Abstract: The present invention is directed to a method and apparatus for forming soot used in making glass, and in particular, optical waveguides. A liquid precursor (66) is first fed into orifice (52) of a liquid orifice insert (48) within an injector (44) positioned within an atomizing burner assembly, and is thereafter discharged from the injector into a pressurization chamber (56). An atomization gas (70) is also fed into the pressurization chamber (56) to mix with the liquid precursor liquid stream (68) which breaks into droplets (76). The liquid precursor and atomization gas arm forced under pressure out of an atomization orifice (32) on the face of the burner (30) assembly. Flame gas (74), reaction gas (84) and shield gas (82) are ejected from burner orifices (40, 38, 36 and 34) to produce the flame.

Abstract: The present invention provides a method for drawing microstructured fibers. A preform having a first set of holes and a second set of holes is provided, and the first set of holes is coupled to a first pressure system, while the second set of holes remains substantially uncoupled to the first pressure system. The pressures of the sets of holes may be independently set or controlled to yield a desired hole geometry in the drawn microstructured optical fiber. The present invention also provides preforms suitable for use with the methods of the invention.

Abstract: The present invention relates to an optical fiber including a fiber core and at least one coating substantially encapsulating the fiber core, wherein the at least one coating includes a material forming a data storage medium which is capable of digitally encoding information at a data density of at least about 4 bits per centimeter. Both magnetically and optically encoded fibers are disclosed. Also disclosed are a method of making an optical fiber of the present invention, methods of digitally encoding information onto an optical fiber, and a method of retrieving information digitally encoded onto an optical 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: Disclosed are optical gain fibers which include an erbium-containing core and a cladding surrounding the core and which have ripple of less than about 25% over about a 40 nm wide window or ripple of less than about 15% over about a 32 nm wide window, or both. In one embodiment, the optical gain fibers are pumpable at 980 nm and at 1480 nm. In another embodiment, the optical gain fibers are fusion sliceable. In yet another embodiment, the core includes oxides erbium; the cladding includes silicon dioxide; and the optical gain fiber has a passive loss of less than about 0.5% of the peak absorption of the erbium absorption band in the vicinity of 1530 nm. The optical gain fibers of the present invention have a wider gain window, improved flatness across the gain window, and/or increased gain as compared to conventional optical gain fibers.

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 method and apparatus for manufacturing optical components. A burner generates soot, and a surface area collector collects the soot. The burner is disposed such that the soot collected within the surface area collector is substantially not reheated by subsequently deposited soot. Magnetic forces direct the soot to desired location(s) within the surface area collector. The surface area collector operates at relatively low temperatures sufficient to retain rather volatile substances, such as fluorine, in the soot.

Abstract: A burner module for delivering a flow of chemical reactants to a combustion site of a chemical vapor deposition process includes a plurality of substantially planar layers. The substantially planar layers are arranged in a generally parallel and fixed relationship and define an inlet, an outlet and a passage fluidly connecting the inlet and outlet. At least one of the layers is a distribution layer having a plurality of apertures therethrough and fluidly communicating with the passage. The plurality of apertures collectively define a non-uniform pattern arranged and configured to improve the uniformity of a flow out through the outlet. Burner adapter and assembly embodiments are also included.

Abstract: The present invention is directed to a method for making fused silica glass. A liquid, preferably halide-free, silicon-containing compound capable of being converted by thermal oxidative decomposition to SiO2 is provided and introduced directly into the flame of a combustion burner, thereby forming finely divided amorphous soot. The amorphous soot is deposited on a receptor surface where, either substantially simultaneously with or subsequently to its deposition, the soot is consolidated into a body of fused silica glass. The invention further relates to an apparatus for forming fused silica from liquid, preferably halide-free, silicon-containing reactants which includes: a combustion burner which, in operation, generates a flame; an injector for supplying a liquid silicon-containing compound to the flame to convert the compound by thermal oxidative decomposition to a finely divided amorphous soot; and a receptor surface on which the soot is deposited.

Abstract: A method of manufacturing a glass article, such as an optical fiber. The method comprises the steps of providing a glass tube with an annular passage, forming a preform from the glass tube while maintaining the annular passage, and drawing the preform into the glass article such that the annular passage closes during drawing. The preform is formed by the steps of providing glass on an inner surface of the glass tube while maintaining the annular passage and providing glass on an outer surface of the glass tube. The preform has a predetermined value &agr; that is an inner diameter of the preform after providing glass on the inner surface divided by an outer diameter of the glass tube. The preform has a predetermined value &bgr; that is the inner diameter of the preform after providing glass on the inner surface divided by the outer diameter of the preform.

Abstract: A method of manufacturing an optical waveguide preform includes providing a first process gas atmosphere to a soot preform contained in a vessel. The first atmosphere is held in the vessel for a first reacting time sufficient to at least partially dope or dry the soot preform. The vessel is then at least partially refilled with a second doping or drying atmosphere. The second doping or drying atmosphere is held in the vessel for a second reacting time sufficient to further dope or dry the soot preform.

Abstract: Optical fiber structures having at least two cores, whether unitary or separable, may be fabricated by controlling the placement of the cores prior to final processing to make the multi-core fiber structure. When the fiber is to be separable, at least two performs are attached, and the attachment height between adjacent canes is controlled to allow separation to be realized (or attachment to be maintained there between) anywhere along the separable multi-core fiber. These canes are then drawn together to form a desired composite fiber, either or both ends of which may be separated to allow for individual manipulation of fiber ends.

Abstract: An improved telecommunications link is provided which includes a dispersion managed fiber with smoothly varying dispersion. The dispersion map may vary sinusoidally or as a sawtooth, for example. The smoothly varying dispersion works well for high data rate transmissions in a return to zero signal format. The dispersion managed fiber with smoothly varying dispersion may be formed by a wide variety of techniques. A method of forming dispersion managed fiber by localized heating or cooling is also provided.

Abstract: Optical fiber structures having at least two cores, whether unitary or separable, may be fabricated by controlling the placement of the cores prior to final processing to make the multi-core fiber structure. When the fiber is to be separable, at least two performs are attached, and the attachment height between adjacent canes is controlled to allow separation to be realized (or attachment to be maintained there between) anywhere along the separable multi-core fiber. These canes are then drawn together to form a desired composite fiber, either or both ends of which may be separated to allow for individual manipulation of fiber ends.

Abstract: The present invention relates to an optical fiber including a fiber core and at least one coating substantially encapsulating the fiber core, wherein the at least one coating includes a material forming a data storage medium which is capable of digitally encoding information at a data density of at least about 4 bits per centimeter. Both magnetically and optically encoded fibers are disclosed. Also disclosed are a method of making an optical fiber of the present invention, methods of digitally encoding information onto an optical fiber, and a method of retrieving information digitally encoded onto an optical fiber.

Abstract: Disclosed are optical gain fibers which include an erbium-containing core and a cladding surrounding the core and which have ripple of less than about 25% over about a 40 nm wide window or ripple of less than about 15% over about a 32 nm wide window, or both. In one embodiment, the optical gain fibers are pumpable at 980 nm and at 1480 nm. In another embodiment, the optical gain fibers are fusion sliceable. In yet another embodiment, the core includes oxides erbium; the cladding includes silicon dioxide; and the optical gain fiber has a passive loss of less than about 0.5% of the peak absorption of the erbium absorption band in the vicinity of 1530 nm. The optical gain fibers of the present invention have a wider gain window, improved flatness across the gain window, and/or increased gain as compared to conventional optical gain fibers.

Abstract: An apparatus for forming optical fiber from a glass preform using a forming gas includes a draw furnace having first and second opposed ends. The draw furnace defines an exit opening at the second end and a furnace passage extending between the first and second ends. A control tube extends through the exit opening of the draw furnace. The control tube defines first and second opposed tube openings and a tube passage extending between the first and second tube openings. The control tube includes a first tube section and a second tube section. The first tube opening and the first tube section are disposed in the furnace passage and cooperate with the passage of the draw furnace to form a buffer cavity adjacent the control tube. The second tube opening and the second tube section are disposed downstream of the draw furnace. The tube passage includes an inner diameter. The inner diameter of the tube passage is less than an inner diameter of the furnace passage.

Abstract: A cylindrical glass body having a low water content centerline region and method of manufacturing such a cylindrical glass body for use in the manufacture of optical waveguide fiber is disclosed. The centerline region of the cylindrical glass body has a water content sufficiently low such that an optical waveguide fiber made from the cylindrical glass body of the present invention exhibits an optical attenuation of less than about 0.35 dB/km, and preferably less than about 0.31 dB/km at a measured wavelength of 1380 nm. A low water content plug used in the manufacture of such a cylindrical glass body, an optical waveguide fiber having a low water peak, and an optical fiber communication system incorporating such an optical waveguide fiber is also disclosed.

Abstract: An apparatus for producing a glass soot includes a first a burner having a droplet-emitting first region, a gas-emitting second region surrounding the first region, and a gas-emitting third region surrounding the second region. The first region emits a glass-forming mixture, the second region emits an inert gas, and the third region emits a combination of oxygen and a combustible gas. The apparatus further includes a combustion area having a first section proximate the first burner and a second section distal from the first burner. A glass-forming mixture is at least partially vaporized in the first section of the combustion area. The apparatus further includes at least one secondary burner having gas-emitting fourth and fifth regions. The fourth region of the secondary burner emits oxygen and the fifth region of the secondary burner emits a combustible gas.

Abstract: An apparatus for producing the glass soot used in the formation of optical fiber includes a burner with an internal atomizer. The atomizer includes an outer tube having a nozzle at an end thereof, and an inner tube located within the outer tube and having a closed end restricting fluid flow therethrough and defining a cylindrical sidewall having radially extending apertures spaced there along. The outer tube receives the glass-forming mixture in liquid form and the inner tube receives an atomizing gas which flows through the apertures in the sidewall of the inner tube and atomizes the glass-forming mixture as the glass-forming mixture travels through the outer tube.