Lucent Technologies Inc.

At+t Corp.

Montri Viriyayuthakorn

Terry D Mathis

John T Chapin

Carla Green Wilson

James Robert Holman

Lionell Graham

Wayne McCall Newton

Lee L Blyler

Jim Jenqtsong Sheu

Todd Richard Salamon

Mark I Shmukler

Ruben Travieso

Arthur Clifford Hart, Jr

Parry A Moss

J Thomas Chapin

Artis Cornell Jenkins

Loinell Graham

A simplex optical fiber cable includes an optical fiber, a buffer surrounding and in contact with the optical fiber, a layer of strength fibers disposed about the buffer, and a sheath member surrounding and in contact with the yarn layer. In cross section the cable has a diameter of less than 2.0 millimeters (mm) and thus is much smaller in diameter than optical fiber cables presently available. Preferably, if the buffer is relatively thin a slick substance is applied to the outer surface of the buffer to allow the buffer and the strength fiber layer to slide relation to each other. If the buffer is relatively thick, a friction-reducing substance can be applied to the optical fiber to facilitate stripping of the buffer from the fiber a duplex optical fiber cable includes two simplex optical fiber cables having their respective sheaths joined to produce a figure-eight configuration. A second duplex optical fiber cable includes two simplex optical fiber cables arranged side-by-side and an oversheath surrounds both cables.

Sub-miniature optical fiber cables, and apparatuses and methods for making the sub-miniature optical fiber cables

The present invention relates to a buffered optical fiber which has a high flame resistance and high modulus. The buffered optical fiber comprises a cladded glassy core through which optical signals can be transmitted, at least one coating layer surrounding the cladded glassy core which protects the core from microbending forces, and a buffer layer material that surrounds the at least one coating layer to form a buffer layer that protects the coated optical fiber from mechanical forces and from flame. In the preferred embodiment, the buffer material comprises homopolymer of polyvinylidine fluoride.

Plenum rated high modulus buffered optical fiber

A continuous extrusion process is provided capable of producing graded index plastic optical fiber at commercially useful speeds, e.g., at least 1 m/sec for 250 &mgr;m outer diameter fiber. Moreover, it is possible to predict the refractive index profile of the fiber, prior to actual fabrication, by performing a finite element analysis using various parameters of the extrusion process. Such prediction allows one to tune the parameters of the process to obtain a desirable outcome, while avoiding the need for substantial trial and error with the extrusion equipment.

Process for fabricating plastic optical fiber

A preferred embodiment of the dry core optical fiber cable of the present invention incorporates a plurality of sub-units with each of said sub-units being arranged adjacent another of the sub-units so that the plurality of sub-units define an outer periphery. Preferably, each of the sub-units includes a plurality of optical fibers, a yarn layer and a sub-unit jacket, with each of the optical fibers being arranged adjacent another of the optical fibers. The sub-unit jacket surrounds the optical fibers, with the yarn layer being disposed between the optical fibers and the sub-unit jacket. An outer jacket surrounds the plurality of sub-units, with water-blocking tape being disposed between the outer jacket and the outer periphery of the sub-units. A method of manufacture of the cable also is provided.

Dry core optical fiber cables for premises applications and methods of manufacture

A fiber optic cable having stress indicating means and a method for making same. The stress indicating means provides a cost effective method for determining whether an optical cable has been bent, stressed or otherwise mishandled, which may cause optical loss when the cable is placed in service. Broadly stated, the fiber optic cable according to the instant invention includes an optical fiber, comprised of a core and a cladding and a stress indicator concentrically disposed about the fiber that changes color when subjected to stress. A technician can thereby visually identify cables that have been bent or mishandled and subject them to testing before installation.

Optical fiber cable products having a stress indicating capability and

A simplex optical fiber cable of this invention includes an optical fiber, a buffer preferably of nylon, surrounding and in contact with the optical fiber, a yarn layer with strength fibers, preferably aramid fibers, disposed about the buffer and a sheath preferably formed of polyvinyl chloride (PVC) surrounding and in contact with the yarn layer. In cross-section, the simplex optical fiber cable has a diameter less than 2.0 millimeters (mm), and thus is much smaller in diameter than optical fiber cables presently available. Preferably, if the buffer is relatively tin providing limited protection to the optical fiber, a slick substance such as talc is applied to an outer surface of the buffer before the yam layer is disposed thereon. The slick substance allows the buffer of the optical fiber to slide to a degree in contact with the yarn layer and thus reduces fatigue caused by axial movement of a ferrule of the connector terminating the optical fiber cable. On the other hand, if the buffer is relatively thick, a friction-reducing substance such as Modaflo.TM. can be applied to the optical fiber to allow the buffer to be stripped relatively easily. A zip-cord duplex optical fiber cable of this invention includes essentially two simplex optical fiber cables with their respective sheaths joining at a middle portion along the axial length of the simplex optical fiber cables. Thus, in cross-section, the zip-cord duplex optical fiber cable has a figure-eight shape with a relatively thin portion in the middle which can be manually pulled apart to separate the zip-cord duplex optical fiber cable into separate simplex optical fiber cables. This feature of the invention allows the zip-cord duplex optical fiber cable to be split at its ends to allow connectors attached to respective ends of the optical fiber cables for connection to respective spaced connector receptacles. A second duplex optical fiber cable of this invention includes two simplex optical fiber cables arranged side-by-side with an oversheath extruded about and holding together the two simplex optical fiber cables. In cross-section, the two duplex optical fiber cables of this invention are less than 2.0 mm in height and 4.0 mm in width, and thus are much smaller than currently available duplex optical fiber cables. The invention also includes die assemblies and methods for making the simplex and duplex optical fiber cables.

Sub-miniature optical fiber cables, and apparatuses and methods for

The present invention provides a color-coded optical fiber cable and a method for manufacturing the color-coded optical fiber cable. The optical fiber cable of the present invention comprises a glass fiber, a buffer surrounding the fiber, which may be comprised of nylon, an aramid fiber strength member surrounding the fiber buffer, and an outer sheath surrounding the aramid fiber strength member. In accordance with a first embodiment of the present invention, optical fiber cables are color coded by using aramid fiber strength members of different colors. Once a color-coded aramid fiber strength member has been placed about the fiber buffer, it is surrounded by a light-transmissive outer sheath so that the color of the aramid fiber strength member can be easily ascertained, even when the optical fiber cable is wound up on a reel. When employed with a duplex cable, this embodiment allows a technician to easily determine which miniature jumper cable of the duplex cable is the transmit jumper cable and which is the receive jumper cable. In accordance with a second embodiment of the present invention, an optical fiber cable is color coded by placing a colored jacket about the aramid fiber strength member of the optical fiber cable. An outer light-transmissive jacket is then placed about the colored jacket. When a duplex optical fiber cable is color coded in accordance with this embodiment, the colored jackets of each of the jumper cables are simultaneously covered with the light-transmissive outer sheath by extruding the light-transmissive outer sheath over the colored jackets. The light-transmissive outer sheath holds the jumper cables together. The colored jackets of the jumper cables can be easily seen by a technician through the outer light-transmissive jacket of the duplex cable. The present invention can be used in a similar manner to color code optical fiber jumper cables contained in optical fiber quad cables and in optical fiber break-out cables.

Color-coded optical fiber cable and a method for manufacturing the same

The breakout cable is made up of an arrangement of optical fiber ribbon structures. Arranged above and/or below the optical fibers in each of the ribbon structures are strength members which are preferably made of an aramid fiber, such as KEVLAR. The combined optical fibers and strength members are surrounded by a sheath, which is preferably made of a suitable plastic, such as a material selected from the group consisting of polyolefin, PVC, low smoke PVC, EVA, FEP, PVDF, and thermoplastic fluoropolymers, thereby forming the high strength, sheathed optical fiber ribbon structure arrangement. A plurality of these individually sheathed ribbon structures can be stacked to form higher density ribbon bundles, or subunits, which can be further surrounded by sheaths. Similarly, a large numbers of such high density ribbon bundle subunits can be combined within a protective sheath to form cables which can be pulled through risers and plenums in the construction of premises, such as apartment buildings or commercial buildings, or used in appropriate indoor/outdoor applications. Accordingly, even as subunits are broken out of the cables, and as ribbon structures are broken out of the subunits, the optical fibers will still be surrounded by high strength members which will help protect them from breakage.

High density riser and plenum breakout cables for indoor and outdoor

An optical fiber cable includes one or more component cables. In one embodiment, the component cable has an elongated central aramid yarn member surrounded by at least one, and preferably six, optical fibers. An aramid yarn layer surrounds and contacts the optical fibers, and a plastic jacket envelopes and contacts the aramid yarn layer. In a second embodiment, the component cable includes optical fibers, preferably twelve in number, embedded in aramid fibers. A plastic jacket in contact with the aramid fibers, encloses the aramid fibers with its embedded optical fibers. In the cable of this invention, component cables of the first and/or second embodiments are wound about an elongated, central strength member with a reverse-oscillated lay. An outer jacket encloses and holds the reverse-oscillated lay of the component cables. The invention also includes a system for manufacturing the cables of this invention.

Wound optical fiber cable including robust component cable(s) and a

A buffered optical fiber (20) includes an optical fiber (21) comprising a core and a cladding. Typically, the optical fiber is enclosed by at least one layer (23) of coating material. The optical fiber is enclosed by a plastic buffer layer (30). Interposed between the optical fiber and the buffer layer is a boundary layer (40). Importantly, the boundary layer of the present invention is a low modulus material applied as a substantially thick layer relative to the buffer layer. In a preferred embodiment, the wall thickness of the boundary layer is about one-forth to one-third the wall thickness of the buffer layer. However, depending on the particular materials selected for the buffer and boundary layer, the wall thickness of the boundary layer can be as thin as one-twenty-fifth (1/25) of the buffer layer. As a result of the present design, there is sufficient adhesion between the buffer layer and the underlying coating material to maintain the buffer layer in place during normal use of the buffered optical fiber. On the other hand, the adhesion is low enough so that the buffer layer may be removed upon the application of reasonably low mechanical stripping forces. Advantageously, the boundary layer also allows the selective removal of the optical fiber coating material as well as the plastic buffer layer.

Growing community of inventors

Norcross, GA, United States of America

Montri Viriyayuthakorn