Abstract: This invention relates to a novel design for a low-loss optical power splitter, in particular Y-branch types resulting from chemical vapor deposition (CVD) fabricated silica waveguides. More specifically, the present invention utilizes mode matching of the fundamental modes between the input and the output waveguides of a splitter to optimize the splitters operational performance. The optical power splitter of the present invention comprising an input waveguide region having a predetermined width (W) and capable of transmitting optical energy having a fundamental mode E.sub.1.sup.0. Additionally, the splitter includes at least two output waveguide regions positioned to receive at least a portion the optical energy from the input waveguide region wherein the output waveguide regions each have predetermined widths (w) and are capable of transmitting optical energy having a fundamental mode E.sub.2.sup.

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: The present invention provides a dielectric optical fiber cable which is capable of being remotely detected while buried. Specifically, this invention incorporates magnetic materials into a layer of epoxy to from a distinct layer within the sheath system of a communications cable. The magnetic particles generate a detection signal which is distinguishable from that generated by a solid metallic pipe and does not adversely affect the operation of existing components of the cable nor does the incorporation of the magnetic marker layer of the present invention unduly limit the speeds at which the overall cable can be manufactured.

Abstract: A hybrid cable (20) includes a first transmission portion such as a metallic conductor portion (22) and a second transmission portion such as an optical fiber portion (24). The metallic conductor portion includes a core which includes twisted pairs of metallic conductors enclosed in a plastic core wrap, a shielding system and a plastic jacket (48). A longitudinally extending duct (52) is disposed in engagement with an outer surface of the plastic jacket of the metallic conductor portion. An outer plastic jacket (60) is disposed about the duct and the metallic conductor portion. An optical fiber cable (50) or optical fibers (51, 51) may be caused to become disposed initially in the duct or when the use of fibers becomes economically justified.

Abstract: The present invention relates to an optical fiber cable which includes magnetically locatable materials within the sheath system thereby allowing the cable to be located after it has been buried. More specifically, at least a portion of the magnetic particles are purposely oriented in a particular alignment based on their magnetic properties. Such an arrangement not only allows the generation of a detection signal which is distinguishable from that generated by a solid metallic pipe, but also can greatly enhance the level of the detection signal generated. The enhanced detection signal provides for more reliable detection of buried all-dielectric cables and also allows them to be located even when buried at greater depths, such as six feet or more. In specific embodiments of the present invention, the magnetic particles may be aligned and/or magnetized either longitudinally, vertically or transversely relative to the cable.

Abstract: The present invention continuously monitors the amount of curing radiation available for curing coating material on a moving optical fiber and includes a curing system having a radiation source capable of providing radiation energy for curing coating material on an optical fiber and a reflector system which redirects non-direct radiation back toward the article. An optical fiber which has been provided with a curable coating material is moved along a path of travel through a curing area. The coating material is cured by causing the radiation source to emit energy suitable for curing the curable coating material. The predictable average amount of light energy properly redirected by the reflector system toward the curable article is sensed as the curable coating material is being cured to obtain continuous in-process reading. The average radiation value is obtained by positioning three longitudinally aligned holes adjacent the fiber path and between the fiber and a radiation sensing device.

Abstract: The foregoing problems of the prior art have been overcome by cables of this invention. An optical fiber cable includes a core comprising at least one optical fiber transmission medium, a tubular member in which is disposed the core and which is made of a plastic material and a sheath system which is disposed about the tubular member. Additionally, a compositional blend is disposed in the tubular member and capable of performing dual functions by blocking the longitudinal flow of water as well as preventing freezing of water or moisture within the cable. Preferably, the composition includes a superabsorbent constituent blended with an antifreeze constituent, which is then disposed along one longitudinally extending member. In addition to being sprayed onto a tape or other longitudinal member, the compositional blend may also be electronically deposited directly onto the transmission matter, sheath system or core tube.

Abstract: A communications cable (20) comprising a core (22) of at least one transmission media and a plastic jacket (34) includes provisions for preventing the movement of water within the cable. The cable includes a strength system (32) including longitudinally extending fibrous strength members (33--33) having a relatively high modulus and having water blocking provisions. In one embodiment, each fibrous strength member is treated with a superabsorbent liquid material which when dry fills interstices and covers portions of the exterior thereof. In another embodiment, a filamentary strand material comprising a water swellable fibrous material is wrapped about each fibrous strength member.

Abstract: A communication cable includes a core comprising at least one transmission medium and a sheath system which is disposed about the core. Means are disposed within the cable for preventing the longitudinal migration of water through the cable core, said means including both a hydrophilic material and a hydrophobic material in cooperative communication with each other. Specifically, a hydrophilic, water-absorptive material is supported by a yarn which is helically wrapped about various sections of the communication core. In a copper cable, the water-absorptive yarn may be wrapped about individual twisted pair conductors or a unit consisting of a plurality of twisted pair conductors or the cable core itself. In addition to the helically-wrapped, water-absorptive yarn, the cable of the present invention includes a hydrophobic, water-blocking material interdisposed to fill all voids and interstices within the communication core.

Abstract: An optical fiber splicing device includes a clip (20) which aligns and secures cylindrical rods (28, 30 and 32) utilized within a three-rod optical fiber splicing device. The clip (20) is a generally cylindrically shaped component which is made of a resilient material and is positionable so as to encase three cylindrical rods (28, 30 and 32). The clip (20) comprises a circular body portion (22) and two protruding leg portions (24 and 26) which extend from an point on the outer periphery of clip body (22). The two leg portions (24 and 26) are constructed and oriented such that they may be manipulated to controllably expand the inner diameter of clip body (22). To facilitate an optical fiber splice or connection, the clip (20) of the present invention allows the clip body (22) to be expanded to loosen the grip on rods (28, 30 and 32) held therein, thereby allowing the optical fiber ends to be inserted between the rods.

Abstract: An optical cable portion (10), resident within a cable closure (14), is caused to receive a water blocking arrangement which is effective to prevent water, which enters an internal cable portion (24) through an unintended cut (21) in an outer jacket (18) of a cable portion (20), from entering an interior of the cable closure. A plurality of water blocking materials (30 and 32) are coaxially disposed about the outer jacket and a core tube (26) of the cable portion, respectively, and cooperate with a heat shrinkable plastic tube (34) which substantially covers the water blocking materials to prevent the movement of water from the internal cable portion past the water blocking materials.

Abstract: A cable (20) which may be used for communications, for example, include transmission media (24-24), each having a plastic composition of matter disposed thereabout. The insulation (26) comprises a polyvinyl chloride composition which includes a lubricant and a lead-free stabilization system. The stabilization system includes a calcium-zinc constituent in combination with an antioxidant-metal deactivator complex which provides a sacrificial function to prevent the formation of calcium or zinc chloride which would affect adversely the electrical properties of the insulated conductor. A jacket (28) typically is disposed about a plurality of the transmission media and comprises a non-lead stabilized plastic composition of matter.

Abstract: An optical fiber cable (20) includes provisions in a core thereof for preventing the flow of water longitudinally along the core and for preventing freezing of such water. The provisions for preventing freezing of water within the core, which could effect adversely the optical fibers, includes an antifreeze material. Each of two tapes may be impregnated with an antifreeze material such as propylene glycol, for example, and used to provide a laminate with a superabsorbent powder therebetween. Advantageously, the cable may have suitable flame retardance so that it may extend from an outside manhole to distribution points within a building.

Abstract: Methods and apparatus are provided for providing an electrically matched pair (20) of insulated metallic conductors (21, 21). Insulation is applied to successive portions of a length of wire-like metallic conductor (22) after which a colorant material (37) is applied to the surface of a plastic insulation material of a first portion of the length of the metallic conductor which is being moved along a path of travel. Facilities are provided for shielding a supply of the colorant material from the moving insulated metallic conductor and for then exposing a second portion of the length of the insulated metallic conductor to a different colorant material. The insulation and the colorant materials and their disposition with respect to the insulation are such that the dielectric constant of one insulated metallic conductor of the pair is substantially equal to that of the other.

Abstract: Short and long wavelength absorption losses contribute to loss at the operating wavelength of an optical fiber drawn from a preform. Excess losses over and above Rayleigh scattering losses have been attributed to conditions such as temperature and the speed during drawing. Typically, after optical fiber (21) is drawn from an optical preform in a furnace (23) wherein temperatures may be 2200.degree. C. or higher, the fiber is moved out of the furnace and immediately through ambient environment to other portions of a draw line such as, for example, measuring and coating apparatus. It has been found that these absorption losses may be reduced substantially by application of a magnetic field to the optical fiber after it has been drawn and prior to it being coated.

Abstract: A tool (150) of this invention assembles stackable elements (52, 54 and 56) to form a multiple conductor connector (50). A holding bracket assembly (100) is incorporated in the tool (150) to prohibit undesirable movement of the lowermost connector element (52) and to maintain alignment of the various elements of the connector (50) during the connectorization process. In accordance with the present invention, at least one protrusion (112) is manipulated into physical engagement with a side portion of the lowermost connector element (52). The protrusion (112) is spring-loaded and includes a sharp, tapered edge constructed of hardened material which provides a position-securing force to the connector (50) by becoming embedded into the side portion of the lowermost connector element (52). In addition, a second protrusion (110) is aligned opposite each of the sharp protrusions (112) and capable of providing an additional position-securing force to a second side portion of the lowermost connector element (52).

Abstract: A cable (20) includes a plurality of conductors (24) included in a core (22) enclosed in a sheath system. Voids between the conductors are filled by a mixture of a filling composition characterized by a styrene-rubber block copolymer having a styrene/rubber ratio of from 0.2 to 0.5, an ASTM Type 104A oil and polyethylene and a superabsorbent polymer material. The mixture has a viscosity in the range of about 400 cps at 88.degree. C. to 11 cps at 110.degree. C. and may be used to fill substantially voids in a cable comprising as many as 3000 pairs of insulated metallic conductors. The superabsorbent polymer is incorporated into the gel composition in a concentration of about 10 parts by weight to per 100 parts by weight of the filling mixture. A flooding material which comprises a mixture of a flooding composition and a superabsorbent polymer may be used to flood voids between layers of the sheath system.