Abstract: An inverse dispersion fiber having a large effective area and a transmission system that incorporates the fiber for providing dispersion and dispersion slope compensation in a transmission fiber. The large-effective-area inverse dispersion optical fiber (IDF) has a negative dispersion and a negative dispersion slope. The effective area, Aeff, of the IDF preferably is greater than approximately 31 micrometers squared (?m2) at a transmission wavelength of approximately 1550 nm. The large-effective-area IDF is suitable for use with super-large-effective-area (SLA) transmission fiber for compensating dispersion in the SLA transmission fiber while reducing nonlinear effects between wavelength channels and cabling loss, which is especially advantageous in transoceanic and long-haul terrestrial systems. These nonlinear effects are inversely related to the effective area of the fiber (i.e., nonlinearities˜1/Aeff).

Abstract: A method and an apparatus for obtaining measurements of eccentricity in optical fibers, from which the spin imparted to the optical fiber can be ascertained. The method and apparatus enable eccentricity to be measured in such a way that this measurement can be utilized to determine the amount of spin imparted to an optical fiber as the optical fiber was being drawn, although the eccentricity measurement may be used for purposes other than to determine the amount of spin in the fiber. By viewing the fiber from one or more positions along the length of the fiber, the eccentricity of the fiber as a function of position along the length of the fiber can be determined. The amount of spin in the fiber can then be determined from the eccentricity measurement.

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: A super-large-effective-area (SLA) optical fiber that is suitable for communicating over a wide wavelength range and that, because of its large effective area, suppresses nonlinear effects that typically result from interaction between signal channels. The effective area, Aeff, of the SLA fiber of the present invention preferably is equal to or greater than approximately 80 ?m2 at a wavelength window around 1310 nm. The cutoff wavelength of the SLA fiber of the present invention preferably is less than 1310 nm. Thus, the SLA fiber of the present invention has a very large effective area and a very low cutoff wavelength. In accordance with the present invention, a variety of SLA fibers are provided that all have very large effective areas and desirable transmission properties. The large effective areas of the SLA fibers of the present invention enable nonlinear effects to be suppressed, as well as Stimulated Brillouin Scattering in analog transmission.

Abstract: An inverse dispersion fiber having a large effective area and a transmission system that incorporates the fiber for providing dispersion and dispersion slope compensation in a transmission fiber. The large-effective-area inverse dispersion optical fiber (IDF) has a negative dispersion and a negative dispersion slope. The effective area, Aeff, of the IDF preferably is greater than approximately 31 micrometers squared (&mgr;m2) at a transmission wavelength of approximately 1550 nm. The large-effective-area IDF is suitable for use with super-large-effective-area (SLA) transmission fiber for compensating dispersion in the SLA transmission fiber while reducing nonlinear effects between wavelength channels and cabling loss, which is especially advantageous in transoceanic and long-haul terrestrial systems. These nonlinear effects are inversely related to the effective area of the fiber (i.e., nonlinearities ˜1/Aeff).

Abstract: A super-large-effective-area (SLA) optical fiber that is suitable for communicating over a wide wavelength range and that, because of its large effective area, suppresses nonlinear effects that typically result from interaction between signal channels. The effective area, Aeff, of the SLA fiber of the present invention preferably is equal to or greater than approximately 80 &mgr;m2 at a wavelength window around 1310 nm. The cutoff wavelength of the SLA fiber of the present invention preferably is less than 1310 nm. Thus, the SLA fiber of the present invention has a very large effective area and a very low cutoff wavelength. In accordance with the present invention, a variety of SLA fibers are provided that all have very large effective areas and desirable transmission properties. The large effective areas of the SLA fibers of the present invention enable nonlinear effects to be suppressed, as well as Stimulated Brillouin Scattering in analog transmission.

Abstract: A monitoring system for detection of defects in an optical fiber coating during production of the fiber has first and second beam generating means which produce planar coherent beams which cross each other at the fiber passing through the system creating one or more diffraction patterns. A first plurality of photodetectors are mounted in a mount, the front face of which is impinged by the planar diffraction pattern, and a second plurality of photodetectors is similarly mounted in position below the impinging pattern. A defect in the fiber coating, regardless of shape or orientation, will cause the pattern or patterns to be tilted or shifted upward, downward, or planarly tilted to impinge one or more of the photodiodes which, as a result, generates a signal which is applied to a comparator and control circuit.

Abstract: Apparatus and methods are provided for reducing end effect on a preform assembly during manufacture of optical fiber. The present invention provides apparatus and methods that apply a first vacuum pressure to a preform assembly during a first portion of the draw of optical fiber from the preform assembly and a second lesser vacuum pressure during a second portion of the draw. The second vacuum pressure may be a step down pressure or a gradual or an incremental decrease in pressure over time. The present invention further provides apparatus and methods that use an intermediate rod such as a dummy preform core rod and/or a support rod placed at the back of the preform core rod, wherein the preform end effect occurs on the dummy preform core rod, as opposed to the core rod of the preform assembly or is eliminated altogether by the support rod.

Abstract: An optical fiber product comprises an optical fiber through which optical signals can be transmitted. A primary coating comprising a foam material surrounds the optical fiber. A secondary coating surrounds the primary coating. At least one of the primary coating and the secondary coating protect the optical fiber and resists microbending forces. A method of manufacture is also provided.

Abstract: A pull-proof optical fiber connector for use with robust optical fiber has a housing and a ferrule bearing barrel member therein having a first outside diameter over a front portion thereof and a second, lesser outside diameter rearward portion, and a bore extending therethrough forming an optical fiber passage.

Abstract: A variable attenuator has first and second substantially identical ferrules or capillaries, each being mounted in a barrel or splice housing and extending toward each other, with their distal ends being separated by a gap of a first width. The width of the gap is controlled by a sleeve into which the ferrules are inserted, the ends of the sleeve butting against the front faces of the barrels. The ferrules are made by producing a glass rod mounted between the barrels and having a bore offset from and parallel to the centerline of the rod and breaking or cleaving the rod at its longitudinal center. The broken ends are then polished. The barrels are keyed to a housing member so that the offset bores are coincident in the zero position as defined by the keys.