Abstract: Method of producing glass components and preforms for use in the method. The preform includes a primary rod having a constant outside diameter and a flat bottom portion, wherein the primary rod comprises a core rod surrounded by at least one outer cladding layer; and a cylindrical sacrificial tip having a first end attached to the flat bottom portion of the primary rod, a second end opposite the first end, and a hollow interior region extending fully from the first end to the second end, wherein the sacrificial tip is circular in cross section and the first end of the sacrificial tip has a constant inside diameter and outside diameter along its entire length from the first end to the second end, and wherein the constant outside diameter is equal to the outside diameter of the primary rod. When the preform is heated in a furnace, the sacrificial tip melts and collapses into a drawing bulb which either draws the primary rod directly into the glass fiber or results in a tapered (i.e.

Abstract: A device for connecting a fiber preform including a plurality of elongate holes extending substantially parallel to a longitudinal axis of the fiber preform to a pressure supply system, the device including a first surface to be connected to an end face of the fiber preform where the plurality of elongate holes end, a second surface including at least two ports configured to be in fluid connection with the pressure supply system, and a channel system within the device connecting the plurality of elongate holes at the first surface to the at least two ports, wherein a density of the at least two ports at the second surface is smaller than a density of the plurality of corresponding elongate holes at the first surface.

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: In an optical fiber manufacturing method, the cooling device and the coating device are connected in an airtight manner and by preventing a cooling gas, flowing inside the cooling device, from flowing into the coating device by a meniscus of resin inside of the coating device, a flow of the cooling gas inside the cooling device is discharged to an outside of an upper end of the cooling device as an upward stream; helium gas as the cooling gas flows into a lower portion of the cooling device and carbon dioxide gas as the cooling gas which is separated from the helium gas flows into a side lower than a position where the helium gas flows in, during the forcible cooling; and a flow rate of the helium gas and a flow rate of the carbon dioxide gas are individually controlled.

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: 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: An apparatus for adjusting the cooling members located beneath fiberizing bushings is disclosed having the capability of moving each cooling member, or one portion of each cooling member, in a generally vertical direction, and/or in a lateral and/or tilting direction. Also disclosed is a process of using the apparatus to make fibers from molten material including molten glass.

Abstract: A furnace for drawing an optical fiber includes a body having an upper and lower openings for supplying a preform and discharging a drawn optical fiber, a heating unit installed in the body for receiving and melting the preform, an atmosphere blocking tube installed to the lower opening for discharging the drawn optical fiber and blocking the optical fiber from the atmosphere, an upper introduction port formed at an upper portion of the body for introducing an inert gas toward the preform and partially discharged outside through a gap between the preform and the upper opening, a central and lower introduction ports formed at central and lower portions for introducing an inert gas into the body, a first flow guiding means for guiding the inert gas introduced through the central introduction port upward and then flowed down along a surface of the preform, and a second flow guiding means for guiding the inert gas introduced through the lower introduction port upward and then discharged outside through the atmosp

Abstract: An induction furnace capable of drawing large diameter preforms of up to 130 mm is described. The induction furnace has top and bottom chimneys surrounding the entire preform during operation of the furnace with an inert conditioning gas which is introduced into the top chimney and flows downward through the furnace body and bottom chimney without significant turbulence. A distributor ring inside the top chimney redirects flow from a circumferential direction to a downward direction. The top chimney also includes a resilient seal to releasably hold the top of the preform. The bottom chimney has a smoothly decreasing cross-sectional area preventing turbulence at the furnace exit. The furnace insulation is preferably a rigid self-supporting graphite cylinder. A method of drawing large diameter preforms either to an optical fiber or to a preform of smaller diameter using such a furnace is also described.

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 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: An optical fiber cooling tube includes an internal cavity through which an optical fiber passes and a set of injection passages that are distributed along the tube, open into the cavity, and are oriented in a contraflow direction relative to the direction in which the optical fiber moves.

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: An apparatus and method for curing a coating applied to an optical fiber. A water-jacketed UV lamp is provided adjacent a first reflector. An optical fiber is drawn between a second reflector opposite the first reflector and at least one quartz plate, while a cross flow of a cooling gas is passed around the optical fiber. Apertures may be formed in the second reflector for passing the cooling gas while the optical fiber is passed between the second reflector and the at least one quartz plate. Alternatively, two or more quartz plates may be provided and the cooling gas and the optical fiber passed between the quartz plates. The cooling gas experiences laminar flow.

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: 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: An end heating and processing method of an optical fiber preform. In this method, an optical fiber preform is processed by heating and melting an end of a vitrified optical fiber preform including a core portion and a cladding portion formed on an outer circumference thereof to process the end having a shape for drawing as an optical fiber.

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: An optical fiber cooling tube includes an internal cavity through which an optical fiber passes and a set of injection passages that are distributed along the tube, open into the cavity, and are oriented in a contraflow direction relative to the direction in which the optical fiber moves.

Abstract: What is disclosed is a cooling unit with a sealing cap, for high speed optical fiber drawing in an optical fiber drawing process. The cooling unit includes: a cooling body through which the optical fiber drawn in high speed passes and in which heat exchange is performed by provided helium gas; and a sealing cap mounted on upper and lower ends of the cooling body, wherein at least more than one supplying member of ring type are provided in an inside of the sealing cap more than one time along progress direction of the optical fiber, for providing flow rate of reverse direction opposite to external air introduced along the drawing optical fiber so that the influence of the external air is minimized.

Abstract: A method and device for reducing the temperature of an optical fiber wherein a housing body is provided a plurality of inner cooling chambers which are-, partitioned from each other by a plurality of partition walls. An axial through hole extends through each of the inner cooling chambers from an upper end of the housing body to a lower end of the housing body for the axial passage of an optical fiber therethough. A plurality of gas injection holes corresponding to the inner cooling chambers are provided in a side wall of the housing body for injecting gas into the inner cooling chambers. A plurality of coolant pipes through which a liquid coolant is circulated extend through each of the inner cooling chambers from the upper end to the lower end of the housing body. The coolant pipes are disposed between the gas injection holes and the axial through hole so that the gas which is injected into the inner cooling chambers via the gas injection holes is not blown directly against the fiber.

Abstract: The invention relates to a device for drawing optical fibers from a preform, comprising: a furnace comprising a tube for heating one end of said preform to the drawing temperature thereof, which tube comprises: i) a central tube, ii) an upper extension tube connected to the lower part of said central tube so as to obtain a gas tight seal against an ambient atmosphere exterior said furnace, wherein the upper extension tube comprises an inlet for an inert gas in the top region of the upper extension tube, as a result of which the preform and the fiber to be drawn therefrom are surrounded by an inert gas, iii) a lower extension tube connected to said upper extension tube in such a manner that a gas tight seal against an ambient atmosphere exterior said furnace is obtained, iv) a tube outlet connected to said lower extension tube, means for drawing the fiber, means for supporting the preform in the furnace.

Abstract: Disclosed is a system for drawing an optical fiber for controlling polarization mode dispersion. A furnace is provided for uniformly heating an optical fiber preform in the drawing system mounted to an optical fiber draw tower. The furnace comprises: (a) a main body; (b) a sub-body placed coaxially with the main body and having a diameter smaller than that of the main body; and (c) an upper gas feeding section over the main body, wherein the upper gas feeding section includes a first hollow rotary body having at least one slit in the inner surface thereof along the longitudinal direction of an optical fiber and at least one opening extended in the direction of the center, whereby a gas artificially/periodically creates non-contact polarization to the optical fiber by the first hollow rotary body. Effective non-contact control can be carried out about polarization mode dispersion of the optical fiber.

Abstract: An apparatus and method for curing a coating applied to an optical fiber. A water-jacketed UV lamp is provided adjacent a first reflector. An optical fiber is drawn between a second reflector opposite the first reflector and at least one quartz plate, while a cross flow of a cooling gas is passed around the optical fiber. Apertures may be formed in the second reflector for passing the cooling gas while the optical fiber is passed between the second reflector and the at least one quartz plate. Alternatively, two or more quartz plates may be provided and the cooling gas and the optical fiber passed between the quartz plates. The cooling gas experiences laminar flow.

Abstract: An apparatus and process for cooling a quartz tube used in fabrication of an optical fiber preform by modified chemical vapor deposition. The apparatus has a nozzle ring supplied with a coolant. The nozzle ring has at least two vent sections that are be separatable for detaching the quartz tube from a lathe during processing, and a plurality of vents formed along the inside of the two vent sections for ejecting the coolant.

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: An end heating and processing method of an optical fiber preform. In this method, an optical fiber preform is processed by heating and melting an end of a vitrified optical fiber preform including a core portion and a cladding portion formed on an outer circumference thereof to process the end having a shape for drawing as an optical fiber.

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 and apparatus for manufacturing optical fibers provided with hermetic coatings, wherein the bare fiber made from a heated preform advances through a stream of reactive gaseous medium which flows at a constant speed in the direction of advance of the fiber, which is then accelerated, and which is finally removed remote from the fiber by a stream of inert gas flowing in the opposite direction from the direction of the stream of reactive gaseous medium. Application is to manufacturing optical fibers for telecommunications.

Abstract: A coated optical fiber is produced by the steps of cooling through a cooling assembly an optical fiber obtained by drawing, heating and spinning an optical fiber base material and thereafter coating the optical fiber with a resin wherein a gas mixture including an He gas and possible ambient air is sucked out of the cooling assembly and purified to collect the He gas to be a recovery gas of He which is to be recycled to the cooling assembly together with a pure He gas, but the gas mixture sucked out of the cooling assembly is compressed and stored until the gas mixture reaches a predetermined pressure or more and then purified when it reaches the predetermined pressure while the compressed gas mixture is returned to an upstream side of a compressor which serves to compress the gas mixture so that the flow quantity of gas suction varies in accordance with the flow of He gas supplied to the cooling assembly whereby the gas mixture from the cooling assembly is prevented from lowering an He gas concentration of t

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: A furnace and method for drawing an optical fiber is provided. The furnace included a furnace core chamber in which a preform is inserted into the chamber through the upper end thereof and a drawn optical fiber is pulled out of the chamber through an opening positioned at the lower end thereof. The furnace also includes a gas-supply means for introducing an inert gas into the furnace core chamber to thus establish an inert gas atmosphere within the chamber, and a heater for heating the preform so that the lower part of the preform is molten and drawn into the optical fiber, which is positioned around the outer periphery of the furnace core chamber. The furnace further includes an inner furnace core tube, which is positioned within the furnace core chamber and which has a cylindrical part whose lower part is communicated to the opening of the furnace core chamber and a funnel-like part which is positioned on the upper end of the cylindrical part.

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.