Abstract: The present invention provides an optical fiber suitable for the manufacture of optical fiber couplers and having low bend loss, low splice loss, and low attenuation. The optical fibers according to one aspect of the invention have bending loss of less than 0.5 dB at 1560 nm when wrapped 5 turns around a 20 mm mandrel; and an average fiber pull test loss of less than 0.1 dB in the wavelength range of 1530 nm to 1550 nm. The present invention also includes optical fiber components made from these optical fibers.

Abstract: The present invention provides an optical fiber suitable for the manufacture of optical fiber couplers and having low bend loss, low splice loss, and low attenuation. The optical fibers according to one aspect of the invention have bending loss of less than 0.5 dB at 1560 nm when wrapped 5 turns around a 20 mm mandrel; and an average fiber pull test loss of less than 0.1 dB in the wavelength range of 1530 nm to 1550 nm. The present invention also includes optical fiber components made from these optical fibers.

Abstract: Optical fiber is provided with a periodically reversing spin while the fiber is pulled through a melt zone. A cooled region of the fiber downstream from the melt zone passes between a pair of opposed elements. The opposed elements are moved so that surface regions engaging the fiber move in opposite lateral directions relative to one another, thus spinning the fiber about its axis. The lateral movement of the engaged surface portions is periodically reversed to reverse the spin direction. The opposed elements may include belts or rollers, which can be tilted to orientations oblique to the longitudinal direction of the fiber.

Abstract: Optical fiber is provided with a periodically reversing spin while the fiber is pulled through a melt zone. A cooled region of the fiber downstream from the melt zone passes between a pair of opposed elements. The opposed elements are moved so that surface regions engaging the fiber move in opposite lateral directions relative to one another, thus spinning the fiber about its axis. The lateral movement of the engaged surface portions is periodically reversed to reverse the spin direction. The opposed elements may include belts or rollers, which can be tilted to orientations oblique to the longitudinal direction of the fiber.

Abstract: Optical fiber is provided with a periodically reversing spin while the fiber is pulled through a melt zone. A cooled region of the fiber downstream from the melt zone passes between a pair of opposed elements. The opposed elements are moved so that surface regions engaging the fiber move in opposite lateral directions relative to one another, thus spinning the fiber about its axis. The lateral movement of the engaged surface portions is periodically reversed to reverse the spin direction. The opposed elements may include belts or rollers, which can be tilted to orientations oblique to the longitudinal direction of the fiber.

Abstract: A bobbin for holding a filament pack having a base layer wound of optical waveguide fiber. A method for winding the base layer on the bobbin base is disclosed.The optical waveguide base layer closely matches the properties of the glass and coating of the optical waveguide which makes up the filament pack. Thus, the long term stability of the filament pack is enhanced. Examples are given in which bobbins incorporating the inventive base layer were successfully unwound at high speed.

Abstract: An optical fiber waveguide of the type comprising an outer cladding layer, an axially disposed core of SiO.sub.2 doped with GeO.sub.2 and a first inner cladding layer of SiO.sub.2 doped with an oxide such as P.sub.2 O.sub.5 for lowering the preform processing temperature. A second inner cladding layer of pure SiO.sub.2 is disposed between the first inner cladding layer and the core to prevent P.sub.2 O.sub.5 from diffusing into the core, thereby eliminating absorption losses from the P--O--H band in the 1.1-1.8 .mu.m region.

Abstract: A method of producing optical fibers having improved core roundness and core-clad axis concentricity. Prior to the step of forming a layer of core material on the inner surface of a bait tube, the tube is pressurized and heated and shrunk at least 1 mm and thereafter the pressure is increased to inflate the tube until the outside diameter thereof approximates that of the originally provided bait tube.

Abstract: This invention relates to the preparation of silica-containing particulate materials and monolithic structures exhibiting high porosity with exceptionally uniform pore size. The bodies are produced through gelation of aqueous alkali metal silicate and/or colloidal silica solutions, optionally contaiing dispersed particulate phases, with organic reagents followed by a leaching step. Uniformity of pore size is achieved through careful control of such variables as the ratio of alkali metal silicate to colloidal silica solutions, the concentration of silica, the amount of dispersed phase employed, and the like.