ВОЛОКОННЫЙ СВЕТОВОД (ВАРИАНТЫ) И СПОСОБ ЕГО ПОЛУЧЕНИЯ

Изобретение относится к области волоконно-оптических стойких линий связи, к воздействию ионизирующего и ультрафиолетового излучения, и может быть использовано в устройствах для передачи изображений и рамановских волоконных лазерах и усилителях. Волоконный световод состоит из сердцевины, оболочки и герметичного покрытия и содержит от 1•1019 до 5• 1021 см-3 молекул водорода или от 1•1020 до 5•102 см-3 молекул дейтерия. При изготовлении световода после нанесения герметичного покрытия его помещают в газовую атмосферу под давлением от 1 до 1000 МПа и температуре от 20 до 1000oС на время от 20 мин до 100 дней. Обеспечено повышение стойкости к воздействию ионизирующего излучения, включающего ультрафиолетовое излучение, гамма-излучения, нейтроны, протоны, электроны, альфа-частицы, и увеличено рамановское рассеяние. 3 c. и 20 з.п. ф-лы, 3 ил.

ТЕЛЕКОММУНИКАЦИОННЫЙ КАБЕЛЬ, СНАБЖЕННЫЙ ПЛОТНО БУФЕРИЗОВАННЫМИ ОПТИЧЕСКИМИ ВОЛОКНАМИ

Телекоммуникационный кабель содержит по меньшей мере одно оптическое волокно, покрытое плотным буферным слоем, имеющим внутренний диаметр, который по существу равен наружному диаметру упомянутого оптического волокна. Упомянутый плотный буферный слой выполнен из полимерного материала, имеющего предельное удлинение, равное или меньшее чем 100%, и предельную прочность на растяжение, равную или меньшую чем 10 МПа. Технический результат - эффективная защита волокна во время монтажных работ и во время использования, и в то же самое время легкую зачистку без использования каких-либо приспособлений для зачистки путем приложения небольшого давления пальцами руки и умеренного усилия отрыва вдоль оси волокна, при этом зачистка может быть выполнена за один проход, но не более чем на 100 см ±30 см. 2 н. и 29 з.п. ф-лы, 5 ил.

ОПТИЧЕСКОЕ ВОЛОКНО С НИЗКИМИ ИЗГИБНЫМИ ПОТЕРЯМИ

Изобретение относится к одномодовым оптическим волокнам с низкими изгибными потерями. Оптическое волокно включает в себя центральную область стеклянной сердцевины, имеющую максимальное приращение Δпоказателя преломления в процентах. Первая внутренняя кольцевая область окружает сердцевину и имеет приращение Δпоказателя преломления в процентах. Кольцевая область с понижением окружает внутреннюю кольцевую область и имеет приращение Δ. Третья кольцевая область окружает кольцевую область с понижением и имеет приращение Δпоказателя преломления в процентах. При этом Δ>Δ>Δ>Δ. Разность между Δи Δпревышает 0,01, а объем |V| профиля составляет, по меньшей мере, 60%Δ мкм. 2 н. и 18 з.п. ф-лы, 1 ил.

ОПТИЧЕСКОЕ ВОЛОКНО С НИЗКИМИ ПОТЕРЯМИ НА ИЗГИБАХ

Изобретение относится к оптической волоконной технике. Одномодовое оптическое волокно включает (I) сердцевину, содержащую внешний радиус r, максимальное приращение Δпоказателя преломления в процентах и альфа сердцевины, α, большее чем 5; и (II) оболочку, окружающую сердцевину. Оболочка содержит (i) внутреннюю область оболочки, имеющую внешний радиус rи приращение Δпоказателя преломления в процентах, причем Δ>Δ. Также оболочка содержит (ii) канальную область, окружающую внутреннюю область оболочки, причем канальная область имеет внешний радиус r, причем r>10 мкм, и приращение Δпоказателя преломления в процентах. Кроме того, оболочка содержит (iii) внешнюю область оболочки, имеющую концентрацию хлора ≥1,2% по весу, окружающую канальную область и содержащую приращение Δпоказателя преломления в процентах; причем Δ>Δ, и Δ>Δ, и Δ>Δи причем разница между Δи Δ≥0,12%. Технический результат заключается в обеспечении возможности снижения оптических потерь на изгибах волокна. 25 з.п. ф-лы, 7 ил., 3 ...

ОДНОМОДОВЫЙ ВОЛНОВОД, КОМПЕНСИРУЮЩИЙ ДИСПЕРСИЮ

Одномодовое оптическое волокно с компенсацией дисперсии предназначено для перемещения рабочего окна линии связи от длины волны 1310 нм к длине волны 1550 нм. Оптическое волокно характеризуется профилем показателя преломления области стеклянной сердцевины, содержащим по меньшей мере три части. Часть в центре волокна имеет положительный относительный показатель преломления. По меньшей мере одна часть, расположенная на расстоянии от центральной оси оптического волокна, имеет отрицательный относительный показатель преломления. Отрицательная полная дисперсия на длине волн 1550 нм не превышает -150 пс/нм•км. Линия связи содержит два отрезка оптических волокон, параметры которых выбраны так, что нелинейный дискриминирующий фактор линии связи не превышает нелинейный дискриминирующий фактор первого оптического волокна. При изготовлении волновода вытягивают заготовку с натяжением менее 100 г. 3 с. и 16 з.п. ф-лы, 5 ил., 2 табл.

ОПТИЧЕСКОЕ ВОЛОКНО С НЕБОЛЬШИМ НАКЛОНОМ ХАРАКТЕРИСТИКИ ДИСПЕРСИИ В ОБЛАСТИ ЧАСТОТ ЭРБИЕВОГО УСИЛИТЕЛЯ

Оптическое волокно используется в системах со спектральным уплотнением каналов, работающих с легированным эрбием волоконным усилителем. Волокно имеет хроматическую дисперсию, абсолютное значение которой в диапазоне длин волн от 1530 до 1565 нм превышает 0,8 пс/(нм•км), а наклон характеристики дисперсии меньше 0,05 пс/(нм2•км). Оптическое волокно имеет потери, не превышающие 0,20 дБ/км, и сравнительно мало чувствительно к изгибу, эффективная площадь его поперечного сечения превышает 50 мкм2. Оптическое волокно имеет центральную жилу из прозрачного материала с максимальным показателем преломления n, и нанесенный на нее снаружи слой образующего оболочку материала с показателем преломления nl. Центральная жила имеет кольцо из прозрачного материала с минимальным показателем преломления n3, который меньше n2. Показатели преломления должны удовлетворять следующим условиям: 0,50 <(n1-n2)/n2< 0,70 и - 0,30 <(n3-n2)/n2< -0,05. Приведены примеры применения волокон с небольшим наклоном характеристики ...

ОПТИЧЕСКОЕ ВОЛОКНО С ЦВЕТНОЙ МАРКИРОВКОЙ

Оптическое волокно 1 имеет покрытие 4 на окружающей сердцевину 2 волокна оболочке 3, состоящее из одного или нескольких пластмассовых слоев, а также с цветной маркировкой в виде кольцевой разметки на или в наружном пластмассовом слое. Кольцевая разметка выполнена в виде разомкнутых цветных колец 5. Разомкнутая часть цветных колец по периметру оптического волокна составляет максимально 180°. Маркировка исключает влияние колебаний температур на передаточные характеристики волокна. Обеспечена возможность нанесения маркировки на любое число волокон. 14 з.п.ф-лы, 5 ил.

ОПТИЧЕСКОЕ ВОЛОКНО С ЦВЕТНОЙ МАРКИРОВКОЙ

Оптическое волокно с цветной маркировкой используется для обеспечения распознавания волокон при сращивании. Оптическое волокно содержит сердцевину, на которую нанесено покрытие. состоящее из одно- или многослойных слоев синтетического материала. На наружный слой синтетического материала нанесена или заделана в этот слой цветная маркировка. Цветная маркировка покрыта слоем прозрачного или полупрозрачного лака по всей длине волокна. Повышена стойкость маркировки. 18 з.п. ф-лы, 3 ил.

ФОТОННО-КРИСТАЛЛИЧЕСКОЕ ХАЛЬКОГЕНИДНОЕ ВОЛОКНО И СПОСОБ ЕГО ИЗГОТОВЛЕНИЯ

Изобретение относится к волоконной оптике. Фотонно-кристаллическое халькогенидное волокно состоит из центрального волноведущего стержня из халькогенидного стекла, микроструктурной волноведущей оболочки из чередующихся слоев халькогенидного стекла и воздушных зазоров и второй защитной микроструктурной оболочки из многокомпонентного стекла. Способ его изготовления включает предварительную вытяжку стержней. Далее формируют халькогенидную вставку путем укладки стержней из халькогенидного стекла с соответствующими воздушными зазорами, а затем укладывают внешние поддерживающие тонкостенные капилляры из многокомпонентного стекла в толстостенную трубку из многокомпонентного стекла. Технический результат - обеспечение высокой нелинейности. 2 н. и 3 з.п. ф-лы, 2 ил.

ОПТИЧЕСКОЕ ВОЛОКНО

... 1. Оптическое волокно, содержащее, по меньшей мере: центральную часть сердцевины, имеющую максимальный показатель N1 преломления и внешний диаметр 2а, вогнутую часть, предусмотренную на внешней периферии указанной центральной части сердцевины, имеющую минимальный показатель N2 преломления и внешний диаметр 2b, и часть оболочки, предусмотренную на внешней периферии вогнутой части и имеющую максимальный показатель N3 преломления, ! при этом указанные соответствующие максимальные показатели преломления указанной центральной части сердцевины, указанной вогнутой части и указанной части оболочки удовлетворяют следующему соотношению: ! N1>N3>N2, ! где относительная разность Δ1 показателей преломления указанной центральной части сердцевины по отношению к указанной части оболочки составляет более 1,0%, и относительная разность Δ2 показателей преломления указанной вогнутой части по отношению к части оболочки составляет менее -0,3%, и ! где на длине волны 1,05 мкм вторая производная β2 постоянной ...

Оптическое волокно и оптическа лини св зи

... 1. Оптическое волокно, содержащее центральный участок (1) сердцевины, краевой участок (2) сердцевины и участок (3) оболочки, в порядке следования изнутри наружу, при этом значение дисперсии указанного волокна больше или равно 14 пс/(нм·км) и меньше или равно 20 пс/(нм·км) на длине волны 1550 нм, наклон дисперсионной кривой больше или равен 0,05 пс/(нм2·км) и меньше или равен 0,08 пс/(нм2·км) на длине волны 1550 нм и коэффициент ослабления меньше или равен 0.2 дБ/км на длине волны 1550 нм, отличающееся тем, что относительная разность Δ1 показателей преломления между центральным участком (1) сердцевины и участком (3) оболочки больше или равна 0,25% и меньше или равна 0,50%, относительная разность Δ2 показателей преломления между краевым участком (2) сердцевины и участком (3) оболочки больше или равна 0,05% и меньше или равна 0,30%, выполняется неравенство Δ2<Δ1, отношение а/b между наружным диаметром а центрального участка (1) сердцевины и наружным диаметром b краевого участка (2) сердцевины ...

ОПТИЧЕСКОЕ ВОЛОКНО, КОМПЕНСАТОР ДИСПЕРСИИ, ИСПОЛЬЗУЮЩИЙ ОПТИЧЕСКОЕ ВОЛОКНО, ОПТИЧЕСКАЯ ЛИНИЯ ПЕРЕДАЧИ, ИСПОЛЬЗУЮЩАЯ ОПТИЧЕСКОЕ ВОЛОКНО, И ОПТИЧЕСКАЯ СИСТЕМА ПЕРЕДАЧИ, ИСПОЛЬЗУЮЩАЯ ОПТИЧЕСКОЕ ВОЛОКНО

... 1. Оптическое волокно, которое содержит сердцевину и плакировочную оболочку, включающую внутренний слой и внешний слой, и имеет структуру распределения показателя преломления, удовлетворяющую условиям 0,8%≤Δ1≤1,3% и -0,7%≤Δ2≤-0,4%, где Δ1 представляет относительную разность показателя преломления сердцевины относительно показателя преломления внешнего слоя плакировочной оболочки, а Δ2 представляет относительную разность показателя преломления внутреннего слоя плакировочной оболочки относительно показателя преломления внешнего слоя плакировочной оболочки, и также удовлетворяет условиям -20≤D≤0, -0,1≤S<0, а также 0≤(D/S)≤200 в заданной полосе длин волн, имеющей ширину полосы по меньшей мере 20 нм в диапазоне длин волн 1,5 мкм, где D представляет хроматическую дисперсию пс/(нм·км) на заданной длине волны в диапазоне длин волн 1,5 мкм, а S представляет наклон дисперсионной кривой пс/(нм2·км). 2. Оптическое волокно по п.1, отличающееся тем, что оптическое волокно удовлетворяет следующим условиям ...

Ermüdungsfeste optische Faser

Optische Faser zum Anschluss an einen Wellenleiter und Verfahren zu ihrer Herstellung

Optische Wellenleiterfaser mit sehr dünner äusserer TiO2-SiO2-Überzugsschicht und Verfahren zu ihrer Herstellung

Optische Monomodefaser mit optimierter chromatische Dispersion

Nichtanzapfbare optische Monomodefaser und diese Faser verwendendes Übertragungsverfahren.

MONOMODIGER WELLENLEITER HOHER LEISTUNGSFÄHIGKEIT

Lichtleitfaser mit grosser effektiver Fläche

SCHMALBAND-SPERRFILTER IM LICHTWELLENLEITER

OPTISCHE-LEISTUNG-ÜBERWACHUNGSEINRICHTUNG UND LASERVORRICHTUNG

Optische-Leistung-Überwachungseinrichtung (1), welche eine optische Leistung erfasst, die sich durch eine Lichtleitfaser mit zumindest einem Kern (21, 31) und einem Mantel (22, 32) ausbreitet, mit:einer ersten Lichtleitfaser (2);einer zweiten Lichtleitfaser (3) mit einem größeren Kerndurchmesser als die erste Lichtleitfaser (2);einem Verbindungsteil (4), wo eine Endoberfläche der ersten Lichtleitfaser (2) und eine Endoberfläche der zweiten Lichtleitfaser (3) gespleißt sind;einem ersten Leckageteil (23) zur Leckage eines Strahls von der ersten Lichtleitfaser (2) zu der Außenseite;einem zweiten Leckageteil (33) zur Leckage eines Strahls von der zweiten Lichtleitfaser (3) zu der Außenseite;einem ersten Photodetektor (5), welcher eine optische Leistung erfasst, die von dem ersten Leckageteil (23) austritt; undeinem zweiten Photodetektor (6), welcher eine optische Leistung erfasst, die von dem zweiten Leckageteil (33) austritt,wobei eine Laservorrichtung (100, 200, 300) zumindest umfassteinen ...

Glasfaser und optisches Modul mit Dispersions-Kompensation

SOLITONEN IN EINEM WELLENLEITER MIT GLEICHMÄSSIGER DISPERSION

Optische Einmodennachrichtenfaser und Verfahren zur Herstellung der Faser

Single mode optical fiber having multi-step core structure and method of fabricating the same

Optical fiber, optical fiber amplifier and optical fiber laser light source

An optical fiber with a plurality of holes

An optical fiber 10 can efficiently excite metallic ions by a pump lightwave, and an optical fiber amplifier and an optical fiber laser light source both incorporate the optical fiber. The optical fiber 10 comprises (a) a solid region that has a first region [Figure 2A, 12] doped with metallic ions and a second region [Figure 2A, 13] surrounding the first region and that allows a lightwave for exciting the metallic ions to travel in a multiple mode and (b) a third region [Figure 2A, 16] surrounding the second region and having a plurality of holes [Figure 2A, 15] stretching along the length of the optical fiber. The optical fiber 10 has a structure in which the first region is supplied with the power of a lightwave that is included in the pump lightwave and that is in a mode having no intensity peak at the center axis of the solid region. The optical fiber may be formed by twisting.

Optical fiber with tin doped core-cladding interface

The present invention concerns an optical fiber 10 comprising a substantially pure silica glass core 12, a concentric tin-doped core/cladding interface region 14, and a concentric fluorine-doped depressed cladding layer 16. The tin-doped core/cladding interface region 14 comprises a low concentration gradient of tin dioxide, which advantageously results in a de minimis refractive index change, resistance to hydrogen incursion, and thermal stability of any fiber Bragg gratings written into the interface region 14.

Low dispersion single mode fiber

A low-loss single mode fiber with low total dispersion within the wavelength range 1.25-1.385 mu m and low added cabling loss is disclosed. The fiber has relatively high DELTA to assure low cabling loss. The high DELTA is obtained, however, without paying a cost in high material dispersion by providing at least 20 percent of the DELTA by down-doping of the fiber cladding.

OPTICAL FIBERGUIDE

Optical fiber

An optical fiber 10 for enhancing the sensitivity of a sensing system. The optical fiber 10 having at least one core 12, a core diameter, a core numerical aperture, a core refractive index and a core Rayleigh backscatter coefficient. The optical fiber 10 further comprising a first cladding layer 14 having a first cladding layer thickness, and a first cladding layer refractive index; and a second cladding layer 16 having a second cladding layer inner diameter, a second cladding layer outer diameter and a second cladding layer thickness. The core comprising at least one core dopant selected from the range of: germanium, phosphorus, aluminium, boron, fluorine. The at least one core dopant is used to increase the core refractive index and enhance the core Rayleigh backscatter coefficient. The first cladding layer comprises at least one first cladding layer dopant selected from the range of: germanium, phosphorus, aluminium, boron, fluorine Wherein at least one first cladding layer dopant is ...

OPTICLE FIBRE MANUFACTURE

MULTIPLE MODE WAVEGUIDES

LOWLOSS MULTILAYER OPTICAL FIBRE

Single-mode optical fiber and manufacture method thereof

Single-mode optical fiber and manufacture method thereof.

Single-mode optical fiber and manufacture method thereof.

Single-mode optical fiber and manufacture method thereof.

FIBER-OPTIC TRANSVERSE ELECTROMAGNETIC WAVE

OPTISCHER GRADIENTENINDEX-WELLENLEITER UND VERFAHREN ZUR HERSTELLUNG EINER VORFORM HIEVON

OPTICAL FIBER FOR THE COMPENSATION OF CHROMATIC DISPERSION

MONO MODE OPTICAL FIBER WITH LOW CURVATURE LOSS

MULTIMODEN-WELLENLEITER UND VERFAHREN ZU DESSEN HERSTELLUNG

DISPERSION-SHIFTED OPTICAL FIBER FOR A FIBER-OPTIC WAVELENGTH MULTIPLEX TRANSMISSION SYSTEM

OPTICAL FIBER WITH COMPENSATION OF THE CHROMATIC DISPERSION

LOW-LOSS MONODECAY OPTICAL TRANSVERSE ELECTROMAGNETIC WAVE WITH LOW DISPERSION.

OPTICAL TRANSVERSE ELECTROMAGNETIC WAVE WITHIN THE INFRARED RANGE WITH SMALL LOSSES.

MULTI-FASHION TRANSVERSE ELECTROMAGNETIC WAVE AND PROCEDURE FOR ITS PRODUCTION

MONO MODE OPTICAL FIBER AND PROCEDURE FOR THE PRODUCTION.

OPTICAL FIBER FOR WAVELENGTH MULTIPLEX TRANSMISSION SYSTEM

OPTICAL SYSTEM AND PROCEDURE WITH SMALL LOSSES AND NONLINEAR EFFECTS

MONO MODE OPTICAL FIBER AND OPTICAL DATENÜBERTRAGUNGSSYSTEM

PROCEDURE FOR MANUFACTURING GATHERING MOLDS FOR OPTICAL TRANSVERSE ELECTROMAGNETIC WAVE WITH A SEGMENT CORE

DISPERSION-COMPENSATING FIBER FOR A FIBER-OPTIC WAVELENGTH MULTIPLEX TRANSMISSION SYSTEM WITH A DISPERSION-SHIFTED FRAY-STRAINS

OPTICAL TRANSVERSE ELECTROMAGNETIC WAVE DEVICE WITH FIBER LATTICE AND PROCEDURE FOR THEIR PRODUCTION

Optical fibre lens and method of forming same

Single-mode optical fiber and its production method

Hinged optical fiber ribbon moveable between aligned and collapsed positions

An optical fiber ribbon and a related cable are provided. The ribbon includes a first group of at least one optical fiber and a second group of at least two optical fibers coupled together. The ribbon includes a first hinge coupling the first group to the second group. The hinge allows movement of the first group and the second group of optical fibers relative to each other such that the ribbon is moveable between an aligned position and a collapsed position. The number of optical fibers in the first group is less than the number of optical fibers in second group.

Metallic coated dielectric substrates comprising parylene polymer protective layer

Unequal couplers for multimode pumping optical amplifiers

Optical fiber having low loss at 1385nm and method for making same

OPTICAL FIBER HAVING ENHANCED BEND RESISTANCE

Dispersion and dispersion slope compensating optical fiber

An optical light source

Optical waveguide fiber with very thin titania-silica outer cladding layer and method for manufacturing same

Partially detached core optical waveguide

SOOT PREFORM

Optical fiber having low-dispersion slope in the erbium amplifier region

Method of having optical fiber having depressed index core region

Waveguide profile for large effective area

Optical fiber with tantalum doped clad

Optical transmission line

Optical transmission line

Broadband pulse-reshaping optical fiber

Optical waveguides and method of fabrication thereof

Dispersion compensating module and mode converter, coupler and dispersion compensating optical waveguide therein

Single mode optical waveguide fiber with reduced dispersion

OPTICAL FIBER AND NONLINEAR OPTICAL FIBER, OPTICAL AMPLIFIER AND WAVELENGTH CONVERTER USING THE SAME, AND METHOD OF MAKING OPTICAL FIBER

Employed as a structure of a highly nonlinear optical fiber (nonlinear optical fiber) is a double-cladding structure in which a first cladding region 20 and a second cladding region 30 are disposed on the outer periphery of a core region 10. Since the double-cladding structure is employed, the cutoff wavelength .lambda.c can sufficiently be shortened even when, in order to increase the nonlinear coefficient .gamma., the concentration of GeO2 added into the core is enhanced so as to raise the nonlinear refractive index, or the relative refractive index difference between the core and cladding is increased so as to reduce the effective area A eff. This realizes an optical fiber or nonlinear optical fiber shortening its cutoff wavelength while having a sufficient nonlinearity, an optical amplifier and wavelength converter using the same, and a method of making an optical fiber.

PHOTOCONDUCTIVE FIBER OR ROD

OPTICAL SYSTEM AND METHOD HAVING LOW LOSS AND NON-LINEAR EFFECTS

An apparatus and method for transmitting an optical signal. The invention is directed to a transmission line having first (16) and second (18) spans of single mode fiber. The fiber of the first span has a negative dispersion with an absolute value of between about 2.5 ps/nm/km and 10 ps/nm/km at the operating wavelength. The second span (18) is connected to the first span (16) and has a positive dispersion at the operating wavelength. The positive dispersion of the second span compensates for the negative dispersion of the first span such that the cumulative dispersion across the first and second spans is approximately zero. The increased dispersion of the first span coincides with characteristics to lower non-linear effects, permits a longer length of the second span, and helps lower attenuation in the transmission line.

FIBER STRUCTURE AND A METHOD FOR DISCRIMINATING HIGH ORDER MODES IN THE FIBER STRUCTURE

The invention relates to a fiber structure(700), which has one or more refractive index disturbances(750, 760)outside a fiber core (710)for discriminating one or more high order modes in the fiber structure. The invention also relates to a method for discriminating one or more high order modes,an arrangement having the high order modes discriminating fiber struc-ture, and a device having the high order mode discriminating fiber structure.

HIGH POWER OPTICAL FIBER

An optical fiber for use with high power infrared radiation. The cladding, which may be restricted to the ends, consists of alternating layers of different refractive indices. Preferably the core is a crystalline halide of silver, thallium or cesium, one of the alternating cladding layers is crystaline lead floride and the other alternating cladding layer is crystalline germanium or silver halide. The middle portion of the core may be not covered by the cladding or covered by fewer layers. A metal layer may cover the cladding. A resin layer having a refractive index not larger than those of the cladding layers may cover the cladding.

GLASS FIBERS FOR OPTICAL TRANSMISSION

A reinforced glass fiber for use in optical transmission comprising an optical fiber coated with (1) a coating of a first curable organopolysiloxane composition having a refractive index higher than that of the clad glass which forms the outermost layer of the optical fiber, said first curable organopolysiloxane composition being baked, (2) a coating of a second curable organopolysiloxane composition which can be the same as or different from the first curable organopolysiloxane composition, the second curable organopolysiloxane composition being provided on the first curable organopolysiloxane composition and being baked, and (3) optionally a coating of a thermoplastic resin composition.

HIGH BANDWIDTH OPTICAL WAVEGUIDE

An optical waveguide filament comprising a cladding layer, a core and a barrier layer disposed between the core and cladding. The barrier layer comprises silica doped with B2O3, P2O5 and GeO2. The core consists of an inner region and an outer region, the boundary between which is referred to as the core break-point. In the outer region of the core, the concentration of B2O3 decreases linearly from its barrier layer level to zero at the core break-point, the P2O5 increases at a rapid rate from the barrier layer level to a first concentration level at the core break-point and the GeO2 remains at a constant value between zero and the barrier level. In the outer region of the. core, the GeO2 increases from some level up to the barrier layer level to a greater value at the filament axis in a power law fashion. The P2O5 also increases in a power law fashion from the value thereof at the core break-point to a higher value at the filament axis, the increase in concentration of P2O5 in the outer ...

OPTICAL TRANSMISSION LINE AND OPTICAL COMMUNICATION SYSTEM

An optical communication system has a configuration in which an optical transmission line is laid between a repeater (transmitter) and another repeater (receiver). The optical transmission line is formed by fusion- splicing a first optical fiber on the upstream side and a second optical fiber on the downstream side. The first optical fiber has a transmission loss of 0.25 dB or less, and an effective area of 80 .mu.m2 or above (preferably 100.mu.m2 or above), at a wavelength of 1550 nm, which is the wavelength of signal light. The second optical fiber is connected to the downstream end of the first optical fiber and has positive dispersion regions and negative dispersion regions which are alternately arranged along the longitudinal direction and whose chromatic dispersions at a wavelength of 1550 nm are positive and negative, respectively.

OPTICAL FIBER FOR EXTENDED WAVELENGTH BAND

An optical transmission fiber for use in a wavelength division multiplexing transmission system is disclosed. The transmission fiber includes an inner core surrounded by a first, second and at least a third glass layer along the length of the fiber. The first glass layer has a depressed refractive-index difference and the second glass layer has a refractive-index difference of substantially zero. The third glass layer has a positive refractive-index difference. The fiber has an improved relationship between dispersion slope and depressed profile volume. The fiber can have a dispersion value of at least 1.5 ps/nm/km and a dispersion slope of less than about 0.07 ps/nm2/km over an extended range of carrier wavelengths for the transmission system, such as the range 1450-1650 nm.

OPTICAL WAVEGUIDE HAVING NEGATIVE DISPERSION AND LARGE AEFF

The invention is directed to a single mode optical waveguide fiber profile (18, 20, 22, 24) that provides relatively large effective area while limiting macrobend loss. The large effective area results from configuring the core of the waveguide fiber to shift propagated light power away from the waveguide center. Macrobend loss, as measured by pin array or 20 mm mandrel testing, is maintained low by means of a power-limiting index depression (24) surrounding the central core region of the waveguide. In addition, low attenuation is achieved and cut off wavelength is controlled to provide a telecommunications operating window in the wavelength range of about 1250 nm to 1700 nm.

COATED OPTICAL FIBER, FABRICATION PROCESS THEREOF AND FABRICATION APPARATUS THEREOF

FIBER OPTIC SCANNER

OPTICAL FIBER

An optical fiber capable of producing white light with a sufficiently wide wavelength band and of stabilizing the polarized state. The optical fiber can produce white light in wavelength bands on both sides of a pumping light pulse inputted by a nonlinear phenomenon. A core (1) of the optical fiber is clad with a first clad (2), which is clad with a second clad (3). The ratio (.DELTA. 2/.DELTA. 1) between the relative refractive-index differences .DELTA. 1, .DELTA. 2 of the core (1) and the first clad (2) with reference to that of the second clad (3) is -0.4 to -0.85. The ratio of the outside diameter of the core (1) to that of the first clad (2) is 0.4 to 0.7. The relative refractive-index difference .DELTA. 1 is 0.6 to 1.2%. The transmission loss of light with a wavelength near 1.4 .mu.m is 10 Db/km or less. Stress imparting parts (4) for imparting stress to the core (1) are provided on both sides of the core (1) in the second clad (3) to make the fiber a constant polarization optical ...

OPTICAL FIBER AND OPTICAL COMMUNICATION SYSTEM COMPRISING THE SAME

An optical fiber having a structure suitable for long-distance optical communication and an optical transmission line comprising the same. The optical fiber comprises a core region extending along a predetermined axis and a clad region surrounding the core region. The optical fiber has characteristics at the 1.55 .mu.m wavelength, such as an effective cross section of more than 110 .mu.m2, a dispersion of 18 to 23 ps/nm/km, and a dispersion slope of 0.058 to 0.066 ps/nm2/km.

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 ...

BINDER FILM FOR A FIBER OPTIC CABLE

A fiber optic cable includes a cable core of core elements and a protective sheath surrounding the core elements, an armor surrounding the cable core, the armor comprising a single overlap portion when the fiber optic cable is viewed in cross-section, and a jacket surrounding the armor, the jacket having at least two longitudinal discontinuities extruded therein. A method of accessing the cable core without the use of ripcords includes removing a portion of the armor in an access section by pulling the armor away from the cable core so that an overlap portion separates around the cable core as it is being pulled past the cable core. A protective sheath protects the core elements as the armor is being pulled around the cable core.

OPTICAL FIBER

An optical fiber that can sufficiently suppress the generation of four-wave mixing and that can widen the bandwidth of wavelength of signal light. The optical fiber of the present invention has (a) a chromatic dispersion whose absolute value is not less than 8 ps~nm -1~km -1 and not more than 15 ps~nm 1-km 1- at a wavelength of 1.55 .mu.m and (b) a dispersion slope whose absolute value is not more than 0.05 ps~nm -2~km -1 at a wavelength of 1.55 .mu.m. It is more desirable that the optical fiber have (a) a chromatic dispersion whose absolute value is not less than 8 ps ~ nm -1~km -1 and not more than 12 ps~nm -1~km -1 at a wavelength of 1.55 .mu.m, (b) a dispersion slope whose absolute value is not more than 0.03 ps~nm -2~km -1 at a wavelength of 1.55 .mu.m, (c) a chromatic dispersion whose absolute value is not less than 5 ps~nm -1~km -1 at wavelengths between 1.45 and 1.65 .mu.m, (d) an effec- tive area not less than 45 .mu.m2 at a wavelength of 1.55 .mu.m, and (e) a two- meter cutoff ...

MULTI-WAVEGUIDE LIGHT FIELD DISPLAY

A multi-waveguide optical structure, including multiple waveguides stacked to intercept light passing sequentially through each waveguide, each waveguide associated with a differing color and a differing depth of plane, each waveguide including: a first adhesive layer, a substrate having a first index of refraction, and a patterned layer positioned such that the first adhesive layer is between the patterned layer and the substrate, the first adhesive layer providing adhesion between the patterned layer and the substrate, the patterned layer having a second index of refraction less than the first index of refraction, the patterned layer defining a diffraction grating, wherein a field of view associated with the waveguide is based on the first and the second indices of refraction.

RARE EARTH ELEMENT-DOPED MULTIPLE-CORE OPTICAL FIBER AND OPTICAL SYSTEMS USING THE SAME

SMALL BENDING RADIUS SINGLE-MODE OPTICAL FIBER WITH COMPATIBILITY WITH CONVENTIONAL G.652 OPTICAL FIBERS

A small bending radius single-mode optical fiber with compatibility comprises a core gradient layer (1), a germanium-doped core layer (2), a first transition layer (3), a first wrapping layer (4), a second transition layer (5), a second wrapping layer (6), a third transition layer (7) and a third wrapping layer (8), said layers being arranged concentrically from the inner to the outer. The difference of relative index of refraction of the core gradient layer (1) is ?n1, which is realized through an equation: ?n1 = a1(x1 + x_ + x_) + b1; the difference of relative index of refraction of the first transition layer (3) is ?n3, which is realized through an equation: ?n3 = b3(1 - a3x_)0.5; the difference of relative index of refraction of the second transition layer (5) is ?n5, which is realized through an equation: ?n5 = a5x_ + b5; the difference of relative index of refraction of the third transition layer (7) is ?n7, which is realized through an equation: ?n7 = a7x_+ b7. The small bending ...

ARMORED OPTICAL FIBER CABLE

An optical communication cable includes a core, armor surrounding the core, a jacket surrounding and bonded to the armor, and a binder film also surrounding the core and interior to the armor. The core includes buffer tubes surrounding sets of optical fibers and a central strength member. The buffer tubes are stranded around the central strength member in a pattern of stranding including reversals in lay direction of the buffer tubes and the binder film holds the buffer tubes in position. The binder film is bonded to an interior of the armor, thereby providing a quick access capability to access the core via simultaneous removal of the binder film when the armor and jacket are removed.

Low bend loss optical fiber

An optical fiber having both low macrobend loss and low microbend loss. The fiber has a first inner cladding region having an outer radius r 2 >8 microns and refractive index Δ 2 and a second outer cladding region surrounding the inner cladding region having refractive index Δ 4 , wherein Δ 1 >Δ 4 >Δ 2 . The difference between Δ 4 and Δ 2 is greater than 0.002 percent. The fiber exhibits a 22 m cable cutoff less than or equal to 1260 nm, and r 1 /r 2 is greater or equal to 0.25.

Dispersion-Compensating System And Dispersion-Compensating Fiber with Improved Figure of Merit

A dispersion-compensating system and a dispersion-compensating fiber have an improved figure of merit and effective area. The dispersion-compensating system comprises a bulk dispersion-compensating module for providing optical-domain bulk dispersion compensation for an optical signal transmission. Additionally, the system may further comprise residual dispersion compensation, which can be performed in the electrical domain following coherent detection of both amplitude and phase of an optical signal. The dispersion-compensating fiber comprises an up-doped core region; a down-doped trench; an up-doped ring; and an outer cladding, and is configured to have a high figure of merit (FOM).

Multi-core optical fiber

The present invention relates to a multi-core optical fiber including a plurality of cores, in each of which an effective area at the wavelength of 1550 nm, a transmission loss at the wavelength of 1550 nm, a chromatic dispersion at the wavelength of 1550 nm, a cable cutoff wavelength, and a bending loss in a bending radius of 30 mm at the wavelength of 1625 nm are set so as to increase a transmission capacity in each core in a state in which a difference of the transmission loss at the wavelength of 1550 nm between different cores is controlled to at most 0.02 dB/km or less.

Large Mode Area Optical Fibers With Bend Compensation

A LMA, single-mode optical fiber comprises a core region, an inner cladding region surrounding the core region, and an outer cladding region surrounding the inner cladding region. The inner cladding region is configured to provide bend compensation. In one embodiment the index profile of the inner cladding region is graded with a slope of γn core /R b , where n core is the refractive index of the core region, R b is the bend radius, and γ=0.6-1.2. In addition, the inner cladding is annular and the ratio of its outer radius to its inner radius is greater than 2. In a preferred embodiment this ratio is greater than 3. The overall index profile may be symmetric or asymmetric.

Optical fiber

An optical fiber comprising a first core, a second core, a third core, and a cladding, wherein with a refractive index of the cladding as a reference, Δ1 is a maximum value of a relative refractive index difference of the first core, Δ2 is a maximum value of a relative refractive index difference of the second core, Δ3 is a minimum value of a relative refractive index difference of the third core, “a” is a half-value radial width for the relative refractive index difference (Δ1−Δ2) of the first core, “b” is a radius of a second core/third core boundary, and “c” is a radius of a third core/cladding boundary, the expressions 0.30%≦Δ1≦0.45%, −0.05%≦Δ2≦0.05%, −0.6%≦Δ3≦−0.3%, 2.85≦b/a, 10 μm≦b≦15 μm, and 3 μm≦c−b≦5.5 μm are satisfied, and transmission loss for a wavelength of 1550 nm when the optical fiber is wound around a mandrel with a diameter of 10 mm is no greater than 0.2 dB/turn.

Optical fiber

In order to decrease transmission loss caused by Rayleigh scattering in an optical fiber, without negatively affecting the curvature loss, provided is an optical fiber comprising a core at a center thereof, a low refractive index layer that is adjacent to the core and covers an outer circumference of the core, and a cladding that is adjacent to the low refractive index layer and covers an outer circumference of the low refractive index layer, wherein a refractive index of the core is higher than a refractive index of the cladding, a refractive index of the low refractive index layer is lower than the refractive index of the cladding, and the refractive index of the low refractive index layer decreases in a direction from an inner portion of the low refractive index layer to an outer portion of the low refractive index layer.

Autostereoscopic display illumination apparatuses and autostereoscopic display devices incorporating the same

Embodiments are generally directed to autostereoscopic display device illumination apparatuses having one or more optical fibers (i.e., flexible light diffusing waveguides) as linear emitters for illuminating columns of pixels of a display panel within the autostereoscopic display device. In some embodiments, the linear emitters are defined by a single optical fiber that is arranged on a substrate in a serpentine manner to form an array of linear emitters. In some embodiments, the linear emitters are defined by several optical fibers. Illumination apparatuses of some embodiments may also include a prism device configured to create multiple images of the optical fiber(s).

OPTICAL FIBER WITH LARGE EFFECTIVE AREA AND LOW BENDING LOSS

An optical fiber with large effective area, low bending loss and low attenuation. The optical fiber includes a core, an inner cladding region, and an outer cladding region. The core region includes a spatially uniform updopant to minimize low Rayleigh scattering and a relative refractive index and radius configured to provide large effective area. The inner cladding region features a large trench volume to minimize bending loss. The core may be doped with Cl and the inner cladding region may be doped with F. 1. An optical fiber comprising:{'sub': 1', 'l, 'a core region comprising Cl-doped silica glass having a chlorine concentration greater than 1.5 wt %, said core region having an outer radius rin the range from 6.0 microns to 10.0 microns and a relative refractive index A;'}{'sub': 2', '2, 'an inner cladding region surrounding said core region, said inner cladding region having an outer radius rin the range from 22 microns to 38 microns and a relative refractive index Δ; and'}{'sub': 3', '3', '2, 'an outer cladding region surrounding said inner cladding region, said outer cladding region having a relative refractive index Δ, said relative refractive index Δexceeding said relative refractive index Δby at least 0.06%;'}{'sup': '2', 'wherein said optical fiber has a cable cutoff of less than 1550 nm, an effective area at 1550 nm of at least 100 micron, and a bending loss at 1550 nm, determined from a mandrel wrap test using a mandrel with a diameter of 20 mm, of less than 3.5 dB/turn.'}2. The optical fiber of claim 1 , wherein the cable cutoff is less than 1500 nm.3. The optical fiber of claim 1 , wherein the cable cutoff is less than 1450 nm4. The optical fiber of claim 1 , wherein said core is free of Ge.5. The optical fiber of claim 1 , wherein said outer radius ris in the range from 7.0 μm to 10.0 μm.6. The optical fiber of claim 1 , wherein said relative refractive index Δis in the range from 0.08% to 0.30%.7. The optical fiber of claim 1 , wherein said relative ...

COATED LOW LOSS OPTICAL FIBER WITH SMALL DIAMETER

A multi-purpose optical fiber with coating is provided. The optical fiber can function as a transmission fiber or as a coupling fiber for optical data links that features low coupling loss to silicon photonics lasers, VCSELs, single mode transmission fibers, multimode transmission fibers, and high speed receivers. The fiber includes a core, an optional inner cladding region, a depressed index cladding region, an outer cladding region, and a coating. The relative refractive index profile of the coupling fiber includes a small-radius core region with α profile and a depressed index cladding region that facilitates low bending loss and high bandwidth. The coating thickness and overall diameter of the fiber is small. 2. The multimode optical fiber of claim 1 , wherein said outer radius ris in the range from 13 μm to 17 μm.3. The multimode optical fiber of claim 1 , wherein said cladding includes a depressed index cladding region surrounding said core region and an outer cladding region surrounding said depressed index cladding region claim 1 , said depressed index cladding region having an inner radius in the range from 10 μm to 20 μm claim 1 , an outer radius rin the range from 14 μm to 24 μm claim 1 , and a relative refractive index Δin the range from −0.8% to −0.1%.4. The multimode optical fiber of claim 3 , wherein said depressed index cladding region has an inner radius in the range from 13 μm to 18 μm.5. The multimode optical fiber of claim 1 , wherein said effective modal bandwidth at 1310 nm is at least 4 GHz-km.6. The multimode optical fiber of claim 1 , wherein said multimode optical fiber has a mode field diameter for the LP01 mode at 1310 nm between 8.8 μm and 9.6 μm.7. The multimode optical fiber of claim 1 , wherein said cladding has an outer radius rin the range from 35 μm to 45 μm.8. The multimode optical fiber of claim 1 , wherein said coating has an outer radius rless than 90 μm.13. The optical data link of claim 12 , wherein said light source is a ...

Multicore optical fiber and multicore optical fiber cable

An MCF cable according to an embodiment contains a plurality of MCFs each including at least one coupled core group and a common cladding. Λ is set such that κ at a wavelength of 1550 nm is falls within a range of from 1×10−1 [m−1] to 1×103 [m−1], and ((3ACavg)/(2-K) or (βΛCf)/(2κ) is set in a specific range in a wavelength band of from 1530 nm to 1625 nm, where Cavg [m−1], Cf [m−1], and ftwist [turn/m] represent the average curvature, the pseudo-curvature, and the average torsion, respectively, for each MCF, and κ [m−1], β [m−1], and Λ [m] represent the coefficient of mode coupling between adjacent cores, the average of propagation constants, and the core center-to-center distance, respectively.

Optical fibers having a varying clad index and methods of forming same

An optical fiber with low attenuation and methods of making same are disclosed. The optical fiber has a core, an inner cladding surround the core, and an outer cladding surrounding the inner cladding. The outer cladding is chlorine-doped such that the relative refractive index varies as a function of radius. The radially varying relative refractive index profile of the outer cladding reduces excess stress in the core and inner cladding, which helps lower fiber attenuation while also reducing macrobend and microbend loss. A process of fabricating the optical fiber includes doping an overclad soot layer of a soot preform with chlorine and then removing a portion of the chlorine dopant from an outermost region of the overclad soot layer. The soot preform with the modified chlorine dopant profile is then sintered to form a glass preform, which can then be used for drawing the optical fiber.

OPTICAL FIBERS, METHODS OF THEIR FORMATION, AND METHODS OF THEIR USE

An example of an optical fiber includes an attenuating cladding disposed around a first waveguide (e.g., a core) and a waveguide (e.g., a waveguide cladding) disposed around the attenuating cladding. An attenuating cladding may be a doped layer that may be doped with, for example, a dopant comprising metal. A first waveguide and a second waveguide may each transmit light for a distinct sample characterization technique. An example of an optical fiber includes a core, a first intermediate cladding disposed around the core, an attenuating cladding disposed around the first intermediate cladding, an attenuating cladding disposed around the first intermediate cladding, a second intermediate cladding disposed around the attenuating cladding, a waveguide cladding disposed around the second intermediate cladding, and outer cladding disposed around the waveguide cladding, and an outer coating around the outer cladding. An optical fiber may be formed using a rod-in-tube process. 1. An optical fiber (e.g. , a characterization fiber) comprising a first waveguide (e.g. , a core) , an attenuating cladding disposed around the first waveguide , and a second waveguide (e.g. , a waveguide cladding) disposed around the attenuating cladding.2. The optical fiber of claim 1 , wherein the attenuating cladding comprises a dopant.3. The optical fiber of or claim 1 , wherein the attenuating cladding comprises a glass claim 1 , wherein the dopant is dispersed within the glass.4. The optical fiber of or claim 1 , wherein the dopant comprises a metal.5. The optical fiber of claim 4 , wherein the dopant comprises a metallic oxide or a metallic chloride.6. The optical fiber of claim 5 , wherein the dopant is a pure metal.7. The optical fiber of or claim 5 , wherein the dopant comprises boron.8. The optical fiber of or claim 5 , wherein the dopant comprises one or more Rayleigh scatterers.9. The optical fiber of any one of the preceding claims claim 5 , wherein the attenuating cladding is opaque. ...

CONCENTRIC FIBER FOR SPACE-DIVISION MULTIPLEXED OPTICAL COMMUNICATIONS AND METHOD OF USE

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode. 1. An optical fiber , comprising:a relatively high refractive index optical core region formed of material having a first refractive index;a first low index region surrounding the optical core region and formed from a material having a second refractive index lower than the first refractive index;a first high index ring region surrounding the first low index region and formed of a material having a third refractive index higher than the second refractive index; anda second low index region surrounding the first high index region and formed from a material having a fourth refractive index lower than the third refractive index;wherein the optical core region supports propagation of light along at least a first radial mode associated with the optical core region and the first high index ring region supports propagation of light along at least a second radial mode associated with the first high index ring region, the second radial mode being different from the first radial mode.2. An optical fiber as recited in claim 1 , wherein the first refractive index is substantially equal to the third refractive index.3. An optical fiber as recited in claim 1 , wherein the first refractive index is greater than the third refractive index.4. An optical fiber as recited in claim 1 , wherein the second refractive index is substantially equal to the fourth refractive index.5. An optical fiber as recited in ...

HIGH CHLORINE CONTENT LOW ATTENUATION OPTICAL FIBER

An optical fiber having a core comprising silica and greater than 1.5 wt % chlorine and less than 0.5 wt % F, said core having a refractive index Δ, and a inner cladding region having refractive index Δsurrounding the core, where Δ>Δ. 1. A single mode optical fiber comprising:{'sub': 1MAX', '2MIN', '1MAX', '2MIN, 'a core comprising silica and greater than or equal to 1.5 wt % chlorine and less than 0.6 wt % F, said core having a refractive index Δ, and a cladding region having refractive index Δsurrounding the core, where Δ>Δ, and wherein said fiber is single moded at 1550 nm.'}2. The optical fiber of claim 1 , wherein said cladding region comprises fluorine claim 1 , and the molar ratio of chlorine in the core to fluorine in the cladding is greater than 1.3. The single mode optical fiber of claim 1 , wherein said core comprises greater than 2 wt % chlorine.4. The single mode optical fiber of claim 1 , wherein said core comprises greater than 3 wt % chlorine.5. The single mode optical fiber of claim 1 , wherein said core comprises greater than 4 wt % chlorine.6. The single mode optical fiber of claim 1 , wherein said core is essentially free of fluorine.7. The single mode optical fiber of claim 2 , wherein said fiber is essentially free of fluorine.8. The single mode fiber of claim 2 , wherein said cladding comprises an inner cladding comprising fluorine and an outer cladding region surrounding the inner cladding region claim 2 , said outer cladding region having refractive index Δ claim 2 , wherein Δ>Δ>Δ.9. The single mode optical fiber of claim 2 , wherein said cladding comprises from greater than or equal to about 0.1 weight % fluorine to less than or equal to about 1 weight % fluorine.10. The single mode optical fiber of claim 1 , wherein the core has a maximum relative refractive index claim 1 , Δ claim 1 , from greater than or equal to about 0.15% to less than or equal to about 0.5%.11. The single mode optical fiber of claim 2 , wherein said cladding has a ...

Dispersion shifted optical fiber

A dispersion shifted optical fiber where a radius r 0 of a first center segment is 0.5 μm to 2.8 μm, and a relative refractive index difference Δ 0 is 0.4% or more and 0.9% or less. A radius r 1 of a first segment is 1.8 μm or more and 4.5 μm or less. A radius r 2 of a second segment is 4.0 μm or more and 8.0 μm or less, and a relative refractive index difference Δ 2 is 0.00% or more and 0.07% or less. A radius r 3 of a third segment is 4.5 μm or more and 8.5 μm or less, and a relative refractive index difference Δ 3 is 0.285% or more and 0.5% or less. A radius r 4 of a fourth segment is 8.0 μm or more and 16.0 μm or less, and a relative refractive index difference Δ 4 is 0.005% or more and 0.04% or less.

OPTICAL FIBER MANUFACTURING METHOD

An optical fiber manufacturing method includes setting a first holding member and a rod inside a glass pipe, the first holding member made of glass and having plural holes formed, so that the rod is supported by the first holding member; filling glass particles between the rod and a glass pipe inner wall; holding the rod such that the rod and the filled glass particles are enclosed by the glass pipe inner wall and the first and second holding members, and sealing one end of the glass pipe and manufacturing an intermediate; and manufacturing an optical fiber from the intermediate, wherein a bulk density of the first and second holding members is set with reference to a bulk density of a filling portion made from the glass particles, and the predetermined range is determined according to a core diameter permissible variation range in its longitudinal direction. 1. An optical fiber manufacturing method for manufacturing an optical fiber that includes a core portion made of glass and a cladding portion made of glass and formed on outer periphery of the core portion , the optical fiber manufacturing method comprising:setting such that a first holding member and a core rod are placed inside a glass pipe constituting the cladding portion, the first holding member being one of a pair of holding members that are made of glass and have a plurality of holes formed thereon, the core rod including a core forming portion serving as the core portion and including a cladding forming portion serving as a portion adjacent to the core portion across outer periphery of the core portion, in such a way that the core rod is supported by the first holding member;filling glass particles in a gap between the core rod and an inner wall of the glass pipe;holding the core rod such that a second holding member of the pair of holding members is placed inside the glass pipe, in such a way that the core rod is held in a sandwiched manner in between the first holding member and the second holding ...

HIGH BANDWIDTH RADIATION-RESISTANT MULTIMODE OPTICAL FIBER

A high bandwidth radiation-resistant multimode optical fiber includes a core and a cladding layer surrounding the core. The core is a fluorine-doped quartz glass layer with a graded refractive index distribution and a distribution power exponent α of 1.7-2.2. The core has R1 of 15-35 μm and Δ1%min of −0.8% to −1.2%. The cladding layer has an inner cladding layer having R2 of 15-38 μm and Δ2% of −0.8% to −1.2% and/or a depressed inner cladding layer having R3 of 15-55 μm and Δ3 of −1.0% to −1.4%, an intermediate cladding layer having R4 of 15.5-58 μm and Δ4 of −0.7% to −0.2% a depressed cladding layer hasving R5 of 16-60 μm and Δ5 of −0.8% to −1.2%, and an outer cladding layer sequentially formed from inside to outside. The outer cladding layer is a pure silica glass layer. 1. A high bandwidth radiation-resistant multimode optical fiber , comprising a core layer and a cladding layer ,wherein the core layer is a fluorine-doped quartz glass layer with a graded refractive index distribution and a distribution power exponent α in a range from 1.7 to 2.2, and the core layer has a minimum relative refractive index difference Δ1% min in a range from −0.8% to −1.2% and a radius R1 in a range from 15 μm to 35 μm; andwherein the cladding layer outside of the core layer comprises an inner cladding layer and/or a depressed inner cladding layer, an intermediate cladding layer, a depressed cladding layer, and an outer cladding layer in sequence from inside to outside, wherein: the inner cladding layer has a radius R2 in a range from 15 μm to 38 μm and a relative refractive index difference Δ2% in a range from −0.8% to −1.2%; the depressed inner cladding layer has a radius R3 in a range from 15 μm to 55 μm and a relative refractive index difference Δ3 in a range from −1.0% to −1.4%; the intermediate cladding layer has a radius R4 in a range from 15.5 μm to 58 μm and a relative refractive index difference Δ4 in a range from −0.7% to −0.2%; the depressed cladding layer has a radius ...

OPTICAL FIBER WITH LOW LOSS AND NANOSCALE STRUCTURALLY HOMOGENEOUS CORE

An optical fiber has a core region that is doped with one or more viscosity-reducing dopants in respective amounts that are configured, such that, in a Raman spectrum with a frequency shift of approximately 600 cm, the fiber has a nanoscale structure having an integrated D2 line defect intensity of less than 0.025. Alternatively, the core region is doped with one or more viscosity-reducing dopants in respective amounts that are configured such that the fiber has a residual axial compressive stress with a stress magnitude of more than 20 MPa and a stress radial extent between 2 and 7 times the core radius. 1. An optical fiber , comprising:a plurality of concentric fiber regions, including a core region and surrounding cladding regions, wherein the concentric fiber regions are doped with one or more index-modifying dopants in respective amounts and radial positions that are configured to create a selected index profile,{'sup': '−1', 'wherein the core region is doped with one or more viscosity-reducing dopants in respective amounts that are configured, such that, in a Raman spectrum with a frequency shift of approximately 600 cm, the fiber has a nanoscale structure having an integrated D2 line defect intensity of less than 0.025.'}2. The optical fiber of claim 1 ,wherein the core region is doped with one or more viscosity-reducing dopants in respective amounts and radial positions that are configured such that the fiber has an attenuation of less than 0.18 dB/km at 1550 nm.3. The optical fiber of claim 1 ,wherein the core region is doped with one or more viscosity-reducing dopants in respective amounts and radial positions that are configured such that the fiber has an attenuation of less than 0.17 dB/km at 1550 nm.4. The optical fiber of claim 1 ,wherein the fiber is drawn at a speed of greater than 3 meters per second.5. The optical fiber of claim 1 , wherein the amount of P dopant is between 0.2% and 2%,', 'wherein the amount of Cl dopant is between 0 and 15,000 ppm ...

LOW BEND LOSS SINGLE MODE OPTICAL FIBER WITH CHLORINE UPDOPED CLADDING

An optical fiber having both low macrobend loss and low microbend loss. The fiber has a central core region, a first (inner) cladding region surrounding the central core region and having an outer radius r>16 microns and relative refractive index Δ, and a second (outer) cladding region surrounding the first cladding region having relative refractive index, Δ, wherein Δ>Δ>Δ. The difference between Δand Δis greater than 0.12 percent. The fiber exhibits a 22 m cable cutoff less than or equal to 1260 nm, and r/ris greater or equal to 0.24 and bend loss at 1550 nm for a 15 mm diameter mandrel of less than 0.5 dB/turn. 1. An optical fiber comprising:(i) a central core region having outer radius r1 and refractive index Δ1 (a) a first cladding region having an outer radius 25 microns>r2>16 microns and relative refractive index Δ2, wherein the ratio of r1/r2 is larger than 0.24 and', '(b) a second cladding region surrounding the first cladding region and having a relative refractive index Δ3 and an outer radius r3, wherein the second cladding region comprises at least 1.25 wt % chlorine (Cl), and wherein Δ1>Δ3>Δ2, and wherein the difference between Δ3 and Δ2 is greater than 0.12%, and Δ3>0.12%;, '(ii) a cladding surrounding the central core region, the cladding comprisingand said fiber exhibits a bend loss at 1550 nm for a 15 mm diameter mandrel of less than 0.5 dB/turn.2. The optical fiber of claim 1 , wherein the difference between Δ3 and Δ2 is greater than 0.13%.3. The optical fiber of claim 1 , wherein the difference between Δ3 and Δ2 is between 0.12% and 0.25%.4. The optical fiber of claim 1 , wherein said fiber exhibits a 22 m cable cutoff less than or equal to 1260 nm.5. The optical fiber of claim 1 , wherein the central core region of said fiber exhibits an alpha less than 10.6. The optical fiber of claim 1 , said fiber further exhibiting a wire mesh covered drum microbend loss at 1550 nm which is less than or equal to 0.07 dB/km.7. The optical fiber of claim 1 , ...

OPTICAL FIBER

An optical fiber in which the increase of attenuation can be reduced is offered. An optical fiber is made of silica glass and includes a core and a cladding enclosing the core. The refractive index of the cladding is smaller than that of the core. The core includes chlorine and any of the alkali metal group. The chlorine concentration is 1 ppm or more in the whole region of the core. In the whole region of the core, the absolute value of rate of radial change of the chlorine concentration is smaller than 2000 ppm/μm. 1. An optical fiber made of silica glass and containing a core and a cladding ,the cladding enclosing the core and having a refractive index smaller than the refractive index of the core,the core containing chlorine as well as an alkali metal or an alkaline-earth-metal element,the core having a chlorine concentration of 1 ppm or more in the whole region thereof, andthe absolute value of rate of radial change in the chlorine concentration being smaller than 2000 ppm/μm.2. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is less than 1000 ppm/μm.3. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is less than 500 ppm/μm.4. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is less than 300 ppm/μm.5. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is more than 100 ppm/μm.6. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is more than 200 ppm/μm.7. An optical fiber as set forth in claim 1 , whereinthe core ...

Ultra-low-loss coupled-core multicore optical fibers

A coupled-core multicore optical fiber has a plurality of cores that are doped with alkali metals or chlorine to achieve low attenuation and a large effective area. The cores may be embedded in a common cladding region that may be fluorine doped. The cores may also be doped with chlorine, either with the alkali metals described above or without the alkali metals.

OPTICAL FIBER AND METHOD OF MANUFACTURING THE SAME

An optical fiber includes a core, a depressed layer surrounding the core, and a cladding surrounding the depressed layer, where a refractive index profile of the core is an α power distribution in which an index α is 3 or more and 6 or less, a relative refractive index difference Δ of the depressed layer with respect to the adding is set such that an absolute value |Δ| thereof is 0.01% or more and 0.05% or less, a radius r1 of the core and an outer circumference radius r2 of the depressed layer are set such that a ratio r1/r2 thereof is 0.2 or more and 0.5 or less, a cable cutoff wavelength λof 22 m is 1260 nm or less, and a mode field diameter MFD at a wavelength of 1310 nm is 8.6 μm or more and 9.5 μm or less. 1. An optical fiber , comprising:a core;a depressed layer surrounding the core; anda cladding surrounding the depressed layer,wherein:a refractive index profile of the core is an α power distribution in which an index α is 3.5 or more and 6 or less,a relative refractive index difference Δ− of the depressed layer with respect to the cladding is set such that an absolute value |Δ−| thereof is 0.01% or more and 0.05% or less,a radius r1 of the core and an outer circumference radius r2 of the depressed layer are set such that a ratio r1/r2 thereof is 0.2 or more and 0.5 or less,a cable cutoff wavelength λcc of 22 m is 1260 nm or less, anda mode field diameter MFD at a wavelength of 1310 nm is 8.6 μm or more and 9.5 μm or less.2. The optical fiber according to claim 1 , whereinthe relative refractive index difference Δ− is set such that the absolute value |Δ−| thereof is 0.01% or more and 0.03% or less.3. The optical fiber according to claim 1 , whereinthe radius r1 and the outer circumference radius r2 are set such that the ratio r1/r2 thereof is 0.25 or more and 0.45 or less.4. The optical fiber according to claim 1 , whereina relative refractive index difference Δ+ of the core with respect to the cladding is set to be 0.30% or more and 0.45% or less.5. The ...

OPTICAL FIBERS FOR SINGLE MODE AND FEW MODE VERTICAL-CAVITY SURFACE-EMITTING LASER-BASED OPTICAL FIBER TRANSMISSION SYSTEMS

The optical fibers disclosed have single mode and few mode optical transmission for VCSEL-based optical fiber transmission systems. The optical fibers have a cable cutoff wavelength λof equal to or below 1260 nm thereby defining single mode operation at wavelengths greater than 1260 nm and few-mode operation at wavelengths in a wavelength range from 800 nm and 1100 nm. The mode-field diameter is in the range from 8.0 microns to 10.1 microns at 1310 nm. The optical fibers have an overfilled bandwidth OFL BW of at least 1GHz·km at at least one wavelength in the wavelength range. The optical fibers have a single-step or two-step core and can have a trench refractive index profile. VCSEL based optical transmission systems and methods are disclosed that utilize both single core and multicore versions of the optical fiber. 1. An optical fiber , comprising: an inner core region having a first relative refractive index and a first radius, and', 'an outer core region surrounding the inner core region, having a second relative refractive index less than the first relative refractive index, and a second radius greater than the first radius; and, 'a core having a step index profile, comprisinga cladding surrounding the core;wherein the optical fiber is single mode at wavelengths greater than 1260 nm, and is few mode in a wavelength range between 800 to 1100 nm with an overfilled bandwidth greater than 1 GHz·km at at least one wavelength in the wavelength range.2. The optical fiber of claim 1 , wherein:the first relative refractive index is between 0.36% and 0.40%;the first radius is between 2.0 nm and 2.4 nm;the second relative refractive index is between 0.28% and 0.32%;the second radius is between 4.2 nm and 4.6 nm; andthe cladding has a third relative refractive index that is substantially zero, and a third radius between 40 μm and 100 μm.3. The optical fiber of claim 1 , wherein:the first relative refractive index is between 0.38% and 0.44%;the first radius is between 2.2 μ ...

OPTICAL FIBER CABLE

An optical fiber cable has a sectional area of Ac [mm] and housing a number N of optical fibers. A transmission loss α[dB/km], a mode field diameter W [μm], an effective area Aeff [μm], an effective length L[km], and a wavelength dispersion D [ps/nm/km] of each of the optical fibers at a wavelength of 1550 nm satisfy a predetermined, equation and the transmission loss of the optical fiber at the wavelength of 1550 nm is 0.19 dB/km or less, and the effective area of the optical fiber is in a range from 125 to 155 μm. 2. The optical fiber cable according to claim 1 ,wherein the mode field diameter of the optical fiber at the wavelength of 1550 nm is in a range from 12.0 to 13.5 μm.3. The optical fiber cable according to claim 1 ,wherein the wavelength dispersion of the optical fiber at the wavelength of 1550 nm is in a range from 19 to 22 ps/nm/km.4. The optical fiber cable according to claim 1 ,wherein the optical fiber has a cutoff wavelength in a range from 1400 to 1600 nm.5. The optical fiber cable according to claim 1 ,wherein the optical fiber comprises:a core having a diameter in a range from 12 to 15 μm; anda cladding surrounding the core and having a refractive index that is smaller than a refractive index of the core,wherein a relative refractive index difference of the core with respect to the cladding is in a range from 0.28% to 0.35%.6. The optical fiber cable according to claim 5 ,wherein a relative refractive index difference of the core with respect to pure silica is in a range from −0.1% to +0.1%.7. The optical fiber cable according to claim 1 ,wherein the optical fiber comprises:a core having a diameter in a range from 12 to 15 μm;an inner cladding surrounding the core and having a refractive index that is smaller than a refractive index of the core; andan outer cladding having a refractive index that is smaller than a refractive index of the core and larger than a refractive index of the inner cladding,wherein a relative refractive index difference ...

FIBER OPTIC CABLES AND ASSEMBLIES AND THE PERFORMANCE THEREOF

A fiber optic drop cable includes an optical fiber, a tight buffer layer on the optical fiber, at least one strength member, and a jacket surrounding the tight buffer layer. The jacket is coupled to the at least one strength member by at least partial embedment of at least one of the strength members in the jacket, which facilitates coupling between the jacket and strength member. The fiber optic drop cable has an average delta attenuation of 0.4 dB or less at a reference wavelength of 1625 nanometers with the fiber optic cable wrapped 2 turns about a 7.5 millimeter diameter mandrel. 1. A fiber optic drop cable , comprising:an optical fiber;at least one strength member;a jacket surrounding the optical fiber, wherein the jacket comprises a bend radius control mechanism for protecting the optical fiber by inhibiting damage and breaking of the optical fiber as the cable is bent into small bend radii while still providing a highly flexible cable, wherein the bend radius control mechanism maintains a minimum bend diameter for the optical fiber;wherein the fiber optic drop cable has an average delta attenuation of 0.4 dB or less at a reference wavelength of 1625 nanometers with the fiber optic cable wrapped 2 turns about a 7.5 millimeter diameter mandrel.2. The fiber optic drop cable of claim 1 , wherein the minimum bend diameter is about two times the radius of the cable.3. A fiber optic cable claim 1 , comprising:optical fibers, wherein the optical fibers are arranged side-by-side as part of a ribbon structure where the optical fibers are enclosed or encased in a matrix around the optical fibers;at least one strength member;a jacket surrounding the optical fibers, wherein the jacket is coupled to the at least one strength member by at least partial embedment of at least one of the strength members in the jacket, thereby facilitating coupling between the jacket and strength member;wherein the fiber optic drop cable has an average delta attenuation of 0.4 dB or less at a ...

OPTICAL FIBER CABLE

An optical fiber cable has a sectional area of Ac [mm] and housing a number N of optical fibers. A transmission loss α[dB/km], a mode field diameter W [μm], an effective area Aeff [μm], an effective length L[km], and a wavelength dispersion D [ps/nm/km] of each of the optical fibers at a wavelength of 1550 nm satisfy a predetermined, equation and the transmission loss of the optical fiber at the wavelength of 1550 nm is 0.19 dB/km or less, and the effective area of the optical fiber is in a range from 125 to 155 μm. 2: The optical fiber cable according to claim 1 ,wherein the mode field diameter of the optical fiber at the wavelength of 1550 nm is in a range from 12.0 to 13.5 μm.3: The optical fiber cable according to claim 1 ,wherein the wavelength dispersion of the optical fiber at the wavelength of 1550 nm is in a range from 19 to 22 ps/nm/km.4: The optical fiber cable according to claim 1 ,wherein the optical fiber has a cutoff wavelength in a range from 1400 to 1600 nm.5: The optical fiber cable according to claim 1 ,wherein the optical fiber comprises:a core having a diameter in a range from 12 to 15 μm; anda cladding surrounding the core and having a refractive index that is smaller than a refractive index of the core,wherein a relative refractive index difference of the core with respect to the cladding is in a range from 0.28% to 0.35%.6: The optical fiber cable according to claim 5 ,wherein a relative refractive index difference of the core with respect to pure silica is in a range from −0.1% to +0.1%.7: The optical fiber cable according to claim 1 ,wherein the optical fiber comprises:a core having a diameter in a range from 12 to 15 μm;an inner cladding surrounding the core and having a refractive index that is smaller than a refractive index of the core; andan outer cladding having a refractive index that is smaller than a refractive index of the core and larger than a refractive index of the inner cladding,wherein a relative refractive index difference ...

SINGLE-MODE LARGE EFFECTIVE AREA OPTICAL FIBERS

Optical fibers having a large effective area are disclosed. Three main embodiments of the optical fiber allow for single-mode operation at wavelengths of 850 nm, 980 nm and 1060 nm, respectively and have a large effective area with low bend losses. The large effective area optical fiber is expected to be particularly useful for data center applications due to its ability to efficiently optically couple with photonic integrated devices. Integrated systems and optical communication systems that employ the optical fibers are also disclosed. 1. An optical fiber comprising:{'sub': 1', '1max, 'a core region comprising an outer radius rin the range from 3.0 to 6.0 microns and a relative refractive index Δin the range from 0.12% to 0.35%;'}{'sub': 3', '3, 'sup': '2', 'a depressed index cladding region surrounding said core region, said depressed index cladding region comprising an outer radius rand a relative refractive index Δless than −0.1%, and a trench volume of at least 20% Δ-micron;'}{'sub': '4', 'an outer cladding region surrounding said depressed index cladding region, said outer cladding region comprising an outer radius r; and'}{'sup': '2', 'wherein said optical fiber has a mode field diameter (MFD) at 850 nm≧6.0 microns, a cable cutoff wavelength≦850 nm, an effective area at 850 nm of at least 30 micron, and a bending loss at 850 nm as determined by the mandrel wrap test using a mandrel comprising a diameter of 15 mm of ≦1.0 dB/turn.'}2. The optical fiber of claim 1 , wherein said outer radius ris in the range from 3.0 to 5.0 microns and said relative refractive index Δis in the range from 0.15% to 0.3%.3. The optical fiber of claim 2 , wherein said outer radius ris in the range from 12 to 20 microns claim 2 , said relative refractive index Δis less than −0.1% claim 2 , and said trench volume is at least 20% Δμm.4. The optical fiber of claim 3 , wherein said outer radius ris at least 60 microns and said relative refractive index Δis in the range from −0.05% to 0. ...

Low-dispersion single-mode optical fiber

A low-dispersion single-mode fiber includes a core and claddings covering the core. The core layer has a radius in a range of 3-5 μm and a relative refractive index difference in a range of 0.15% to 0.45%. The claddings comprise a first depressed cladding, a raised cladding, a second depressed cladding, and an outer cladding arranged sequentially from inside to outside. The first depressed cladding has a unilateral width in a range of 2-7 μm and a relative refractive index difference in a range of −0.4% to 0.03%. The raised cladding has a unilateral width in a range of 2-7 μm and a relative refractive index difference in a range of 0.05% to 0.20%. The second depressed cladding has a unilateral width in a range of 0-8 μm and a relative refractive index difference in a range of 0% to −0.2%. The outer cladding is formed of pure silicon dioxide glass.

Few mode optical fibers for mode division multiplexing

Few mode optical fibers for mode division multiplexing. The Few Mode Fiber supporting 25 or 30 LP guided modes and includes a graded index core with a α-profile, a radius R1 (at 0 refractive index difference) between 21.5 and 27 μm and a maximum refractive index difference Dn1 between 12.5×10−3 and 20×10−3, and an end of the α- profile at a radius R1b, with index difference Dn1b; a trench surrounding the core with radius R3 between 30 and 42 μm and refractive index difference Dn3 between −15.10−3 and −6.10−3, an intermediate depressed trench with a radius R2, with R1b<R2<R3 and a refractive index difference Dn2, with Dn3<Dn2<0, wherein: for |Dn1b−Dn2|>=0.5×10−3, Min(Dn1b, Dn2)≤−1.5×10−3, and for |Dn1b−Dn2|<0.5×10−3, Dn2 is between −5×10−3 and −3.5×10−3.

UNIVERSAL OPTICAL FIBER

The present disclosure provides a universal optical fiber (). The universal optical fiber () includes a core () extended from a central longitudinal axis () to a first radius r. In addition, the universal optical fiber () includes a buffer clad () region extending from the first radius rto a second radius r. Further, the universal optical fiber () includes a trench region () extending from the second radius rto a third radius r. Furthermore, the universal optical fiber () includes a cladding () extending from the third radius to a fourth radius r. Moreover, the core (), the buffer clad region (), the trench region () and the cladding () are concentrically arranged. 1100. A universal optical fiber () comprising:{'b': 102', '110', '100', '102, 'sub': 1', '1, 'a core () defined along a central longitudinal axis () of the universal optical fiber (), wherein the core () has a first radius rand a first refractive index Δ;'}{'b': 104', '102, 'sub': 1', '2', '2', '1, 'a buffer clad region () concentrically surrounding the core (), wherein the buffer clad region is defined between the first radius rand a second radius rand has a refractive index Δless than the refractive Δ; and'}{'b': 106', '106, 'sub': 2', '3', '3', '3', '4, 'a trench region (), wherein the trench region () is defined by a second radius rand the third radius rand a refractive index Δand wherein the refractive index Δis less than the refractive index Δand is a negative refractive index;'}{'b': 108', '108', '100, 'sub': 3', '4', '4', 'l', '2, 'a cladding (), wherein the cladding () is defined by a third radius rand a fourth radius rof the universal optical fiber () and a refractive index Δless than the refractive indices Δand Δ,'}{'b': '100', 'wherein the universal optical fiber () has a mode field diameter in range of about 8.7 micrometer to 9.5 micrometer,'}{'b': '100', 'wherein the universal optical fiber () has at least one of macro-bend loss up to 0.5 decibel per turn corresponding to wavelength of 1550 ...

Cutoff shifted optical fibre

The present disclosure provides an optical fibre. The optical fibre includes a core extended from a central longitudinal axis to a first radius r1. Further, the optical fibre includes a first trench region extended from a second radius r2 to a third radius r3, a second trench region extended from the third radius r3 to a fourth radius r4 and a cladding region extended from the fourth radius r4 to a fifth radius r5.

Micromodule cables and breakout cables therefor

A breakout cable includes a polymer jacket and a plurality of micromodules enclosed within the jacket. Each micromodule has a plurality of bend resistant optical fibers and a polymer sheath comprising PVC surrounding the bend resistant optical fibers. Each of the plurality of bend resistant optical fibers is a multimode optical fiber including a glass cladding region surrounding and directly adjacent to a glass core region. The core region is a graded-index glass core region, where the refractive index of the core region has a profile having a parabolic or substantially curved shape. The cladding includes a first annular portion having a lesser refractive index relative to a second annular portion of the cladding. The first annular portion is interior to the second annular portion. The cladding is surrounded by a low modulus primary coating and a high modulus secondary coating.

MULTIMODE OPTICAL FIBER

An embodiment of the invention relates to a BI-MMF with OH group concentrations controlled along a radial direction. In the BI-MMF, an OH group concentration distribution along the radial direction has a shape in which a concentration peak is located in a concentration control interval provided between an outer periphery of a core and a trench part, including an interface between the core and trench part. 1: A multimode optical fiber comprising:{'sub': '2', 'b': '2', 'i': 'a;', 'a core extending along a predetermined axis, doped with GeO, and having an outside diameter'}{'b': '2', 'i': 'b', 'a trench part surrounding an outer peripheral surface of the core, doped with fluorine, having a refractive index lower than a maximum refractive index of the core, and having an outside diameter ; and'}{'b': '2', 'i': 'c,', 'a cladding surrounding an outer peripheral surface of the trench part, having a refractive index lower than the maximum refractive index of the core and higher than the refractive index of the trench part, and having an outside diameter'}wherein in a cross section of the multimode optical fiber perpendicular to the predetermined axis, an OH group concentration distribution along a radial direction of the multimode optical fiber has a shape in which a concentration peak thereof is located in a concentration control interval where a distance from a center of the core is defined in the range of a/2 to b.2: The multimode optical fiber according to claim 1 , wherein in the cross section of the multimode optical fiber claim 1 , an OH group concentration at a first position separated by a distance a from the center of the core is higher than an OH group concentration at a second position separated by a distance a/2 from the center of the core and higher than an OH group concentration at a third position separated by a distance b from the center of the core.3: The multimode optical fiber according to claim 2 , wherein the OH group concentration distribution has a ...

MULTI-OPTICAL FIBER AGGREGATE

A multi-fiber aggregate is provided. The multi-fiber aggregate includes at least two optical fibers, each of the at least two optical fibers having a core member formed from a silica-based glass and an outer cladding layer formed from a silica-based glass surrounding and in direct contact with the core member. The multi-fiber aggregate also includes a polymeric binding coating surrounding the at least two optical fibers and holding the at least two fibers in a predetermined geometry. 1. A multi-optical fiber aggregate comprising:at least two optical fibers, each of the at least two optical fibers having a core region formed from a silica-based glass and an outer cladding region formed from a silica-based glass surrounding and in direct contact with the core region; anda polymeric binding coating surrounding the at least two optical fibers and holding the at least two fibers in a predetermined geometry.2. The multi-fiber aggregate of claim 1 , wherein at least two optical fibers have a diameter of less than about 125 microns.3. The multi-fiber aggregate of claim 2 , wherein the at least two optical fibers have a diameter of between about 40 microns and about 120 microns.4. The multi-fiber aggregate of claim 1 , wherein the outer cladding region comprises a reduced refractive index region.5. The multi-optical fiber aggregate of claim 4 , wherein the outer cladding region further comprises an inner cladding region surrounding the core region claim 4 , wherein the reduced refractive index region surrounds the inner cladding region.6. The multi-optical fiber aggregate of claim 4 , wherein the reduced refractive index region comprises silica-based glass doped with fluorine.7. The multi-optical fiber aggregate of claim 1 , wherein the at least two optical fibers comprise an optical coating surrounding and in direct contact with the outer cladding region.8. The multi-optical fiber aggregate of claim 1 , wherein the at least two optical fibers comprise a substantially ...

LOW BEND LOSS OPTICAL FIBER WITH A CHLORINE DOPED CORE AND OFFSET TRENCH

An optical fiber includes (i) a chlorine doped silica based core having a core alpha (Core)≥4, a radius r, and a maximum refractive index delta Δ% and (ii) a cladding surrounding the core. The cladding surrounding the core includes a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ, b) a second inner cladding adjacent to and in contact with the first inner cladding having a refractive index Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ, and c) an outer cladding region surrounding the second inner cladding region and having a refractive index Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ. The optical fiber has a mode field diameter MFD at 1310 of ≥9 microns, a cable cutoff of ≤1260 nm, a zero dispersion wavelength of 1300 nm≤zero dispersion wavelength≤1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel of less than 0.75 dB/turn. 1. A single mode optical fiber comprising:{'sub': α', '1', '1 max, '(i) a chlorine doped silica based core comprising a core alpha (Core)≥4, a radius rand a maximum refractive index delta Δ;'} [{'sub': 2', '2', '2 min', '2 min', '1 max, 'a. a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ; and'}, {'sub': 5', 'max', '2 min', '5, 'b. an outer cladding region surrounding the second inner cladding region and having a refractive index Δand a radius r, such that Δ≥Δ;'}], '(ii) a cladding surrounding the core, the cladding comprising{'sub': '0', 'wherein the optical fiber has a mode field diameter MFD at 1310 of ≥9 microns, a cable cutoff of ≤1260 nm, a zero dispersion wavelength ranging from 1300 nm≤λ≤1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel of less than 0.75 dB/turn.'}2. The single mode optical fiber of claim 1 , further ...

OPTICAL FIBER AND METHOD OF MANUFACTURING THE SAME

An optical fiber includes a core, a depressed inner cladding surrounding the core, and an outer cladding surrounding the inner cladding, where a refractive index profile of the core includes an α power distribution in which an index α is 3.5 or more and 6 or less, a relative refractive index difference Δ of the inner cladding with respect to the adding is set such that an absolute value |Δ| thereof is 0.01% or more and 0.045% or less, a radius r1 of the core and an outer circumference radius r2 of the inner cladding are set such that a ratio r1/r2 thereof is 0.2 or more and 0.6 or less, a cable cutoff wavelength λof 22 m is 1260 nm or less, and a mode field diameter MFD at a wavelength of 1310 nm is 8.6 μm or more and 9.5 μm or less. 1. An optical fiber , comprising:a core;a depressed inner cladding surrounding the core; andan outer cladding surrounding the inner cladding, a refractive index profile of the core comprises an α power distribution in which an index α is 3.5 or more and 6 or less,', {'sup': −', '−, 'a relative refractive index difference Δ of the inner cladding with respect to the outer cladding is set such that an absolute value |Δ| thereof is 0.01% or more and 0.045% or less,'}, 'a radius r1 of the core and an outer circumference radius r2 of the inner cladding are set such that a ratio r1/r2 thereof is 0.2 or more and 0.6 or less,', {'sub': 'cc', 'a cable cutoff wavelength λof 22 m is 1260 nm or less, and'}, 'a mode field diameter MFD at a wavelength of 1310 nm is 8.6 μm or more and 9.5 μm or less., 'wherein2. The optical fiber according to claim 1 , whereinthe refractive index profile of the core comprises an α power distribution in which an index α is 5 or more and 6 or less.3. The optical fiber according to claim 1 , wherein{'sup': −', '−, 'the relative refractive index difference Δ is set such that the absolute value |Δ| thereof is 0.01% or more and 0.03% or less.'}4. The optical fiber according to claim 1 , whereinthe radius r1 and the outer ...

HALOGEN CO-DOPED OPTICAL FIBERS

A method of forming an optical fiber, including: exposing a soot core preform to a dopant gas at a pressure of from 1.5 atm to 40 atm, the soot core preform comprising silica, the dopant gas comprising a first halogen doping precursor and a second halogen doping precursor, the first halogen doping precursor doping the soot core preform with a first halogen dopant and the second halogen precursor doping the soot core preform with a second halogen dopant; and sintering the soot core preform to form a halogen-doped closed-pore body, the halogen-doped closed-pore body having a combined concentration of the first halogen dopant and the second halogen dopant of at least 2.0 wt %. 1. A method of forming an optical fiber , comprising:exposing a soot core preform to a dopant gas at a pressure of from 1.5 atm to 40 atm, the soot core preform comprising silica, the dopant gas comprising a first halogen doping precursor and a second halogen doping precursor, the first halogen doping precursor doping the soot core preform with a first halogen dopant and the second halogen precursor doping the soot core preform with a second halogen dopant; andsintering the soot core preform to form a halogen-doped closed-pore body, the halogen-doped closed-pore body having a combined concentration of the first halogen dopant and the second halogen dopant greater than 2.0 wt %.2. The method of claim 1 , wherein the first halogen dopant is Cl.3. The method of claim 2 , wherein the Cl dopant has a halogen co-doping ratio in a range from 20% to 90% in the halogen-doped closed-pore body.4. The method of claim 2 , wherein the second halogen dopant is Br.5. The method of claim 1 , wherein the combined concentration of the first halogen dopant and the second halogen dopant is in the range from 3.0 wt % to 8.0 wt %.6. The method of claim 1 , wherein the exposing of the soot core preform is performed at a temperature of from 1300° C. to 1550° C.7. The method of claim 1 , wherein the soot core preform is ...

MULTIMODE OPTICAL FIBER AND OPTICAL CABLE INCLUDING THE SAME

An embodiment of the invention relates to a MMF with a structure for enabling stable manufacture of the MMF suitable for wide-band multimode optical transmission, for realizing faster short-haul information transmission than before. In the MMF, when an input position of a DMD measurement pulse on an input end face is represented by a distance r from a center of a core with a radius a, a power of the DMD measurement pulse on an output end face with the input position r of the DMD measurement pulse being 0.8a is not more than 70% of a power of the DMD measurement pulse on the output end face with the input position r of the DMD measurement pulse being 0. 1. A multimode optical fiber comprising:an input end face;an output end face opposed to the input end face;a core with an outside diameter 2a extending from the input end face to the output end face and having an α-power refractive index profile; anda cladding provided on an outer peripheral surface of the core,wherein, when an input position of a DMD measurement pulse on the input end face is represented by a distance r from a center of the core,a power of the DMD measurement pulse on the output end face with the input position r of the DMD measurement pulse being 0.8a is not more than 70% of a power of the DMD measurement pulse on the output end face with the input position r of the DMD measurement pulse being 0.2. A multimode optical fiber comprising:an input end face;an output end face opposed to the input end face;a core with an outside diameter 2a extending from the input end face to the output end face and having an α-power refractive index profile;a cladding provided on an outer peripheral surface of the core; anda trench part provided between the core and the cladding and having a lower refractive index than the cladding,wherein, when an input position of a DMD measurement pulse on the input end face is represented by a distance r from a center of the core,a power of the DMD measurement pulse on the output ...

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.

CONCENTRIC FIBER FOR SPACE-DIVISION MULTIPLEXED OPTICAL COMMUNICATIONS AND METHOD OF USE

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode. 120-. (canceled)21. An optical communication system , comprising:a first transmitter unit to generate a first optical signal;a concentric spatial division multiplexed (SDM) fiber having a first core concentric with a second core, the second core radially separated within the concentric SDM fiber from the first core, the concentric SDM fiber having a first end and a second end;a first spatial multiplexer/demultiplexer disposed on a path of the first optical signal from the first transmitter unit to a first end of the concentric SDM fiber;a first receiver unit disposed to receive the first optical signal after the first optical signal has propagated along the first core of the SDM fiber from the first transmitter;a second spatial multiplexer/demultiplexer disposed on a path of the first optical signal from a second end of the concentric SDM fiber to the first receiver unit;a second transmitter unit to generate a second optical signal;a second receiver unit disposed to receive the second optical signal after the second optical signal has propagated along the second core of the SDM fiber from the second transmitter and through the first and second spatial multiplexer/demultiplexers.22. The system as recited in claim 21 , wherein the second transmitter unit is disposed to direct the second optical signal into the first end of the concentric SDM fiber and the second receiver unit is disposed to ...

LOW BEND LOSS SINGLE MODE OPTICAL FIBER WITH CHLORINE UPDOPED CLADDING

An optical fiber having both low macrobend loss and low microbend loss. The fiber has a central core region, a first (inner) cladding region surrounding the central core region and having an outer radius r>16 microns and relative refractive index Δ, and a second (outer) cladding region surrounding the first cladding region having relative refractive index, 4, wherein Δ>Δ>Δ. The difference between Δand Δis greater than 0.12 percent. The fiber exhibits a 22m cable cutoff less than or equal to 1260 nm, and r/ris greater or equal to 0.24 and bend loss at 1550 nm for a 15 mm diameter mandrel of less than 0.5 dB/turn. 1. An optical fiber comprising:{'sub': 1', '1, '(i) a central core region having outer radius rand refractive index 4'} [{'sub': 2', '2', '1', '2, '(a) a first cladding region having an outer radius 25 microns>r>16 microns and relative refractive index 4, wherein the ratio of r/ris larger than 0.24 and'}, {'sub': 3', '3', '1', '3', '2', '3', '2', '3, '(b) a second cladding region surrounding the first cladding region and having a relative refractive index Δand an outer radius r, wherein the second cladding region comprises at least 1.2 wt % chlorine (Cl), and wherein Δ>Δ>Δand wherein the difference between Δand Δis greater than 0.12%, and Δ>0.12%;'}], '(ii) a cladding surrounding the central core region, the cladding comprisingand said fiber exhibits a mode field diameter MFD>9 microns at a 1310 nm wavelength; and bend loss at 1550 nm for a 15 mm diameter mandrel of less than 0.5 dB/turn.2. The optical fiber of claim 1 , wherein the difference between Δand Δis greater than 0.13%.3. The optical fiber of claim 1 , wherein the difference between Δand Δis between 0.12% and 0.25%.4. The optical fiber of claim 1 , wherein said fiber exhibits a 22 m cable cutoff less than or equal to 1260 nm.5. The optical fiber of claim 1 , wherein the central core region of said fiber exhibits an alpha less than 10.6. The optical fiber of claim 1 , said fiber further exhibiting a ...

OPTICAL FIBER AND OPTICAL TRANSPORT SYSTEM

The present invention relates to an optical fiber which can improve OSNR in an optical transmission system in which Raman amplification and an EDFA are combined. With respect to the optical fiber, a predetermined conditional formula is satisfied by an effective area Aeff[μm] at a wavelength of 1450 nm, a transmission loss α[/km] at a wavelength of 1450 nm, and a transmission loss α[dB/km] at a wavelength of 1550 nm. Further, with respect to the optical fiber, another predetermined conditional formula is satisfied by an effective area Aeff[μm] at a wavelength of 1550 nm, and a transmission loss α[/km] at a wavelength of 1550 nm. 2. The optical fiber according to claim 1 , wherein each of the core and the cladding is configured to satisfy the following formula:{'br': None, 'sub': 1550', '1550, 'Aeff·α>2.2'}{'sub': 1550', '1550, 'sup': '2', 'where Aeff[μm] is an effective area at a wavelength of 1550 nm; and α[/km] is a transmission loss at a wavelength of 1550 nm.'}3. The optical fiber according to claim 1 , wherein the transmission loss αat a wavelength of 1550 nm is 0.17 dB/km or less.4. The optical fiber according to claim 1 , wherein an effective area Aeffat a wavelength of 1550 nm is 70 μmto 160 μm.5. The optical fiber according to claim 1 , wherein a transmission loss αat a wavelength of 1450 nm is 0.19 dB/km to 0.22 dB/km.6. The optical fiber according to claim 1 , wherein the effective area Aeffat a wavelength of 1450 nm is 60 μmto 140 μm.7. The optical fiber according to claim 1 , wherein a relative refractive index difference of the core with respect to pure silica is −0.1% to +0.1%.8. The optical fiber according to claim 7 , wherein a relative refractive index difference of the core with respect to a reference area of the cladding is 0.18% to 0.45% claim 7 , and a diameter of the core is 9 μm to 15 μm.9. The optical fiber according to claim 1 , wherein a fiber cutoff wavelength is 1600 nm or less.10. The optical fiber according to claim 9 , wherein the ...

OPTICAL FIBERS HAVING A VARYING CLAD INDEX AND METHODS OF FORMING SAME

An optical fiber with low attenuation and methods of making same are disclosed. The optical fiber has a core, an inner cladding surround the core, and an outer cladding surrounding the inner cladding. The outer cladding is chlorine-doped such that the relative refractive index varies as a function of radius. The radially varying relative refractive index profile of the outer cladding reduces excess stress in the core and inner cladding, which helps lower fiber attenuation while also reducing macrobend and microbend loss. A process of fabricating the optical fiber includes doping an overclad soot layer of a soot preform with chlorine and then removing a portion of the chlorine dopant from an outermost region of the overclad soot layer. The soot preform with the modified chlorine dopant profile is then sintered to form a glass preform, which can then be used for drawing the optical fiber. 1. An optical fiber comprising:{'sub': 1', '1', '1MAX, 'a core having an outer radius rand a relative refractive index Δ(r) having a maximum value Δ, the core being centered on a central axis and having an alpha value greater than 1;'}{'sub': 2', '2, 'an inner cladding surrounding the core and having a relative refractive index Δand an outer radius rgreater than 9 microns;'}{'sub': 3', '3', 'MAX', '3MAX', '2', 'MIN', '3MIN', 'MIN', 'MAX, 'an outer cladding immediately surrounding the inner cladding and having an outer radius rand a relative refractive index Δ(r) that includes at a radius r=r, a maximum relative refractive index Δ>Δ, and that includes at a radius r=r, a minimum relative refractive index Δ, wherein r>r;'}{'sub': 1MAX', '3MAX', '2, 'claim-text': [{'sub': 3MAX', '2, 'ii) Δ−Δ>0.005 Δ%;'}, {'sub': 3MAX', '3MIN, 'iii) Δ−Δ≧0.01 Δ%; and'}], 'wherein: i) Δ>Δ>Δ;'}wherein the outer cladding comprises chlorine doped silica with a chlorine concentration C that varies with the radial coordinate.2. An optical fiber according to claim 1 , wherein the alpha value is less than 10.3. An ...

ADJUSTABLE BEAM CHARACTERISTICS

Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery device, comprising a first length of fiber comprising a first RIP formed to enable modification of one or more beam characteristics of an optical beam by a perturbation device and a second length of fiber having a second RIP coupled to the first length of fiber, the second RIP formed to confine at least a portion of the modified beam characteristics of the optical beam within one or more confinement regions. 1. An optical beam delivery device , comprising:a first length of fiber comprising a first refractive index profile (RIP) formed to enable modification of two or more beam characteristics of an optical beam by a perturbation device; anda second length of fiber having a second RIP coupled to the first length of fiber, the second RIP formed to confine at least a portion of the modified beam characteristics of the optical beam within one or more confinement regions, wherein the first RIP and the second RIP are different.2. The optical beam delivery device of wherein the second length of fiber comprises at least two confinement regions.3. The optical beam delivery device of claim 1 , wherein the perturbation device is coupled to the first length of fiber or integral with the first length of fiber or a combination thereof.4. The optical beam delivery device of claim 1 , wherein the first length of fiber comprises a graded-index RIP in at least a radially central portion and the second length of fiber has a first confinement region comprising a central core and a second confinement region that is annular and encompasses the first confinement region.5. The optical beam delivery device of claim 4 , wherein the first confinement region and the second confinement region are separated by a cladding structure having a refractive index that is lower than the indexes of first confinement region and the second confinement region.6. The optical beam delivery device of claim 5 , wherein ...

WIDEBAND MULTIMODE CO-DOPED OPTICAL FIBER EMPLOYING GeO2 AND Al2O3 DOPANTS

The wideband multimode co-doped optical fiber has a silica core co-doped with GeOand AlO. The GeOconcentration is maximum at the fiber centerline and monotonically decreases radially out to the core radius. The AlOconcentration is minimum at the centerline and monotonically increases radially out to maximum concentration at the core radius. The cladding has an inner cladding region of relative refractive index Δ2, an intermediate cladding region having a relative refractive index Δ3, and an outer cladding region having a relative refractive index Δ4, wherein Δ3<Δ2, Δ4. The optical fiber has a bandwidth BW≥5 GHz·km with a peak wavelength λwithin a wavelength range of 800 nm to 1200 nm and over a wavelength band Δλ of at least 100 nm. 1. A wideband multimode co-doped optical fiber having a centerline and comprising:{'sub': 2', '2', '3', '2', '2', '3, 'a core of radius r1 and comprising silica and co-doped with a first concentration of GeOand a second concentration of AlO, wherein the first concentration of GeOhas a first maximum concentration at the centerline and monotonically decreases radially out to the radius r1 and wherein the second concentration of AlOhas a minimum at the centerline and monotonically increases radially out to a second maximum concentration at the radius r1, wherein the first maximum concentration is in a range from 5 wt % to 25 wt % and the second maximum concentration is in a range from 1 wt % to 10 wt %;'}{'sub': 'MIN', 'a cladding immediately surrounding the core and comprising silica, the glass cladding having an inner cladding region of relative refractive index Δ2, an intermediate cladding region having a relative refractive index Δ3, and an outer cladding region having a relative refractive index Δ4, wherein Δ3<Δ2, Δ4; and'}{'sub': 'P', 'a wavelength band Δλ of at least 100 nm, the wavelength band Δλ having a peak wavelength λin a wavelength range from 800 nm to 1200 nm and a bandwidth BW≥5 GHz·km.'}2. The wideband multimode co-doped ...

METHOD OF ASSEMBLING OPTICAL FIBER PREFORMS

The present disclosure provides optical fiber preforms formed from core canes having large core-clad ratio, intermediate core-cladding assemblies, and methods for making the preforms and core cladding assemblies. The preforms are made from core canes having a contoured end surface. The contoured end surface(s) include a depression that acts to reduce the stress that develops at the junction of the end surface of the core cane with a soot cladding monolith arising from differences in the coefficient of thermal expansions of the core can and soot cladding monolith. The contoured end surface(s) leads to preforms having low defect concentration and low probability of failure during fiber draw. 1. A core-cladding assembly comprising:a porous soot cladding monolith, said porous soot cladding monolith including a first porous cladding glass layer surrounding an internal cavity, said porous soot cladding monolith having a first coefficient of thermal expansion, said internal cavity including a first entrance;a consolidated glass body positioned in said internal cavity, said consolidated glass body having a second coefficient of thermal expansion and a first end surface within said internal cavity, said first end surface facing said first entrance and including a first depression.2. The core-cladding assembly of claim 1 , wherein said consolidated glass body comprises doped silica.3. The core-cladding assembly of claim 1 , wherein said first porous cladding glass layer is in direct contact with said consolidated glass body.4. The core-cladding assembly of claim 2 , wherein said consolidated glass body has a core-clad ratio of at least 0.70.5. The core-cladding assembly of claim 1 , wherein said second coefficient of thermal expansion is greater than said first coefficient of thermal expansion.6. The core-cladding assembly of claim 1 , wherein said first depression has an ellipsoidal claim 1 , conical claim 1 , hemispherical claim 1 , annular claim 1 , cylindrical claim 1 , ...

SMALL CORE-DIAMETER GRADED-INDEX OPTICAL FIBER

A small core-diameter graded-index optical fiber include a core layer and a cladding having an inner cladding layer, a depressed cladding layer, and an outer cladding layer from inside to outside thereof. The core layer has a parabolic refractive index profile with a distribution index in a range of 1.9-2.1, a radius in a range of 10-21 μm, and a Δ1 max in a range of 0.7-1.7% at a core layer center, and is a silica glass layer co-doped with germanium, phosphorus, and fluoride. The inner cladding layer is a pure silica layer or an F-doped silica glass layer, and has a unilateral width in a range of 0.5-5 μm and a Δ2 in a range of −0.4-0%. The depressed cladding layer has a unilateral width in a range of 2-10 μm and a Δ3 in a range from −0.8% to −0.2%. The outer cladding layer is a pure silica glass layer. 1. A small core-diameter graded-index optical fiber , comprising:a core layer and a cladding that includes an inner cladding layer, a depressed cladding layer, and an outer cladding layer from inside to outside thereof,wherein the core layer has a parabolic refractive index profile with a distribution index α in a range from 1.9 to 2.1, a radius R1 in a range from 10 to 21 μm, and a maximum relative refractive index difference Δ1 max in a range from 0.7% to 1.7% at a core layer center, and is a silica glass layer co-doped with germanium Ge, phosphorus P, and fluoride F;wherein the inner cladding layer is a pure silica layer or an F-doped silica glass layer, and has a unilateral width R2−R1 in a range from 0.5 to 5 μm and a relative refractive index difference Δ2 in a range from −0.4% to 0%;wherein the depressed cladding layer has a unilateral width R3−R2 in a range from 2 to 10 μm and a relative refractive index difference Δ3 in a range from −0.8% to −0.2%; andwherein the outer cladding layer is a pure silica glass layer.2. The small core-diameter graded-index optical fiber according to claim 1 , wherein P and Ge are used as positive dopants in the core layer claim ...

MULTI-MODE OPTICAL FIBER AND METHODS FOR MANUFACTURING THE SAME

Methods of manufacturing multi-mode optical fiber, and multi-mode optical fiber produced thereby, are disclosed. According to embodiments, a method for forming an optical fiber may include heating a multi-mode optical fiber preform and applying a draw tension to a root of the multi-mode optical fiber preform on a long axis of the multi-mode optical fiber preform thereby drawing a multi-mode optical fiber from the root of the multi-mode optical fiber preform. The draw tension may be modulated while the multi-mode optical fiber is drawn from the root of the multi-mode optical fiber preform. Modulating the draw tension introduces stress perturbations in the multi-mode optical fiber and corresponding refractive index perturbations in a core of the multi-mode optical fiber. 1. A method for forming an optical fiber comprising:heating a multi-mode optical fiber preform;applying a draw tension to a root of the multi-mode optical fiber preform on a long axis of the multi-mode optical fiber preform thereby drawing a multi-mode optical fiber from the root of the multi-mode optical fiber preform; andmodulating the draw tension while the multi-mode optical fiber is drawn from the root of the multi-mode optical fiber preform, wherein modulating the draw tension introduces stress perturbations in the multi-mode optical fiber and corresponding refractive index perturbations in a core of the multi-mode optical fiber.2. The method of claim 1 , wherein the draw tension is periodically modulated.3. The method of claim 1 , wherein the draw tension is aperiodically modulated.4. The method of claim 1 , wherein the stress perturbations in the multi-mode optical fiber have a pitch greater than or equal to 0.1 mm and less than or equal to 50 mm.5. The method of claim 1 , wherein modulating the draw tension comprises increasing the draw tension by greater than or equal to 1 gram and less than or equal to 50 grams.6. The method of claim 1 , wherein a diameter variation of the multi-mode ...

OPTICAL FIBER FOR FIBER BRAGG GRATING

An optical fiber having a composition that is most suitable from the viewpoint of filter formation time and filter properties of slanted fiber grating (SFG) is provided. An optical fiber made of silica-based glass comprises a core region, which does not contain GeOand includes the optical axis, and a cladding region formed around the core region. The cladding region has a refractive index smaller than that of the core region and contains GeOof 6.8 wt % or more. SFG made with the optical fiber enables base loss of 2 dB or less, peak wavelength shift of 1.2 nm or less, and change of 0.2 nm or less in width at half maximum. 1. An optical fiber made of silica-based glass , comprising:a core region including an optical axis of the fiber and{'sub': '2', 'a cladding region formed around the core region, the cladding region having a refractive index smaller than a refractive index of the core region and containing GeOhaving a concentration of 6.8 wt % or more at least at a part thereof.'}2. An optical fiber according to claim 1 , whereinthe concentration is 7.4% or less.3. An optical fiber according to claim 1 , whereinthe concentration is 8.7% or less.4. An optical fiber according to claim 2 , whereinsaid part of the cladding region has an outer diameter, the outer diameter being 1.5 to 4.0 times larger than a mode field diameter at a wavelength in the C-band.5. An optical fiber according to claim 3 , whereinsaid part of the cladding region has an outer diameter, the outer diameter being 1.5 to 4.0 times larger than a mode field diameter at a wavelength in the C-band.6. An optical fiber according to claim 1 , wherein{'sub': 2', '2', '2', '2, 'said part of the cladding region includes an inner circumference and an outer circumference around the inner circumference, the concentration of GeOat the inner circumference is larger than the concentration of GeOat the outer circumference, and the difference between the GeOconcentration at the inner circumference and the ...

Graded refractive index bending-resistant multimode optical fiber

A graded refractive index bending-resistant multimode optical fiber includes a core layer and claddings. The core layer has a radius in a range of 22.5-27.5 μm; refractive indexes being a gradient-graded refractive index distribution with a distribution exponent α in a range of 1.99-2.06; and a maximum relative refractive index difference (RRID) Δ1% max in a range of 0.9%-1.3%. The claddings has an inner cladding surrounding the core layer, an intermediate cladding surrounding the inner cladding and an outer cladding surrounding the inner cladding. The inner cladding has a radius in a range of 25.5-34.5 μm, and an RRID Δ2% in a range of −0.02%-0.02%. The intermediate cladding is a pure quartz glass layer, and has a radius in a range of 30.5-49.5 μm, and an RRID Δ3% in a range of −0.01%-0.01%. The outer cladding has a radius in a range of 61.5-63.5 μm, and an RRID Δ4% is in a range of −0.20%-0.30%.

OPTICAL FIBER STRUCTURES AND METHODS FOR VARYING LASER BEAM PROFILE

In various embodiments, the beam parameter product and/or numerical aperture of a laser beam is adjusted utilizing a step-clad optical fiber having a central core, a first cladding, an annular core, and a second cladding. 131.-. (canceled)32. A step-clad optical fiber for use in a laser system comprising (I) a beam source for emission of an input laser beam and (ii) a controller for adjusting a position , at an input end of the step-clad optical fiber , of the input laser beam relative to a longitudinal axis of the step-clad optical fiber , whereby a resulting output beam is emitted from an output end of the step-clad optical fiber opposite the input end , the step-clad optical fiber comprising:a central core having a first refractive index;surrounding the central core, a first cladding having a second refractive index smaller than the first refractive index;surrounding the first cladding, a first annular core having a third refractive index larger than the second refractive index;surrounding the first annular core, a second cladding having a fourth refractive index smaller than the third refractive index;surrounding the second cladding, a second annular core having a fifth refractive index larger than the fourth refractive index; andsurrounding the second annular core, a third cladding having a sixth refractive index smaller than the fifth refractive index.33. The step-clad optical fiber of claim 32 , wherein the third refractive index is substantially equal to the first refractive index.34. The step-clad optical fiber of claim 32 , wherein the second refractive index is larger than the fourth refractive index.35. The step-clad optical fiber of claim 32 , wherein the second refractive index is larger than the sixth refractive index.36. The step-clad optical fiber of claim 32 , wherein a numerical aperture of the first cladding is larger than 0.12.37. The step-clad optical fiber of claim 32 , wherein a thickness of the first cladding ranges from approximately 40 μm ...

Light diffusing fibers with integrated mode shaping lenses

A method including the steps of providing a light-diffusing optical fiber ( 12 a ) having a glass core ( 20 ), a cladding ( 40 ) surrounding the core ( 20 ), and a plurality of nano-sized structures in the form of voids ( 32 ) situated within said core ( 20 ) or at a core-cladding boundary; cleaving the light-diffusing fiber ( 12 a ), thereby forming a cleaved end face ( 66 ); and applying energy to one or more of 1) the cleaved end face ( 66 ) and 2) the light-diffusing fiber ( 12 b ) along a portion of the length thereof adjacent the cleaved end face ( 66 ), the amount of energy being sufficient to collapse and seal the voids ( 32 ) exposed at the cleaved end face ( 66 ), leaving a sealed cleaved end face ( 68 ). A lens may then be attached to the sealed cleaved end face ( 68 ), or the sealed cleaved end face ( 68 ) may be softened sufficiently to induce formation of a lensing surface such as a convex lensing surface ( 60 ) on the sealed end face ( 68 ).

OPTICAL FIBER STRUCTURES AND METHODS FOR VARYING LASER BEAM PROFILE

In various embodiments, the beam parameter product and/or numerical aperture of a laser beam is adjusted utilizing a step-clad optical fiber having a central core, a first cladding, an annular core, and a second cladding. 131.-. (canceled)32. A step-clad optical fiber having an input end and an output end opposite the input end , the step-clad optical fiber comprising:a central core having a first refractive index;surrounding the central core, a first cladding having a second refractive index;surrounding the first cladding, an annular core having a third refractive index; andsurrounding the annular core, a second cladding having a fourth refractive index,wherein (i) the first refractive index is larger than the second refractive index and larger than the fourth refractive index, and (ii) the third refractive index is larger than the second refractive index and larger than the fourth refractive index.33. The step-clad optical fiber of claim 32 , wherein the second refractive index is larger than the fourth refractive index.34. The step-clad optical fiber of claim 32 , wherein the second refractive index is equal to the fourth refractive index.35. The step-clad optical fiber of claim 32 , wherein the second cladding is present as an unbroken layer extending between the input end and the output end.36. The step-clad optical fiber of claim 32 , wherein the central core is composed of fused silica or fused silica doped with fluorine claim 32 , titanium claim 32 , germanium claim 32 , and/or boron.37. The step-clad optical fiber of claim 32 , wherein the annular core is configured for the receipt of laser energy at the input end and the transmission of laser energy therethrough from the input end to the output end.38. The step-clad optical fiber of claim 32 , wherein the step-clad optical fiber is a multi-mode optical fiber.39. The step-clad optical fiber of claim 32 , wherein the first refractive index is equal to the third refractive index.40. The step-clad optical ...

HYDROGEN-RESISTANT OPTICAL FIBER

Embodiments of the invention relate to a hydrogen-resistant optical fiber with a core having a central axis. The core may include only silica, or only silica and fluorine, while a cladding region surrounding the core may be made of silica and fluorine, along with at least one of germanium, phosphorus, and titanium. 1. A hydrogen-resistant , graded-index optical fiber comprising:a core having a central axis, the core consisting essentially of silica and fluorine, wherein a concentration of fluorine within the core increases as a radial distance from the central axis increases; anda cladding region surrounding the core, the cladding region comprising silica, fluorine, and at least one of germanium, phosphorus, and titanium.2. The hydrogen-resistant claim 1 , graded-index optical fiber of claim 1 , wherein the cladding region comprises an inner cladding region claim 1 , the inner cladding region (i) comprising silica claim 1 , fluorine claim 1 , and at least one of germanium claim 1 , phosphorus claim 1 , and titanium claim 1 , and (ii) having a refractive index lower than a refractive index of the core.3. The hydrogen-resistant claim 2 , graded-index optical fiber of claim 2 , wherein a concentration of fluorine and at least one of germanium claim 2 , phosphorus claim 2 , and titanium in the inner cladding region varies substantially across the inner cladding region.4. The hydrogen-resistant claim 2 , graded-index optical fiber of claim 2 , wherein a concentration of fluorine and at least one of germanium claim 2 , phosphorus claim 2 , and titanium in the inner cladding region is substantially constant across the inner cladding region.5. The hydrogen-resistant claim 2 , graded-index optical fiber of claim 2 , wherein the inner cladding region comprises about 0.1 wt % to about 5.0 wt % of at least one of germanium claim 2 , phosphorus claim 2 , and titanium.6. The hydrogen-resistant claim 2 , graded-index optical fiber of claim 2 , wherein the inner cladding region ...

Low bend loss single mode optical fiber

An optical fiber comprising: (i) a core region comprising an outer radius r 1 , and 3.0≤r 1 ≤7.0 microns and a relative refractive index Δ 1max and 0.32%≤Δ 1max ≤0.5%; (b) a depressed index cladding region surrounding the core region comprising an outer radius r 3 and a relative refractive index Δ 3 less than −0.2%, and trench volume V 3 wherein 45% Δ-micron 2 ≤|V 3 |≤200% Δ-micron 2 ; (c) a first outer cladding region surrounding the depressed index cladding region and comprising a relative refractive index Δ 4 and an outer radius r 4 ; and (d) a second outer cladding layer comprising 5 wt %-20 wt % titania, a relative refractive index Δ 5 , and a thickness T M , wherein 3 micron≤T M ≤30 microns, and outer radius r 5 ≤65 microns; the optical fiber has a mode field diameter MFD 1550 and 8 microns≤MFD 1550 ≤10.5 microns, a cutoff wavelength <1550 nm when bent 1 turn around a 2.5 mm radius mandrel, and a bending loss at 1550 nm when using a mandrel comprising a radius of 2.5 mm of ≤10 dB/turn.

Polarization-Maintaining (PM) Double-Clad (DC) Optical Fiber

A double-clad (DC) polarization-maintaining (PM) optical fiber comprises a core, an inner cladding, an outer cladding, and stress rods. The core has a core refractive index (n). The inner cladding is located radially exterior to the core and has an inner cladding refractive index (n), which is less than n. The stress rods are located in the inner cladding, and each stress rod has a stress rod refractive index (n), which is substantially matched to n. The outer cladding is located radially exterior to the inner cladding. The outer cladding has an outer cladding refractive index (n), which is less than n. 1. A high-power optical system , comprising: (a1) a substantially perpendicular leading edge;', '(a2) a core;', {'sub': '1', '(a3) an inner cladding surrounding the core; the inner cladding having an inner cladding refractive index (n); and'}, {'sub': 2', '2', '1, 'claim-text': (a4A) a bowtie configuration;', '(a4B) a panda configuration; and', '(a4C) an elliptical region radially exterior to the core;, '(a4) a stress region located in the inner cladding, the stress region comprising a stress region refractive index (n), a difference between nand nbeing between approximately 0.001 and approximately 0.003, the stress region being stress rods exhibiting a configuration selected from the group consisting of], '(a) a double-clad (DC) polarization-maintaining (PM) optical fiber comprising(b) an input fiber core-match spliced to the core of the PM-DC fiber at the substantially perpendicular leading edge, the input fiber for introducing a signal to the core of the DC-PM optical fiber; and(c) a pump combiner optically spliced to the PM-DC fiber at the perpendicular leading edge of the stress region, the pump combiner for introducing pump light into the inner cladding at the substantially perpendicular leading edge, the pump combiner further for introducing pump light into the stress region at the substantially perpendicular leading edge.2. The system of claim 1 , further ...

OPTICAL CONNECTION COMPONENT

The embodiment relates to an optical connection component including a bent optical fiber having a bent portion including a region where a curvature of the bent portion is maintained at 0.4 [l/mm] or more while substantially no bending stress remains. The bent optical fiber comprises a core, a first cladding, a second cladding, and a third cladding. Based on the third cladding, a relative refractive index difference Δ1 of the core, a relative refractive index difference Δ2 of the first cladding, and a relative refractive index difference Δ3 of the second cladding satisfy relationships of Δ1>Δ2>Δ3 and Δ3<−0.5 [%]. The product V3 of the Δ3 and a cross-sectional area S of the second cladding is less than −200 [%·μm]. The curvature in the bent portion is 0.6 [l/mm] or less over an entire length of the bent portion. 1. An optical connection component comprisinga bent optical fiber having:{'sub': '2', 'a glass fiber mainly comprising of SiOglass; and'}a resin coating surrounding the glass fiber while being removed from an end of the glass fiber,whereinthe glass fiber at least includes a core, a first cladding surrounding the core, a second cladding surrounding the first cladding, and a third cladding surrounding the second cladding, {'br': None, 'Δ1>Δ2>Δ3 and Δ3<−0.5[%],'}, 'a relative refractive index difference Δ1 of the core with respect to the third cladding, a relative refractive index difference Δ2 of the first cladding with respect to the third cladding, and a relative refractive index difference Δ3 of the second cladding with respect to the third cladding satisfy relationships of'}{'sup': '2', 'a product V3 of the relative refractive index difference Δ3 and a cross-sectional area S of the second cladding is less than −200 [%·μm], and'} 'a bent portion including a region where a curvature of the bent portion is maintained at 0.4 [l/mm] or more in a state where substantially no bending stress remains, the curvature in the bent portion being 0.6 [l/mm] or less over an ...

Optical fiber with low macrobend loss at large bend diameter

The present disclosure provides optical fibers that exhibit low macrobend loss at 1550 nm at bend diameters greater than 40 mm. The relative refractive index profile of the fibers includes a trench cladding region having a trench volume configured to minimize macrobend loss at large bend diameters. The thickness and/or depth of the trench cladding region are controlled to reduce trench volume to a degree consistent with reducing macrobend loss at bend diameters greater than 40 mm. The optical fiber includes an outer cladding region that surrounds and is directly adjacent to the trench cladding region and an optional offset cladding region between the trench cladding region and the core region. In some embodiments, the core region is a segmented core region that includes inner and outer core regions. The low macrobend loss available from the optical fibers makes them particularly suitable for applications in submarine telecommunications systems.

OPTICAL FIBER

The optical fiber includes a core, the first cladding, and second cladding. The core is made of silica based glass containing Cl. The first cladding and the second cladding are made of silica based glass containing fluorine. The refractive index of the first cladding is lower than that of the core. The refractive index of the second cladding is lower than that of the core and higher than that of the first cladding. The second cladding is divided into an outer region having a uniform refractive index and an inner region having a refractive index higher than that of the outer region. The difference ΔP between the maximum refractive index of the inner region and the refractive index of the outer region is 0.02% to 0.10% in terms of relative refractive index with respect to pure silica based glass. The radial thickness R of the inner region is 10 μm to 25 μm. 1. An optical fiber comprising:a core made of silica based glass containing Cl;a first cladding that surrounds the core, that has a refractive index lower than a refractive index of the core, and that is made of silica based glass containing fluorine; anda second cladding that surrounds the first cladding, that has a refractive index lower than the refractive index of the core and higher than the refractive index of the first cladding, and that is made of silica based glass containing fluorine,wherein the second cladding is divided into an outer region that has a substantially uniform refractive index and an inner region that is located inside of the outer region and that has a refractive index higher than the refractive index of the outer region,wherein a difference between a maximum refractive index of the inner region and the refractive index of the outer region is 0.02% or greater and 0.10% or smaller in terms of relative refractive index with respect to pure silica glass, andwherein a radial thickness of the inner region is 10 μm or greater and 25 μm or smaller.2. The optical fiber according to claim 1 , ...

Method of making optical fibers in a reducing atmosphere

A method for forming an optical fiber preform and fibers drawn from the preform. The method includes forming a soot cladding monolith, inserting a consolidated core cane into the internal cavity, and processing the resulting core-cladding assembly to form a preform. Processing may include exposing the core-cladding assembly to a drying agent and/or dopant precursor, and sintering the core-cladding assembly in the presence of a reducing agent to densify the soot cladding monolith onto the core cane to form a preform. The preform features low hydroxyl content and low sensitivity to hydrogen. Fibers drawn from the preform exhibit low attenuation losses from absorption by the broad band centered near 1380 nm.

OPTICAL FIBER AND OPTICAL FIBER TRANSMISSION PATH

The present embodiment relates to an optical fiber having a W-type refractive index d profile or a trench-type refractive index profile and having reduced microbending loss in a wavelength band to be actually used. The optical fiber includes a center core, an inner cladding surrounding the center core, and an outer cladding surrounding the inner cladding. The inner cladding has a refractive index lower than a refractive index of at least the center core and the outer cladding has a refractive index lower than the refractive index of the center core and higher than the refractive index of the inner cladding. Wavelength dependency of microbending loss has a local maximal value and a shortest wavelength λwhere the microbending loss becomes 10% of the local maximal value is longer than 1560 nm. 1. An optical fiber comprising:a center core;an inner cladding surrounding the center core and having a refractive index lower than a refractive index of the center core; andan outer cladding surrounding the inner cladding and having a refractive index lower than the refractive index of the center core and. higher than the refractive index of the inner cladding,{'sub': 'th', 'wherein the center core, the inner cladding, and the outer cladding are configured such that wavelength dependency of microbending loss of the optical fiber has a local maximal value and a shortest wavelength λwhere the microbending loss becomes 10% of the local maximal value is longer than 1560 nm.'}2. The optical fiber according to claim 1 , further comprising a pedestal located between the center core and the inner cladding and having a refractive index lower than the refractive index of the center core and higher than the refractive index of the inner cladding.3. The optical fiber according to claim 1 ,wherein the optical fiber has a cable cutoff wavelength of 1710 nm or more.4. The optical fiber according to claim 1 ,wherein the local maximal value is 0.6 dB/km or less.5. The optical fiber according to ...

Multicore optical fiber and design method

An object of the present invention is to provide a multi-core optical fiber that can prevent an increase in bending loss even when a distance between a peripheral core and a cladding boundary is decreased, and can improve a bending loss characteristic in a state where an influence on a cutoff wavelength and a mode field diameter is small, and a design method thereof.The multi-core optical fiber according to the present invention is an optical fiber in which two or more core regions are arranged in a cladding region having a refractive index lower than a refractive index of the core at a minimum core interval, a ring-shaped low refractive index region surrounding the core and having a refractive index lower than the refractive index of the cladding region is provided, a bending loss after the provision of the ring-shaped low refractive index region is reduced as compared with a characteristic in a case where the ring-shaped low refractive index region is not provided, and at the same time, a change in mode field diameter after the provision of the ring-shaped low refractive index region is not changed as compared with a characteristic in a case where the ring-shaped low refractive index region is not provided.

HIGH-BANDWIDTH BEND-INSENSITIVE MULTIMODE FIBER

A high-bandwidth bend-insensitive multimode fiber includes a core laver and a cladding including an inner cladding, a depressed cladding, and an outer cladding arranged sequentially from inside to outside. The core layer is a silicon dioxide glass layer co-doped with germanium, phosphorus (P), and fluorine (F) and has a refractive index profile in a shape of a parabola, a distribution index in a range of 2.0-2.3, a radius in a range of 23-27 μm, and a maximum relative refractive index difference in a range of 0.9-1.2% at its center. A contribution amount of P at the center is in a range of 0.01-0.30%. A doping amount of F increases from the center to the edge of the core layer. A contribution amount of F at the center and edge of the core layer is in range of 0.0% to −0.1%, and −0.40% to −0.20%, respectively. 2. The high-bandwidth bend-insensitive multimode fiber according to claim 1 , wherein the inner cladding is a silicon dioxide glass layer co-doped with phosphorus P and fluorine F claim 1 , wherein a contribution amount of doping of F claim 1 , i.e. claim 1 , ΔF2 claim 1 , is in a range of −0.18% to −0.08%; a contribution amount of P at an outer edge of the inner cladding claim 1 , i.e. claim 1 , ΔP2 claim 1 , is in a range of 0% to 0.40%; and a difference between the contribution amount of P at the boundary of the core layer and the inner cladding and the contribution amount of P at the outer edge of the inner cladding is ΔP21 claim 1 , and ΔP21=ΔP2−ΔP1 claim 1 , ΔP21 being in a range of −0.3% to −0.01% or in a range of 0.01% to 0.20%.3. The high-bandwidth bend-insensitive multimode fiber according to claim 2 , wherein the inner cladding is divided into a platform area and a graded area from inside to outside according to variation of a concentration of P claim 2 , wherein the concentration of P in the platform region remains substantially consistent claim 2 , and then the concentration of P gradually increases or decreases claim 2 , the platform area having a ...

MULTIMODE OPTICAL FIBER

The present invention relates to an MMF with a structure for relaxing wavelength dependence of transmission bandwidth. In the MMF, a doping amount of a dopant for control of refractive index is adjusted, so as to make each of an OFL bandwidth at a wavelength of 850 nm and an OFL bandwidth at a wavelength of at least one of 980 nm, 1060 nm, and 1300 nm become not less than 1500 MHz·km, make the OFL bandwidth at the wavelength of at least one of 980 nm, 1060 nm, and 1300 nm become wider than the OFL bandwidth at the wavelength of 850 nm, and effectively suppress increase in transmission loss. 1. A multimode optical fiber having: a core extending along a predetermined axis; and a cladding provided on an outer peripheral surface of the core ,wherein when a first condition is defined as a condition that an OFL bandwidth at a wavelength of 850 nm is not less than 1500 MHz·km and an OFL bandwidth at a wavelength of at least one of 980 nm, 1060 nm, and 1300 nm is not less than 1500 MHz·km and when a second condition is defined as a condition that the OFL bandwidth at the wavelength of at least one of 980 nm, 1.060 nm, and 1300 nm is wider than the OFL bandwidth at the wavelength of 850 nm, a doping amount of a dopant for control of refractive index in a region corresponding to at least either of the core and the cladding of the multimode optical fiber is adjusted so as to satisfy both of the first condition and the second condition, andwherein transmission loss in a wavelength range of 850 nm to 1300 nm is not more than 4.0 dB/km.2. The multimode optical fiber according to claim 1 , wherein the cladding is comprised of silica glass doped with the dopant for control of refractive index claim 1 , or claim 1 , a material other than the silica glass.3. The multimode optical fiber according to claim 1 , wherein the core has a GI refractive index profile and the GI refractive index profile is formed by doping the core with a plurality of dopants different from each other claim 1 ...

Bend-insensitive multimode optical fiber with reduced impact of leaky modes

A multimode optical fiber is provides, which includes an optical core and an optical cladding surrounding the optical core. The optical core has a refractive graded-index profile. The optical cladding includes: an inner layer surrounding the optical core, an intermediate layer, called a “depressed trench”, surrounding the inner layer, and an outer layer surrounding the depressed trench and having a constant refractive index. The depressed trench has a width W and a negative refractive index difference Δn t with respect to the outer layer, and is designed so as to satisfy the following inequality: |0.585677−114.681× S +13.7287× S 2 +18.7343× S×W −4.61112× S×Δn t ·10 3 −0.913789× W×Δn t ·10 3 |+2× W×Δn t ·10 3 <−30 wherein: S is the width of the inner cladding, which is included between 0.6 μm and 1.6 μm; Δn t is included between −11.10 −3 and −4.10 −3 ; and W×Δn t ·10 3 is lower than −25 μm.

RAMAN-ENHANCED TRANSMISSION FIBER

According to some embodiments an optical fiber comprising: (I) a silica based core having: an inner core region with maximum refractive index delta of the core, Δin % measured relative to pure SiO≦0.1%, and an outer core region with a minimum refractive index delta Δ, where Δ<Δ; such that the fiber has: (i) an effective area Aeffof LPmode at a wavelength λ=1525 nm such that 80 μmAeff, and (Aeff−Aeff)/Aeff≧0.07; and'}], 'such that the fiber has'} [{'sub': RMIN', 'R,MIN', '1, '(i) a low index ring surrounding the core and having a minimum refractive index delta Δ, where Δ<Δ; and'}, {'sub': Outer-Clad', 'Outer-Clad', 'R,MIN, '(ii) an outer cladding with a refractive index delta Δrelative to pure silica, such that Δ>Δ.'}], '(II) an annular cladding surrounding the core, the cladding including'}2. The optical fiber of wherein{'sub': 0', '1, '−0.02%≦Δ≦0.1%, and −0.25≦Δ<−0.08; and'}{'sub': RMIN', '2, 'Δ≦−0.30, measured relative to pure SiO.'}3. The optical fiber of claim 2 , wherein the core is Ge free claim 2 , and the absolute difference between the relative refractive index of the core Δand the outer cladding Δis: |Δ−Δ|>0.05%.4. The optical fiber of claim 2 , wherein 75 μm Подробнее

OPTICAL TRANSMISSION SYSTEMS AND METHODS USING A QSM LARGE-EFFECTIVE-AREA OPTICAL FIBER

Optical transmission systems and methods are disclosed that utilize a QSM optical fiber with a large effective area and that supports only two modes, namely the fundamental mode and one higher-order mode. The optical transmission system includes a transmitter and a receiver optically coupled by an optical fiber link that includes at least one section of the QSM optical fiber. Transmission over optical fiber link gives rise to MPI, which is mitigated using a digital signal processor. The QSM optical fiber is designed to have an amount of DMA that allows for the digital signal processor to have reduced complexity as reflected by a reduced number of filter taps as compared to if the DMA were zero. 1. An optical transmission system , comprising:{'sub': 'eff', 'sup': '2', 'a quasi-single mode (QSM) optical fiber configured to support a fundamental mode having effective area A>170 μmand an attenuation of no greater than 0.2 dB/km for a wavelength of 1530 nm, and to support a single higher-order mode having a differential modal attenuation (DMA) of at least 1.0 dB/km at a wavelength of 1530 nm;'}an optical transmitter optically coupled to the QSM optical fiber and configured to emit light that defines an optical signal that carries information;an optical receiver optically coupled to the optical transmitter by the QSM optical fiber and configured to receive the light emitted by the optical transmitter and transmitted over the QSM optical fiber in the fundamental mode and the single higher-order mode, wherein the transmission of the optical signals over the QSM optical fiber gives rise to multipath interference (MPI), and wherein the optical receiver generates an analog electrical signal representative of the received light;an analog-to-digital converter (ADC) electrically connected to the optical receiver and that converts the analog electrical signal into a corresponding digital electrical signal; and{'sub': T', 'T, 'a digital signal processor electrically connected to ...

MULTICORE OPTICAL FIBER WITH CHLORINE DOPED CORES

A multicore optical fiber includes a first core, a second core, and a common cladding. The first core includes silica and greater than 3 wt % chlorine, a first core centerline, a relative refractive index Δ, and an outer radius r. The second core includes silica and greater than 3 wt % chlorine, a second core centerline, a relative refractive index Δ, and an outer radius r. A spacing between the first core centerline and the second core centerline is at least 28 micrometers and a crosstalk between the first core and the second core is ≤−30 dB, as measured for a 100 km length of the multicore optical fiber operating at a wavelength of 1550 nm. 1. A multicore optical fiber , comprising:{'sub': 1MAX', '1, 'a first core comprising silica and greater than 3 wt % chlorine, wherein the first core comprises a first core centerline, a relative refractive index Δ, and an outer radius r;'}{'sub': IC1', 'IC1', '1MAX', 'IC1, 'a first inner cladding surrounding the first core and comprising a relative refractive index Δand a width δr, wherein Δ>Δ;'}{'sub': 2MAX', '2, 'a second core comprising silica and greater than 3 wt % chlorine, wherein the second core comprises a second core centerline, a relative refractive index Δ, and an outer radius r;'}{'sub': IC2', 'IC2', '2MAX', 'IC2, 'a second inner cladding surrounding the second core and comprising a relative refractive index Δand a width δr, wherein Δ>Δ; and'}{'sub': 'CC', 'a common cladding surrounding the first core and the second core, wherein the common cladding comprises a relative refractive index Δ, and'}wherein a spacing between the first core centerline and the second core centerline is at least 28 micrometers and a crosstalk between the first core and the second core is ≤−30 dB, as measured for a 100 km length of the multicore optical fiber operating at a wavelength of 1550 nm.2. The multicore optical fiber of claim 1 , wherein the first inner cladding and the second inner cladding comprise one of undoped silica and ...

Distributed Brillouin Sensor

A distributed Brillouin sensor system comprising a pump laser, a Brillouin sensor fiber, and a detector system is described. The pump laser is arranged so as to send a pump signal into a first end of the Brillouin sensor fiber, and the detector system is arranged to detect Brillouin backscattering from the Brillouin sensor fiber. The Brillouin sensor fiber is characterized by having a negative dispersion, and further by an effective area of the sensor fiber being less than or equal to 50 μm. 1. A distributed Brillouin sensor system comprising a pump laser , a Brillouin sensor fiber , and a detector system , whereinthe pump laser is arranged so as to send a pump signal into a first end of the Brillouin sensor fiber, and a negative dispersion, and wherein', {'sup': '2', 'an effective area of the sensor fiber is less than or equal to 50 μm.'}], 'the detector system is arranged to detect Brillouin backscattering from the Brillouin sensor fiber, wherein the Brillouin sensor fiber is characterized by having'}2. The distributed Brillouin sensor system according to claim 1 , wherein the sensor system further comprises a probe laser arranged so as provide a probe signal into an opposite end of the Brillouin sensor fiber.3. The distributed Brillouin sensor system according to claim 1 , wherein the Brillouin sensor fiber is further characterized by havinga low attenuation, anda high Brillouin gain.4. The distributed Brillouin sensor system according to claim 3 , wherein the attenuation is less than 0.25 dB/km.5. The distributed Brillouin sensor system according to claim 3 , wherein the attenuation is less than 0.20 dB/km6. The distributed Brillouin sensor system according to claim 1 , wherein the dispersion is more negative than −2 ps/nm/km claim 1 , advantageously more negative than −5 ps/nm/km.7. The distributed Brillouin sensor system according to claim 3 , wherein the Brillouin gain is at least twice the Brillouin gain of a G.652 standard single-mode fiber.8. The ...

LOW BEND LOSS OPTICAL FIBER WITH A CHLORINE DOPED CORE AND OFFSET TRENCH

An optical fiber includes (i) a chlorine doped silica based core having a core alpha (Core)≥4, a radius r, and a maximum refractive index delta Δ% and (ii) a cladding surrounding the core. The cladding surrounding the core includes a) a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ, b) a second inner cladding adjacent to and in contact with the first inner cladding having a refractive index Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ, and c) an outer cladding region surrounding the second inner cladding region and having a refractive index Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ. The optical fiber has a mode field diameter MFD at 1310 of ≥9 microns, a cable cutoff of ≤1260 nm, a zero dispersion wavelength of 1300 nm≤zero dispersion wavelength ≤1324 nm, and a macrobending loss at 1550 nm for a 20 mm mandrel of less than 0.75 dB/turn. 1. A single mode optical fiber comprising:{'sub': α', '1', '1max, '(i) a chlorine doped silica based core comprising a core alpha (Core)≥4, a radius r, and a maximum refractive index delta Δ;'} [{'sub': 2', '2', '2min', '2min', '1max, 'a. a first inner cladding region adjacent to and in contact with the core and having a refractive index delta Δ, a radius r, and a minimum refractive index delta Δsuch that Δ<Δ;'}, {'sub': 3', '3', '3max', '2min', '3max, 'b. a second inner cladding adjacent to and in contact with the first inner cladding and having a refractive index Δ, a radius r, and a maximum refractive index delta Δsuch that Δ<Δ; and'}, {'sub': 5', 'max', '5', '3max, 'c. an outer cladding region surrounding the second inner cladding region and having a refractive index Δand a radius r, such that Δ<Δ;'}], '(ii) a cladding surrounding the core, the cladding comprising{'sub': '0', 'wherein the optical fiber has a mode field diameter MFD at 1310 of ≥9 microns, a ...

LOW LOSS OPTICAL FIBER WITH CORE CODOPED WITH TWO OR MORE HALOGENS

A co-doped optical fiber is provided having an attenuation of less than about 0.17 dB/km at a wavelength of 1550 nm. The fiber includes a core in the fiber having a graded refractive index profile with an alpha of greater than 5. The fiber also includes a cladding in the fiber that surrounds the core addition, the core includes silica that is co-doped with two or more halogens. 1. A single mode optical fiber , comprising:a core having a graded refractive index profile with an alpha of less than 5; andthe cladding comprising a depressed cladding region and an outer cladding region in contact with and surrounding the depressed cladding region,wherein the core has a relative refractive index of greater than +0.25% compared to that of the outer cladding region, wherein the core comprises silica co-doped with a first halogen and a second halogen, wherein the concentrations of said first and said second halogen within the core are non-uniform, such that:(a) the ratio of maximum and minimum concentration of the first halogen in the core is at least 3,(b) the ratio of maximum and minimum concentration of the second halogen in the core is at least 3,(c) the concentration within the core of one halogen increases as distance from the center of the core increases,(d) and the concentration within the core of the other halogen decreases as distance from the center of the core increases,wherein a fiber has an attenuation of less than about 0.17 dB/km at a wavelength of 1550 nm.2. The single mode optical fiber of claim 1 , wherein the ratio of maximum and minimum concentration of the first halogen in the core is at least 10.3. The single mode optical fiber of claim 2 , the ratio of maximum and minimum concentration of the second halogen in the core is at least 10.4. The single mode optical fiber of wherein the first halogen is Cl or Br claim 1 , and the second halogen is F.5. A single mode optical fiber claim 1 , comprising:a core having a graded refractive index profile with an ...

Low Loss Optical Fiber And Method Of Making The Same

The core region of an optical fiber is doped with chlorine in a concentration that allows for the viscosity of the core region to be lowered, approaching the viscosity of the surrounding cladding. An annular interface region is disposed between the core and cladding and contains a concentration of fluorine dopant sufficient to match the viscosity of the core. By including this annular stress accommodation region, the cladding layer can be formed to include the relatively high concentration of fluorine required to provide the desired degree of optical signal confinement (i.e., forming a “low loss” optical fiber). The inclusion of the annular stress accommodation region allows for the formation of a large effective area optical fiber that exhibits low loss (i.e., <0.19 dB/km) in both the C-band and L-band transmission ranges. 1. An optical fiber comprisinga chlorine-doped silica core region;a fluorine-doped cladding region; anda fluorine-doped annular stress-accommodation region disposed between the core region and the cladding region, the fluorine-doped annular stress-accommodation region including a concentration of a fluorine dopant sufficient to exhibit a viscosity similar to the core region, the cladding region exhibiting a fluorine dopant concentration greater than the annular stress accommodation region and at least sufficient to provide confinement of the propagating optical signal to the combination of the core region and the annular stress-accommodation region.2. The optical fiber of wherein the optical fiber has an attenuation of less than about 0.17 dB/km for a propagating signal in the C-band transmission wavelength range.3. The optical fiber of wherein the optical fiber has an effective area greater than 100 μmwhen supporting the transmission of an optical signal in the C-band transmission wavelength range.4. The optical fiber of wherein the effective area is greater than 150 μmfor a C-band transmission wavelength of about 1550 nm.5. The optical fiber of ...

Low bend loss optical fiber with graded index core

A single mode optical fiber, comprising: (i) a silica based core having a graded refractive index profile with an alpha of less than 5, a relative refractive index Δ1max, and an outer radius r1, wherein 10 microns>r1≥6.5 microns, the core comprising Cl, Ge, or a combination thereof; (ii) a first cladding region in contact with and surrounding the core, the first cladding region having a relative refractive index Δ2min, an inner radius r1, and an outer radius r2, wherein r2<20 microns; and (iii) an outer cladding region surrounding the first cladding region, the outer cladding region having a relative refractive index Δ3. The fiber has MFD at 1310 nm>than 9 microns, a zero dispersion wavelength <1306 nm; a 22 m cable cutoff wavelength <1260nm; and a bend loss <0.005 dB/turn when the fiber is bent around a 30 mm mandrel; and <0.5dB/turn when the fiber is bent around a 20 mm mandrel.

FEW MODE OPTICAL FIBER

The present disclosure provides a few mode optical fiber. The few mode optical fiber includes a core region. A core region defined by a region around a central longitudinal axis of the few mode optical fiber. In addition, the core region has a first annular region extended from central longitudinal axis to radius r, a second annular region extended from radius rto radius r, a third annular region extended from radius rto radius r, a fourth annular region extended from radius rto radius rand a fifth annular region extended from radius rto radius r. Also, the few mode optical fiber has a cladding defined by the sixth annular region extended from radius rto radius r. 1. A few mode optical fiber comprising: [{'sub': '1', 'a first annular region, wherein the first annular region is between the central longitudinal axis and a first radius r, wherein the first annular region has a first refractive index delta-1;'}, {'sub': 1', '2, 'a second annular region, wherein the second annular region is between the first radius rand a second radius r, wherein the second annular region has a second refractive index delta-2;'}, {'sub': 2', '3, 'a third annular region, wherein the third annular region is between the second radius rand a third radius r, wherein the third annular region has a third refractive index delta-3;'}, {'sub': 3', '4', '4', '4, 'a fourth annular region, wherein the fourth annular region is between the third radius rand a fourth radius r, wherein the fourth annular region has a fourth refractive index Δ, wherein the fourth radius ris in a range of 8.3 microns to 9.9 microns and the fourth refractive index delta-4 is approximately zero;'}, {'sub': 4', '5', '5, 'a fifth annular region, wherein the fifth annular region is between the fourth radius rand a fifth radius r, wherein the fifth region has a fifth refractive index delta-5, wherein the fifth radius ris in a range of 10.9 microns to 12.6 microns and the fifth refractive index delta-5 is in a range of 0.41 to 0. ...

NON-ZERO DISPERSION SHIFTED FIBER WITH LOW CUT OFF WAVELENGTH AND LARGE EFFECTIVE AREA

The present disclosure provides an optical fiber. The optical fiber includes a core region. The core region is defined by a region around central longitudinal axis of the optical fiber. In addition, the core region has a first annular region. The first annular region is defined from the central longitudinal axis to a first radius rfrom the central longitudinal axis. Moreover, the core region has a second annular region. The second annular region is defined from the first radius rto a second radius r. Further, the core region has a third annular region. The third annular region is defined from the second radius rto a third radius r. Also, the optical fiber includes a cladding. The cladding region has a fourth radius r. 1. An optical fiber comprising: [{'sub': 1', '1, 'a first annular region defined from the central longitudinal axis to a first radius rfrom the central longitudinal axis of the optical fiber, wherein the first annular region has a first refractive index delta, wherein the first annular region in the core region has a parameter Υ (gamma), wherein the first annular region has a super Gaussian profile;'}, {'sub': 1', '2', '2, 'a second annular region defined from the first radius rto a second radius rfrom the central longitudinal axis of the optical fiber, wherein the second annular region has a second refractive index delta;'}, {'sub': 2', '3', '3, 'a third annular region defined from the second radius rto a third radius rfrom the central longitudinal axis of the optical fiber, wherein the third annular region has a third refractive index delta, wherein the first annular region, the second annular region and the third annular region are concentrically arranged; and'}, {'sub': 3', '4', '4, 'a cladding region defined from the third radius rto a fourth radius rfrom the central longitudinal axis of the optical fiber, wherein the cladding region has a fourth refractive index delta, the cladding region is further defined by a fourth annular region ...

Few-mode optical fiber

Provided is a few-mode optical fiber. The optical fiber includes: a core and a cladding enclosing the core. The cladding includes: a first inner cladding surrounding the core; a first high-refractive-index mode filter layer surrounding the first inner cladding; a second inner cladding surrounding the first high-refractive-index mode filter layer; a second high-refractive-index mode filter layer surrounding the second inner cladding; and an outer cladding surrounding the second high-refractive-index mode filter layer.

LASER SYSTEMS UTILIZING FIBER BUNDLES FOR POWER DELIVERY AND BEAM SWITCHING

In various embodiments, the beam parameter product and/or beam shape of a laser beam is adjusted by coupling the laser beam into an optical fiber of a fiber bundle and directing the laser beam onto one or more in-coupling locations on the input end of the optical fiber. The beam emitted at the output end of the optical fiber may be utilized to process a workpiece. 167.-. (canceled)68. A method of adjusting at least one of a beam parameter product or a beam shape of a laser beam , the method comprising:providing a fiber bundle comprising a plurality of optical fibers, each of the optical fibers having (i) an input end for receiving a laser beam, and (ii) opposite the input end, an output end for delivery of the received laser beam;directing a laser beam toward a selected one of the optical fibers of the fiber bundle; andthereduring, selecting at least one of a beam parameter product or a beam shape of the laser beam by directing the laser beam onto one or more in-coupling locations on the input end of the selected optical fiber,wherein at least one of the in-coupling locations intersects a cladding region of the selected optical fiber.69. The method of claim 68 , further comprising processing claim 68 , with the laser beam claim 68 , a workpiece disposed proximate the output end of the selected optical fiber.70. The method of claim 69 , wherein the at least one of the beam parameter product or the beam shape of the laser beam is selected based at least in part of a characteristic of the workpiece.71. The method of claim 70 , wherein the characteristic of the workpiece comprises at least one of a thickness of the workpiece or a composition of the workpiece.72. The method of claim 68 , wherein directing the laser beam toward the selected one of the optical fibers comprises at least one of (i) reflecting the laser beam with one or more reflectors or (ii) focusing the laser beam with one or more optical elements.73. The method of claim 68 , wherein a physical ...

BROMINE-DOPED OPTICAL FIBER

Bromine doping of silica glass is demonstrated. Bromine doping can be achieved with SiBras a precursor. Bromine doping can occur during heating, consolidation or sintering of a porous silica glass body. Doping concentrations of bromine increase with increasing pressure of the doping precursor and can be modeled with a power law equation in which doping concentration is proportional to the square root of the pressure of the doping precursor. Bromine is an updopant in silica and the relative refractive index of silica increases approximately linearly with doping concentration. Bromine can be used as a dopant for optical fibers and can be incorporated in the core and/or cladding regions. Core doping concentrations of bromine are sufficient to permit use of undoped silica as an inner cladding material in fibers having a trench in the refractive index profile. Co-doping of silica glass with bromine and chlorine is also demonstrated. 1. An optical fiber comprising Br.2. The optical fiber of claim 1 , wherein said optical fiber further comprises silica glass and said Br is a dopant in said silica glass.3. The optical fiber of claim 1 , further comprising Cl.4. The optical fiber of claim 1 , wherein said optical fiber includes a core and a cladding claim 1 , said core comprising Br.5. The optical fiber of claim 4 , wherein said core comprises silica glass doped with Br.6. The optical fiber of claim 4 , wherein said cladding comprises Br.7. The optical fiber of claim 5 , wherein the concentration of Br in said silica glass of said core is in the range from 1.5 wt %-3.0 wt %.8. The optical fiber of claim 5 , wherein said core further comprises Cl.9. The optical fiber of claim 5 , wherein said cladding includes an inner cladding and an outer cladding claim 5 , said inner cladding having a lower relative refractive index than said outer cladding and said outer cladding having a lower relative refractive index than said core.10. The optical fiber of claim 9 , wherein said inner ...

OPTICAL FIBER

An optical fiber including a core and a cladding including an inner cladding layer and an outer cladding layer is provided. The refractive index of the core Δ the refractive index of the inner cladding layer Δ and the refractive index of the outer cladding layer Δ have a relationship denoted by the following expressions: Δmax>Δmin and Δmax>Δ and 0.01%<|Δmin−Δ0.03%. An outer circumference radius r of the core, an outer circumferential radius r of the inner cladding layer, and an outer circumferential radius r of the outer cladding layer have a relationship denoted by the following expressions: rrr, and 0.2≦rr≦0.5. A cable cut-off wavelength λcc 1260 nm or less. A mode field diameter at a wavelength of 1310 nm is 8.6 μm or more and 9.5 μm or less. 1. An optical fiber comprising a core and a cladding formed on an outer periphery of the core , wherein:the cladding comprises at least an inner cladding layer adjacent to the core and an outer cladding layer formed on the outer circumference side of the inner cladding layer;{'b': 1', '1, 'a refractive index of the core is Δ and a maximum refractive index of the core is Δmax;'}{'b': 2', '2, 'a refractive index of the inner cladding layer is Δ and a minimum refractive index of the inner cladding layer is Δmin;'}{'b': '3', 'a refractive index of the outer cladding layer is Δ;'} [{'br': None, 'Δ1max>Δ2min and Δ1max>Δ3 \u2003\u2003(1)'}, {'br': None, '0.01%<|Δ2min−Δ3|<0.03% \u2003\u2003(2)'}], 'the refractive index of the core, the refractive index of the inner cladding layer, and the refractive index of the outer cladding layer have a relationship denoted by Expressions (1) and (2);'}{'b': 1', '2', '3, 'claim-text': [{'br': None, 'r1 Подробнее

COUPLED FEW MODE FIBERS, AND CORRESPONDING OPTICAL LINK AND OPTICAL SYSTEM

An optical fiber having an optical core and an optical cladding surrounding the optical core, the optical core having a single α graded-index profile with α≥ α being a non-dimensional parameter that defines the index profile shape of the optical core, and the optical core having a maximal refractive index nat its center; the optical cladding has at its outer edge a refractive index n, and comprises a region of depressed refractive index n, called a trench, with a negative refractive index difference Δn=n−nwith respect to said optical cladding, the trench having an outer radius R. The optical core and cladding are configured to support propagation of at least six spatial modes and at maximum fifty-five spatial modes at an operating wavelength λbetween, and including, 1460 nm and 1675 nm, and the optical core satisfies an ovality criterion between 0.05 and 0.3, when said ovality criterion is measured at a circumference of equal index nwithin said core, such that Δn−n−nis less than 75% of Δn=n−n, said ovality criterion o being defined by the following equation: 2. The optical fiber according to claim 1 , wherein said ovality criterion of said optical core varies as a function of a distance to the optical core center.3. The optical fiber according to claim 2 , wherein said ovality criterion of said optical core increases from a first low ovality value measured at a circumference of equal index n′within said core claim 2 , such that Δn′=n′−nis more than 75% of Δn=n−n claim 2 , to an optimum ovality value measured at said circumference of equal index nwithin said core claim 2 , such that Δn=n−nis less than 75% of Δn=n−n claim 2 , andwherein said ovality criterion of said optical core decreases from said optimum ovality value to a second low ovality value measured at a core-cladding interface.4. The optical fiber according to claim 3 , wherein said optimum ovality value is between 0.10 and 0.30.5. The optical fiber according to claim 3 , wherein said first and second low ...

OPTICAL FIBER WITH REDUCING HYDROGEN SENSITIVITY

The present disclosure is directed to a method of making an optical fiber with improved bend performance, the optical fiber having a core and at least one cladding layer, and a chlorine content in the in the last layer of the at least one cladding layer that is greater than 500 ppm by weight. The fiber is prepared using a mixture of a carrier gas, a gaseous chlorine source material and a gaseous reducing agent during the sintering of the last or outermost layer of the at least one cladding layer. The inclusion of the reducing gas into a mixture of the carrier gas and gaseous chlorine material reduces oxygen-rich defects that results in at least a 20% reduction in TTP during hydrogen aging testing. 1. An optical fiber comprising a core and at least one cladding layer , the at least one cladding layer including a chlorine dopant concentration of at least 500 ppm by weight , the optical fiber containing less than 1 ppb by weight of OD groups and having a time-to-peak (TTP) hydrogen aging value at 23° C. of less than 100 hours upon exposure to a gas atmosphere having a total pressure of 1 atm and containing a partial pressure of 0.01 atm Hand a partial pressure of 0.99 atm N.2. The optical fiber of claim 1 , wherein the time-to-peak (TTP) hydrogen aging value is less than 80 hours.3. The optical fiber of claim 1 , wherein the time-to-peak (TTP) hydrogen aging value is less than 60 hours.4. The optical fiber of claim 1 , wherein the time-to-peak (TTP) hydrogen aging value is less than 40 hours.5. The optical fiber of claim 1 , wherein the time-to-peak (TTP) hydrogen aging value is less than 30 hours.6. The optical fiber of claim 1 , wherein the at least one cladding layer includes a chlorine dopant concentration of at least 500 ppm by weight.7. The optical fiber of claim 1 , wherein the at least one cladding layer includes a chlorine dopant concentration of at least 1000 ppm by weight.8. The optical fiber of claim 1 , wherein the at least one cladding layer includes a ...

CONCENTRIC FIBER FOR SPACE-DIVISION MULTIPLEXED OPTICAL COMMUNICATIONS AND METHOD OF USE

A space-division multiplexed optical fiber includes a relatively high refractive index optical core region surrounded by alternating regions of relatively low and relative high refractive index material, forming concentric high index rings around the core. The optical core region supports propagation of light along at least a first radial mode associated with the optical core region and a high index ring region supports propagation of light along at least a second radial mode associated with the high index ring region. The second radial mode is different from the first radial mode. 1. A method of communicating , comprising:generating a first optical signal;generating a second optical signal;providing a concentric spatial division multiplexed (SDM) fiber having a central core formed of a first material, the central core being surrounded by a first concentric core formed of a second material, the core and the first concentric core being separated by a first cladding ring formed of a third material having a refractive index lower than a refractive index of the first material and lower than a refractive index of the second material;transmitting the first optical signal into the core of the SDM fiber;transmitting the second optical signal into the first concentric core of the SDM fiber;detecting the first optical signal after propagating along the central core of the SDM fiber; anddetecting the second optical signal after propagating along the first concentric core of the SDM fiber.2. A method as recited in claim 1 , wherein transmitting the first optical signal into the central core of the SDM fiber comprises transmitting the first optical signal into a first end of the SDM fiber and wherein transmitting the second optical signal into the first concentric core of the SDM fiber comprises transmitting the second optical signal into the first end of the SDM fiber.3. A method as recited in claim 1 , wherein transmitting the first optical signal into the central core of the ...

OPTICAL FIBER AND MANUFACTURING METHOD THEREOF

An optical fiber includes a core, and a clad surrounding an outer circumference of the core, in which a first relative refractive index difference Δ1a is greater than 0, a second relative refractive index difference Δ1b is greater than 0, the first relative refractive index difference Δ1a is greater than the second relative refractive index difference Δ1b, the first relative refractive index difference Δ1a and the second relative refractive index difference Δ1b satisfy a relationship denoted by the following expression: 0.20≦(Δ1a−Δ1b)/Δ1a≦0.88, and a refractive index profile A of the core in an entire region of a section of 0≦r≦r1 as a function Δ(r) of a distance r from a center of the core in the radial direction is denoted by the following expression: Δ(r)=Δ1a−(Δ1a−Δ1b)r/r1. 1. An optical fiber , comprising:a core; anda clad surrounding an outer circumference of the core,wherein when a radius of the core is r1, a relative refractive index difference between a center of the core and the clad is a first relative refractive index difference Δ1a, and a relative refractive index difference between a position in which a distance from the center of the core in a radial direction is r1 and the clad is a second relative refractive index difference Δ1b,the first relative refractive index difference Δ1a is greater than 0,the second relative refractive index difference Δ1b is greater than 0,the first relative refractive index difference Δ1a is greater than the second relative refractive index difference Δ1b, {'br': None, 'i': a−Δ', 'b', 'a<, '0.20<(Δ11)/Δ10.88, and'}, 'the first relative refractive index difference Δ1a and the second relative refractive index difference Δ1b satisfy a relationship denoted by the following expression {'br': None, 'i': r', 'a', 'a−Δ', 'b', 'r/r, 'Δ()=Δ1−(Δ11)1.'}, 'a refractive index profile A of the core in an entire region of a section of 0≦r≦r1 as a function Δ(r) of a distance r from the center of the core in the radial direction is denoted ...

MULTIMODE OPTICAL FIBER

An embodiment of the present invention relates to an MMF with a structure for reducing length dependence of optical characteristics while maintaining bend-insensitivity. The MMF has a trench portion provided between a core portion and a cladding portion and having a refractive index lower than that of the cladding portion. In a cross section of the MMF, the trench portion in at least a partial section of the MMF has a non-circularly symmetric shape with respect to an intersection between the optical axis and the cross section. 1. A multimode optical fiber comprising:{'sub': '2', 'a core portion extending along an optical axis and doped with GeO;'}a first cladding portion provided around an outer periphery of the core portion and having a refractive index lower than a maximum refractive index of the core portion; anda trench portion provided between the core portion and the first cladding portion and having a refractive index lower than the refractive index of the first cladding portion,wherein an α value to define a shape of a portion corresponding to the core portion in a refractive index profile in a radial direction of the multimode optical fiber is from 1.9 to 2.2, a maximum relative refractive index difference Δ of the core portion to the first cladding portion is from 0.8 to 2.4%, and a diameter of the core portion is from 25 μm to 65 μm, andwherein in a cross section of the multimode optical fiber perpendicular to the optical axis, the trench portion in a section of a predetermined length forming at least a part of the multimode optical fiber has a non-circularly symmetric shape with respect to an intersection between the optical axis and the cross section.2. The multimode optical fiber according to claim 1 , further comprising:a second cladding portion provided between the core portion and the trench portion and having a refractive index lower than the maximum refractive index of the core portion and higher than the refractive index of the trench portion.3. ...

OPTICAL FIBERS AND OPTICAL SYSTEMS COMPRISING THE SAME

An optical fiber for converting a Gaussian laser beam into a Bessel laser beam may include a first segment optically coupled to a second segment with a transition region, the first segment having a first outer diameter greater than a second outer diameter of the second segment. The first segment may include a first core portion with a first cladding portion extending around the first core portion. The first core portion may have an annular core region with a relative refractive index relative to the first cladding portion. The second segment may include a second core portion with a second cladding portion extending around the second core portion. The second core portion has a relative refractive index relative to the second cladding portion and the relative refractive index of the first annular core region may be substantially equal to the relative refractive index of the second core portion. 1. An optical fiber comprising: [{'sub': 1', '0', 'AC', '1', '0, 'a first core portion having a radius Rfrom an axial centerline of the optical fiber, the first core portion comprising a first annular core region centered on the axial centerline of the optical fiber and having an inner radius Rand a first radial thickness T=R−R; and'}, {'sub': CL', 'AC, 'a first cladding portion extending around the first core portion, the first cladding portion having a radial thickness T, the first annular core region having a relative refractive index Δ% relative to the first cladding portion;'}], 'a first segment comprising [{'sub': 1', '1', '1, 'a second core portion having a radius rfrom the axial centerline of the optical fiber, wherein at least a portion of the second core portion is optically coupled to the first annular core region and the radius Ris greater than the radius r; and'}, {'sub': cl', 'CL', 'c', 'AC', 'c, 'a second cladding portion extending around the second core portion, the second cladding portion having a radial thickness tthat is less than the radial thickness Tof the ...

MULTI-CLAD OPTICAL FIBER WITH DELOCALIZATION OF PEDESTAL MODES

A multi-clad optical fiber is provided. The fiber includes, concentrically and radially outwards from the center of the optical fiber, a core doped with at least one rare-earth dopant material, a pedestal cladding structure, an inner cladding and an outer cladding. The pedestal cladding structure includes a pedestal layer having a refractive index smaller than a refractive index of the core, and a raised index layer having a refractive index larger than the refractive index of the pedestal layer. The raised index layer has a thickness and a refractive index which preserve the confinement of the core mode in the core and minimize the overlap of one or more pedestal modes with the core. 1. A multi-clad optical fiber comprising , concentrically and radially outwards from a center axis of the optical fiber:{'sub': core', 'core, 'a core configured to guide a light signal in a core mode, said core having a core diameter dsmaller than about 30 μm, the core being doped with at least one rare-earth dopant material providing amplification of the light signal, the core having a refractive index n;'}{'sub': pcs', 'pcs', 'core, 'claim-text': [{'sub': ped', 'core, 'a pedestal layer contiguously surrounding the core and configured to confine the light signal in said core mode, the pedestal layer having a refractive index nsmaller than the refractive index of the core n; and'}, {'sub': ril', 'ped', 'core', 'ril, 'a raised index layer contiguously surrounding the pedestal layer and having a thickness Δw, the raised index layer having a refractive index nlarger than the refractive index of the pedestal layer nand smaller than the refractive index of the core n, the thickness Δw and the refractive index nof the raised index layer preserving a confinement of the core mode in the core and minimizing an overlap of one or more modes of the plurality of pedestal modes with the core;'}], 'a pedestal cladding structure supporting light propagation in a plurality of pedestal modes, the ...

FEW MODE OPTICAL FIBERS FOR SPACE DIVISION MULTIPLEXING

The invention relates to an optical fiber comprising an optical core and an optical cladding surrounding the optical core, the optical core having a single α graded-index profile with α≧1, and the optical core having a radius R1 and a maximal refractive index n, said optical cladding having a refractive index n. Said optical cladding comprises a region of depressed refractive index n, having an inner radius R, with R≧R, and an outer radius R3, with R3>R2. According to embodiments of the invention, the α-value of said graded index profile and the optical core radius Rare chosen such that R≧13.5 μm and so as to satisfy a criterion C of quality. Thus, the invention provides a few-mode optical fiber, which allow guiding an increased number of LP modes as compared to prior art FMFs, while reaching the lowest Differential Mode Group Delay. The system reach is thus increased over prior art. 2. The optical fiber according to claim 1 , wherein{'sub': 1', '1, 'said optical core radius Ris R≦20 μm.'}3. The optical fiber according to claim 1 , wherein said trench satisfies the following: 55≦100C·|(R−R)·Dn·(R·Dn)|≦150 where Dn=n−nis the trench-cladding index difference at λ=λ.4. The optical fiber according to claim 3 , wherein Dn≦−3.10.5. The optical fiber according to claim 1 , wherein the fiber guides 4 to 16 LP modes.6. The optical fiber according to claim 1 , wherein the fiber guides 6 to 16 LP modes.7. The optical fiber according to claim 1 , wherein said optical core has a minimal refractive index n=n claim 1 , and wherein said optical cladding also comprises an inner cladding layer directly surrounding said optical core claim 1 , with an inner radius Rand an outer radius R≧R claim 1 , said inner cladding layer having a constant refractive index n claim 1 , such that n≠nand n>n.8. The optical fiber according to claim 1 , wherein said optical core has a minimal refractive index n≠n claim 1 , and wherein said optical cladding further comprises an inner cladding layer ...

OPTICAL FIBER

Provided is an optical fiber that is suitable for high-density packing and long-haul transmission. An optical fiber according to the present invention includes a core and a cladding. At a wavelength of 1550 nm, an effective area Aeff is 100 μmor less and a chromatic dispersion Disp is 19.0 ps/nm/km or more and 22 ps/nm/km or less, and, when an effective length is denoted by Leff and an attenuation is denoted by cc, a figure of merit FOM represented by an expression “FOM=5 log{|Disp|·Leff}−10 log {Leff/Aeff}−100α” is 3.2 dB or more. 2. The optical fiber according to claim 1 ,wherein the attenuation α at a wavelength of 1550 nm is 0.164 dB/km or less.3. The optical fiber according to claim 1 ,{'sup': '2', 'wherein the effective area Aeff at a wavelength of 1550 nm is 76 μmor more.'}4. The optical fiber according to claim 1 ,{'sup': '2', 'wherein the effective area Aeff at a wavelength of 1550 nm is 62 μmor more.'}5. The optical fiber according to claim 1 ,wherein a fiber cut-off wavelength measured on a 2 m length of the optical fiber is 1.30 or more and 1.60 μm or less.6. The optical fiber according to claim 1 ,{'sup': 2', '2, 'wherein a dispersion slope S at a wavelength of 1550 nm is 0.05 ps/nm/km or more and 0.07 ps/nm/km or less.'}7. The optical fiber according to claim 1 ,{'sup': '2', 'wherein a splice loss when spliced to a single-mode optical fiber having an effective area of 80 μmat a wavelength of 1550 nm is 0.05 dB/facet or less.'}8. The optical fiber according to claim 1 ,wherein a relative refractive index difference of the core with respect to a refractive index of pure silica glass is 0.1% or more and 0.1% or less.9. The optical fiber according to claim 8 ,wherein the core is made of a silica-based glass that is doped with chlorine with an average concentration of 1000 atomic ppm or more.10. The optical fiber according to claim 8 ,wherein the core is doped with an alkali metal with an average concentration of 0.01 atomic ppm or more and 50 atomic ppm or ...

OPTICAL FIBER

Provided is an optical fiber having a W-type refractive-index profile and having a reduced bend loss at a practically used bend radius. The optical fiber of the invention comprises: a core; an inner cladding enclosing the core and having a refractive index smaller than the refractive index of the core; and an outer cladding enclosing the inner cladding and having a refractive index which is smaller than the refractive index of the core and larger than the refractive index of the inner cladding, whereas the bend radius Rt is 25 mm or less when 2. The optical fiber according to claim 1 , wherein{'sup': 2', '2, 'the optical fiber has an effective area of 110 μmor more and 170 μmor less, and has a cutoff wavelength of 1600 nm or less.'}3. The optical fiber according to claim 2 , wherein{'sup': 2', '2, 'the effective area is 110 μmor more and 160 μmor less.'}4. The optical fiber according to claim 3 , wherein{'sup': 2', '2, 'the effective area is 120 μmor more and 140 μmor less.'}5. The optical fiber according to claim 2 , whereinthe cutoff wavelength is 1500 nm or less.6. The optical fiber according to claim 1 , whereinthe core has a radius a, the inner cladding has an outside radius b, and a ratio b/a is 2.0 or more and 4.5 or less, and a relative refractive index difference of the outer cladding relative to the inner cladding is 0.01% or more and 0.15% or less.7. The optical fiber according to claim 6 , whereinthe core has a diameter of 12.0 μm or more and 15.5 μm or less, and a relative refractive index difference of the core relative to the inner cladding is 0.25% or more and 0.35% or less.8. The optical fiber according to claim 7 , whereinthe diameter is 12.0 μm or more and 14.5 μm or less.9. The optical fiber according to claim 6 , whereinthe core has a depressed portion existing at the center thereof and having a refractive index lower than that of a circumference thereof.10. The optical fiber according to claim 9 , whereinthe core has a diameter of 12.0 μm or ...

Optical fiber span with low differential mode delay

A fiber span comprising: a first optical fiber and a second optical fiber coupled to the first optical fiber, both fibers comprising the an inner core region with maximum refractive index delta, Δ 0 ≦0.1% and an outer radius R 1 >4.5 μm, an outer core region with an outer radius R 2 and a minimum refractive index delta Δ 1 and alpha value α≧5, wherein Δ 1 <Δ 0 , 5.5 μm≦R 2 −R 1 ≦12 μm; a cladding including a low index ring surrounding the core and a minimum refractive index delta Δ R,MIN <Δ 1 ; and an outer cladding having Δ Outer-Clad >Δ R,MIN ; the first fiber introducing differential mode delay DMD 1 for wavelengths between 1525 and 1570 nm such that |DMD 1 |≦100 ps/km, and a first differential mode delay slope DMDS 1 ; the second fiber introducing differential mode delay DMD 2 for wavelengths between 1525 and 1570 nm such that |DMD 2 |≦100 ps/km, and a second differential mode delay slope DMDS 2 that has an opposite sign from the first dispersion slope DMDS 1 ; wherein total differential mode delay provided by the first fiber in conjunction with the second fiber is DMD tot =DMD 1 +DMD 2 , and −1.0 ps/km<DMD tot <1.0 for all wavelengths between 1525 nm and 1570 nm.

FEW MODE OPTICAL FIBER LINKS FOR SPACE DIVISION MULTIPLEXING

The invention relates to an optical link comprising N optical fibers, with N≧2. Each optical fiber comprises an optical core and an optical cladding surrounding the optical core, the optical core having a single αgraded-index profile with α≧1, and the optical core having a radius R, where i E [1; N] is an index designating said optical fiber. Said optical cladding comprises a region of depressed refractive index n, called a trench, surrounding the optical core. According to embodiments of the invention, for all optical fibers in said link, said optical core radius Rand said length Lare chosen such that R≧13.5 μm and so as to satisfy a criterion C of quality. Thus, the invention provides a few-mode optical fiber link, which allow guiding an increased number of LP modes as compared to prior art FMF links, while reaching low Differential Mode Group Delay. 2. The optical link according to claim 1 , wherein at least one of said optical fibers has trench parameters 55≦1000·|(R−R)·Dn·(R·Dn)|≦150 where Dn=n−n claim 1 , is the trench-cladding index difference at λ=λ.3. The optical link according to claim 2 , wherein Dn≦−3.10.5. The optical link according to claim 4 , wherein said optical fiber R≦20 μm.6. The optical link according to claim 1 , wherein the optical link guides 4 to 16 LP modes.7. The optical link according to claim 1 , wherein the optical link guides 6 to 16 LP modes.8. The optical link according to claim 1 , wherein for all optical fibers iε[[1; N]] in said link claim 1 , said lengths Lare chosen so as to minimize Max|DMGD| on said link.9. The optical link according to claim 1 , wherein at least two optical fibers in said link have DMGDshowing opposite signs for at least one mode guided by said optical fibers claim 1 , where DMGDis the Differential Mode Group Delay between said one mode and any other guided mode in optical fiber i.10. The optical link according to claim 1 , wherein claim 1 , for at least one of said fibers iε[[1; N]] in said optical link ...

MULTIMODE OPTICAL FIBERS FOR ATTENUATORS

According to embodiments, an optical fiber may include a core portion comprising a radius r, a centerline C, a numerical aperture NA greater than or equal to 0.15 and less than or equal to 0.25, a graded relative refractive index profile having a maximum relative refractive index Δand an α value greater than or equal to 1 and less than or equal to 3. The core portion may include an up-dopant with a graded concentration from the radius rto the centerline Cand an attenuation dopant with a constant concentration from the centerline Cof the core portion to the radius rof the core portion. The optical fiber is multi-moded for wavelengths of light within a range from 800 nm to 1350 nm and an attenuation of the optical fiber wavelengths between 800 nm and 1000 nm is greater than or equal to 0.5 dB/m. 1. An optical fiber comprising:{'sub': C', 'L', 'max, 'claim-text': [{'sub': C', 'C', 'L, 'an up-dopant, wherein a concentration of the up-dopant in the core portion is graded such that the concentration of the up-dopant is lowest at the radius rand increases from the radius ralong a direction towards the centerline Cof the core portion; and'}, {'sub': L', 'C, 'an attenuation dopant, wherein a concentration of the attenuation dopant in the core portion is constant from the centerline Cof the core portion to the radius rof the core portion;'}], 'a core portion having a radius r, a centerline C, a numerical aperture NA greater than or equal to 0.15 and less than or equal to 0.25, a graded relative refractive index profile having a maximum relative refractive index ΔCand an α value greater than or equal to 1 and less than or equal to 3, the core portion formed from silica-based glass comprising{'sub': 'OC', 'claim-text': [{'br': None, 'sub': max', 'OC, 'ΔC>Δ;'}, 'the optical fiber is multi-moded for wavelengths of light within a range from about 800 nm to about 1000 nm; and', 'an attenuation of the optical fiber for at least one wavelength between 800 nm and 1000 nm is greater ...

Multimode Optical Fiber with High Bandwidth Over an Extended Wavelength Range, and Corresponding Multimode Optical System

The invention concerns a multimode optical fiber, with a graded-index core co-doped with at least fluorine F and germanium GeO 2 and a refractive index profile with at least two α-values. According to the invention, the concentration of fluorine F at the core center ([F] r=0 ) is between 0 and 3 wt % and the concentration of fluorine F at the core outer radius ([F] r=α ) is between 0.5 wt % and 5.5 wt %, with [F] r=α −[F] r=0 >0.4 wt %. For wavelengths comprised between 850 nm and 1100 nm, said multimode optical fiber has an overfilled launch bandwidth (OFL-BW) greater than 3500 MHz·km and a calculated effective modal bandwidth (EMBc) greater than 4700 MHz·km over a continuous operating wavelength range greater than 150 nm.

LOW ATTENUATION FIBER WITH STRESS RELIEVING LAYER AND A METHOD OF MAKING SUCH

A single mode optical fiber having a core made from silica and less than or equal to about 11 weight % germania and having a maximum relative refractive index Δ. The optical fiber also has an inner cladding surrounding the core and having a minimum relative refractive index Δ, a first outer cladding surrounding the inner cladding and a second outer cladding surrounding the first outer cladding. The viscosity at 1650° C. of the second outer cladding minus the viscosity at 1650° C. of the first outer cladding is greater than 0.1ePoise, and Δ>Δ. The single mode optical fiber may also have an outer cladding surrounding the inner cladding made from silica or SiON. The first outer cladding has a maximum relative refractive index Δ, and Δ>Δ. 1. A single mode optical fiber comprising:{'sub': '1MAX', 'a core comprising silica and less than or equal to about 11 weight % germania and having a maximum relative refractive index Δ;'}{'sub': 2', '1MAX', '2, 'an inner cladding surrounding the core and having a minimum relative refractive index Δsuch that Δ>Δ;'}{'sup': '6', 'an outer cladding surrounding the inner cladding and comprising a first outer cladding portion and a second outer cladding portion surrounding the first outer cladding portion; wherein the viscosity at 1650° C. of the second outer cladding portion minus the viscosity at 1650° C. of the first outer cladding portion is ≧1×10Poise.'}2. The single mode optical fiber of claim 1 , wherein the first outer cladding portion has a softening point claim 1 , T claim 1 , and the second outer cladding portion has a softening point claim 1 , T; and{'sub': soft-2', 'soft-1, 'the difference between the glass softening point of the second outer cladding portion, T, and the glass softening point of the first cladding outer cladding portion, T, is greater than 2° C.'}3. The single mode optical fiber of claim 1 , where the first outer cladding portion has a softening point claim 1 , T claim 1 , and the second outer cladding portion ...

BIODEGRADABLE OPTICAL FIBERS AND METHODS OF USE THEREOF

A device and methods of use thereof are disclosed herein for a biodegradable optical fiber and a method of producing a device including a biodegradable optical fiber. A device is disclosed that includes: a biodegradable optical fiber including; a biodegradable optically functional inner fiber including an optically-transmitting cladding in contact with and surrounding an optically-transmitting core, wherein the inner fiber is biodegradable on a first time scale; and an outer layer in contact with and surrounding the optically-transmitting cladding, wherein the outer layer is biodegradable on a controllably-defined delayed time scale, and the controllably-defined delayed time scale is of greater duration than the first time scale. 1. A device comprising:a biodegradable optical fiber including:a biodegradable optically functional inner fiber including an optically-transmitting cladding in contact with and surrounding an optically-transmitting core, wherein the inner fiber is biodegradable on a first time scale; andan outer layer in contact with and surrounding the optically-transmitting cladding, wherein the outer layer is biodegradable on a controllably-defined delayed time scale, and the controllably-defined delayed time scale is of greater duration than the first time scale.2. (canceled)3. The device of claim 1 , wherein the outer layer is less optically transmissive than the cladding or the core.4. The device of claim 1 , wherein the outer layer has an index of refraction greater than an index of refraction of the cladding.5. The device of claim 1 , wherein a composition of the outer layer determines rate of biodegradation at the controllably-defined delayed time scale of the outer layer.6. The device of claim 1 , wherein thickness of the outer layer determines rate of biodegradation at the controllably-defined delayed time scale of the outer layer.7. The device of claim 1 , wherein the optically functional inner fiber is biodegradable on a substantially ...

Bend-Resistant Multimode Optical Fiber

A multimode optical fiber includes a central core surrounded by an outer cladding. The central core has a graded-index profile with respect to the outer cladding and an outer radius rof between about 30 microns and 50 microns (e.g., between about 35 microns and 45 microns). The optical fiber also includes an inner cladding positioned between the central core and the outer cladding, and a depressed trench positioned between the inner cladding and the outer cladding. The multimode optical fiber exhibits reduced bending losses. 1{'sub': c1', '1', '0, 'a central core surrounded by an outer optical cladding having a refractive index value n, said central core having (i) an outer radius rof 36 microns or greater, (ii) a maximum refractive index value n, (iii) a graded-index profile with respect to said outer optical cladding, and (iv) a relative refractive index difference. A multimode optical fiber, comprising:{'sub': '2', 'an inner cladding positioned between said central core and said outer cladding, said inner cladding having an outer radius r; and'}{'sub': 3', '3', '3, 'a depressed trench positioned between said inner cladding and said outer optical cladding, said depressed trench having an outer radius r, a refractive index difference Δnwith respect to said outer optical cladding, and a volume V;'}whereinis 5.6×10μmor greater. This application is a continuation of commonly assigned U.S. patent application Ser. No. 13/428,520 for a “Bend-Resistant Multimode Optical Fiber” (filed Mar. 23, 2012, and published Sep. 27, 2012, as Publication No. 2012/0243843 A1), now U.S. Pat. No. 9,341,771.Parent U.S. patent application Ser. No. 13/428,520 claims the benefit of European Application No. 11305328.4 for a “Multimode Optical Fiber with Improved Bend Resistance” (filed Mar. 24, 2011, at the European Patent Office).Parent U.S. patent application Ser. No. 13/428,520 further claims the benefit of commonly assigned U.S. Provisional Patent Application Ser. No. 61/511,672 for a “ ...

Distributed Brillouin Sensor

A distributed Brillouin sensor system comprising a pump laser, and a combined fiber assembly including at least a first optical fiber section and a second optical fiber section is described. The pump laser is arranged so as to send a pump signal into a first end of combined fiber assembly, and the detector system is arranged to detect Brillouin backscattering from the combined fiber assembly. The combined fiber assembly is characterized by the first section having a low Brillouin gain, and the second fiber section having a high Brillouin gain. 1. A distributed Brillouin sensor system comprising a pump laser , and a combined fiber assembly including at least a first optical fiber section and a second optical fiber section , whereinthe pump laser is arranged so as to send a pump signal into a first end of combined fiber assembly, andthe detector system is arranged to detect Brillouin backscattering from the combined fiber assembly, wherein the combined fiber assembly is characterized bythe first section having a low Brillouin gain, and the second fiber section having a high Brillouin gain.2. The distributed Brillouin sensor system according to claim 1 , wherein the sensor system further comprises a probe laser arranged so as provide a probe signal into an opposite end of the Brillouin sensor fiber.3. The distributed Brillouin sensor system according to claim 1 , wherein the Brillouin gain of the second fiber section is at least 2.0 times larger than the Brillouin gain of the first fiber section.4. The distributed Brillouin sensor system according to claim 1 , wherein the first fiber section has a first effective area claim 1 , and the second fiber section has a second effective area claim 1 , and wherein the first effective area is at least 1.5 times larger than the second effective area.5. The distributed Brillouin sensor system according to claim 1 , wherein the first fiber section has a first effective area claim 1 , and the second fiber section has a second ...

Low loss wide bandwidth optical fiber

A single mode optical fiber, comprising: A single mode optical fiber, comprising: (i) a silica based core having a refractive index profile with an alpha (α) between 1.8 and 200, a relative refractive index Δ 1max %, and an outer radius r 1 , wherein 7 microns >r 1 ≥4.5 microns, the core further comprising silica doped with chlorine, wherein the maximum chlorine concentration in the core is greater than 0.5 wt %; and wherein 1.40 <X< 1.7 where X =[( 2 πn 1 ( 2Δ 1max % r 1 2 ) 1/2 /V c )+( 0.0028 *V m )], n 1 is maximum refractive index of the core, V m is moat volume, and V c is a function of core alpha (α) and (ii) an outer cladding region surrounding the first cladding region, the outer cladding region having a relative refractive index Δ 4 % such that Δ 1max >Δ 4 %.

OPTICAL FIBER

An optical fiber in which the increase of attenuation can be reduced is offered. An optical fiber is made of silica glass and includes a core and a cladding enclosing the core. The refractive index of the cladding is smaller than that of the core. The core includes chlorine and any of the alkali metal group, The chlorine concentration is 1 ppm or more in the whole region of the core. In the whole region of the core, the absolute value of rate of radial change of the chlorine concentration is smaller than 2000 ppm/μm. 1. An optical fiber made of silica glass and containing a core and a cladding ,the cladding enclosing the core and having a refractive index smaller than the refractive index of the core,the core containing chlorine as well as an alkali metal or an alkaline-earth-metal element,the core having a chlorine concentration of 1 ppm or more in the whole region thereof the chlorine concentration being measured with an EPMA using an electron beam having a diameter of 1 μm, andthe absolute value of rate of radial change in the chlorine concentration being smaller than 2000 ppm/μm.2. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is less than 1000 ppm/μm.3. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is less than 500 ppm/μm.4. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is less than 300 ppm/μm.5. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region of the core is more than 100 ppm/μm.6. An optical fiber as set forth in claim 1 , whereinthe absolute value of the rate of radial change in the chlorine concentration of the whole region ...

Low-loss and low-bend-loss optical fiber

A single-mode fiber with low loss and low bend loss is disclosed. The fiber is single mode and has a central core (10), an inner cladding (20) and an outer cladding (30). The central core (10) has a radius r1 and relative refractive index with a maximum value of Δ1max and a core alpha greater than 1 and less than 10, and a Ge02 dopant concentration of greater than 1 wt. % and less than or equal to 5 wt. %. The inner cladding (20) has an outer radius r2>9 micrometers and a relative refractive index Δ2 where Δ2 is less then −0.15%. The outer cladding (30) has a refractive index Δ3, wherein Δ1>Δ3>Δ2. The difference Δ3−Δ2>0.005%. The inner cladding includes fluorine having a concentration of greater than or equal to 0.5 wt. % and the outer cladding is updoped with respect to inner cladding.