Abstract: A precision burner for oxidizing halide-free, silicon-containing compounds, such as, octamethyl-cyclotetrasiloxane (OMCTS), is provided. The burner includes a subassembly (13) which can be precisely mounted on a burner mounting block (107) through the use of an alignment stub (158), a raised face (162) on the burner mounting block (107), and a recess (160) in the back of the subassembly (13). The burner's face includes four concentric gas-emitting regions: a first central region (36, 90) from which exits a mixture of OMCTS and O.sub.2, a second innershield region (38, 92) from which exits N.sub.2, a third outershield region (40, 42, 94, 96) from which exits O.sub.2, and a fourth premix region (44, 98) from which exits a mixture of CH.sub.4 and O.sub.2. The burner provides more efficient utilization of halide-free, silicon-containing raw materials than prior burners.

Abstract: A vaporizer (film evaporator) (13) for halide-free, silicon-containing liquid reactants used in producing preforms is provided. The vaporizer includes a plurality of packed-bed columns (22) surrounding a central tube (24). A mixture of liquid reactant, e.g., octamethyl-cyclotetrasiloxane, and gas, e.g., oxygen, is sprayed onto the top surfaces (54) of the columns (22) by a set of spray nozzles (32). The liquid reactant and the gas flow downward together through the columns and are heated by hot oil (28) which flows around the columns' walls (50). The liquid reactant evaporates into the gas until the dew point temperature is reached, at which point all of the liquid reactant will have been converted into vapor. The vapor/gas mixture exits the bottom surfaces 56 of columns (22), where its direction of flow changes from downward to upward. This change in flow direction separates higher molecular weight species (46) from the vapor/gas mixture.

Abstract: Disclosed is a method and apparatus for providing reactant vapors to a utilization site. The apparatus includes a vaporization chamber enclosed by top and bottom walls, side walls and first and second end walls. The first end wall is elevated with respect to the second end wall. The reactant is supplied in liquid form to a flow distributor that delivers the liquid to that portion of the bottom wall near the first end wall. The angle with which the bottom wall is inclined with respect to horizontal is sufficient to cause the liquid to flow down the bottom wall at a rate sufficient to form a film, the thickness of which is smaller than that thickness which would support a bubble during heating of the film. The surface is heated to a temperature greater than the boiling point of the liquid, thereby converting the liquid reactant to a vapor that is delivered to the vapor utilization site.

Abstract: A method and apparatus for cooling a glass optical fiber drawn from a glass preform, prior to applying a protective coating to the fiber, wherein the fiber is transported through a cooling zone containing coolant consisting of a solid or liquid dispersion of a condensible gas, the gas being a chemical element or compound having a vapor pressure of at least 1 atmosphere at 25.degree. C. such that rapid coolant vaporization at ambient temperatures is insured, are provided.

Abstract: A fiber optic coupler is formed by providing a glass tube having a longitudinal aperture extending therethrough. Glass optical fibers, each having a core, cladding and coating are disposed within the longitudinal aperture, the fibers extending beyond each end thereof. The coating is removed from that portion of the fibers in the midregion of the tube. The midregion of the tube is heated, collapsed about the fibers, and drawn to reduce the diameter thereof over a predetermined length. The fibers that are used in the process of making the coupler are initially provided with a coating that is too thin to provide good handleability and strength. However, the thin initial coating enables the use of a tube having a small aperture and thereby enhances the tube collapse step. After the coupler is formed, the fibers extending therefrom are overcoated. The process can be used to make other kinds of optical devices including integrated optical components.

Abstract: Optical communication media particularly adapted for blow-in installation, including single optical fibers and lightweight flexible optical cables comprising one or more glass optical fibers in a multilayer polymer coating, are disclosed. The multilayer coating includes a textured polymer outer layer and at least one soft buffer layer positioned between the textured polymer outer layer and the glass optical fiber or fibers, the buffer layer comprising a low T.sub.g polymer and preferably having a layer thickness at least sufficient to maintain thermally induced microbending loss in the optical communication medium below about 0.5 db/km at medium operating temperatures in the range of 0.degree. C. to -60.degree. C.

Abstract: Plastic ducts suitable for use alone or as components of telecommunications cables to provide for easy installation of optical fibers by blow-in methods, together with optical cable designs incorporating such ducts, are described. The ducts, most preferably provided as plastic tubes, are characterized by inner sidewall compositions of a modified polyvinyl chloride (PVC)-based compound, the compound consisting at least predominantly of PVC polymer but additionally containing up to about 20% by weight of fluorocarbon polymers compounded directly with the PVC.

Abstract: A liquid cooling method and apparatus for rapid cooling of a hot glass fiber. In FIG. 1, an open ended liquid coolant container (12) is provided at its lower end with an inverted funnel surface (34). A vertically running, hot glass fiber (42) of indefinite length is continuously drawn through the container, as the container continuously receives a coolant liquid at its upper open end (30). The liquid continuously drains from the container lower open end (32) by flowing along flow surface (36) of the inverted funnel (34), downwardly and away from the glass fiber (42). The temperature of the fiber relative to the temperature of the coolant liquid is such that a vapor barrier surrounding the hot fiber is formed due to boiling of the liquid in a zone surrounding the fiber. This vapor zone facilitates diversion of the liquid (change in direction of flow) from the vertical to an angle thereto, along the inverted funnel surface.

Abstract: A fiber optic coupler is formed by providing a glass tube having a longitudinal aperture extending therethrough. Glass optical fibers, each having a core, cladding and coating are disposed within the longitudinal aperture, the fibers extending beyond each end thereof. The coating is removed from that portion of the fibers in the midregion of the tube. The midregion of the tube is heated, collapsed about the fibers, and drawn to reduce the diameter thereof over a predetermined length. The fibers that are used in the process of making the coupler are initially provided with a coating that is too thin to provide good handleability and strength. However, the thin initial coating enables the use of a tube having a small aperture and thereby enhances the tube collapse step. After the coupler is formed, the fibers extending therefrom are overcoated. The process can be used to make other kinds of optical devices including integrated optical components.

Abstract: A method and apparatus for the rapid on-line coating of optical fibers with two-package polymer coating systems utilizing conventional liquid fiber coaters is described. The A and B parts of the two-package coating system are continuously combined and mixed together to form a polymerizable coating liquid as the fiber is drawn. This polymerizable coating liquid is continuously delivered to the liquid coater at a rate corresponding to the rate at which it is applied to the fiber, suitable control of the delivery rate being achieved via the use of a feedback signal to the coating liquid delivery system from, e.g., the fiber coater.