Abstract: An optical fiber draw system and method of coating an optical fiber. The system includes a furnace for heating an optical fiber preform, a draw assembly for drawing the optical fiber at a draw speed greater than 50 meters per second, a first coating applicator for applying a first coating onto the fiber, and a first curing assembly comprising a first plurality of light sources comprising light-emitting diodes for partially curing the first coating. The optical fiber draw system also includes a second coating applicator for applying a second coating onto the fiber on top of the first coating, and a second curing system comprising a second plurality of light sources for curing the second coating, wherein the first coating is further cured in the range of 15-50 percent after leaving the first curing assembly.

Abstract: This ultra-low-loss optical fiber comprises a core having a higher relative refractive index difference than silica and a cladding having a lower relative refractive index difference than silica. The relative refractive index difference of the core with respect to the refractive index of silica is 0.0030 to 0.0055, for example, and the relative refractive index difference of the cladding with respect to the refractive index of silica is ?0.0020 to ?0.0003. The ultra-low-loss optical fiber has the loss characteristic of simultaneously having optical losses of at most 0.324 dB/km at a wavelength of 1310 nm, at most 0.320 dB/km at a wavelength of 1383 nm, at most 0.184 dB/km at a wavelength of 1550 nm, and at most 0.20 dB/km at a wavelength of 1625 nm. The ultra-low-loss optical fiber is supercooled when the surface temperature of the optical fiber has a temperature range in a glass transition section during drawing.

Abstract: A method of cooling a glass ribbon formed using a fusion draw process. The method includes forming a glass ribbon using the fusion draw process. The glass ribbon, once formed, passes vertically through a glass transition temperature region. The glass ribbon is directed through a protective plenum at least partially located in a bottom of the draw region. A gas is directed into the protective plenum and vertically along a broad surface of the glass ribbon. The gas is directed out of the protective plenum through at least one outlet slot formed through a sidewall of the protective plenum at no less than about 100 Nm3/h.

Abstract: The invention relates to a device (1, 1?, 1?) for cooling an optical fiber (13), including two portions (20, 29), each of the portions (20, 29) including at least one receiving surface (204, 294) on which a half-channel (240, 2490) is provided, such that, once the two portions (20, 29) are placed in contact at the receiving surface (204, 294) thereof, the two portions (20, 29) form a main through-channel for accommodating the passage of the optical fiber (13), characterized in that each of the portions (20, 29) is a block of a thermally conductive material and in that at least one (20) of the portions includes a cylindrical secondary channel (209), which is in fluid connection with a plurality of openings (2046) distributed along the half-channel (2040) of said portion (20), in order to form a heat-transfer fluid distribution chamber for the plurality of openings (2046).

Abstract: When a lower gauge pressure of a cooling tube part is set at A, and the number of divided units of the cooling tube part is set at N, and a length of each of the divided units of the cooling tube part is set at Li (i=1 to N), and a radius of each of the divided units of the cooling tube part is set at Ri (i=1 to N), and a gas flow rate of a coolant gas passed through each of the divided units of the cooling tube part is set at Qi (i=1 to N), and a viscosity coefficient of a coolant gas is set at ?1, and a radius of an optical fiber is set at r1, and a drawing speed of the optical fiber is set at V1, and a pressure loss of a straight tube part is set at B, and the number of divided units of the straight tube part is set at n, and a length of each of the divided units of the straight tube part is set at LLj (j=1 to n), and a radius of each of the divided units of the straight tube part is set at RRj (j=1 to n), and a gas flow rate of a pressurized gas passed through the straight tube part is set at Qgas, and a

Abstract: Methods and apparatuses for cooling optical fibers are disclosed. In one embodiment, In some embodiments, a cooling apparatus for cooling an optical fiber in a production process includes a channel defined by at least one sidewall assembly and a plurality of interior cavities positioned along the interior of the sidewall assembly. The interior cavities include at least one plenum, a first plurality of fluid supply cavities in fluid communication with the at least one plenum, and a second plurality of fluid supply cavities in fluid communication with the at least one plenum. Cooling fluid is supplied from the at least one plenum to the first plurality of fluid supply cavities in a first direction and the second plurality of fluid supply cavities in a second direction opposite the first direction.

Abstract: Methods and apparatuses for cooling optical fibers are disclosed. In one embodiment, In some embodiments, a cooling apparatus for cooling an optical fiber in a production process includes a channel defined by at least one sidewall assembly and a plurality of interior cavities positioned along the interior of the sidewall assembly. The interior cavities include at least one plenum, a first plurality of fluid supply cavities in fluid communication with the at least one plenum, and a second plurality of fluid supply cavities in fluid communication with the at least one plenum. Cooling fluid is supplied from the at least one plenum to the first plurality of fluid supply cavities in a first direction and the second plurality of fluid supply cavities in a second direction opposite the first direction.

Abstract: An optical fiber production system and method are provided for producing optical fiber. An optical fiber is drawn from a preform in a furnace and passes through a treatment device under a reduced pressure in the range of 0.01 to 0.80 atm. The treatment device cools the bare optical fiber as it cools to a temperature in the range of at least 1,600° C. to 1,300° C. A non-contact fiber centering device is located near an exit of the treatment device to provide centering of the optical fiber as it exits the treatment device.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: A known method for producing a hollow cylinder of synthetic quartz glass comprises the steps of: (a) providing an inner tube of synthetic quartz glass having an inner bore defined by an inner wall, (b) cladding the inner tube (3?) with an SiO2 soot layer (4?), and (c) sintering the SiO2 soot layer with formation of the hollow cylinder. Starting therefrom, to indicate a method in which on the one hand the sintering process is completed before the hollow cylinder is further processed together with the core rod, and in which on the other hand a complicated machining of the inner bore of the hollow cylinder of quartz glass is not required, the invention suggests that during sintering the surface temperature of the inner wall of the inner tube should be kept below the softening temperature.

Abstract: The invention relates to a process for making a SiO2—RExOy—Al2O3 glass comprising preparing a glass according to a conventional process wherein the conventional process comprises a step of heat treating a mixture of SiO2, RExOy, and Al2O3 at a temperature greater than the spinodal temperature for 0.1 to 10 hours wherein RExOy is a rare earth oxide and RE is a rare earth element chosen from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof. The invention also relates to glasses prepared by the process and glass lasers, optical amplifiers and laminated glass that comprise the glass prepared by the process.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: In one embodiment, an optical fiber cooling system includes a first cooling tube oriented substantially in parallel with and spaced apart from a second cooling tube such that an optical fiber pathway is positioned between the first cooling tube and the second cooling tube. The first cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the first cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the second cooling tube. The second cooling tube includes a plurality of cooling fluid outlets positioned along an axial length of the second cooling tube which are oriented to direct a flow of cooling fluid across the optical fiber pathway towards the first cooling tube.

Abstract: A method for forming an optical fiber includes drawing the optical fiber from a glass supply and treating the fiber by maintaining the optical fiber in a treatment zone wherein the fiber is cooled at a specified cooling rate. The optical fiber treatment reduces the tendency of the optical fiber to increase in attenuation due to Rayleigh scattering, and/or over time following formation of the optical fiber due to heat aging. Methods for producing optical fibers along nonlinear paths incorporating fluid bearings are also provided thereby allowing for increased vertical space for the fiber treatment zone.

Abstract: An optical fiber apparatus and manufacturing method thereof includes: forming a bare optical fiber by melting and deforming an optical fiber preform; cooling the bare optical fiber after the bare optical fiber forming step by passing it through a flow channel of a cooling unit through which cooling gas flows; and forming a protective coating layer by supplying a molten resin to a periphery of the bare optical fiber after the cooling step thereby forming an optical fiber. The cooling gas flowing toward a vertically lower end of the flow channel is blocked by the molten resin used to form the protective coating layer, and carbon dioxide gas is supplied toward the flow channel from a position which is vertically below the supply position of the cooling gas and vertically above the blocking position of the molten resin.

Abstract: To optimize an optical component of synthetic quartz glass, in the case of which a quartz glass blank is subjected to a multistage annealing treatment, with respect to compaction and central birefringence, the present invention suggests a method comprising the following steps: (a) a first treatment phase during which the quartz glass blank is treated in an upper temperature range between 1130° C. and 1240° C., (b) cooling the quartz glass blank at a first-higher-mean cooling rate to a quenching temperature below 1100° C., a fictive temperature with a high mean value of 1100° C. or more being reached in the quartz glass, (c) a second treatment phase which comprises cooling of the quartz glass blank at a second-lower-mean cooling rate, and in which the quartz glass blank is treated in a lower temperature range between 950° C. and 1100° C. such that a fictive temperature is reached in the quartz glass with a low mean value which is at least 50° C.

Abstract: A method is provided for eliminating crystals in non-oxide optical fiber preforms as well as optical fibers drawn therefrom. The optical-fiber-drawing axis of the preform is aligned with the force of gravity. A magnetic field is applied to the preform as it is heated to at least a melting temperature thereof. The magnetic field is applied in a direction that is parallel to the preform's optical-fiber-drawing axis. The preform is then cooled to a temperature that is less than a glass transition temperature of the preform while the preform is maintained in the magnetic field. When the processed preform is to have an optical fiber drawn therefrom, the preform's optical-fiber-drawing axis is again aligned with the force of gravity and a magnetic field is again applied along the axis as the optical fiber is drawn from the preform.

Abstract: An optical fiber apparatus and manufacturing method thereof includes: forming a bare optical fiber by melting and deforming an optical fiber preform; cooling the bare optical fiber after the bare optical fiber forming step by passing it through a flow channel of a cooling unit through which cooling gas flows; and forming a protective coating layer by supplying a molten resin to a periphery of the bare optical fiber after the cooling step thereby forming an optical fiber. The cooling gas flowing toward a vertically lower end of the flow channel is blocked by the molten resin used to form the protective coating layer, and carbon dioxide gas is supplied toward the flow channel from a position which is vertically below the supply position of the cooling gas and vertically above the blocking position of the molten resin.

Abstract: A thermally stable chalcogenide glass, a process for making the same, and an optical fiber drawn therefrom are provided. A chalcogenide glass having the composition Ge(5?y)As(32?x)Se(59+x)Te(4+y) (0?y?1 and 0?x?2) is substantially free from crystallization when it is heated past the glass transition temperature Tg or drawn into optical fibers. A process for making the thermally stable chalcogenide glass includes purifying the components to remove oxides and scattering centers, batching the components in a preprocessed distillation ampoule, gettering oxygen impurities from the mixture, and heating the components to form a glass melt. An optical fiber formed from the chalcogenide glass is substantially free from crystallization and exhibits low signal loss in the near-infrared region, particularly at wavelengths of about 1.55 ?m.

Abstract: A method for manufacturing an optical fiber by drawing an optical fiber preform softened by heating, includes cooling the optical fiber at a cooling rate of not more than 4000° C. per second at a temperature of 1200 to 1400° C. of the optical fiber; and cooling the optical fiber at a cooling rate of not more than 8000° C. per second at a temperature of 850 to 1200° C. of the optical fiber. A drawing rate of the optical fiber is not less than 1000 meters per minute.

Abstract: A method for forming an optical fiber includes drawing the optical fiber from a glass supply and treating the fiber by maintaining the optical fiber within a treatment temperature range for a treatment time. Preferably also, the fiber is cooled at a specified cooling rate. The optical fiber treatment reduces the tendency of the optical fiber to increase in attenuation due to Rayleigh scattering, and/or over time following formation of the optical fiber due to heat aging. Apparatus are also provided.

Abstract: A method for forming an optical fiber includes drawing the optical fiber from a glass supply and treating the fiber by maintaining the optical fiber in a treatment zone wherein the fiber is cooled at a specified cooling rate. The optical fiber treatment reduces the tendency of the optical fiber to increase in attenuation due to Rayleigh scattering, and/or over time following formation of the optical fiber due to heat aging. Methods for producing optical fibers along nonlinear paths incorporating fluid bearings are also provided thereby allowing for increased vertical space for the fiber treatment zone.

Abstract: In the known method for producing an optical fiber, a coaxial arrangement comprising a core rod and an outer jacket tube is elongated, the coaxial arrangement being supplied in a vertical orientation to a heating zone and being softened therein zonewise, starting with the lower end thereof, and the optical fiber being withdraw downwards from the softened portion, whereby an annular gap existing between core rod and jacket tube is collapsed. Starting therefrom, in order to provided a method which makes it possible to produce optical fibers with a minimum curl and at low costs, the invention suggests that a quartz glass cylinder treated mechanically to its final dimension and having an outer diameter of at least 100 mm should be used as the jacket tube. An optical fiber obtained according to the method is characterized in that without the action of external forces it assumes a radius of curvature of at least 6 mm.

Abstract: The invention is directed to the production of optical fibers from optical fiber preforms using flow physics. The present methods provide for the “drawing” of an optical fiber preform using focusing of the preform by a surrounding fluid, e.g. a heated gas.

Abstract: A cap assembly for collecting cooling gas from a coolant chamber tube is disclosed. The cap assembly having connecting means and outlet means extending from its side walls being generally shaped and sized for detachable mounting on the body of the cooling gas chamber tube. The cap assembly is also employed in a hot optical fiber process which is being cooled by helium.

Abstract: A coolant system for cooling a fiber includes a heat exchanger with an internal passage disposed between a fiber inlet and fiber outlet to cool the fiber moving through the internal passage. A plurality of chambers are disposed within the internal passage, and at least one fluid medium flows within at least a portion of the internal passage, and at least one adjustable seal is positioned within the internal passage to form a partition between two adjacent chambers. A gas analyzer communicates with at least one chamber of the internal passage to extract a fluid sample from the chamber and to measure a concentration of a gas in the extracted fluid sample. A controller communicates with the analyzer and controls at least one of the adjustable seal and the flow rate of fluid medium within the internal passage based upon the measured concentration.

Abstract: A cap assembly for collecting cooling gas from a coolant chamber tube is disclosed. The cap assembly having connecting means and outlet means extending from its side walls being generally shaped and sized for detachable mounting on the body of the cooling gas chamber tube. The cap assembly is also employed in a hot optical fiber process which is being cooled by helium.

Abstract: The present invention relates to a method and apparatus for cooling an optical fiber during the drawing process of said fiber. In particular the present method for cooling an optical fiber comprises flowing a cooling gas onto the optical fiber wherein the flow direction of the cooling gas is substantially transversal with respect the longitudinal axis of the fiber. It has been found that by employing a flow of cooling gas being substantially transversal to the longitudinal axis of the drawn fiber, the cooling efficiency of the fiber may be substantially improved.

Abstract: The present invention provides a drawing method for optical fiber, which is capable of reducing attenuation at 1.55 um due to Rayleigh scattering, even if the drawing speed is high. The reduction of the attenuation of the optical fiber 3 is realized by conducting a preliminary cooling in a first cooling zone 4, which has a low convection heat transfer coefficient, for reducing the temperature of the as-drawn optical fiber just before entering into a second cooling zone 5. The optical fiber is obtained after being cooled in the second cooling zone 5, which has a higher convection heat transfer coefficient.

Abstract: This invention is directed to a process for recovering helium. The process includes a) passing a first gas containing helium to an eductor to produce a second gas; b) passing the second gas through a heat exchanger to produce a third gas; and c) recovering the third gas into the eductor to combine with the first gas.

Abstract: A method and apparatus are described for efficient and economical cooling of drawn optical fibers prior to coating with resins. Optimum cooling is achieved employing a tubular cooling device with multiple cooling stages using gaseous coolants. A first stage uses a gas essentially free of helium while a second stage uses a helium-containing gas. The cooling apparatus includes a tubular device having a longitudinal axis, an inlet and outlet for passage of a drawn optical fiber, a wall extending transverse to the longitudinal axis of the cooling device dividing the space between the inlet and outlet into at least two cooling compartments, where the wall has an aperture to allow for passage of the fiber, means for passing gaseous coolant into the compartments, a jacket surrounding the compartments defining a space to circulate a cooling fluid, and porous means for minimizing flow-induced vibration of the fiber.

Abstract: A method for forming a doped optical fiber includes drawing the optical fiber from a doped glass supply at a draw speed and a draw tension sufficient to introduce a heat aging defect in the optical fiber. The optical fiber is treated by maintaining the optical fiber within a treatment temperature range for a treatment time while preferably maintaining the optical fiber within a treatment tension range to reduce the tendency of the optical fiber to increase in attenuation over time following formation of the optical fiber. Apparatus are also provided.

Abstract: A cap assembly for collecting cooling gas from a coolant chamber tube is disclosed. The cap assembly having connecting means and outlet means extending from its side walls being generally shaped and sized for detachable mounting on the body of the cooling gas chamber tube. The cap assembly is also employed in a hot optical fiber process which is being cooled by helium.

Abstract: A method of drawing an optical fiber which can improve the efficiency in manufacture without deforming resin coatings is provided.

Abstract: Heat transfer fluid mixtures and methods of making and using same are presented. The inventive heat transfer fluid mixtures consist essentially of a light gas, such as helium, and at least one heavy fluid, such as argon, which may be adjusted between a first composition having a high heat transfer coefficient and high cost, and a second composition having a lower cost.

Abstract: Cooling systems and the methods of cooling filaments using the cooling systems are disclosed. One embodiment of the cooling system includes a layer of nozzles that spray air on the filaments above a pre-pad water spray. Alternatively, another cooling system utilizes air-atomizing nozzles to spray a mixture of air and water on the filaments.

Abstract: A filament forming apparatus and cooling apparatus for and method of inducing a uniform air flow between a filament forming area beneath a bushing and the cooling apparatus are disclosed. The cooling apparatus includes an air housing extending beneath the bushing. The air housing has a top wall and side walls defining an air chamber therebetween.

Abstract: In a known process for the manufacture of an elongated porous SiO2 preform, SiO2 particles are deposited on the mantle surface of a cylindrical carrier rotating about its longitudinal axis. The SiO2 particles are formed by means of a plurality of deposition burners which are arranged, at a distance from one another, in at least one burner row extending parallel to the longitudinal axis of the carrier. The burners are moved in a repeated cycle back and forth along the forming preform and between turnaround points where the direction of their motion is reversed. Measures are taken in the process to prevent or reduce overheating of the preform in the turnaround point regions. These measures can lead to variations in the rate of deposition.

Abstract: A method of cooling an optical fiber during drawing through contact with at least one cooling fluid in at least one cooling area,

Abstract: A method of cooling an optical fiber while it is being drawn through contact with at least one cooling fluid in at least one cooling area, wherein said method is such that fast cooling, i.e. cooling that is faster than cooling in the surrounding air, is followed by slow cooling, i.e. cooling slower than cooling in the surrounding air, the temperature of the fiber in an intermediate area between the two cooling areas lying in the range 1200° C. to 1700° C. in the case of silica glass fibers.

Abstract: Helium recycling for optical fiber manufacturing in which consolidation process helium is recycled either directly for use in consolidation at high purity or recycled at lower purity adequate for usage in draw or other processes having a lower helium parity. Integrated processes for recycling helium from two or more helium using processes in the optical manufacturing process are also described. Substantial helium and cost savings are recognized.

Abstract: A method for drawing a glass ingot into a rod having a given outer diameter is described. The method is characterized in that when the glass ingot is fed into a heating zone at a final tapered portion thereof, a temperature in the heating zone is decreased so that the final tapered portion is prevented from being drawn in excess owing to the heat from the heating zone.

Abstract: The transmission properties of an optical fiber are enhanced by cooling the fiber gradually to temperatures of at least -300.degree. Fahrenheit, maintaining the fiber at such reduced temperature for a time suitable to stabilize the transmission properties of the fiber, and then allowing the fiber gradually to return to normal room temperature. The heating of the fiber to restore it to room temperature in part is accomplished by transmitting through the fiber optical pulses of the frequency and repetition rate the fiber will experience in normal use.

Abstract: Fiber bow makes mass fusion splicing of optical fiber difficult and this is undesirable. We have found that fiber bow can be significantly reduced if the fiber that is being drawn from a heated optical fiber preform is caused to run through a tubular cooling chamber that extends from the draw furnace, the cooling chamber comprising a tube of inner diameter d.sub.1 <35 mm, preferably <20 mm. In a preferred embodiment the cooling chamber includes an upper cooling chamber of inner diameter d.sub.2 >d.sub.1, with a transition element providing a smooth transition between the two chambers. The cooling chamber desirably is free of turbulence-causing air leaks and/or geometrical features.

Abstract: To draw an optical fiber (10) from one end of a glass preform (9) which is heated to above the glass softening temperature at least in that area, a gas (21) flows around the preform (9) into a furnace space (16) during the drawing process and subsequent feeding of the preform. During the feeding, the areas that are adjacent to the drawing end of the preform (9) pass through gas zones in which the helium content of the furnace gas increases in the drawing direction.

Abstract: The invention provides a process and apparatus for producing a quench gas mixture for increasing the cooling rate of an article. The quench gas mixture is produced by introducing helium gas into the bottom of a vessel containing a cryogenic liquid. Heat is transferred directly from the helium gas to the cryogenic liquid as the helium bubbles rise through the liquid to the surface. The resulting cryogenic vapor mixes with the helium gas in the ullage space at the top of the vessel, and the gas mixture is taken off from the ullage space and supplied to a cooling process.

Abstract: A filament cooler suitable for cooling freshly drawn optical fibre preparatory for being coated with a protective plastics coating has a water-cooled body member provided with a through hole opening out abruptly into a succession of spherical chambers in which a cyclonic gas flow is induced by the tangential injection of helium.

Abstract: A system and process for recovering high purity coolant gas from at least one fiber optic heat exchanger, characterized by controlling a flow of coolant gas into and out of the heat exchanger using a pressure, impurity and/or flow rate monitoring or transmitting means in conjunction with a flow adjusting or controlling device to limit air or other gas infiltration into at least one fiber optic passageway of the heat exchanger. A sealing means may also be used at at least one end of the fiber optic passageway to further reduce air or other gas infiltration into the passageway. The resulting high purity coolant gas from the outlet of the heat exchanger is delivered to the inlet of the heat exchanger. Optionally, the resulting coolant gas from the outlet of the heat exchanger may be cooled, filtered and/or purified before being delivered to the inlet of the heat exchanger.