Abstract: A method of fabricating an optical fiber preform includes an operation of glazing the outside surface of the preform using inductive heating, of the plasma torch type, for localized heating of the preform. A flow of gas between the plasma and the preform in the area of the outside face of the preform on which the plasma impinges reduces the power of the plasma in this outside surface area.

Abstract: An object is to provide a method for producing an optical synthetic quartz glass and an optical synthetic glass, having a birefringence of lower than 0.5 nm/cm and having favorable refractive index distribution, yet without lowering the productivity, as well as to provide an annealing furnace suitably used in practicing said method. In a step of raising the temperature of a columnar optical synthetic quartz glass preform to a temperature of from 800° C. to 1200° C., and after keeping for a definite time, lowering the temperature, the temperature is lowered with a temperature difference of from 1 to 20° C. between the temperature of the light transmitting surface of the optical synthetic quartz glass preform and the temperature of the outer peripheral side surface of the optical synthetic quartz glass preform at temperature-lowering rates of from 2 to 50° C./hour, respectively.

Abstract: On the basis of a known process for the production of a preform for an optical fiber for optical data transmission technology, the productivity of the process for the production of complex refractive index profiles is to be improved by providing a quartz glass substrate tube which exhibits different doping in radial direction, introducing a core glass made of synthetic quartz glass into the substrate tube and covering the substrate tube with a jacket tube. A substrate tube suitable therefor is also being provided which tube requires less core glass material for the production of the preform, whether during the internal deposition or for the core glass rod in the rod-in-tube technique.

Abstract: The present invention provides a method for making a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, two or more inner cores, a cladding surrounding the two or more inner cores, and one or more side holes for reducing the bulk modulus of compressibility and maintaining the anti-buckling strength of the large diameter optical waveguide. The method features the steps of: assembling a preform for drawing a multicore large diameter optical waveguide having a cross-section of at least about 0.3 millimeters, by providing an outer tube having a cross-section of at least about 0.3 millimeters and arranging two or more preform elements in relation to the outer tube; heating the preform; and drawing the large diameter optical waveguide from the heated preform. In one embodiment, the method also includes the step of arranging at least one inner tube inside the outer tube.

Abstract: A method of making an optical fibre including providing an increased diameter portion on a rod. The rod is assembled by positioning the rod in a tube such that an annular gap is defined between an outer surface of the rod and an inner surface of the tube, and such that the increased diameter portion of the rod engages the tube and supports the rod with respect to the tube, and supporting the rod and tube assembly by gripping the tube. At the lower end of the rod and tube assembly, portions of the tube are collapsed onto the rod such that the tube portions fuse to the rod forming collapsed portions of the rod and the tube assembly. The collapsed portions are drawn to form an optical fibre. The vertically oriented rod and tube assembly can also be collapsed to form an optical fibre preform.

Abstract: An apparatus for manufacturing a glass base material, which is a base material of an optical fiber, comprising: a base rod, around and along which said glass base material is formed; a burner that hydrolyzes and accumulates a gas material, which is a base material of said glass base material, around and along said base rod; a first burner-moving-unit that moves said burner in a direction parallel with a longitudinal direction of said base rod; and a second burner-moving-unit that moves said first burner-moving-unit in a same moving direction of said first burner-moving-unit.

Abstract: A glass tube for use in an optical fiber preform is produced by applying a first soot on an end face of a starting member to form an elongated, porous cylindrical soot core having a first density, and applying a second soot including SiO2 on the periphery of the soot core to form a porous soot cladding having a second density greater than that of the soot core at the periphery of the core. The core and the cladding are later heated together at a temperature sufficient for sintering to form a core glass and a cladding glass. Because the soot core collapses at a greater rate than the soot cladding during sintering, the core glass separates or delaminates radially from the cladding glass. The core glass is then removed from the surrounding cladding glass, and the latter is treated to provide a high purity glass tube suitable for use as part of an optical fiber preform.

Abstract: A waveguide having an angled surface is created by depositing an optical core material onto a substrate having two levels. In one embodiment, a high density plasma deposition may be used to deposit the optical core material.

Abstract: An inlet arrangement for inserting a preform (3?) into a furnace (1?) for drawing a fiber (2?). The furnace includes an enclosure (4?) at the top of which there are both an opening to allow insertion of a preform which moves in translation, and a preform inlet arrangement (13?). The inlet arrangement comprises both an injector (6?) situated at the level of the opening to inject inert gas around the preform and to fill the enclosure, and at least one seal (17B) fixed above the injector and designed to allow the preform to pass therethrough, with its cylindrical main body (9?) being surrounded. The inlet arrangement further comprises an airlock (13) for closing and sealing the top of the furnace, above the injector, whether a preform is present or absent, which airlock is pressurized to prevent the surrounding air entering. The rods of the equipped preforms carry respective continuity tubes (20) of the same diameter as the bodies.

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: According to a prior art method for producing a cylindrical component comprised of silica glass, a cylinder comprised of a softened silica glass mass is drawn in a predetermined drawing direction along a drawing axis by means of a drawing device which acts upon said cylinder. The aim of the invention is to provide a method which prevents, to the greatest possible extent, warping of the drawn cylinder and other deviations from the ideal cylinder dimensions and to prevent, to the greatest possible extent, the outer surface of the drawn cylinder from being touched. To these ends, the invention provides that the drawing device comprises a plurality of guide elements which are arranged one behind the other along the drawing axis, and which can be displaced independently of one another in a drawing direction and in a direction opposite thereto.

Abstract: Methods and apparatuses estimate and control optical fiber primary coating diameter for wet-on-wet optical fiber manufacturing. The primary coating diameter for a particular length of optical fiber is calculated based upon a measurement of the weight of primary and/or secondary coating material consumed during optical fiber manufacturing. Control of the primary coating diameter is effected by a coating controller which can increase or decrease the primary coating diameter through control of glass temperature, coating viscosity and/or other parameters during wet-on-wet fiber manufacture.

Abstract: The invention concerns a device (1) for sintering of a porous mold body (2) in a gas-tight chamber (3), with the mold body (2) hanging loose from a link chain (7) so that it can be fed continuously to a heating zone (5). In the area of the upper boiler (10), the traction direction of the link chain (7) is reversed by a deviation wheel (11). The tensile force is transmitted via a traction rope (13) that can be taken up on a take-up reel (14), such take-up reel (14) being driven by a drive (16) arranged outside the chamber (3). A drive shaft (15) for the take-up reel (14) provides for easy sealing of the duct (18) towards the chamber (3), because only a rotation and not a simultaneous axial displacement is required for the hoisting movement, and moreover, because the duct (18) is arranged at a spatial distance from the heating zone (5).

Abstract: Optical waveguide fiber having low water peak as well as optical waveguide fiber preforms and methods of making optical waveguide fiber preforms from which low water peak and/or low hydrogen aged attenuation optical waveguide fibers are formed, including optical waveguide fiber and preforms made via OVD. The fibers may be hydrogen resistant, i.e. exhibit low hydrogen aged attenuation. A low water peak, hydrogen resistant optical waveguide fiber is disclosed which exhibits an optical attenuation at a wavelength of about 1383 nm which is less than or equal to an optical attenuation exhibited at a wavelength of about 1310 nm.

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 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: A burner and a method for producing an inorganic soot such as silica comprising a plurality of substantially planar layers having multiple openings therethrough formed by a micromachining process. The openings are in fluid communication with a precursor inlet and a gas inlet to permit the gas and the precursor to flow through and exit the burner. The burner produces a flame from a combustible gas in which the precursor undergoes a chemical reaction to form the soot.

Abstract: A glass fixative composition for bonding glass materials to non-glass materials is provided. The fixative composition is selected for its thermal expansion coefficient, its viscosity, its adhesion to glass, melting point, and bond strength. The glass fixative is in particular useful for bonding optical fibers to metallic materials such as Kovar. The low melting point of the glass fixative enables localized heating methods to be used, in particular, as Kovar is a ferromagnetic material, induction heating can be used to form a bond. The bond formed provides a compressive joint which enables the fiber to be hermetically fixed in position.

Abstract: Dynamically controlling the reaction temperature at the tip of a soot preform by controlling the flow of hydrogen gas to the core torch provides a wide latitude of control over the temperature range necessary to produce uniform composition of the preform.

Abstract: A method for manufacturing optical fiber with enhanced photosensitivity comprising the step of: forming a molten layer of glass and drawing a fiber from the molten layer of glass at a temperature of between about 1900° C. and 1995° C. Draw tension can be adjusted to attain the desired draw speed.