Abstract: An ultra-low loss optical fiber is provided. The ultra-low loss optical fiber includes a core having the maximum refractive index inside an optical fiber, and placed at the central portion of the optical fiber, a trench having the minimum refractive index inside the optical fiber and encompassing the core, and a cladding encompassing the trench. The core includes a first sub-core layer having the maximum refractive index inside the optical fiber, and placed at the center of the optical fiber, a second sub-core layer having a refractive index lower than that of the first sub-core layer and encompassing the first sub-core layer, and a third sub-core layer having a refractive index lower than that of the second sub-core layer and encompassing the second sub-core layer.

Abstract: A branching device for enclosing a hybrid fan-out cable the hybrid fan-out cable comprising plural optical cables and power cables, the branching device includes: an enclosure having a first end, through which the hybrid fan-out cable is inserted, and a second end that is opened; and a gasket provided at the second end of the enclosure and having plural through-holes; and a cover thread-coupled to the second end of the enclosure to fasten the gasket to the second end of the enclosure in such a manner that the through-holes are exposed. In the enclosure, the hybrid fan-out cable is branched out into plural individual sub-part cable components, and each of the sub-part cable components is drawn out through one of the through-holes of the gasket to the outside. The gasket is formed from an elastic material which forms a tight seal between the inner peripheral surface of the enclosure and with the outer peripheral surface of each of the sub-part cable components to seal the other end of the enclosure.

Abstract: An optical fiber is provided. The optical fiber includes a core located at the center of the optical fiber and having a maximum refractive index in the optical fiber, and a cladding located at a circumference of the core and having a refractive index lower than that of the core. The core has a structure in which sub-core areas having the refractive index higher than those of adjacent sub-core areas and sub-core areas having the refractive index lower than those of adjacent sub-core areas are alternately repeated.

Abstract: Provided is an extreme bending insensitive optical fiber. The optical fiber includes a core comprising a maximum refractive index difference ?n1 in the optical fiber, an inner layer comprising a refractive index difference ?n2 that is smaller than the maximum refractive index of the core and decreases in a direction away from the core, the inner layer being positioned outside the core, and a trench layer comprising an inner-circumference refractive index difference ?n3 that is smaller than the refractive index difference of the inner layer and an outer-circumference refractive index difference ?n4 that is a minimum refractive index difference in the optical fiber.

Abstract: Provided is an extreme bending insensitive optical fiber. The optical fiber includes a core comprising a maximum refractive index difference ?n1 in the optical fiber, an inner layer comprising a refractive index difference ?n2 that is smaller than the maximum refractive index of the core and decreases in a direction away from the core, the inner layer being positioned outside the core, and a trench layer comprising an inner-circumference refractive index difference ?n3 that is smaller than the refractive index difference of the inner layer and an outer-circumference refractive index difference ?n4 that is a minimum refractive index difference in the optical fiber.

Abstract: Disclosed is an optical fiber, which includes: a core positioned at the center of an optical fiber to have the maximum refractive index within the optical fiber; an inner clad surrounding the core to have the minimum refractive index within the optical fiber; and an outer clad surrounding the inner clad to have a refractive index lower than that of the core and higher than that of the inner clad, wherein a difference ?ncore-inner—clad between the refractive index of the core and the minimum refractive index of the inner clad is within the range of 0.00615 to 0.00645, and a difference ?nouter—clad-inner—clad between the refractive index of the outer clad and the minimum refractive index of the inner clad is 0.0006 or more.

Abstract: Disclosed is a method for fabricating an optical fiber preform. The method includes: (a) growing a first soot preform on a starting member along a lengthwise direction of the starting member by a soot deposition; (b) dehydrating the first soot preform; (c) sintering the dehydrated first soot preform, to obtain a first glassed optical preform; and (d) elongating the first optical fiber preform by heating the first optical fiber with a heat source that excludes hydrogen, wherein the first glassed optical fiber is elongated by means of only a heat source that excludes the use of hydrogen.

Abstract: Disclosed are a method for fabricating an optical fiber preform and a method for fabricating an optical fiber using the optical fiber preform. The method for fabricating the optical fiber preform including the steps of: (a) growing a first soot preform on a starting member by a soot deposition; (b) dehydrating the first soot preform; (c) sintering the first dehydrated soot preform to obtain a first glassed optical fiber perform; (e) growing an over-clad soot layer on the first optical fiber preform by soot deposition to obtain a second soot preform; and (f) sintering the second soot preform so as to obtain a second optical fiber preform which is glassed, wherein an average density of the first soot preform is substantially within a range of 0.19˜0.30 g/cc, and the average density of the over-clad soot layer is substantially within a range of 0.5˜0.75 g/cc.

Abstract: Vapor Axial Deposition (VAD) apparatus and method is provided. The VAD apparatus includes a first torch, a second torch, a thermometer, a controller, and a moving device. The first torch grows a core by depositing a soot at an end of a soot preform arranged on an axis. The second torch grows a clad by depositing a soot on the face of the core. The thermometer detects the temperature of the end of the soot preform along the axis and the temperature of an other/lower portion of the core. The controller calculates a difference between a temperature (T1) of the end of the soot preform and a temperature (T4) of a lower portion of the core and controls the movement of the soot preform according to the difference. The moving device moves the soot preform along the axis according to the instruction of the controller.

Abstract: Disclosed is a method for fabricating an optical fiber having attenuation loss, in which non-uniformity of the attenuation loss in the lengthwise direction of the optical fiber is equal to or less than 0.05 dB/km in the wavelength band of 1383 nm and an average value of the attenuation loss is equal to or less than 0.35 dB/km. The method comprising the steps of (a) fabricating a soot preform while maintaining an average temperature of a core surface at a level equal to or less than 1000° C. and temperature variation of the core surface according to a growing length of the soot preform in a range of ?10 to 10° C./cm, fabricating an optical fiber preform by dehydrating, consolidating and vitrifying the soot preform and (c) drawing the optical fiber from the optical fiber preform under a temperature range between 1900 to 2300° C.

Abstract: An apparatus for fabricating a soot preform includes at least one torch for depositing soot generated by flame hydrolysis on the soot preform. A vaporizer vaporizes a liquid source material. A heater heats a dilution gas. The vaporizer and the heater respectively supply, to the torch, the vaporized source material and the heated dilution gas together through a single pipe.

Abstract: Disclosed is a vapor axial deposition apparatus. The vapor axial deposition apparatus includes a first torch, a second torch, a temperature measuring unit and a controller unit. The first torch deposits soot on a distal end of a soot preform aligned with a vertical axis to thereby grow a core. The second torch deposits soot on an outer circumferential surface of the core to thereby grow a clad. The temperature measuring unit detects the temperature distribution of an end portion of the soot preform along the vertical axis. The controller unit determines first and second relative maximum temperatures T1 and T3, and relative minimum temperature T2 between T1 and T3 in the detected temperature distribution, and controls T1 to be within a predetermined range and the greater one of the difference (T1?T2) and (T3?T2) to not exceed a predetermined temperature.

Abstract: A plasma apparatus is disclosed. The plasma apparatus includes an internal electrode having a hollow section for receiving precursor gas and oxygen gas therein, an external electrode accommodating the internal electrode therein while forming a gap therebetween in such a manner that inert gas and oxygen gas are introduced into the gap. The plasma apparatus also includes a power source for applying a DC voltage or a radio frequency (RF) AC voltage to the internal and external electrodes in order to generate plasma between the internal and external electrodes.

Abstract: Disclosed is an apparatus for fabricating an optical fiber preform through an external vapor deposition process. The apparatus includes a lathe on which a primary preform is rotatably mounted by chucks, a burner assembly including a burner installation block having an inclined surface and a plurality of burners installed on the inclined surface of the burner installation block in such a manner that the burners spray flames and source gas towards the primary preform with mutually different spraying angles, and a carrier unit for moving the burner assembly lengthwise along the primary preform.

Abstract: A method for fabricating a multimode optical fiber preform having a longitudinal uniformity is provided. The method of fabricating includes performing a plurality of radial deposition passes using a thermal source while inserting raw materials into a glass tube. A reference chemical core shape index is set to determine a refractive index profile of a preform section. A core shape index distribution of each longitudinal deposition pass varying in a longitudinal direction of the glass tube is set such that an error of a reference chemical core shape index distribution in the longitudinal direction of the preform defined by the reference chemical core shape index is compensated for and such that a uniform chemical core shape index is obtained in the longitudinal direction. Deposition is performed while an amount of raw materials corresponding to a preset chemical core shape index is inserted in each longitudinal deposition pass of each radial deposition pass.

Abstract: A method for dehydrating and consolidating a porous optical fiber preform in a heating apparatus is provided. The apparatus includes a muffle in which the porous optical fiber preform is placed and a plurality of multi-stage heaters attached to an outer circumference of the muffle in a longitudinal direction of the preform. The preform is placed in the muffle such that the multi-stage heaters surround a total length of the preform. The preform is heated and dehydrated in a state in which a temperature of the multi-stage heaters reaches a dehydrating temperature of the preform. A temperature of one heater selected from the heaters is raised to a consolidating temperature of the preform. The dehydrated preform is moved and is passed through a high temperature zone formed by the selected heater in the muffle. The dehydrated preform is consolidated.

Abstract: Disclosed is a wide-band dispersion controlled optical fiber. The optical fiber enables the use of optical signals in various wavelength regions in a wavelength division multiplexing mode communication network by controlling the position of the zero dispersion wavelength, and enables long distance transmission by controlling dispersion slope and bending loss. Furthermore, there is an advantage in that the optical fiber enables not only short distance transmission but also middle/long distance transmission using a single type of optical fiber because the optical fiber is controlled to have negative dispersion values in the O-band wavelength region and positive dispersion values with small deviations in the C-band and L-band wavelength regions.

Abstract: Disclosed is an optical fiber comprising a center core which forms a passageway for transmitting optical signals and has a refractive index N1, and a cladding which encloses the center core and has a refractive index N0. The optical fiber further comprises an upper core, which has a distribution of refractive indices increased starting from a refractive index N2 (>N0) at its outer circumference to the refractive index N1 at its internal circumference, and a minutely depressed refractive index region, which is interposed between said upper core and cladding and has a refractive index N3. The refractive index N3 is lower than the refractive index N0.

Abstract: Disclosed is an amplifying optical fiber for amplifying optical signal transmitted therethrough by stimulated emission, the amplifying optical fiber comprising: an inner core disposed at a center of said optical fiber and containing MX, GaS3/2 and RE; an outer core surrounding said inner core and containing SiO2; and a cladding surrounding said outer core and containing SiO2, wherein said M contained in MX is one component selected from the group consisting of Na, K, Rb and Cs; said X contained in MX is one component selected from the group consisting of F, Cl, Br, and I; and said RE is one component selected from the group consisting of Ce, Pr, Pm, Nd, Sm, Eu, Gd, Tb, Ho, Dy, Er, Tm and Yb.

Abstract: A wide band dispersion-controlled fiber which comprises a core forming an optical signal transmission path and having a peak refractive index, and a cladding surrounding the core and having a peak refractive index lower than the peak refractive index of the core. The wide band dispersion-controlled fiber further comprises at least one dispersion control layer arranged between the core and the cladding and having a refractive index profile such that its refractive index increases from an inner periphery to an outer periphery. The minimum refractive index of the dispersion control layer is less than the peak refractive indices of the core and cladding.