Abstract: A method of fabricating an optical fiber preform is disclosed which includes a step of outside deposition of silica possibly doped with at least one dopant by injecting at least one substance in the form of silica or a precursor of silica in the vicinity of a heating area created by a heating system during at least one pass of an injector system and the heating system along a longitudinal axis of the preform during which the relative positions of the injector and heating systems ore adjusted so that silica is deposited in the heated area regardless of the position of the heating system.

Abstract: A method and apparatus for separating a first and second optical fibers including a fiber feed mechanism adapted to feed the first optical fiber and the second optical fiber, and a nozzle adapted to provide a displacing force on the second optical fiber, where the second optical fiber is displaced away from the first optical fiber to thereby separate the second optical fiber from the first optical fiber. In one embodiment, the displacing force is provided by a gas stream directed away from the nozzle while in another embodiment, the displacing force is directed towards the nozzle. In another embodiment, the apparatus includes a separation mechanism with a first guide, a second guide, a guide separator, and a deflector plate. In another embodiment, the apparatus includes a clamp mechanism with a first clamping pad having an offset extension that extends beyond an edge of a second clamp pad.

Abstract: An apparatus and a method for centering a core of a waveguide amplifier. One embodiment of the invention comprises axially rotating a waveguide which has a core, shining a light through a light transmission pathway in the core of the waveguide, and shaping an outer surface of the waveguide in a predetermined pattern with respect to the light transmission pathway.

Abstract: In method of making an optical fiber and an apparatus, an optical fiber coated with UV curable resin is drawn at a drawing speed of 1000 m/min or more so that the optical fiber 5 has predetermined coating diameter from 235 &mgr;m to 265 &mgr;m. A transit time from an exit of a UV curing furnace to an entrance portion of a capstan for pulling the optical fiber downstream is set to be 0.5 seconds or more.

Abstract: An apparatus for drawing an optical fiber and a method for controlling the feed speed of an optical fiber preform whereby the drawing speed of an optical fiber is stabilized to keep the size of the outer diameter uniform. The capstan speed is determined based on the outer diameter of the optical fiber. When the capstan speed is out of a target speed range, the preform feed speed is controlled to bring the capstan speed into the target range. A control unit includes a calculation unit for receiving a drawing speed signal output from the capstan and calculating a feed speed of the perform. The control unit regulates the outer diameter of the optical fiber by regulating the speed of the capstan according to a signal received from the outer diameter measurement unit indicating a change in the outer diameter of the optical fiber.

Abstract: A neutralization system for controlling the pH of the washwater used to clean and maintain polyacrylic bound glass forming equipment. The neutralization system introduces a base solution to a washwater solution when the pH of the washwater solution contained in a closed loop washwater recovery system falls below about 8.5, thereby substantially reducing the corrosion rate of the components of the equipment associated with acidic polyacrylic acid binder, maleic acid cobinder or maleic anhydride cobinder and washwater solution. A closed-loop hoodwall washwater recovery system may also be introduced in addition to the neutralization system that allows for the recovery and reuse of polyacrylic acid binder and maleic acid cobinder or maleic anhydride cobinder with a minimal amount of base solution, thereby minimizing degradation of insulation properties of polyacylic acid bound glass fiber products.

Abstract: A neutralization system for controlling the pH of the washwater used to clean and maintain polyacrylic bound glass forming equipment. The neutralization system introduces a base solution to a washwater solution when the pH of the washwater solution contained in a closed loop washwater recovery system falls below approximately 8.0, thereby substantially reducing the corrosion rate of the components of the equipment associated with acidic polyacrylic acid binder and washwater solution. A closed-loop hoodwall washwater recovery system may also be introduced in addition to the neutralization system that allows for the recovery and reuse of polyacrylic acid binder with a minimal amount of base solution, thereby minimizing degradation of insulation properties of polyacylic acid bound glass fiber products.

Abstract: A method of controlling process variables, for a fiberizing assembly including a rotary fiberizing disk in the manufacture of fibers from a high temperature, molten, clear or translucent, thermoplastic, fiberizable material, utilizes an optical sensor assembly. The optical sensor assembly includes a water-cooled optical fiber sensor probe which, in effect, only gathers light emitted from the external sidewall surface of the rotary fiberizing disk. The light is conducted from the probe to an electronic unit that converts the light energy into a temperature value. This temperature value is used to monitor the process and to make any changes in process variables, such as but not limited to heat input to the fiberizing disk, rate of rotation of the fiberizing disk, burner air/fuel ratio, required to produce fibers having desired fiber properties.

Abstract: In splicing two optical fibers to each other using an electric arc formed between electrodes images of the regions being heated and thereby fusioned to each other are taken. The images cover a rectangular field (43) having the fibers located centrally, along a center line of the field and parallel to the long sides of the field. The images are evaluated to determine a value of the position of the center of the electric arc in relation to the position of the end surfaces of the fibers. This value can then be used for placing the end surfaces just at the arc center. In the image the image of the optical fibers can be excluded so that only light intensity from the air discharge of the electric arc is recorded in the captured images. The field (41) excluded can be a narrow strip of uniform width located symmetrically around the image of the fibers.

Abstract: Systems devices and methods in accordance with the invention impart high strength index of refraction patterns to photosensitive optical devices, such as Bragg gratings written in optical fibers. A length of small diameter fiber retaining photosensitivity is fabricated by flame elongation of an optical fiber precursor having dopant containing cladding, using a diffuse, low velocity inverted flame that does not introduce water, OH or H2 into the fiber. By varying the flame velocity during each scan the fiber is diminished to a small, uniform diameter, waist region. Photosensitivity is preserved and enhanced by exposure of the prepared waist region to scanning actinic illumination within an in-diffusing environment of pressurizing hydrogen or deuterium, and controlling the exposure to optimize the photo-induced index change.

Abstract: The invention relates to a method of making an optical fiber and an optical fiber made in accordance with the inventive method. The method includes the step of drawing an optical fiber from a multiple crucible apparatus, wherein one of the crucibles of the apparatus has a non-symmetrical orifice (not shown). The inventive fiber has at least a core and cladding. At least one section of the inventive fiber includes an orientation element.

Abstract: Disclosed is a method for controlling a heat treatment in the process of fabricating a high purity silica glass via a sol-gel process using a low temperature heater having an inhalation line and an exhaust line. Accordingly, the method includes the steps of (a) identifying whether or not the diameter of the exhaust line is varied; (b) controlling the mass flow of the process gas according to the changed diameter of the exhaust line in step (a); (c) measuring an exhaust gas velocity discharged through the exhaust line; (d) comparing the exhaust gas velocity measured in the step (c) with the exhaust gas velocity after the scale of the exhaust line is varied; and, (e) repeating steps (b)-(d) if the comparison result in step (d) is different.

Abstract: The present invention relates to a method of applying glass layers, which may or may not be doped, to the interior of a substrate tube by means of a chemical vapor deposition (CVD) technique, using a reactive gas mixture, in order to obtain a preform that exhibits a precisely defined refractive index profile, which method comprises a number of steps.

Abstract: The disclosed invention includes a method of making an optical fiber drawn from a multiple crucible. The method includes moving a first crucible of the multiple crucible relative to a second crucible of the multiple crucible. The invention also includes minimizing core and cladding diffusion. A tip of the first crucible is disposed axially above a tip of the second crucible by a preselected distance. The invention further includes the ability to alter a diameter of the core of the fiber. A differential pressure is applied to the first crucible. A positive differential pressure is applied to increase the core diameter. A negative differential pressure is applied to decrease the core diameter. Furthermore, the invention includes drawing the fiber under non-isothermal conditions; there is a thermal gradient of at least 10° C./m between the two tips.

Abstract: Three or more glass particle synthesizing burners are arranged to be opposed to a rotating glass rod. The glass rod and the glass particle synthesizing burners are reciprocated in parallel and relatively to deposit glass particles synthesized by the burners on the surface of the glass rod, thereby producing a soot body. The glass particle synthesizing conditions of the burners arranged at both ends are changed to have a greater deposition amount of glass particles per unit time in part or all of its movement range than other burners.

Abstract: A method is disclosed for fabricating a preform suitable for use in manufacturing a wide bandwidth multi-mode optical fiber. The method includes steps of employing a liquid phase spray pyrolysis technique for generating silica soot at a high rate, in combination with a non-chlorine containing liquid silica precursor and a refractory, index of refraction raising additive that overcomes the problems inherent in the use of germanium-based chemistry at typical sintering temperatures. The refractory, index of refraction raising additive is preferably comprised of a Group VB element oxide, such as a tantalum oxide. The liquid precursor is preferably comprised of a polymethylsiloxane, such as hexamethyl di-siloxane, octamethylcyclotetrasiloxane (OMCCTS), or tetramethylcyclotetrasiloxane.

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

Abstract: An apparatus and method for cleaving optical waveguides to precise differential length are described. A first end of a waveguide is coupled to an input port of a reflectometer. A reference mirror is then positioned in a path of radiation propagating through the second end of the waveguide. A waveguide cutting tool is then positioned proximate to the waveguide and at a distance relative to a reference mirror. A first reflectometry measurement is performed on the waveguide to a second end of the waveguide. A second reflectometry measurement is performed on the waveguide to the reference mirror. The waveguide is then positioned relative to the reference mirror and waveguide cutting tool so that the first reflectometery measurement is a measurement increment apart from the second reflectometry measurement. The waveguide is then cut with the cutting tool positioned at the distance relative to the reference mirror.

Abstract: An apparatus for manufacturing a glass-base-material, which is a base material of an optical fiber, includes a driving unit that drives a glass rod around an axis of the glass rod; a burner for accumulating glass soot around outside surface of the glass rod, which is driven by the driving unit, to form the glass-base-material; a weight-deducting unit, on which the driving unit is mounted, for deducting a predetermined weight from a total weight of the driving unit and the glass-base-material formed by the burner; and a measuring unit provided under the weight-deducting unit for measuring the total weight, from which the predetermined weight is deducted by the weight-deducting unit.

Abstract: A method and apparatus for controlling an outside diameter of a preform bait tube during a glass layer deposition process. The apparatus includes a gas source in communication with an interior of the preform bait tube. A temperature monitor measures a temperature of a hot zone of the preform bait tube and generates a temperature output signal indicative of the measured temperature. A diameter monitor measures the diameter of the hot zone of the preform bait tube and generates a diameter output signal indicative of the measured diameter. A pressure measuring unit measures the pressure in the interior of the preform bait tube and generates a pressure output signal indicative of the measured pressure.

Abstract: The present invention relates to an optical fiber fabrication method by which an optical fiber having an objective chromatic dispersion characteristic can be obtained readily. In an optical fiber fabrication method, a cutoff wavelength is measured in an optical fiber with a fixed length obtained by first drawing a part of an optical fiber preform. A target glass diameter for yielding an objective chromatic dispersion characteristic is then determined based on the cutoff wavelength thus measured. Then the rest of the optical fiber preform is drawn so that the glass diameter becomes the target glass diameter thus determined, thereby fabricating the optical fiber.

Abstract: An apparatus for conducting a fusion process includes a first chamber and a second chamber which maintains an atmosphere that is substantially free of oxygen. A closeable passage connects the second chamber and the first chamber and selectively provides substantial isolation of the second chamber from the first chamber. A filament normally disposed in the second chamber is moveable between the second chamber and the first chamber when the closeable passage is in an open position.

Abstract: A roll coater for placing binder on the fibers prior to being wound around a rotating drawing drum. The drawing drum draws fibers out of orifices in the bottom of a slowly reciprocating furnace. The fibers form a mat on the drawing drum that is later removed and expanded. The roll coater includes a graphite or other material coating drum that rotates in a bath of liquid binder and/or wetting agents, and reciprocates with the furnace. The fibers scrape over the surface of the coating drum after being formed but before winding around the drawing drum. The binder and/or wetting agent picked up on the surface of the coating drum coats the fibers with binder and/or wetting agent. Liquid binder and/or wetting agent is replenished in the bath in which the coating drum is partially submerged by a float, sensor, pump and large container of binder/wetting agent.

Abstract: The present invention discloses novel methods for fabricating optical fiber glass preforms which may contain alumina, germania, erbium, or other rare earth metals as dopants. Doping with a higher concentration of alumina enhances the solubility of the erbium, or other rare earth, dopant within the glass and the resultant optical properties of the fiber. However, the addition of an alumina dopant can cause processing difficulties due to the formation of inclusions, such as gas bubble, seeds or crystallite formation, within the glass preform or glass cane. The present invention overcomes these processing difficulties and produces glass preforms or canes that are inclusion-free.

Abstract: The method includes axially modulating at least one plasma build-up pass in order to improve the opto-geometrical properties of the preform. The modulation preferably takes place during the final passes of plasma build-up and takes place by modulating the build-up grain flow rate. The diameter of the preform is evaluated (6), and a build-up control device (8) regulates grain flow rate (11, 5) in application of the above method.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: Apparatus (700) for sintering a glass base material (2) which is a base material for an optical fiber. The sintering apparatus (700) includes: a control unit which varies a condition for sintering the glass base material; and a furnace (12) which sinters the glass base material by heating the glass base material in an atmosphere of dehydration gas and inert gas. The control unit includes a drive source (3) which supplies the glass base material to the furnace at various speeds. The control unit includes a temperature control unit which controls the temperature of a heating source provided in the furnace.

Abstract: Making a polymer-clad optical fiber comprising a step of determining at a plurality of temperatures the delamination resistance of the polymer coating from fiber. The delamination resistance at ambient temperature can be compared with a predetermined target value for delamination resistance in use. The delamination resistance at elevated temperature can be compared with a predetermined lower target value for ease of strippability. Coated optical fiber having delamination resistances outside the predetermined ranges will typically be rejected.

Abstract: The present invention provides a method for producing low flow rates of feedstock vapors used in the manufacture of silica glass. The method includes the steps of providing a constant flow of a liquid feedstock, mixing the flow of the liquid feedstock with an injector gas, expelling the mixture of liquid feedstock and inert gas from an injector orifice into a vaporizer chamber, flowing a carrier gas into the vaporizer chamber and through the mixture of liquid feedstock and injector gas, and vaporizing the liquid feedstock in the vaporizer chamber. The present invention is useful in the fabrication of planar silica waveguides.

Abstract: An apparatus and method of manufacturing optical waveguides that comprises non-optically measuring the average temperature of a moving optical waveguide fiber as it exits a heated draw furnace using a temperature device. The device comprises an enclosed chamber that has a plurality of differential thermopiles secured to the inside surface, and a cooling system that substantially maintains a reference surface temperature of one end of each of the thermopiles. Each of the thermopiles are serially interconnected, whereby, in response to a maximum amount of radiant energy absorbed, the thermopiles generate an output signal. The output signal is substantially proportional to the maximum amount of radiant energy absorbed by the thermopiles, which in turn is substantially proportional to the fourth power of the average temperature of the moving optical waveguide fiber within the chamber.

Abstract: A method and apparatus for automated manufacturing of optical fiber. According to one embodiment of the invention, an automated conveyor system automatically moves spools of optical fiber from one manufacturing process step to another. The spools are preferably mounted on pallets which circuit around on a plurality of non-interconnected track segments. The segments may include, for example, a segment transporting spools from draw, one or more test segments, and a shipping segment. Data-containing devices are mounted to the spool or pallet and allow data to be uploaded, downloaded and transferred as the fiber on the spool is processed and tested.

Abstract: A plurality of glass particle synthesizing burners are disposed opposite to a rotating starting rod. The starting rod and the glass particle synthesizing burners are relatively reciprocally moved to each other in parallel to the axial direction, so that glass particles synthesized by the burners are sequentially deposited on the surface of the starting rod. The movement is stopped and restarted repeatedly once or more than once during one reciprocal movement.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method of manufacturing a micro molten glass droplet, has the steps of, colliding a molten glass droplet with a micro through hole formed in a plate-shaped member; and pushing out at least part of the glass droplet to a reverse surface of the micro through hole as a micro droplet, thereby forming a glass droplet with a diameter of not more than 5 mm.

Abstract: An apparatus for grinding a glass base material having a core and a clad comprising: a grinding wheel for grinding the clad; a measuring unit for measuring an eccentricity between a center position of the glass base material and a center position of the core at a plurality of positions along a longitudinal direction of the glass base material; a design unit for calculating target diameters substantially continuous throughout the longitudinal direction of the glass base material so that the eccentricity becomes substantially zero for each of the plurality of positions; and a control unit for controlling the grinding wheel to grind the clad so that a diameter of the glass base material to be the target diameter substantially continuous throughout the longitudinal direction of the glass base material based on the target diameters calculated by the design unit.

Abstract: Methods, systems, and apparatus consistent with the present invention apply one or more laser beams to a glass object, such as a tube. The beams may have differing wavelengths, energy levels, and/or focal length characteristics. As the beam (single or multiple) penetrates the glass tube, it creates a channel. The beam is provided through the channel to a starting point on a region of the glass tube, usually the region below an inside diameter surface of the tube. In one embodiment, the beam is used to selectively heat a reactant gas within the tube to deposit a coating/dopant layer on the inside diameter surface. In another embodiment, the coating layer is already present and the beam selectively heats the layer causing thermal diffusion of the coating material into the glass tube at the region being heated.

Abstract: A method for manufacturing a base material for an optical fiber, includes steps of: holding a bar material by a support member; and adjusting to reduce a difference between an axis of the bar material and a rotational axis of the support member. Furthermore, an optical fiber base material grasping apparatus for holding a bar material having an axis, includes: a support member having a center axis, the support member being rotatable around the center axis; and an adjusting mechanism for reducing a difference between the axis of the bar material and the central axis of the support member.

Abstract: A porous preform vitrification apparatus of the present invention, provided with a means for forcibly feeding nitrogen etc. from a furnace core tube to a discharge gas pipe so as to balance a pressure between a furnace core tube accommodating a porous preform and a heating furnace body surrounding this and so as to suppress pressure fluctuation in the furnace core tube to a minimum level, controlling the gas feed rate and discharge rate to the furnace core tube and the heating furnace body, and controlling the feed rate of the nitrogen from the furnace core tube to the discharge gas pipe based on a differential pressure signal of a pressure in the furnace core tube and a pressure in the heating furnace body.

Abstract: The method consists of increasing the flowrate of argon injected into the bottom of a fiber-drawing furnace when a weld between two sections of a preform is being drawn during the operation of drawing a fiber from a preform. This prevents the weld causing an excessive increase in the diameter of the resulting fiber and/or an excessive variation in the drawing speed.

Abstract: A method for manufacturing a glass base material, which is a base material of an optical fiber, comprising: forming a core of the glass base material; forming the core includes: accumulating glass particles on a starting rod to form a porous glass soot; sintering the porous glass soot in an atmosphere of mixed gas that contains fluorine-compound gas to form a GI type refractive index profile, the refractive index of which gradually decreases with a distance from a center of the core; and forming a clad of the glass base material around the core.

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: Fabricating graded index plastic optical fiber by diffusing a high molecular weight dopant within a step index plastic optical fiber after the step index plastic optical fiber has been drawn from a preform using a conventional draw tower in a first embodiment. Also, the step index plastic optical fiber may be fabricated by extruding one material circumferentially around another material, e.g., by use of a concentric nozzle. The dopant is diffused after the drawing or extruding of the step index plastic optical fiber by heating the plastic optical fiber to a temperature that causes a high rate of diffusion state while measuring the transmission bandwidth of the plastic optical fiber. When the predetermined specified transmission bandwidth is measured, the plastic optical fiber is immediately returned to an ambient temperature. In addition, the plastic optical fiber may be gradually heated to an equilibrium temperature that is just below the temperature required to produce the high rate of diffusion state.

Abstract: A system for automated production of a fiber optic device includes a chamber regulating an environment and/or atmosphere within for the automated production of the fiber optic device. The system also includes a sealable input port, communicating with the chamber and substantially sealing the environment and the atmosphere of the chamber. The sealable input port receives an optical fiber for insertion therethrough into the chamber. A movable holding stage is included within the chamber, including at least one clamp to be secured to the optical fiber. An energy source is disposed within the chamber, and used to apply energy to the optical fiber. The system also includes a gripping device within the chamber. The gripping device includes a cavity adapted for receiving the optical fiber therethrough and for securing thereto.

Abstract: Two contacting test fibers that are radially offset relative to one another with a prescribable initial offset are heated such that an offset-reducing effect occurs. The resultant reduction of the initial offset is utilized for setting, particularly optimizing welding parameters.

Abstract: The production of mineral fibers by centrifuging on rollers (3, 4, 5, 6) with horizontal axes from a stream (1) of molten material includes determining the relative position of the stream (1) of molten material in relation to the first roller (3), and controlling this position by use of CCD cameras (8, 11, 40). A camera (11) observes the periphery of a fiber-drawing roller (4).

Abstract: The invention relates to manufacturing glass fiber preforms. It relates to a method comprising rotating preform about its own axis, and displacing a plasma torch in translation relative to the preform in a direction parallel to the axis of the preform, the axes of the flame and of the preform and being offset by a certain distance, and then inserting glass powder into the plasma flame under gravity. According to the invention, the glass powder is accelerated before penetrating into the plasma flame by means of an accelerator gas, and the offset distance between the axes is reduced with increasing acceleration of the powder. The invention is applicable to manufacturing glass fibers, and in particular optical fibers.

Abstract: An apparatus for forming a optical fiber which includes a furnace for softening an optical fiber blank; a tractor for drawing the optical fiber from the softened optical fiber blank; and a first applicator for applying a coating of a first coating material to the optical fiber, the first applicator having a rotatable die.