast laser source for low-energy industrial, medical and analytical applications. The key features of the laser unit are a reliable, self-starting fiber oscillator and an integrated programmable pulse shaper. The combination of these components allows taking full advantage of the laser's broad bandwidth ultrashort pulse duration and arbitrary waveform generation via spectral phase manipulation. The source can routinely deliver near-TL, sub-60 fs pulses with megawatt-level peak power. The output pulse dispersion can be tuned to pre-compensate phase distortions down the line as well as to optimize the pulse profile for a specific application. 1. A pulse configurable laser unit (PCLU) outputting uniform ultrashort pulses , comprising:a fiber pulse generator operating in a plurality of operational regimes to output a train of coherent uniform amplified giant chirped broadband pulses along a light path;a two-stage compressor including a static compressor, which is configured to compensate for a linear chirp component of each giant chirped broadband pulse, and a pulse shaper which is provided with a programmable spatial light modulator (SLM) to correct for a non-linear chirp component of the giant chirped broadband pulse, wherein the two-stage compressor outputs a train of transform limited (TL) ultrashort coherent pulses in each of the operational regimes of the fiber pulse laser generator; andat least one or more computers executing a software for selectively retrieving a phase mask corresponding to a given operational regime from a library of phase masks, which is stored in a memory of the CPU, and operating the pulse shaper to apply the retrieved mask across to the programmable spatial light modulator (SLM) of the pulse shaper so as to compensate for the nonlinear chirp component of the chirped pulse of the compressed TL ultrashort coherent pulses.2. The PCLU ...

SYSTEM, APPARATUS AND METHOD FOR UTILIZING OPTICAL DISPERSION FOR FOURIER-DOMAIN OPTICAL COHERENCE TOMOGRAPHY

An apparatus can be provided which can include a laser arrangement which can be configured to provide a laser radiation, and can include an optical cavity. The optical cavity can include a dispersive optical first arrangement which can be configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation. Such cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation. The optical cavity can further include a dispersive optical third arrangement which can be configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation. For example, actions by the first, second and third arrangements can cause a spectral filtering of the fourth electro-magnetic radiation(s) relative to the first electro-magnetic radiation(s). The laser radiation can be associated with the fourth radiation(s), and a wavelength of the laser radiation can be controlled by the spectral filtering caused by the actions by the first, second and third arrangements. 1. An apparatus , comprising: a dispersive optical first arrangement which is configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation,', 'an active optical modulator second arrangement which is configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation, and', 'a dispersive optical third arrangement which is configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation,, 'a laser arrangement which is configured to provide a laser radiation, and including an optical cavity which compriseswherein ...

OPTICAL ELEMENT AND ASSOCIATED MANUFACTURING METHOD

An optical element is provided. The optical element may comprise a material, the material being a matrix and a set of particles included in the matrix, the material having a molar fraction of SiOhigher than or equal to 65 percent, each particle having a dimension smaller than or equal to 80 nanometers. 2. The optical element as claimed in claim 1 , wherein the third material (M3) is ELGaO claim 1 , where EL denotes an element chosen from Zn claim 1 , Mg claim 1 , Nb claim 1 , W claim 1 , Ni claim 1 , Sn claim 1 , Ti claim 1 , Bi claim 1 , Ag claim 1 , Ca claim 1 , Mn claim 1 , or a mixture thereof.3. The optical element as claimed in claim 1 , wherein the third material (M3) comprises a doping element.4. The optical element as claimed in claim 3 , wherein the doping element is a transition metal claim 3 , or a rare earth element.5. The optical element as claimed in claim 1 , wherein the second material (M2) comprises SiO.6. The optical element as claimed in claim 1 , wherein the first material (M1) is obtained from a precursor comprising a powder comprising SiO claim 1 , NaO claim 1 , ZnO and GaO claim 1 , the molar fraction of SiOin the precursor being between 50 percent and 80 percent.8. The optical element as claimed in claim 6 , wherein the precursor comprises claim 6 , in addition to the powder claim 6 , a doping element claim 6 , and wherein:a molar fraction of the doping element in the precursor is between 0.001 percent and 3 percent, andthe doping element is a transition metal, or a rare earth element.9. The optical element as claimed in claim 1 , wherein the first material (M1) is a glass-ceramic.10. The optical element as claimed in claim 1 , wherein at least one of the following properties is satisfied:the optical element is a core for an optical fiber, andthe optical element is configured to emit optical radiation.11. The optical element as claimed in claim 1 , wherein the optical element is an optical fiber comprising a core made of the first material ( ...

COMPACT, COHERENT, HIGH BRIGHTNESS LIGHT SOURCES FOR THE MID AND FAR IR

Compact high brightness light sources for the mid and far IR spectral region, and exemplary applications are disclosed based on passively mode locked Tm fiber comb lasers. In at least one embodiment the coherence of the comb sources is increased in a system utilizing an amplified single-frequency laser to pump the Tm fiber comb laser. The optical bandwidth generated by the passively mode locked Tm fiber comb laser is further decreased by using simultaneous 2and 3order dispersion compensation using either appropriate chirped fiber Bragg gratings for dispersion compensation, or fibers with appropriately selected values of 2and 3order dispersion. Fibers with large anomalous values of third order dispersion, or fibers with large numerical apertures, for example fibers having air-holes formed in the fiber cladding may be utilized. 2. The fiber-laser based system according to claim 1 , wherein said dispersion values approximately satisfy the relation:{'br': None, 'i': D', '/D', 'D', '/D, '0.5<(2131)/(2232)<2.'}3. The fiber-laser based system according to claim 1 , wherein said dispersion values approximately satisfy the relation:{'br': None, 'i': D', '/D', 'D', '/D, '0.7<(2131)/(2232)<1.3.'}4. The fiber-laser based system according to claim 1 , wherein said passively mode locked fiber oscillator operates in the wavelength range from about 1700 nm to about 2500 nm.5. The fiber-laser based system according to claim 1 , wherein said passively mode locked fiber oscillator comprises a Tm claim 1 , a Tm:Ho claim 1 , or a Ho doped fiber.6. The fiber-laser based system according to claim 1 , further comprising a continuum fiber for super continuum generation.7. The fiber-laser based system according to claim 6 , further comprising a fiber amplifier inserted between said oscillator and said continuum fiber.8. The fiber-laser based system according to claim 7 , wherein said fiber amplifier is capable of higher order soliton compression claim 7 , nonlinear compression claim 7 , ...

FEMTOSECOND PULSE STRETCHING FIBER OSCILLATOR

A pulse stretching fiber oscillator (or laser cavity) may comprise a chirped fiber Bragg grating (CFBG) and an optical circulator arranged such that a first portion of a beam that is transmitted through the CFBG continues to propagate through the laser cavity while a second portion of the beam that is reflected from the CFBG is stretched and chirped by the CFBG and directed out of the laser cavity by the optical circulator. Accordingly, a configuration of the CFBG and the optical circulator in the laser cavity may enable pulse stretching contemporaneous with outcoupling, which may prevent deleterious nonlinear phase from accumulating prior to stretching. 1. A pulse stretching laser cavity , comprising: 'wherein the pulse propagates in a forward direction through the pulse stretching laser cavity and experiences gain in a first pass through the active fiber;', 'an active fiber configured to transmit a pulse,'} wherein the chirped fiber Bragg grating is configured to transmit a first portion of the pulse out a distal end of the chirped fiber Bragg grating where the first portion of the pulse continues to propagate in the forward direction to complete a round trip to the active fiber while a second portion of the pulse is reflected and thereby stretched, and', 'wherein the second portion of the pulse propagates in a reverse direction where the second portion of the pulse experiences gain in a second pass through the active fiber; and, 'a chirped fiber Bragg grating that comprises an input end arranged to receive the pulse after the pulses passes through the active fiber,'}an optical circulator arranged to receive the second portion of the pulse after the second pass through the active fiber and output the second portion of the pulse.2. The pulse stretching laser cavity of claim 1 , further comprising: 'wherein the beam propagation stage comprises one or more devices arranged to propagate the first portion of the pulse in the forward direction.', 'a beam propagation ...

HOLLOW-CORE OPTICAL FIBERS

An anti-resonant hollow-core fiber comprising a first tubular, cladding element which defines an internal cladding surface, a plurality of second tubular elements which are attached to the cladding surface and together define a core with an effective radius, the second tubular elements being arranged in spaced relation and adjacent ones of the second tubular elements having a spacing therebetween, and a plurality of third tubular elements, each nested within a respective one of the second tubular elements. 153-. (canceled)54. An anti-resonant hollow-core fiber comprising a first tubular , cladding element which defines an internal cladding surface , a plurality of second tubular elements which are attached to the cladding surface and together define a core with an effective radius , the second tubular elements being arranged in spaced relation and adjacent ones of the second tubular elements having a spacing therebetween , and a plurality of third tubular elements , each nested within a respective one of the second tubular elements to provide nested tubular arrangements.55. The fiber of claim 54 , wherein (i) the nested tubular arrangements are arranged in symmetrical relation at the cladding surface claim 54 , and/or (ii) one or more of the tubular elements have different sectional shape.56. The fiber of claim 54 , wherein (i) the first tubular element is circular in section claim 54 , and/or (ii) the second tubular elements are circular in section or have a longer dimension in a radial direction than a tangential direction claim 54 , optionally elliptical or oval in section.57. The fiber of claim 54 , wherein the tubular elements are formed of glass claim 54 , optionally silica claim 54 , optionally the tubular elements are formed of glass having a refractive index of at least about 1.4 claim 54 , optionally about 1.4 to about 3 claim 54 , optionally about 1.4 to about 2.8.58. The fiber of claim 54 , wherein the second tubular elements are attached to the first ...

3D WAVEGUIDE FOR EFFICIENT COUPLING OF MULTIMODE PUMP AND SIGNALS TO A MULTICORE FIBER AMPLIFIER

An optical communication substrate includes a plurality of cores to communicate optical signals; a rectangular input delivering a pump laser, and a shaped portion to combine the optical signals and the pump laser into a ring geometry at an output. 1. A fiber amplifier device , comprising: an input section adapted to be coupled to a laser pump output and a plurality of cores, wherein the cores are optically coupled to the optical signal carrying structures; and', 'a 3D waveguide extending from the input section with a laser pump waveguide having a rectilinear shaped end and a ring-shaped end surrounding the plurality of optical signal carrying structures., 'a substrate having a plurality of optical signal carrying structures formed thereon, the substrate including2. The device of claim 1 , wherein the amplifier comprises a multicore erbium-doped fiber (EDF) amplifier.3. The device of claim 1 , wherein the 3D waveguide comprises a 3D direct laser written glass substrate.4. The device of claim 1 , comprising a multicore fiber claim 1 , wherein the signals propagating in the multicore fiber is coupled to the structures in the glass substrate matching the cores.5. The device of wherein the cores match the location of the cores in the MCF at the input end claim 4 , while the placing of the cores at the output surface of the 3D-WG match the location of the cores in the MC-EDF.6. The device of claim 1 , comprising a pump laser coupled to the rectilinear shaped end.7. The device of claim 6 , wherein the pump laser comprises a laser diode claim 6 , wherein the 3D waveguide brings a multimode pump laser from the laser diode to a substrate.8. The device of claim 1 , comprising a pump laser launched into the 3D waveguide inside the substrate or launched using direct butt coupling.9. The device of claim 1 , wherein the 3D waveguide supports multitude of modes.10. The device of claim 1 , wherein pump laser is confined in the 3D waveguide.11. The device of claim 1 , comprising a ...

CLADDING LIGHT STRIPPER AND METHOD OF MANUFACTURING

A cladding stripper includes a plurality of transversal notches or grooves in the outer surface of an exposed inner cladding of a double clad optical fiber. Position and orientation of the notches can be selected to even out cladding light release along the cladding light stripper, enabling more even temperature distributions due to released cladding light. The notches on the optical fiber can be made with a laser ablation system. 1. A cladding light stripper comprising:a double-clad optical fiber having a core for guiding signal light, an inner cladding surrounding the core, and an outer cladding surrounding the inner cladding,wherein the optical fiber includes a stripped portion wherein the outer cladding is removed, forming an exposed section of an outer surface of the inner cladding, wherein the exposed section includes a plurality of transversal notches disposed along the fiber, to enable light to escape the inner cladding upon impinging on the notches, wherein each of the plurality of notches has a depth of only a partial distance to the fiber core.2. The cladding light stripper of claim 1 , wherein the core includes a dopant for amplifying the signal light when pumped by pump light guided by the inner cladding.3. The cladding light stripper of claim 1 , wherein the plurality of transversal notches has a pitch of from 1 notch/cm to 1000 notches/cm claim 1 , and wherein the plurality of notches includes at least 10 notches.4. The cladding light stripper of claim 1 , wherein the plurality of transversal notches has a pitch gradually varying along a length of the exposed section.5. The cladding light stripper of claim 4 , wherein the pitch varies between 2 notches/cm and 200 notches/cm.6. The cladding light stripper of claim 1 , wherein the depths of the notches are between 5% and 20% of the diameter of the inner cladding claim 1 , or wherein the depths of the notches are between 20 micrometers to 80 micrometers deep.7. The cladding stripper of claim 6 , wherein ...

OPTICAL FIBER FOR LIGHT AMPLIFICATION HAVING A CORE WITH LOW BEND LOSS AND END FEATURES WITH HIGH BEND LOSS AND RELATED METHOD

An apparatus includes an optical fiber configured to transport an optical signal. A cross-section of the optical fiber has a longer slow-axis dimension and a shorter fast-axis dimension. The optical fiber includes a core configured to receive and amplify the optical signal, end features optically coupled to the core at opposite ends of the core, and a cladding surrounding the core and end features. The core has a height in the slow-axis dimension and a width in the fast-axis dimension. Each end feature has a height in the slow-axis dimension and a width in the fast-axis dimension. The core has a lower bend loss than the end features. The optical fiber is configured to confine optical power of a fundamental mode in the core and allow optical power of higher-order mode(s) to leak from the core into the end features. Each end feature's height is less than the core's width. 1. An apparatus comprising: a core configured to receive and amplify the optical signal, the core having a height in the slow-axis dimension and a width in the fast-axis dimension;', 'end features optically coupled to the core at opposite ends of the core, each end feature having a height in the slow-axis dimension and a width in the fast -axis dimension, the core having a lower bend loss than the end features; and', 'a cladding surrounding the core and the end features;, 'an optical fiber configured to transport an optical signal, a cross-section of the optical fiber having a longer slow-axis dimension and a shorter fast-axis dimension, the optical fiber comprisingwherein the optical fiber is configured to confine optical power of a fundamental mode in the core and to allow optical power of one or more higher-order modes to leak from the core into the end features; andwherein the height of each end feature in the slow-axis dimension is less than the width of the core in the fast-axis dimension.2. The apparatus of claim 1 , wherein the optical fiber is bent to allow the optical power in the end ...

MONOMODE OPTICAL FIBER DESIGNED TO COMPENSATE FOR A REFRACTIVE INDEX VARIATION RELATED TO THERMAL EFFECTS AND LASER USING SUCH AN OPTICAL FIBER AS A GAIN MEDIUM

A monomode optical fiber, and a process for manufacturing such a fiber, that comprises a monomode core and at least one cladding encircling the core. The monomode core comprises at least two zones, a first zone with at least one first refractive index and a second zone with at least one second refractive index different from the first refractive index. The difference between the first refractive index and the second refractive index is of the same order of magnitude as the variation in the refractive index of the second zone between the inactive state and the active state of the fiber. 121-. (canceled)22. A single-mode optical fiber comprising , from a center to a periphery:a single-mode core;at least one layer of cladding surrounding said core having at least one cladding refractive index, 'the single-mode core comprising at least two zones, a first zone with at least a first refractive index and a second zone with at least a second refractive index that is different from the first refractive index, the difference between the first refractive index and the second refractive index being of a same order of magnitude as a variation in the second refractive index of the second zone caused by a thermal effect between the inactive state and the active state of the fiber.', 'the optical fiber being configured to occupy an inactive state in which the optical fiber is not subject to a thermal load and an active state in which the optical fiber is subject to a thermal load,'}23. The single-mode optical fiber as claimed in claim 22 , wherein the difference between the first refractive index and the second refractive index is smaller than 1×10−3 in the inactive state of the optical fiber.24. The single-mode optical fiber as claimed in claim 22 , wherein the first refractive index is lower than or equal to the cladding refractive index in the inactive state of the optical fiber.25. The single-mode optical fiber as claimed in claim 22 , wherein the second refractive index is ...

COMPACT, COHERENT, HIGH BRIGHTNESS LIGHT SOURCES FOR THE MID AND FAR IR

Compact high brightness light sources for the mid and far IR spectral region, and exemplary applications are disclosed based on passively mode locked Tm fiber comb lasers. In at least one embodiment the coherence of the comb sources is increased in a system utilizing an amplified single-frequency laser to pump the Tm fiber comb laser. The optical bandwidth generated by the passively mode locked Tm fiber comb laser is further decreased by using simultaneous 2and 3order dispersion compensation using either appropriate chirped fiber Bragg gratings for dispersion compensation, or fibers with appropriately selected values of 2and 3order dispersion. Fibers with large anomalous values of third order dispersion, or fibers with large numerical apertures, for example fibers having air-holes formed in the fiber cladding may be utilized. 2. The fiber-laser based system according to claim 1 , wherein said dispersion values approximately satisfy the relation:{'br': None, 'i': D', '/D', 'D', '/D, 'sub': 1', '1', '2', '2, '0.5<(23)/(23)<2.'}3. The fiber-laser based system according to claim 1 , wherein said dispersion values approximately satisfy the relation:{'br': None, 'i': D', '/D', 'D', '/D, 'sub': 1', '1', '2', '2, '0.7<(23)/(23)<1.3.'}4. The fiber-laser based system according to claim 1 , wherein said passively mode locked fiber oscillator operates in the wavelength range from about 1700 nm to about 2500 nm.5. The fiber-laser based system according to claim 1 , wherein said passively mode locked fiber oscillator comprises a Tm claim 1 , a Tm:Ho claim 1 , or a Ho doped fiber.6. The fiber-laser based system according to claim 1 , further comprising a continuum fiber for super continuum generation.7. The fiber-laser based system according to claim 6 , further comprising a fiber amplifier inserted between said oscillator and said continuum fiber.8. The fiber-laser based system according to claim 7 , wherein said fiber amplifier is capable of higher order soliton compression ...

RARE-EARTH DOPED GAIN FIBERS

Rare earth oxides doped multicomponent glass fibers for laser generation and amplification, including a core and a cladding, the core comprising at least 2 weight percent glass network modifier selected from BaO, CaO, MgO, ZnO, PbO, KO, NaO, LiO, YO, or combinations; wherein the mode of the core is guided with step index difference between the core and the cladding, a numerical aperture of the fiber is between 0.01 and 0.04; core diameter is from 25 to 120 micron, and a length of the gain fiber is shorter than 60 cm. 1. An Erbium doped multicomponent glass fiber for laser generation and amplification from 1.51 to 1.65 micron wavelength , comprising:a core;a cladding; [{'sub': 2', '2', '2', '2', '3, 'said core includes at least 2 weight percent glass network modifier selected from BaO, CaO, MgO, ZnO, PbO, KO, NaO, LiO, YO, or combinations thereof; and'}, 'erbium oxide at a level from about 0.5 to about 20 weight percent; wherein:', 'a mode of the core is guided via a step index difference between the core and the cladding;', 'a numerical aperture of the fiber is between 0.01 and 0.04;', 'a core diameter is from about 30 microns to about 90 microns;', 'a length of the fiber is shorter than 60 cm., 'wherein2. The Erbium doped multicomponent glass fiber of claim 1 , wherein said erbium oxide is present at a level from about 1 to about 5 weight percent.3. The Erbium doped multicomponent glass fiber of claim 1 , wherein the core diameter is from about 35 microns to about 60 microns.4. The Erbium doped multicomponent glass fiber of claim 1 , wherein the length of the fiber is from about 4 cm to about 45 cm.5. The Erbium doped multicomponent glass fiber of claim 1 , wherein the fiber is a polarization maintain fiber. This application is a divisional from U.S. patent application Ser. No. 14/605,740, now published as US 2016/0216441, from which it claims priority. The disclosure of application Ser. No. 14/605,740 is incorporated herein by reference.This invention relates to ...

ACTIVE ELEMENT ADDED-OPTICAL FIBER, PREFORM FOR ACTIVE ELEMENT ADDED-OPTICAL FIBER, RESONATOR, AND FIBER LASER DEVICE

An active element added-optical fiber includes a core, having a radius d and including a first region and a second region, and a cladding that surrounds an outer peripheral surface of the core without a gap and propagates light in a few mode. The first region is a region from a central axis of the core to a radius ra and contains ytterbium as an active element. The second region is a region to the radius d that surrounds the first region without a gap and contains a plurality of dopants, one of which is germanium. The active element is not added to a region within the second region from a radius rc to the radius d. The germanium is not added to a region within the first region from the central axis to a radius rb, and a concentration of the germanium is highest among the plurality of dopants. 118.-. (canceled)19. An active element added-optical fiber comprising:a core, having a radius d and including a first region and a second region, anda cladding that surrounds an outer peripheral surface of the core without a gap and propagates light in a few mode, whereinthe first region is a region from a central axis of the core to a radius ra and contains ytterbium as an active element that can be pumped by light,the second region is a region to the radius d that surrounds the first region without a gap and contains a plurality of dopants, one of which is germanium,the active element is not added to a region within the second region from a radius rc to the radius d,the germanium is not added to a region within the first region from the central axis to a radius rb, anda concentration of the germanium is highest among the plurality of dopants.20. The active element added-optical fiber according to claim 19 , whereinthe active element and the germanium are added to a first diffusion region from the radius rb to the radius rc,in the first diffusion region, a concentration of the active element decreases with increasing radius, and the concentration of the germanium increases ...

HIGH-POWER, SINGLE-MODE FIBER SOURCES

An optical apparatus includes one or more pump sources situated to provide laser pump light, and a gain fiber optically coupled to the one or more pump sources, the gain fiber including an actively doped core situated to produce an output beam, an inner cladding and outer cladding surrounding the doped core and situated to propagate pump light, and a polymer cladding surrounding the outer cladding and situated to guide a selected portion of the pump light coupled into the inner and outer claddings of the gain fiber. Methods of pumping a fiber sources include generating pump light from one or more pump sources, coupling the pump light into a glass inner cladding and a glass outer cladding of a gain fiber of the fiber source such that a portion of the pump light is guided by a polymer cladding surrounding the glass outer cladding, and generating a single-mode output beam from the gain fiber. 1. A method of pumping a high power fiber source , comprising:generating pump light at a pump wavelength from one or more pump sources;coupling the pump light into a glass inner cladding and a glass outer cladding of a gain fiber of the fiber source such that a portion of the pump light is guided by a polymer cladding surrounding the glass outer cladding; andgenerating a single-mode output beam from the gain fiber.2. The method of claim 1 , wherein 10% or more of the pump light is guided by the polymer cladding.3. The method of claim 1 , wherein the pump light has a wavelength between 910 nm and 920 nm.4. The method of claim 1 , wherein the length of the gain fiber is selected based on the coupling of the pump light into the glass inner and outer claddings so as to allow the power of the output beam to be 1 kW or greater and single-mode with out of band optical nonlinearities being generated that are 20% or less than the power of the output beam. This application is a continuation of U.S. patent application Ser. No. 15/810,506, filed Nov. 13, 2017, which is a continuation of U.S. ...

NONLINEAR ULTRAFAST FIBER AMPLIFIERS

Disclosed is a pulsed laser apparatus and method of generating a laser pulse. The apparatus includes an input coupler configured to receive pumping light from a pumping light source and a seed pulse from a seed pulse generator. The apparatus further includes a doped fiber-optic cable with an input port at a first end configured to receive the pumping light and the seed pulse. The doped fiber-optic cable amplifies the seed pulse to generate an output pulse. Along a first length of the doped fiber optic cable, the pulse spectrum broadens rapidly owing to nonlinearity. Beyond the first length in an extended portion, the output pulse shifts towards longer wavelengths and broadens in both spectral and temporal domains The apparatus also includes an output port at a second end of the doped fiber-optic cable, wherein the output pulse exits the doped fiber-optic cable at the output port. 1. A pulsed laser apparatus comprising:an input coupler configured to receive pumping light from a pumping light source and a seed pulse from a seed pulse generator; anda doped fiber-optic cable with an input port at a first end of the doped fiber-optic cable coupled to the input coupler and configured to receive the pumping light and the seed pulse, wherein the doped fiber-optic cable amplifies the seed pulse to generate an output pulse, wherein along a first length of the doped fiber-optic cable the pulse spectrum broadens due to a fiber nonlinearity in the doped fiber-optic cable, wherein in an extended portion of the doped fiber-optic cable beyond the first length the output pulse shifts in wavelength towards longer wavelengths and broadens in both spectral and temporal domains, and wherein the doped fiber-optic cable exhibits normal dispersion and includes an output port at a second end of the doped fiber-optic cable to export the output pulse.2. The pulsed laser apparatus of claim 1 , wherein the doped fiber-optic cable is doped with an active dopant comprising ytterbium (Yb) claim 1 ...

OPTICAL TUBE WAVEGUIDE LASING MEDIUM AND RELATED METHOD

Laser waveguides, methods and systems for forming a laser waveguide are provided. The waveguide includes an inner cladding layer surrounding a central axis and a glass core surrounding and located outside of the inner cladding layer. The glass core includes a laser-active material. The waveguide includes an outer cladding layer surrounding and located outside of the glass core. The inner cladding, outer cladding and/or core may surround a hollow central channel or bore and may be annular in shape. 1. A method of forming a laser waveguide comprising:delivering a first stream of glass soot particles from a soot generating device to a target rod such that a first layer of glass soot particles is formed surrounding the target rod;delivering a second stream of glass soot particles from the soot generating device toward the target rod after formation of the first layer of glass soot particles, wherein the second stream of glass soot particles forms a second layer of glass soot particles and includes a laser-active material;delivering a third stream of glass soot particles from the soot generating device toward the target rod after formation of the second layer of glass soot particles such that a third layer of glass soot particles is formed; andsintering the first, second and third layers of glass soot particles such that first, second and third sintered glass layers are formed from the first, second and third glass soot layers, respectively.2. The method of claim 1 , wherein sintering includes sintering the first layer of glass soot particles before formation of the second layer of glass soot particles.3. The method of claim 1 , wherein sintering includes sintering the second layer of glass soot particles before formation of the third layer of glass soot particles.4. The method of claim 1 , wherein the second layer of glass soot particles is formed surrounding the first layer of glass soot particles and the third layer of glass soot particles is formed surrounding the ...

ANTI-REFLECTION COATED PUMP DUMPS

A pump dump or cladding mode stripper is used to remove unwanted light from the cladding of an optical fiber. Conventional pump dumps include high-index polymer coatings and roughened cladding outer surfaces. Unfortunately, high-index polymer coatings absorb the stripped light, so they melt or burn at high optical powers, and roughening the cladding's outer surface makes the fiber too brittle for many applications. Fortunately, it is possible to frustrate total internal reflection at the interface between the cladding and air by texturing the cladding's outer surface with irregularly distributed, shaped, and size features that are less than a micron in size. These features don't absorb light and are too small to make the fiber brittle, yet they still cause incident pump light to exit the optical fiber. These qualities make them suitable for dumping high-power pump beams from the claddings of fiber amplifiers and fiber lasers. 1. An optical fiber comprising:a core to guide a first beam at a first wavelength;a cladding, disposed about the core, to guide a second beam at a second wavelength, the cladding having an outer surface,wherein a portion of the outer surface is textured with features smaller than the second wavelength to frustrate total internal reflection of the second beam at the outer surface of the cladding.2. The optical fiber of claim 1 , wherein the features are distributed randomly across the portion of the outer surface.3. The optical fiber of claim 1 , wherein the features have heights of between the second wavelength and half the second wavelength.4. The optical fiber of claim 1 , wherein the features cause the second beam to exit the cladding without reflecting at the portion of the outer surface of the cladding.5. A system comprising:a tubular absorber; and{'claim-ref': {'@idref': 'CLM-00001', 'claim 1'}, 'the optical fiber of disposed within the tubular absorber, the optical fiber having an outer diameter smaller than an inner diameter of the ...

MICROSTRUCTURED OPTICAL FIBER, SUPERCONTINUUM LIGHT SOURCE COMPRISING MICROSTRUCTURED OPTICAL FIBER AND USE OF SUCH LIGHT SOURCE

The invention relates to a microstructured optical fiber for generating supercontinuum light. The optical fiber comprises a core and a cladding region surrounding the core. The optical fiber comprises a first fiber length section, a second fiber length section as well as an intermediate fiber length section between said first and second fiber length sections. The first fiber length section has a core with a first characteristic core diameter larger than about 7 μm. The second fiber length section has a core with a second characteristic core diameter, smaller than said first characteristic core diameter. The intermediate length section of the optical fiber comprises a core which is tapered from said first characteristic core diameter to said second characteristic core diameter over a tapered length. The invention also relates to a supercontinuum light source comprising an optical fiber according to the invention and a pump light source. 143-. (canceled)44. A microstructured optical fiber for generating supercontinuum light upon feeding of light having a first wavelength λ , the optical fiber having a length and a longitudinal axis along its length and comprising a core region for guiding light along the length of said optical fiber , and a first cladding region surrounding said core region , wherein:said optical fiber, along its length, comprises a first fiber length section, a second fiber length section as well as an intermediate fiber length section between said first and second fiber length sections,{'sub': '1', 'said first fiber length section has a core region with a first characteristic core diameter Win a cross-section through the microstructured optical fiber perpendicularly to the longitudinal axis, wherein said first characteristic core diameter is larger than about 7 μm,'}{'sub': 2', '2', '1, 'said second fiber length section has a core region with a second characteristic core diameter Win a cross-section through the microstructured optical fiber ...

FIBER LASER SYSTEM BASED ON SOLITONIC PASSIVE MODE-LOCKING

A fiber laser system based in solitonic passive mode-locking, including a laser diode to emit and deliver an optical signal of a first wavelength; a single-fiber laser cavity including a dichroic mirror, a SESAM and a polarization maintaining highly-doped active fiber, to receive the emitted signal and to emit a pulsed optical signal of a second wavelength, generating laser light in the form of mode-locked ultrashort pulses; a unit coupling the laser diode to the single-fiber laser cavity; and an isolator device protecting the cavity from back reflections. The solitonic mode-locked ultrashort pulses are comprised in a range of 100 fs<10 ps with repetition rates of hundreds MHz to tens of GHz. 1. A fiber laser system comprising:a semiconductor laser diode configured to emit and deliver to a fiber laser cavity a continuous wave optical signal of a given first wavelength and power, wherein said wavelength and power are configured to optically pump a doped active fiber of the fiber laser cavity;wherein the fiber laser cavity is configured to receive the emitted continuous wave optical signal and to emit a pulsed optical signal of a given second wavelength generating laser light by the doped active fiber, the fiber laser cavity consisting of:the doped active fiber,a dichroic mirror located at a first end of the doped active fiber, anda semiconductor saturable absorber mirror (SESAM) located at a second end, opposite to the first end, of the doped active fiber,wherein said dichroic mirror and SESAM are configured to reflect resonantly the light generated by the doped active fiber, allowing the gain of the fiber laser cavity to be higher than the losses, to obtain laser emission in the fiber laser cavity, which is generated in the form of mode-locked ultrashort pulses; anda unit configured to couple the semiconductor laser diode to the fiber laser cavity separating the continuous wave optical signal of the semiconductor laser diode received by the unit from the light ...

FIBER LASER

The present disclosure discloses a fiber laser, including a laser seed source, an amplifying optical path, an output optical isolator and an optical fiber cylinder; wherein, the amplifying optical path is connected to the laser seed source and the output optical isolator, the laser seed source is used to output optical source, the amplifying optical path includes a first stage amplifying optical path and a second stage amplifying optical path, the first stage amplifying optical path is connected to the laser seed source and the second stage amplifying optical path respectively, the output optical source is output via the output optical isolator after two-stage amplifying; the second stage amplifying optical path comprises a multi-mode active optical fiber; the multi-mode active optical fiber is coiled on the optical fiber cylinder. By the disposing way above, the present disclosure may improve output optical beam quality of the fiber laser. 1. A fiber laser comprising a laser seed source , an amplifying optical path , an output optical isolator and an optical fiber cylinder , wherein ,the amplifying optical path is connected to the laser seed source and the output optical isolator, the laser seed source is used to output optical source, the amplifying optical path includes a first stage amplifying optical path and a second stage amplifying optical path, the first stage amplifying optical path is connected to the laser seed source and the second stage amplifying optical path respectively, the output optical source is output via the output optical isolator after two-stage amplifying;the second stage amplifying optical path comprises a multi-mode active optical fiber;the multi-mode active optical fiber is coiled on the optical fiber cylinder;wherein the fiber laser further comprises an upper casing and a lower casing,the laser seed source and the first stage amplifying optical path are fixed to the upper casing, the second stage amplifying optical path, the output ...

High Power Single Mode Fiber Laser System for Wavelengths Operating in 2 um Range

A high power fiber laser system is configured with a pump cascade and a laser cascade. The pump cascade includes a fiber amplifier provided with a MM core which is doped with ions of rare-earth element including either Er or Yb/Er. The MM core of fiber amplifier is configured with a double bottleneck-shaped cross section. The laser cascade has a fiber laser configured with a core which is doped with Tm ions. The pump light generated by the amplifier is coupled into the upstream end of the Tm laser. 1. A single mode (SM) high power fiber laser system comprising:a pump having at least one fiber amplifier radiating a pump light and provided with an active fiber with a multimode core which is doped with ions of rare-earth elements selected from the group consisting of Er and ytterbium/erbium; anda fiber laser having a core doped with Tm ions, the Tm fiber laser receiving the pump light and radiating a system output at a wavelength of about 2 micron.2. The fiber laser system of claim 1 , wherein the pump laser amplifier is configured with a double bottleneck-shaped cross-section including input and output end regions claim 1 , a central region between the end regions with a core diameter greater than that one of the end regions claim 1 , and two frustoconical regions each bridging the end and amplifying regions.3. The fiber laser system of claim 2 , wherein the pump laser amplifier further has a single mode input passive fiber and a multimode output fiber having respective ends spliced to respective ends of the active pump fiber.4. The fiber laser of claim 3 , wherein the opposite end regions of the active fiber of the pump amplifier are spliced to respective opposing ends of the input and output passive fibers claim 3 , the input fiber having a core with a diameter at least substantially equal to or smaller than the end region of the core of the active fiber opposing the input fiber claim 3 , and the output fiber having a core with a diameter equal to or larger than the ...

HOLLOW-CORE OPTICAL FIBERS

An anti-resonant hollow-core fiber comprising a first tubular, cladding element which defines an internal cladding surface, a plurality of second tubular elements which are attached to the cladding surface and together define a core with an effective radius, the second tubular elements being arranged in spaced relation and adjacent ones of the second tubular elements having a spacing therebetween, and a plurality of third tubular elements, each nested within a respective one of the second tubular elements. 1. An anti-resonant hollow-core fiber comprising a first tubular , cladding element which defines an internal cladding surface , a plurality of second tubular elements which are attached to the cladding surface and together define a core with an effective radius , the second tubular elements being arranged in spaced relation and adjacent ones of the second tubular elements having a spacing therebetween , and a plurality of third tubular elements , each nested within a respective one of the second tubular elements to provide nested tubular arrangements.2. The fiber of claim 1 , wherein the nested tubular arrangements are arranged in symmetrical relation at the cladding surface.3. The fiber of or claim 1 , wherein the first tubular element is circular in section.4. The fiber of any of to claim 1 , wherein the second tubular elements are circular in section.5. The fiber of any of to claim 1 , wherein the second tubular elements have a longer dimension in a radial direction than a tangential direction claim 1 , optionally elliptical or oval in section.6. The fiber of any of to claim 1 , wherein one or more of the tubular elements have different sectional shape.7. The fiber of any of to claim 1 , wherein the tubular elements are formed of glass claim 1 , optionally silica.8. The fiber of claim 7 , wherein the tubular elements are formed of glass having a refractive index of at least about 1.4 claim 7 , optionally about 1.4 to about 3 claim 7 , optionally about 1.4 to ...

OPTICAL MODE FILTER EMPLOYING RADIALLY ASYMMETRIC FIBER

Fiber amplifier and/or mode filter including a linearly birefringent LMA fiber coiled at a radius of curvature over a bend length to differentiate a fundamental optical mode from supported higher-order modes through bending losses. The LMA fiber may be a polarization-maintaining (PM) fiber having a variety of geometrical core shapes and cladding configurations. In some embodiments, the birefringent LMA fiber includes a radially asymmetric core that is angularly rotated over a length of the coiled fiber to ensure bending losses are experienced in orthogonally oriented higher-order modes associated with some orientation relative to the core orientation. In some embodiments, the fiber coiling is two-dimensional with bending occurring only about one axis. In some embodiments, an asymmetric core is pre-spun to a predetermined axial spin profile. In some embodiments, angular rotation of the core is achieved through mechanically twisting an un-spun fiber over a length of the coil. 1. A fiber amplifier , comprising:a light source to produce an optical beam; and the LMA fiber has a radially asymmetric core; and', 'the asymmetric core has an angular rotation about a fiber axis over a bend length having a radius of curvature about an axis of curvature, non-parallel to the fiber axis, to attenuate the higher-order modes more than the fundamental mode through bend losses., 'a linearly birefringent large mode area (LMA) fiber coupled to the light source to support a fundamental mode and higher-order modes of the optical beam, wherein2. The fiber amplifier of claim 1 , wherein:the axis of curvature is orthogonal to the fiber axis over the bend length; andthe angular rotation over the bend length has a predetermined spin profile providing a suppression of at least 10 dB/meter of bend length for all higher-order modes.3. The fiber amplifier of claim 2 , wherein the LMA fiber is coiled about the axis of curvature with a fixed radius of curvature over the bend length and a rate of the ...

MICROSTRUCTURED OPTICAL FIBER, SUPERCONTINUUM LIGHT SOURCE COMPRISING MICROSTRUCTURED OPTICAL FIBER AND USE OF SUCH LIGHT SOURCE

The invention relates to a microstructured optical fiber for generating incoherent supercontinuum light upon feeding of pump light. The microstructured optical fiber has a first section and a second section. A cross-section through the second section perpendicularly to a longitudinal axis of the fiber has a second relative size of microstructure elements and preferably a second pitch that is smaller than a blue edge pitch for the second relative size of microstructure elements. The invention also relates to an incoherent supercontinuum source comprising a microstructured optical fiber according to the invention. 159-. (canceled)61. A microstructured optical fiber according to claim 60 , wherein said second pitch Λis smaller than a blue edge pitch Λ claim 60 , where said blue edge pitch Λis defined as a specific pitch giving the shortest possible blue edge wavelength of the supercontinuum light for said second relative size d/Λof microstructure elements.62. A microstructured optical fiber according to claim 60 , wherein the relative size d/Λof microstructure elements in the first cross-section is about 0.75 or less.63. A microstructured optical fiber according to claim 60 , wherein said microstructured optical fiber in said second cross-section has a group velocity matched wavelength GVMWin the range from about 650 nm to about 800 nm.64. A microstructured optical fiber according to claim 60 , wherein the second relative size d/Λof the microstructure elements is about 0.75 or less.65. A microstructured optical fiber according to claim 60 , wherein the second pitch Λis about 0.9 times the blue edge pitch Λor smaller.662. A microstructured optical fiber according to claim 60 , wherein said first zero dispersion wavelength ZDWof said second cross-section is less than about 1000 nm claim 60 , such as less than about 900 nm.67. A microstructured optical fiber according to claim 66 , wherein the second pitch Λis smaller than the first pitch Λ.68. A microstructured optical ...

OPTICAL AMPLIFIER, OPTICAL AMPLIFYING SYSTEM, WAVELENGTH CONVERTER, AND OPTICAL COMMUNICATION SYSTEM

An optical amplifier includes: an optical amplifying fiber; and a pump light source that supplies pump light to the optical amplifying fiber, the pump light being used for parametrically amplifying signal light input to the optical amplifying fiber by using a non-linear optical effect of the optical amplifying fiber. The fluctuation of the zero-dispersion wavelength of the optical amplifying fiber in the longitudinal direction is within the limit of 0.5 nm/100 m. 1. An optical amplifier comprising:an optical amplifying fiber; anda pump light source that supplies pump light to the optical amplifying fiber, the pump light being used for parametrically amplifying signal light input to the optical amplifying fiber by using a non-linear optical effect of the optical amplifying fiber, whereina fluctuation of a zero-dispersion wavelength of the optical amplifying fiber in a longitudinal direction is within a limit of 0.5 nm/100 m.2. The optical amplifier according to claim 1 , wherein the optical amplifying fiber has a center core part;', 'an outer core layer which is formed in a surrounding of the center core part and of which a refractive index is lower than that of the center core part; and', 'at least one buffer core layer which is formed between the center core part and the outer core layer and of which a refractive index is lower than that of the center core part and is higher than that of the outer core layer, and, 'a core portion includinga cladding portion which is formed in a surrounding of the outer core layer and of which a refractive index is lower than that of the center core part and is higher than that of the outer core layer, andan effective core area at a wavelength of 1550 nm is 18 μm2 or smaller.3. The optical amplifier according to claim 2 , wherein the optical amplifying fiber is configured so that:the effective core area at the wavelength 1550 nm is in a range from 10.27 μm2 to 18 μm2 inclusive,a relative refractive-index difference of the center ...

FIBER STRETCHER MODULE FOR USE IN THE 1550 NM WAVELENGTH RANGE

Embodiments of the present invention are generally related to embodiments of the present invention relate to a fiber stretchers module for use in the 1550 nm wavelength range. In one embodiment of the present invention, a fiber stretcher module for use in the 1550 nm wavelength range comprises a fiber having a relative dispersion slope, RDS, and a relative dispersion curvature, RDC, wherein a ratio of said slope to said curvature is between about 30 nm and about 0 nm, having a dispersion value of less than about −10 ps/(nm·km) at about 1550 nm, and a RDS is equal to or greater than 0. 1. An optical fiber stretcher module for use in the 1550 nm wavelength range comprising:a fiber having a relative dispersion slope, RDS, and a relative dispersion curvature, RDC, wherein a ratio of said slope to said curvature is between about 30 nm and about 0 nm, having a dispersion value of less than about −10 ps/(nm·km) at about 1550 nm, and a RDS is equal to or greater than 0.2. The fiber stretcher module of claim 1 , wherein the RDS of the fiber in the 1550 nm range is between about 0.004 nmto about 0.03 nm.3. The optical fiber stretcher module of claim 1 , wherein the RDC of the fiber in the 1550 nm range is between about 0.0001 nmto about 0.002 nm.4. The optical fiber stretcher module of claim 1 , wherein the dispersion of the fiber in the 1550 nm range is between about −20 ps/(nm·km) to about −100 ps/(nm·km).5. The optical fiber stretcher module of claim 1 , further comprising:{'sup': '−1', 'a second fiber having a RDC of about zero, a RDS value greater than 0.002 nmand a dispersion value of greater than about 10 ps/(nm·km), at about 1550 nm.'}6. The optical fiber stretcher module of claim 5 , wherein the second fiber comprises a super large effective area fiber claim 5 , having a dispersion value of about 20 ps/(nm·km) and a relative dispersion slope of about 0.003 nm claim 5 , at about 1550 nm.7. The optical fiber stretcher module of claim 5 , wherein the optical fiber ...

FIBER LASER APPARATUS AND METHOD OF MANUFACTURING AMPLIFYING COIL

A fiber laser apparatus includes a pumping light source which launches pumping light, an amplifying optical fiber which includes a core and a noncircular cladding, and absorbs the pumping light to launch laser light, an amplifying coil which has a configuration around which the amplifying optical fiber is wound, a first reflector which is provided on an input side of the amplifying coil and is configured to reflect the laser light toward the amplifying coil, and a second reflector which is provided on a launching side of the amplifying coil, has a lower reflectance than a reflectance of the first reflector, and is configured to reflect the laser light toward the amplifying coil. 1. A fiber laser apparatus , comprising:a pumping light source which launches pumping light;an amplifying optical fiber which includes a core and a noncircular cladding, and absorbs the pumping light to launch laser light;an amplifying coil which has a configuration around which the amplifying optical fiber is wound;a first reflector which is provided on an input side of the amplifying coil and is configured to reflect the laser light toward the amplifying coil; anda second reflector which is provided on a launching side of the amplifying coil, has a lower reflectance than a reflectance of the first reflector, and is configured to reflect the laser light toward the amplifying coil;wherein in the amplifying coil, the amplifying optical fiber is wound with a center axis of the amplifying optical fiber as a center in a state of being twisted in a peripheral direction of the amplifying optical fiber, and the wound amplifying optical fiber is fixed and integrated.2. The fiber laser apparatus according to claim 1 ,wherein in the amplifying coil, a portion between adjacent amplifying optical fibers is filled with a resin.3. The fiber laser apparatus according to claim 1 , further comprising:a cooling member which cools the amplifying coil.4. The fiber laser apparatus according to claim 1 ,wherein a ...

A High-Efficiency Parallel-Beam Laser Optical Fibre Drawing Method and Optical Fibre

Provided are a high-efficiency parallel-beam laser optical fiber drawing method and optical fiber, the method including the steps of: S: providing base planes on the side surfaces of both a gain optical fiber preform and a pump optical fiber preform, inwardly processing the base plane of the gain optical fiber preform to make a plurality of ribs protrude, and inwardly providing a plurality of grooves on the base plane of the pump optical fiber preform; S: embedding the ribs into the grooves, tapering and fixing one end of the combination of the ribs and the grooves to form a parallel-beam laser optical fiber preform; S: drawing the parallel-beam laser optical fiber preform into parallel-beam laser optical fibers. The process has high repeatability, and the obtained parallel-beam laser achieves peelability of pump optical fibers in a set area, thus facilitating multi-point pump light injection of parallel-beam laser optical fibers. 1. A high-efficiency parallel-beam laser optical fibre drawing method , comprising the steps of:{'b': '1', 'S. respectively arranging a base plane at the side surfaces of both a gain optical fibre perform and a pump optical fibre perform; processing the base plane of the gain optical fibre perform inwards to make multiple ribs protrude, planes at both sides of each rib being machined surfaces; and arranging multiple grooves inwards on the base plane of the pump optical fibre perform, the ribs fitting the grooves;'}{'b': '2', 'S. inserting the ribs of the gain optical fibre perform into the grooves of the pump optical fibre perform; and after the two are combined, tapering and fixing one end of the whole to form a parallel-beam laser optical fibre perform; and'}{'b': '3', 'S. by drawing, making the parallel-beam laser optical fibre perform into a parallel-beam laser optical fibre.'}2. The high-efficiency parallel-beam laser optical fibre drawing method according to claim 1 , wherein the ribs are rectangular prisms; and a centre of a cross ...

HIGH-POWER, SINGLE-MODE FIBER SOURCES

An optical apparatus includes one or more pump sources situated to provide laser pump light, and a gain fiber optically coupled to the one or more pump sources, the gain fiber including an actively doped core situated to produce an output beam, an inner cladding and outer cladding surrounding the doped core and situated to propagate pump light, and a polymer cladding surrounding the outer cladding and situated to guide a selected portion of the pump light coupled into the inner and outer claddings of the gain fiber. Methods of pumping a fiber sources include generating pump light from one or more pump sources, coupling the pump light into a glass inner cladding and a glass outer cladding of a gain fiber of the fiber source such that a portion of the pump light is guided by a polymer cladding surrounding the glass outer cladding, and generating a single-mode output beam from the gain fiber. 1. An optical apparatus , comprising:one or more pump sources situated to provide laser pump light; anda gain fiber optically coupled to the one or more pump sources, the gain fiber including an actively doped core situated to produce an output beam, an inner cladding and outer cladding surrounding the doped core and situated to propagate pump light, and a polymer cladding surrounding the outer cladding and situated to guide a selected portion of the pump light coupled into the inner and outer claddings of the gain fiber.2. The apparatus of claim 1 , wherein the pump light coupled into the gain fiber has an NA larger than the NA of the inner cladding.3. The apparatus of claim 1 , wherein the pump light has a wavelength between 910 and 920 nm.4. The apparatus of claim 1 , wherein the core is a few-mode core.5. The apparatus of claim 1 , wherein the one or more pump sources are situated to couple at least 50 W or more of pump light into the gain fiber so as to be guided by the polymer cladding.6. The apparatus of claim 1 , further comprising a pump combiner situated to receive the ...

FIXED BULK COMPRESSOR FOR USE IN A CHIRPED PULSE AMPLIFICATION SYSTEM

A bulk compressor for use in a chirped pulse amplification system (CPA) comprising a tunable pulse stretcher and an amplifier is provided. The bulk compressor includes a mounting block formed as a monolithic structure and made of solid material. The mounting block may define a plurality of mounting surfaces each forming a collar surrounding a light passage. Optical components are mounted on the mounting block in a fixed mutual spatial relationship, each optical component having a front face having a peripheral portion mounted in direct contact with the collar formed by a respective one of the mounting surfaces. The bulk compressor may be provided as a stand-alone component, a part of a stretcher-compressor pair or a full CPA system, and may be used in a method for amplifying input optical pulses. 1. A chirped pulse amplification system for amplifying optical pulses , comprising:a pulse stretcher comprising an optical fiber provided with a Fiber Bragg grating (FBG) having a dispersion profile designed to stretch each of the optical pulses into stretched optical pulses, the pulse stretcher further comprising a tuning mechanism coupled to said FBG for tuning said dispersion profile;an amplifier receiving and amplifying the stretched optical pulses into amplified stretched optical pulses; anda bulk compressor provided downstream the amplifier for compressing the amplified stretched optical pulses into amplified compressed optical pulses, the bulk compressor comprising a mounting block made of solid material and defining a plurality of mounting surfaces, the bulk compressor further comprising a plurality of optical components performing said compressing and mounted on the mounting block in a fixed mutual spatial relationship, each of the optical components being rigidly affixed to a respective one of the mounting surfaces.2. The chirped pulse amplification system according to claim 1 , wherein the pulse stretcher comprises a circulator successively connecting an input ...

FEMTOSECOND LASER SOURCE

A femtosecond laser source includes an injection laser oscillator with an optical fiber doped with a given material, suitable for delivering, via an output optical fiber, a first picosecond pulse, at a first wavelength λ; a power amplifier with an amplifying optical fiber for producing, from the first pulse, a second pulse at the first wavelength, with an energy that is amplified relative to the first pulse, the amplifying optical fiber being doped with the same material as the optical fiber of the injection oscillator and having a length less than or equal to the distance from the point of soliton compression and greater than the distance from which the amplifying optical fiber operates in non-linear mode; a fiber with a frequency shift suitable for receiving the second pulse and generating, by Raman self-shifting, a fundamental soliton at a second wavelength λthat is strictly greater than the first wavelength λ. 1. A femtosecond laser source comprising:an injecting laser oscillator based on optical fiber doped with a given dopant, suitable for delivering, via an exit optical fiber, a first picosecond pulse, at a first wavelength Xi;a power amplifier based on amplifying optical fiber for producing, from the first pulse, a second pulse, at the first wavelength, with an energy that is amplified with respect to the first pulse, the amplifying optical fiber being doped with the same dopant as the optical fiber of the injecting oscillator, and having a length smaller than or equal to the distance of the soliton compression point and larger than the distance from which the amplifying optical fiber operates in non-linear regime; and{'sub': 2', '1, 'a frequency-shifting fiber suitable for receiving the second pulse and generating by Raman self-shifting a fundamental soliton at a second wavelength λstrictly longer than the first wavelength λ.'}2. The femtosecond laser source as claimed in claim 1 , wherein the amplifying optical fiber has a modal area larger than or equal ...

Spun Non-circular and Non-elliptical Core Optical Fibers and Apparatuses Utilizing the Same

Optical fibers are provided for modal discrimination which include a central core and a cladding disposed about the central core. The central core has a non-circular and non-elliptical cross-section, and it is rotated about a central axis of the optical fiber along the length of the optical fiber at a selected pitch resulting in the capability of a fundamental mode beam output for large core sizes. An optical system includes a seed optical source configured to provide a seed beam and an optical amplifier configured to receive and amplify the seed beam. The optical amplifier also includes an active optical fiber having a large mode area non-circular and non-elliptical core rotated about a central axis of said active optical fiber to provide modal discrimination and fundamental mode output.

YB: AND ND: MODE-LOCKED OSCILLATORS AND FIBER SYSTEMS INCORPORATED IN SOLID-STATE SHORT PULSE LASER SYSTEMS

The invention describes classes of robust fiber laser systems usable as pulse sources for Nd: or Yb: based regenerative amplifiers intended for industrial settings. The invention modifies adapts and incorporates several recent advances in FCPA systems to use as the input source for this new class of regenerative amplifier. 1. A pulse source , comprising:a seed source emitting seed pulses, said seed source generating pulses at a repetition rate and comprising a polarization maintaining gain fiber;at least one polarization maintaining fiber amplifier disposed downstream from said seed source;one or more pump laser diodes for pumping said seed source and said at least one fiber amplifier;a bulk optical amplifier receiving amplified pulses from said at least one amplifier and producing output pulses;an electro-optic or acousto-optic modulator configured as a down counter to reduce a repetition rate of pulses generated by said seed source, said modulator disposed between said seed source and said bulk optical amplifier.2. The pulse source according to claim 1 , wherein said seed source comprises a Yb: mode locked oscillator claim 1 , wherein said polarization maintaining gain fiber is Yb: doped fiber operating in a positive dispersion regime claim 1 , and wherein the cavity of said Yb: mode locked oscillator is configured without negative dispersion cavity components.3. The pulse source according to claim 1 , wherein a gain medium of said bulk optical amplifier comprises Yb:YAG crystal material.4. The pulse source according to claim 1 , wherein a gain medium of said bulk amplifier comprises Nd:YAG claim 1 , Nd:YLF claim 1 , Nd:YVO. claim 1 , Nd:glass claim 1 , Yb claim 1 , glass claim 1 , Nd:KGW claim 1 , or a narrow bandwidth Nd-based crystal.5. The pulse source according to claim 1 , wherein said bulk amplifier comprises a regenerative amplifier claim 1 , a rod claim 1 , slab claim 1 , or thin disk claim 1 ,6. The pulse source according to claim 1 , wherein said ...

HIGH-POWER FIBER LASER EMPLOYING NONLINEAR WAVE MIXING WITH HIGHER-ORDER MODES

A high-power fiber laser exploits efficiency and wavelength-conversion of nonlinear wave mixing in a higher-order mode (HOM) fiber providing large effective area and higher-power operation than single-order mode (SMF) fiber. In a “monomode” approach, mixing waves (pump(s), signal, idler) propagate in the same higher-order mode, and in an “intermodal” approach different waves propagate in different modes. The monomode approach can provide high-power wavelength conversion generating output in a desired band where good dopants may be unavailable. The intermodal approach demonstrates coherent combining of outputs of multiple lasers to generate high-power output in a desired band. 1. A fiber laser , comprising:a higher-order-mode (HOM) fiber, the HOM fiber supporting a plurality of guided modes of propagation including higher-order modes, the HOM fiber having a predetermined mode-dependent dispersion characteristic defining a zero-dispersion wavelength for a first higher-order mode, the zero-dispersion wavelength defining a set of respective higher-order modes, wavelengths and phases of constituent optical signals of a predetermined pattern of nonlinear wave mixing in which at least one of the constituent optical signals propagates in the first higher-order mode,an optical signal source having an output coupled to an input point of the HOM fiber and operative to launch a first optical signal into the HOM fiber, the first optical signal being a first one of the constituent optical signals and producing the predetermined pattern of nonlinear wave mixing in the HOM fiber; andan output optical element coupled to an output point of the HOM fiber, the output optical element operative to extract a second optical signal from the HOM fiber, the second optical signal being a second one of the constituent optical signals and produced by the pattern of nonlinear wave mixing, the second optical signal propagating in a second higher-order mode of the set of modes defined by the zero- ...

SUPERCONTINUUM LIGHT SOURCE COMPRISING MICROSTRUCTURED OPTICAL FIBER

The invention relates to a microstructured optical fiber for generating supercontinuum light upon feeding of pump light. The light can be incoherent light. The microstructured optical fiber has a first section and a second section, where the first and second sections have one or more different features. The invention also relates to a supercontinuum source comprising a microstructured optical fiber according to the invention. 159.-. (canceled)61. The microstructured optical fiber according to claim 60 , wherein said second pitch Λis smaller than a blue edge pitch Λ claim 60 , where said blue edge pitch Λ claim 60 , is defined as a specific pitch giving the shortest possible blue edge wavelength of the supercontinuum light for said second relative size d/Λof microstructure elements.62. The microstructured optical fiber according to claim 60 , wherein the relative size d/Λof microstructure elements in the first cross-section is about 0.75 or less.63. The microstructured optical fiber according to claim 60 , wherein said microstructured optical fiber in said second cross-section has a group velocity matched wavelength GVMWin the range from about 650 nm to about 800 nm.64. The microstructured optical fiber according to claim 60 , wherein the second relative size d/Λof the microstructure elements is about 0.75 or less.65. The microstructured optical fiber according to claim 60 , wherein the second pitch Λis about 0.9 times the blue edge pitch Λor smaller.66. The microstructured optical fiber according to claim 60 , wherein said first zero dispersion wavelength ZDW2of said second cross-section is less than about 1000 nm.67. The microstructured optical fiber according to claim 66 , wherein the second pitch Λis smaller than the first pitch Λ.68. The microstructured optical fiber according to claim 66 , where said second pitch Λis in the range from about 1.1 μm to about 1.7 μm.69. The microstructured optical fiber according to claim 60 , wherein the microstructured optical ...

MODE-LOCKED FIBER LASER DEVICE

A mode-locked fiber laser device is provided in the disclosure. The mode-locked fiber laser device includes a non-linear loop mirror, an optical splitter and a uni-directional loop. The uni-directional loop includes a polarization beam splitter and a Faraday rotator. The uni-directional loop is coupled to the non-linear loop mirror by the optical splitter to form a figure-8 optical path. A first output laser pulse output by the optical splitter is propagated to the polarization beam splitter. After being rotated 45 degrees by a Faraday rotator, the first output laser pulse is propagated back to the non-linear loop mirror to form a laser resonator. A second output laser pulse output by the optical splitter is propagated to the Faraday rotator to rotate the second output laser pulse 45 degrees, and the polarization beam splitter reflects the second output laser pulse to the outside of the mode-locked fiber laser device. 1. A mode-locked fiber laser device , comprising:a non-linear loop mirror;an optical splitter; anda uni-directional loop, comprising a polarization beam splitter and a Faraday rotator, wherein the uni-directional loop is coupled to the non-linear loop mirror through the optical splitter to form a figure-8 optical path,wherein a first output laser pulse output by a first port of the optical splitter is propagated to the polarization beam splitter first, and after the Faraday rotator rotates the first output laser pulse 45 degrees, the first output laser pulse is propagated back to the non-linear loop mirror to form a laser resonator, andwherein a second output laser pulse output by a second port of the optical splitter is propagated to the Faraday rotator first to rotate the second output laser pulse 45 degrees, and the polarization beam splitter reflects the second output laser pulse to the outside of the mode-locked fiber laser device.2. The mode-locked fiber laser device of claim 1 , wherein the non-linear loop mirror comprises a non-reciprocal ...

GIANT-CHIRP OSCILLATOR

A laser apparatus operable to generate giant chirp pulses. The pulses have a centre frequency comprising an arrangement of components connected or connectable to form a closed ring cavity. The components comprise a first gain medium, an optical isolator, a length of single mode fibre, a mode locking device, an output coupler, and an optical filter. Each of the components are optical fibre based components. 132-. (canceled)33. A laser apparatus operable to generate giant chirp pulses having a centre frequency , comprising an arrangement of components connected , or connectable to form a cavity , the components comprising a first gain medium , an optical isolator , a length of single mode fibre , a passive mode locking device , an output coupler , and an optical filter , wherein each of the components are optical fibre based components.34. A laser as claimed in claim 33 , wherein the optical fibre components are polarisation maintaining components.35. A laser as claimed in claim 33 , wherein the components have claim 33 , or substantially have claim 33 , a normal dispersion relative to the centre frequency.36. A laser as claimed in claim 33 , wherein the components have a net normal dispersion relative to the centre frequency.37. A laser as claimed in claim 33 , wherein the mode locking device is a nonlinear amplified loop mirror comprising at least an optical coupler operable to provide and input and an output claim 33 , and a second gain medium operable to provide energy to a propagating pulse.38. A laser as claimed in claim 33 , wherein the mode locking device is operable to mode lock the laser by varying the energy of the light from the second pump source.39. A laser as claimed in claim 33 , wherein the length of single mode fibre is operable in the cavity to receive light from the first gain medium and output light to the second gain medium.40. A laser as claimed in claim 33 , wherein the length of single mode fibre is operable to impart broadening to a pulse ...

High power parallel fiber arrays

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.

FIBER WITH DEPRESSED CENTRAL INDEX FOR INCREASED BEAM PARAMETER PRODUCT

A method includes generating a multimode laser beam having an initial beam parameter product (bpp) and directing the multimode laser beam to an input end of a fiber so as to produce an output beam at an output of the fiber with a final bpp that is greater than the initial bpp. Another method includes measuring a base bpp associated with a multimode laser beam generated from a laser source and emitted from an output fiber output end, determining a bpp increase for the multimode laser beam, and selecting a bpp increasing optical fiber having an input end and an output end so that the multimode laser beam with the base bpp coupled to the input end has an output bpp at the output end of the bpp increasing optical fiber corresponding to the determined bpp increase. 1. A method , comprising:generating a multimode laser beam having an initial beam parameter product; anddirecting the multimode laser beam to an input end of a beam parameter product (bpp) increasing fiber so as to produce an output beam at an output of the bpp increasing fiber with a final beam parameter product that is greater than the initial beam parameter product based on a selected refractive index profile of the bpp increasing fiber.2. The method of claim 1 , wherein the initial beam parameter product is increased to the final beam parameter product to within ±5% of a selected final beam parameter product value.3. The method of claim 1 , wherein a coupling loss of the multimode laser beam associated with the bpp increasing fiber is less than about 1%.4. The method of claim 3 , wherein the coupling loss is less than about 0.2%.5. The method of claim 1 , wherein the refractive index profile of the bpp increasing fiber includes a refractive index in a central region of a fiber core that is lower than a refractive index in an outer region of the fiber core.6. The method of claim 1 , wherein the near-field transverse intensity of the output beam is lower in a central region of the bpp increasing fiber ...

METHOD AND APPARATUS FOR ENSURING A UNIFORM TEMPERATURE PROFILE IN RIBBON FIBER LASERS AND AMPLIFIERS

A uniform temperature profile is provided across the width of the core of a ribbon fiber laser or amplifier by the use of insulating elements at the core edges and a spatially variable gain in the fiber core. High average power ribbon fibers, enable a variety of applications such as practical laser cutting and beam combining. 1. A ribbon fiber , comprising:a core including a rare earth dopant and having a length and further including an aspect ratio that is orthogonal to said length, wherein said aspect ratio comprises a long aspect that is orthogonal to a relatively shorter aspect, wherein the concentration of said rare earth dopant varies across said long aspect, wherein said long aspect spans a first edge of said core and a second edge of said core;means for guiding light within said core; andone or more heat insulating elements configured for flattening the thermal profile of said core.2. The ribbon fiber of claim 1 , wherein said one or more heat insulating elements are configured for flattening said thermal profile of said core along said long aspect while said light is guided within said core.3. The ribbon fiber of claim 1 , wherein said one or more heat insulating elements comprises at least a first heat insulating element or a second heat insulating element claim 1 , wherein said first heat insulating element is configured to reduce the amount of heat that can escape from said first edge and wherein said second heat insulating element is configured to reduce the amount of heat that can escape from said second edge.4. The ribbon fiber of claim 3 , wherein said first heat insulating element is not in direct contact with said second heat insulating element.5. The ribbon fiber of claim 3 , wherein said shorter aspect comprises a first side and a second side claim 3 , wherein said first heat insulating element is configured to reduce the amount of heat that can escape from a portion of at least one of said first side and said second side.6. The ribbon fiber of ...

Optical Resonator, Method of Manufacturing the Optical Resonator and Applications Thereof

An optical resonator () comprises an optical waveguide device () having an optical axis (OA) and extending with a longitudinal length between two waveguide end facets (), resonator mirrors () being arranged for enclosing a resonator section () of the optical waveguide device (), and a ferrule () having two ferrule facets (), wherein the optical waveguide device () is mounted to the ferrule () and the ferrule () extends along the full longitudinal length of optical waveguide device (). Furthermore, an optical apparatus () including the optical resonator () and a method of manufacturing the optical resonator () are described. 131-. (canceled)32. Optical resonator , comprisingan optical waveguide device having an optical axis (OA) and extending with a longitudinal length between two waveguide end facets;resonator mirrors including dielectric mirrors each having a stack of dielectric layers and being arranged on the waveguide end facets for enclosing a resonator section of the optical waveguide device; anda ferrule having two ferrule facets, wherein the optical waveguide device is mounted to the ferrule, whereinthe ferrule extends along the full longitudinal length of optical waveguide device,the resonator mirrors provide a passive optical cavity,one of the resonator mirrors has a reflectivity of at least 99.9% and the other resonator mirror has a reflectivity of at least 99%.33. Optical resonator according to claim 32 , whereinthe optical resonator is adapted for light coupling via a direct contact of the ends of the optical waveguide device including the resonator mirrors with adjacent waveguides.34. Optical resonator according claim 32 , whereinthe waveguide end facets are aligned with the ferrule facets.35. Optical resonator according to claim 32 , whereinthe waveguide end facets and the resonator mirrors project beyond the ferrule facets.36. Optical resonator according to claim 34 , whereinthe resonator mirrors at least partially cover the ferrule facets.37. ...

INTERMODE LOSS DIFFERENCE COMPENSATION FIBER, OPTICAL AMPLIFIER, AND TRANSMISSION PATH DESIGN METHOD

Provided is a differential modal attenuation compensation fiber that has a simple structure and can reduce MDL while eliminating the need for precise alignment work, an optical amplifier, and a transmission line design method. The differential modal attenuation compensation fiber according to the present invention, imparts excess loss to a desired propagation mode by forming a cavity portion or a ring-shaped high refractive index portion in a core of an optical fiber. By forming the cavity portion or the ring-shaped high refractive index portion in a part of the profile of the core, electric field distribution of a particular mode propagating through the fiber can be controlled, and different losses can be imparted to different propagation modes at an interface between the cavity portion or the ring-shaped high refractive index portion and a region not including the cavity portion or the ring-shaped high refractive index portion. 1. A differential modal attenuation compensation fiber inserted into an optical fiber having a propagation mode count of N (N is an integer of 2 or more) , the differential modal attenuation compensation fiber comprising:a cladding portion; anda core portion, the core portion having a radius a1, and a specific refractive index difference between the cladding portion and the core portion being Δ1, andfurther including a first section and a second section along a propagation direction of light, wherein:in the first section, part of a region of the core portion in a cross-section is formed with a cavity portion having a radius a2 (a2 Подробнее

SYSTEMS, APPARATUS, AND METHODS FOR PRODUCING ULTRA STABLE, SINGLE-FREQUENCY, SINGLE-TRANSVERSE-MODE COHERENT LIGHT IN SOLID-STATE LASERS

A laser system and method generate milliwatt-power pump light by a fiber-coupled laser diode with a single-mode integrated fiber housed in a pump enclosure. The milliwatt-power pump light is conveyed from the single-mode integrated fiber out of the first enclosure into one end of a single-mode fiber cable that is external to the pump enclosure. The milliwatt-power pump light is conveyed from an opposite end of the external single-mode fiber cable into one end of a single-mode resident fiber disposed internally within a laser-head enclosure. A crystal housed in the laser-head enclosure is pumped with the milliwatt-power pump light that exits into free space from an opposite end of the single-mode resident fiber onto a face of the crystal, to produce stable milliwatt-power single-mode laser light having a frequency stability of less than 3 MHz per minute. The stable milliwatt-power single-mode laser light is emitted from the laser-head enclosure. 1. A laser system comprising:a modular pump enclosure housing a fiber-coupled laser diode with an integrated fiber, the fiber-coupled laser diode with the integrated fiber, when operated, producing and conveying pump light to a fiber optic connector in a wall of the pump enclosure, the fiber optic connector coupling the integrated fiber to a first end of an external fiber optic cable;a modular laser-head enclosure having a wall with a fiber optic connector, the fiber optic connector of the laser-head enclosure being connected to a second end of the external fiber optic cable, the external fiber optic cable delivering the pump light produced by the pump enclosure to the laser-head enclosure, the laser-head enclosure housing a resident fiber and a crystal, an input end of the resident fiber being connected to the fiber optic connector in the wall of the laser-head enclosure to receive the pump light from the external fiber optic cable, an output end of the resident fiber being fixedly coupled to the laser-head enclosure such ...

Suppression of stimulated brillouin scattering in higher-order- mode optical fiber amplifiers

An HOM-based optical fiber amplifier is selectively doped within its core region to minimize the presence of dopants in those portions of the core where the unwanted lower-order modes (particularly, the fundamental mode) of the signal reside. The reduction (elimination) of the gain medium from these portions of the core minimizes (perhaps to the point of elimination) limits the amount of amplification impressed upon the backward-propagating Stokes wave. This minimization of amplification will, in turn, lead to a reduction in the growth of the Stokes power that is generated by the Brillouin gain, which results in increasing the amount of power present in the desired, forward-propagating HOM amplified optical signal output.

Femtosecond mode-locked laser with reduced radiation and temperature sensitivity

In an example, a mode-locked laser includes a resonator cavity having a saturable absorber, a hollow core fiber coupled to the saturable absorber, and an optical amplifier optically coupled between the hollow core fiber and an output coupler. The mode-locked laser further includes a first pump laser and a wavelength division multiplexer coupled to the first pump laser. The wavelength division multiplexer is configured to couple light from the first pump laser into the resonator cavity to pump the optical amplifier. The mode-locked laser is configured to generate a pulse waveform at a repetition rate of approximately 100 MHz to 200 MHz.

Radiation-balanced fiber laser

An apparatus and method for cooling an optical fiber, comprising impinging electromagnetic radiation from a laser on an optical fiber comprising a core, in which the electromagnetic radiation is substantially confined, and a cladding, in thermal communication with the core, configured to provide optically activated cooling of the core via the electromagnetic radiation from the laser.

OPTICAL AMPLIFIER, OPTICAL TRANSMISSION SYSTEM, AND OPTICAL CABLE FAILURE PART MEASUREMENT METHOD

[Problem] To easily measure and detect a failure part of a long-distance optical cable by low-cost equipment in a configuration in which an isolator is disposed in the vicinity of an optical amplifier in order to improve and stabilize optical transmission performance. [Solution] An optical amplifier is configured to be provided with a multiplexing/demultiplexing means as first WDM filters on both sides of a set of an isolator and an EDF of a submarine cable , the first WDM filters multiplexing/demultiplexing OTDR light (measurement light) for measuring a submarine cable failure sent to the submarine cable in opposite directions from the sides of a sending device and a receiving device, and main signal light , transmitting the multiplexed/demultiplexed main signal light to a main path that passes through the isolator and the EDF , and transmitting the multiplexed/demultiplexed OTDR light to a bypass path that bypasses the isolator and the EDF 1. An optical amplifier interposed in an optical cable between a transmission device and a reception device that transmit and receive main signal light and including an isolator configured to pass the main signal light transmitted from the transmission device only in one direction toward the reception device , and an erbium-doped fiber (EDF) configured to amplify the main signal light in response to excitation light , the optical amplifier comprising:a multiplexing/demultiplexing unit on both sides of a set of the isolator and the EDF in the optical cable, the multiplexing/demultiplexing unit multiplexing/demultiplexing the main signal light and measurement light for optical cable fault measurement transmitted from at least one of a front side as a transmission device side and a rear side as a reception device side to the optical cable, transmitting the multiplexed/demultiplexed main signal light to a main path passing through the isolator and the EDF, and transmitting the multiplexed/demultiplexed measurement light to a bypass ...

Fiber delivery of short laser pulses

A method and system for delivering laser pulses achieves the delivery of high quality laser pulses at the location of an application. The method includes the steps of: generating laser pulses, amplifying the laser pulses, temporally stretching the amplified laser pulses, and propagating the amplified laser pulses through an optical delivery fiber of desired length, wherein the laser pulses are temporally compressed in the optical delivery fiber and wherein the laser pulses undergo nonlinear spectral broadening in the optical delivery fiber.

SYSTEMS, APPARATUS, AND METHODS FOR PRODUCING ULTRA STABLE, SINGLE-FREQUENCY, SINGLE-TRANSVERSE-MODE COHERENT LIGHT IN SOLID-STATE LASERS

A laser system has a fiber cable, a pump enclosure connected to the fiber cable outside of the pump enclosure, and a laser-head enclosure connected to the fiber cable disposed outside of the laser-head enclosure. The pump enclosure houses a fiber-coupled laser diode configured to produce and convey pump light through the pump enclosure out to the fiber cable. The laser-head enclosure houses a crystal. The pump light, when produced by the laser diode, propagates out from the pump enclosure through the fiber cable into the laser-head enclosure and into the crystal. The crystal produces a laser beam in response to the pump light. The integrated fiber of the laser diode, the fiber cable, and internal fiber of the laser-head enclosure, through which the pump light propagates, may be single-mode fibers, to achieve superior laser system performance with lower frequency and intensity noise than pumping through multimode fibers. 1. A laser system comprising:a fiber optic cable;a pump enclosure connected to a first end of the fiber optic cable disposed outside of the pump enclosure, the pump enclosure housing a fiber-coupled laser diode configured to produce and convey pump light through the pump enclosure out to the fiber optic cable; anda laser-head enclosure connected to an opposite end of the fiber optic cable disposed outside of the laser-head enclosure, the laser-head enclosure housing a crystal, the pump light, when produced by the fiber-coupled laser diode, propagating out from the pump enclosure through the fiber optic cable into the laser-head enclosure and into the crystal, the crystal being adapted to produce a laser beam in response to the pump light.2. The laser system of claim 1 , wherein the fiber-coupled laser-diode and fiber optic cable comprise single-mode fibers.3. A laser-head module comprising: a laser-crystal assembly with a crystal;', 'a resident fiber having an input end and an output end, the input end of the resident fiber being coupled to the fiber ...

COMPACT FIBER SHORT PULSE LASER SOURCES

Examples of robust self-starting passively mode locked fiber oscillators are described. In certain implementations, the oscillators are configured as Fabry-Perot cavities containing an optical loop mirror on one cavity end and a bulk mirror or saturable absorber on the other end. The loop mirror can be further configured with an adjustable line phase delay to optimize modelocking. All intra-cavity fiber(s) can be polarization maintaining. Dispersion compensation components such as, e.g., dispersion compensation fibers, bulk diffraction gratings or fiber Bragg gratings may be included. The oscillators may include a bandpass filter to obtain high pulse energies when operating in the similariton regime. The oscillator output can be amplified and used whenever high power short pulses are required. For example the oscillators can be configured as frequency comb sources or supercontinuum sources. In conjunction with repetition rate modulation, applications include dual scanning delay lines and trace gas detection. 1. A passively mode locked fiber oscillator evolving from Q-switching , comprising: 'a nonlinear fiber amplifying loop mirror (NALM) at a first cavity end, said nonlinear loop mirror configured to allow the insertion of a linear phase delay along two propagation directions of said nonlinear loop mirror,', 'a Fabry-Perot cavity comprisingwherein said passively mode locked fiber oscillator comprises polarization maintaining (PM) fiber.2. The passively mode locked fiber oscillator according to claim 1 , wherein mode locking of said oscillator evolves via suppression of Q-switching.3. The passively mode locked fiber oscillator according to claim 1 , wherein said loop mirror comprises:an orthogonal splice configured to induce said phase delay, anda temperature control device configured to control the temperature of a section of intra-loop fiber.4. The passively mode locked fiber oscillator according to claim 3 , further comprising:a mirror, a saturable absorber, or a ...

OPTICAL FIBER AND FIBER LASER DEVICE USING SAME

An optical fiber propagates a light beam at a predetermined wavelength at least in an LP mode and an LP mode. In regions and in which the intensity of a light beam in the LP mode is greater than the intensity of a light beam in the LP mode, at least a part of a Young's modulus in the region on the circumferential side of the region in the core in which the intensity of the light beam in the LP mode is greater than the intensity of the light beam in the LP mode is smaller than a Young's modulus in the region in which the intensity of the light beam in the LP mode is greater than the intensity of the light beam in the LP mode. 1. An optical fiber comprising:{'b': 01', '02, 'a core and a cladding that encloses the core, the optical fiber being configured to propagate a light beam at a predetermined wavelength at least in an LP mode and an LP mode,'}{'b': 02', '01', '01', '02', '01', '02, "wherein in a region in which an intensity of the light beam in the LP mode is greater than an intensity of the light beam in the LP mode, at least a part of a Young's modulus in a region on a circumferential side of a region in the core in which the intensity of the light beam in the LP mode is greater than the intensity of the light beam in the LP mode is smaller than a Young's modulus in the region in which the intensity of the light beam in the LP mode is greater than the intensity of the light beam in the LP mode."}2020101020102. The optical fiber according to claim 1 , wherein in the region in which the intensity of the light beam in the LP mode is greater than the intensity of the light beam in the LP mode claim 1 , a Young's modulus in an entire region on the circumferential side of the region in the core in which the intensity of the light beam in the LP mode is greater than the intensity of the light beam in the LP mode is smaller than a Young's modulus in the region in which the intensity of the light beam in the LP mode is greater than the intensity of the light beam in the ...

OPTICAL FIBER FOR LIGHT AMPLIFICATION HAVING A CORE WITH LOW BEND LOSS AND END FEATURES WITH HIGH BEND LOSS AND RELATED METHOD

An apparatus includes an optical fiber configured to transport an optical signal. The optical fiber includes a core configured to receive and amplify the optical signal. The optical fiber also includes end features optically coupled to opposite ends of the core. The core has a lower bend loss than the end features. The optical fiber further includes a cladding surrounding the core and the end features. The optical fiber is configured to confine optical power of a fundamental mode in the core. The optical fiber is also configured to allow optical power of one or more higher-order modes to leak from the core into the end features. 1. An apparatus comprising: a core configured to receive and amplify the optical signal;', 'end features optically coupled to the core at opposite ends of the core, wherein the core has a lower bend loss than the end features; and', 'a cladding surrounding the core and the end features;, 'an optical fiber configured to transport an optical signal, the optical fiber comprisingwherein the optical fiber is configured to confine optical power of a fundamental mode in the core; andwherein the optical fiber is also configured to allow optical power of one or more higher-order modes to leak from the core into the end features.2. The apparatus of claim 1 , wherein the optical fiber is configured to allow the optical power in the end features to leak from the end features into the cladding.3. The apparatus of claim 2 , wherein the optical fiber is bent to allow the optical power in the end features to leak from the end features into the cladding.4. The apparatus of claim 3 , wherein a bend radius of the optical fiber is selected in order to strip the optical power in the end features while allowing the optical fiber to guide the optical power of the fundamental mode in the core.5. The apparatus of claim 1 , wherein a refractive index offset between material in the core and material in the end features is selected to prevent a direct resonance between ...

ALL-FIBER CHIRPED PULSE AMPLIFICATION SYSTEMS

By compensating polarization mode-dispersion as well chromatic dispersion in photonic crystal fiber pulse compressors, high pulse energies can be obtained from all-fiber chirped pulse amplification systems. By inducing third-order dispersion in fiber amplifiers via self-phase modulation, the third-order chromatic dispersion from bulk grating pulse compressors can be compensated and the pulse quality of hybrid fiber/bulk chirped pulse amplification systems can be improved. Finally, by amplifying positively chirped pulses in negative dispersion fiber amplifiers, a low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained. 1. A method for the generation of high quality pulses from a fiber chirped pulse amplification system in the presence of self-phase modulation in the fiber amplifier , comprising:selecting stretched pulses with an input pulse spectrum into the fiber amplifier such that one or a combination of substantial gain-pulling and gain-narrowing occurs in said amplifier, said gain-pulling manifesting itself in a substantial spectral shift of the average optical frequency of the pulse spectrum, said gain-narrowing manifesting itself in the generation of an amplified pulse spectrum with a spectral width not greater than the input pulse spectrum, wherein the quality of the compressed pulses improves in the presence of self-phase modulation.2. A method for improving the output pulse quality in high power waveguide chirped pulse amplification systems , comprising:setting a pulse energy to cause 0.3-10π level of self-phase modulation in said waveguide chirped pulse amplification system, wherein said pulse energy and self-phase modulation produce improved pulse quality characterizable by at least one of: (a) a reduction in pulse width, (b) a corresponding increase in the ratio of a compressed pulse width FWHM to energy in the wings of said pulse, and (c) a peak of a correlation signal relative to the energy in the wings of said ...

A FIBER LASER SYSTEM BASED ON SOLITONIC PASSIVE MODE-LOCKING

A fiber laser system based in solitonic passive mode-locking, including a laser diode to emit and deliver an optical signal of a first wavelength; a single-fiber laser cavity including a dichroic mirror, a SESAM and a polarization maintaining highly-doped active fiber, to receive the emitted signal and to emit a pulsed optical signal of a second wavelength, generating laser light in the form of mode-locked ultrashort pulses; a unit coupling the laser diode to the single-fiber laser cavity; and an isolator device protecting the cavity from back reflections. The solitonic mode-locked ultrashort pulses are comprised in a range of 100 fs<10 ps with repetition rates of hundreds MHz to tens of GHz. 116-. (canceled)18. The fiber laser system of claim 17 , wherein the power of the continuous wave optical signal and of the laser light reaching the SESAM is below a thermal damage threshold of the SESAM.19. The fiber laser system of claim 17 , wherein the dichroic mirror and/or the SESAM include an index matching material on their surface in contact with the active fiber end/ends.20. The fiber laser system of claim 17 , wherein the doped active fiber comprises an Erbium/Ytterbium-doped active fiber.21. The fiber laser system of claim 20 , wherein the Erbium/Ytterbium-doped active fiber has a length in a range comprised between 0.5 to 20 cm.22. The fiber laser system of claim 21 , wherein the Erbium/Ytterbium doped active fiber length is 10 cm.23. The fiber laser system of claim 20 , wherein the Erbium/Ytterbium-doped fiber has an optical pump absorption in the range of hundreds of dB/m.24. The fiber laser system of claim 17 , wherein the first wavelength is comprised in a range between 912 to 918 nm claim 17 , the given power is comprised in a range between 100 to 300 mW claim 17 , and the second wavelength is comprised in a range between 1525 to 1570 nm.25. The fiber laser system of claim 17 , further comprising a polarizing fiber coupler connected to a port of the unit via ...