Abstract: 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.

Abstract: 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 thin providing limited protection to the optical fiber, a slick substance such as talc is applied to an outer surface of the buffer before the yarn 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In an MOCVD reactor, gases are channeled around the periphery of a baffle plate (15) so as to flow radially inwardly along a slotted injection plate (16). The slots (22) in the injection plate extend radially and are of non-uniform width so as to compensate for a non-uniform rate of deposition. The resultant flow over a rotating heated substrate (17) gives a more uniform deposit of epitaxially grown material.

Abstract: In an MOCVD reactor, gases are channeled around the periphery of a baffle plate (15) so as to flow radially inwardly along a slotted injection plate (16). The slots (22) in the injection plate extend radially and are of non-uniform width so as to compensate for a non-uniform rate of deposition. The resultant flow over a rotating heated substrate (17) gives a more uniform deposit of epitaxially grown material.

Abstract: A chemical vapor deposition apparatus particularly useful for forming uniformly thick epitaxial layers of III-V semiconductor compounds on a plurality of substrates comprises a susceptor for supporting the substrates contained within a housing, gas inlet and outlet ports including a plurality of gas inlet ports spaced around the periphery of the housing and wherein the susceptor is provided with a plurality of helical flights extending from top to bottom which control the gas flow pattern.

Abstract: A diverter and coextrusion diverter are described which include means for adjusting the cavity of the diverter so as to control the uniformity of extrudate exiting the diverter.

Abstract: A coating material is applied to drawn lightguide fiber in a manner which substantially prevents the inclusion of bubbles and which causes the fiber to be disposed substantially concentrically within the coating layer. The lightguide fiber is advanced through a continuum of coating material, which extends from a free surface of a reservoir and through two dies that are arranged in tandem, at a velocity which causes air to be entrained in the coating material. A pressure gradient is established between portions of the first die adjacent to its exit orifice. A first one of the dies communicates with the reservoir and the second die and further communicates at the interface of the dies with a pressurized supply of the coating material.

Abstract: Extruder tooling for directing plastic materials to enclose a conductor (26) being advanced along a path of travel through a core tube (97) and aligned dies includes disc-like flow passages (107, 129) which are disposed concentrically about and perpendicularly to the conductor. This arrangement minimizes conductor tension in a pressure extrusion arrangement by significantly reducing the length of the plastic-to-conductor contact within the extruder. The length and width of each flow passage normal to and along a path of travel are sufficient to provide a uniform distribution of plastic material circumferentially about the conductor and to dissipate stresses which have been induced in the plastic materials. In a tubing arrangement, the length of a cantilevered portion of the core tube is reduced significantly which results in improved concentricity of the plastic material about the conductor.

Abstract: A diverter and coextrusion diverter are described which include means for adjusting the cavity of the diverter so as to control the uniformity of extrudate exiting the diverter. The diverter including a gap having beveled opposing faces.

Abstract: A coating material is applied to drawn lightguide fiber in a manner which substantially prevents the inclusion of bubbles and which causes the fiber to be disposed substantially concentrically within the coating layer. The lightguide fiber is advanced through a continuum of coating material, which extends from a free surface of a reservoir and through two dies that are arranged in tandem, at a velocity which causes air to be entrained in the coating material. A pressure gradient is established between portions of the first die adjacent to its exit orifice. A first one of the dies communicates with the reservoir and the second die and further communicates at the interface of the dies with a pressurized supply of the coating material.