Abstract: A dispersion compensating single mode optical waveguide fiber designed to change the wavelength window of operation of a link from 1310 nm to 1550 nm. The dispersion compensating waveguide fiber is characterized by a core glass region refractive index profile comprised of at least three segments. The segment on the waveguide center has a positive relative refractive index. At least one segment, spaced apart from, the waveguide centerline has a negative relative refractive.

Abstract: Methods, apparatus and precursors for producing substantially water-free silica soot, preforms and glass. The methods and apparatus make substantially water-free fused silica preforms or glass by removing water as a reaction product, removing water from the atmosphere, removing water from the transport process, or combinations thereof. In a first embodiment, substantially water-free soot, preforms or glass are achieved by using a hydrogen-free fuel, such as carbon monoxide, in the deposition process. In another embodiment, a soot producing burner has parameters that enable operation on a substantially hydrogen-free fuel. End burners, which minimize water production, are also described. Such water-free methods are useful in depositing fluorine-doped soot because of the low water present and the efficiency in which fluorine is incorporated. In another embodiment, glassy barrier layer methods and apparatus are described for minimizing dopant migration, especially fluorine.

Abstract: A method for producing an optical waveguide component includes providing a glass producing soot, providing a soot delivery device adapted to provide an electrostatic charge to the soot, and providing a substrate material adapted to receive the glass producing soot thereon. The method also includes delivering the soot to the delivery device, and accelerating the soot as it passes through the delivery device. The method further includes charging the soot as the soot is passed through the delivery device with a sufficient charge to attract the soot to the substrate material, and depositing the soot on the substrate material by spraying the soot onto the substrate material via the delivery device.

Abstract: A glass optical fiber includes multiple cores fused into a single fiber. The new optical fiber is coherent, in the sense that the cores maintain their relative position with respect to each other within the fiber throughout the length of the fiber. That is, a core having specific radial and angular positions at one end of the fiber will have the same radial and angular positions throughout the fiber, including at the fibers opposite end. In one aspect of the invention the fiber presents a circular cross section, in another it presents an elliptical cross section of greater eccentricity to ease the task of orienting the cores within the fiber for connection to signal sources, other fibers, integrated optic devices, receivers and other optical components. An orienting core may suitably be included in the fiber to further assist in orienting the fiber end. In manufacturing the new optical fiber, a silica tube is stuffed with core canes.

Abstract: A dispersion compensating single mode optical waveguide fiber designed to change the wavelength window of operation of a link from 1301 nm to 1550 nm. The dispersion compensating waveguide fiber is characterized by a core glass region refractive index profile comprised of at least three segments. The segment on the waveguide center has a positive relative refractive index. At least one segment spaced apart from the waveguide centerline has a negative refractive index.

Abstract: The present invention is directed to a method for making silica glass and silica glass preforms. A liquid, preferably halide-free, silicon-containing compound capable of being converted by thermal oxidative decomposition to SiO.sub.2 is provided and introduced directly into the flame of a combustion burner, which converts the compound to silica, thereby forming finely divided amorphous soot. The soot is vaporized proximate the site where the liquid is converted into silica glass by atomizing the liquid, preferably with a stream of atomizing gas. A heater proximate the burner face and around the burner flame increases soot capture rate and allows for a reduction of the velocity of the atomizing gas. 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.

Abstract: A method and apparatus for drawing an optical waveguide fiber which minimizes fiber bow caused by differential stresses in the cladding layer of the fiber are disclosed. The fiber is drawn from a preform which is heated in a draw furnace. Gases introduced at the top of the furnace form a boundary layer adjacent to the fiber which passes through the furnace, along with the fiber, into a tube. The tube isolates the fiber from the ambient atmosphere so that the boundary layer of gases established in the furnace remains substantially uniform until the viscosity of the cladding layer of the fiber is high enough to minimize differential stresses around the circumference of the fiber.