Abstract: An optical fiber cable core (20) which is sold to a cable manufacturer for oversheathing or for incorporation into electrical power aerial cables, for example, includes in a preferred embodiment at least one bundle (23) of optical fibers (25--25). The at least one bundle is disposed in a tubular member (30) which is made of a plastic material suitable for use in relatively wide temperature range. The core is manufactured to cause a predetermined excess length of fiber to be disposed in the tubular member. The excess length of each fiber is such that it is sufficient to avoid undue strains on the fiber as the cable core is exposed to the elements and to forces imparted during handling such as during installation. On the other hand, the excess fiber length must not be so great as to result in undue curvature of the fiber or excessive interactive engagement of the fiber with an inner wall of the tubular member.

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 decoupling material (40) which provides a controlled coupling of the buffer layer to the underlying coating material. As a result, 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 resonably low stripping forces. Advantageously, the decoupling material also allows the selective removal of the optical fiber coating material as well as the plastic buffer layer.

Abstract: A group of loose cabled optical fibers (32-32) destined to be terminated by a multi-fiber connector device is first fabricated into an optical fiber ribbon (30). The optical fibers of the group are threaded through portions of an organizing shuttle (20) and brought into planar juxtaposition with each other by the cooperation of a curved surface (112) and a burnishing bar assembly (98). As the organinzing shuttle is caused to be moved along a track (42), the burnishing bar assembly causes the planar array of fibers to be embedded into an adhesive coating of a first binding tape (34) which is secured along the length of the track. In a preferred embodiment, a second tape (35) is applied over the fibers and the first tape. The ribbon is trimmed of excess longitudinal side portions of the binding tapes to provide a ribbon of desired width.

Abstract: Spliced end portions (30--30) of two optical fibers are recoated in a manner which results in the cross section of the spliced length of fiber transverse to a longitudinal axis thereof being substantially constant. This is accomplished without compromising the adhesion of a curable recoating material (51) to an adjacent original coating material (38). In order to provide such a recoated portion, original coating material which is removed to permit splicing is removed in such a manner as to leave a tapered portion (52) remaining on the end portion of each optical fiber. As a result, the interface between the recoating material and the original coating material is increased sufficiently to avoid having to overlap some of the recoating material with original coating material on adjacent portions of the fibers being spliced.

Abstract: An underwater optical fiber cable (20) which is substantially free of hydrogen generation includes a core portion (22) which includes an optical transmission medium and which may comprise a terrestrial cable and a sheath system which may be an oversheath for the terrestrial cable. An outer portion of the sheath system includes a plurality of longitudinally extending strength members (42--42) each being made of a metal having a relatively low chemical or electrochemical reactivity. Covering individually each strength member is a plastic material (60) such as polyethylene.

Abstract: An optical fiber cable (20) includes a core (21) comprising a units a unit (22). The unit is formed by a plurality of optical fibers (24-24) which are assembled together without intended standing. The unit is enclosed in a tube (34) which provides a predetermined packing density and which is substantially parallel to the longitudinal axis of the cable. In one embodiment, a waterblocking material (36) is disposed within the tube to fill the interstices between the optical fibers and between the unit and the tube. The waterblocking material is such that its critical yield does not exceed about 70 Pa at 20.degree. C. and such that it has a shear modulus of less than about 13 KPa at 20.degree. C. The tube is enclosed with non-metallic or metallic strength members and a plastic inner jacket and by another layer of strength members and by a plastic outer jacket.

Abstract: In one manufacture of a preform rod from which optical fiber is drawn, chemical materials are moved into a rotating preform tube to which is applied a moving zone of heat. Following a deposition mode, the tube is collapsed to provide the preform rod. Provisions must be made to supply the deposition materials from a rotating supply conduit into the rotating preform tube without leakage and without the ingress of contaminants while an end portion of the tube is gripped securely. This is accomplished by providing non-metallic ferrules about an end portion of the preform tube which are caused to be clamped against the end portion of the preform tube in sealing and gripping engagement therewith.

Abstract: A plenum cable (20) includes a core (22) comprising at least one transmission medium such as a metallic conductor. The metallic conductor is insulated with a layer (27) of a plastic composition of material which includes a non-halogenated constituent such as, for example, a polyetherimide. Covering the insulated metallic conductor is a jacket (39) comprising a halogenated material such as a fluoropolymer. The cable exhibits excellent flame retardant properties as well as acceptable levels of corrosion and toxicity.

Abstract: An optical fiber transmission medium (30) ) includes optical fiber (21) provided with a coating system (31) typically including two layers each of a different coating material. An inner layer (32) of a first coating material is called the primary coating and an outer layer is termed the secondary. In order to achieve desired performance characteristics, performance is related to properties of a coating system. The coating materials have well defined moduli and the second coating material has an elongation which is substantially less than in prior secondary coating materials. Adhesion levels which are optimized rather than maximized are substantially stable with respect to time. Curing of the coating materials may be accomplished simultaneously or in tandem with the application separately of the coating materials.

Abstract: An optical fiber package (20) is provided by winding a plurality of convolutions in a plurality of layers on a bobbin. To each layer is applied an adhesive material (45) which in a preferred embodiment is a mixture comprising a reactive silicone copolymer resin, a solvent system which includes an aromatic constituent, a catalyst and a wetting agent. The mixture has a modulus behavior which is relatively stable with respect to time throughout a relatively wide operating temperature. Inasmuch as the solvent system and the method of application of the mixture are effective to control the rate of precipitation and the rate of cure of the silicone constituent, the surface roughness of the convolutions is controlled. After the desired number of convolutions have been wound, the package is subjected to a heat treatment which relieves stresses in the wound fiber and which completes the cure of the adhesive material.

Abstract: In a system (20) for transmitting voice and data signals, insulated metallic conductor pairs (44--44) which transmit data signals and insulated metallic conductor pairs (46--46) which are capable of transmitting voice signals are enclosed in a common sheath system of a single cable (40). User pickup of station apparatus (34) during the generation of a ringing voltage on a voice conductor pair causes that pair to become disturbing and to impart impulse noise to a closely coupled data pair. The data pair is designated a disturbed pair and the signals transmitted thereby may be affected adversely. This problem is overcome by providing a circuit (80) comprising in parallel a resistance and an inductance and being in series with the station apparatus. Such an arrangement reduces substantially that frequency content of any disturbing signal which appears on the disturbing pair and which is in the range of the data signal spectrum.

Abstract: A plurality of the terminals (42--42) are mounted in slots which open to an inner surface (75) of a well (78) of a housing (41) of a modular plug (23) to terminate conductors (22--22) of an end of accordage (21) that has been secured within the housing. The slots communicate with a cavity in which are disposed conductors of the cordage. Each terminal includes a body portion (84) having first and second ends (87 and 88). Internal contacting portions in the form of tangs (92--92) protrude from the body portion and engage electrically the conductors of the cordage. An external contact portion (94) of each terminal protrudes from and is disposed asymmetrically along the body portion between its ends. The external contact portion of each terminal is disposed between partitions (79--79) which extend from the inner surface of the well to an exterior surface of the housing or between such a partition and a sidewall of the housing.

Abstract: An animal-resistant optical fiber cable (20) includes a core (22) which comprises a transmission medium and a sheath system. The sheath system includes an outer jacket (65) and a dielectric armor (40) in the form of a shell. The shell comprises a plurality of longitudinally extending preformed segments (42--42) each being a composite comprising a substrate portion (50) and a layer (52) of a coating material which has a relatively high hardness disposed on an outer surface of the substrate portion. Each of the segments covers less than half of the periphery of the core and, in a preferred embodiment, eight segments are used. Further, the shell segments are stranded helically about the core with at least portions of longitudinal edge surfaces of adjacent segments being in engagement with each other. The shell segments not only provide rodent protection for the cable, but also they provide suitable tensile and compressive strength as well as suitable flexibility and cable bending performance.

Abstract: An optical preform is prepared first by depositing soot about a glass subate rod (22) to form a boule. Then the soot boule is sintered to consolidate the material and provide a preform from which optical fiber is drawn. The boule is relatively large so that the resulting preform is capable of providing more optical fiber than those used in the past. In order to be able to sinter successfully the enlarged boule, microwave energy from a furnace (60) is coupled to the glass rod so that the sintering proceeds from the rod radially outwardly thereby allowing gases readily to escape and rendering the process highly efficient.

Abstract: A cable which may be used in buildings in concealed areas such as in plenums or in riser shafts includes a core (22) which includes at least one transmission medium which is enclosed in a non-halogenated plastic material. The core is enclosed with a jacket (28) which also is made of a non-halogenated plastic material. The non-halogenated material which encloses the transmission medium and the jacket is a plastic material selected from the group consisting of a filled polyolefin, a polyetherimide and a silicone-polyimide copolymer, and blend compositions of a polyetherimide and a silicone-polyimide copolymer. Interposed between the core and the jacket is a thermal barrier which includes a plastic film which is selected from the group consisting of a polyetherimide, a silicone-polyimide copolymer, a polyimide, and blend compositions of a polyetherimide and a silicone-polyimide copolymer.

Abstract: An animal-resistant optical fiber cable (20) includes a core (22) which comprises a transmission medium and a sheath system. The sheath system includes an outer jacket (65) and a dielectric armor (40) in the form of a shell. The shell comprises a plurality of longitudinally extending preformed segments (42--42) each having a cross section transverse to a longitudinal axis of the cable each of which covers less than half of the periphery of the core. Further, the shell segments are stranded helically about the core with at least portions of longitudinal edge surfaces of adjacent segments being in engagement with each other. The shell segments not only provide rodent protecting for the cable, but also they provide suitable tensile and compressive strength. Further, because the cable in the preferred embodiment has an all-dielectric sheath system, it is inherently lightning, corrosion and EMP resistant.

Abstract: An improved multimode optical fiber having substantially higher bandwidth and lower loss is made by controlling process parameters such as the volume of the silica which is deposited in each pass of a torch assembly (41) along a substrate tube (31) to form a preform tube which is collapsed to provide a preform (80) from which the optical fiber is drawn. As a result, the amplitude variation of the refractive index across each layer is controlled to be within desired limits. Should the volume of the silica deposited in each pass be controlled to control the amplitude variation, the thicknesses of the outermost deposited glassy layers in the preform tube are greater and those of the innermost layers are less than those of layers in a preform tube made by prior art MCVD processes.

Abstract: An optical fiber cable closure (20) includes a cable termination assembly (22) and a cover (23) into which the termination assembly is inserted. The cable termination assembly includes two spaced end plates (34,36) through which cables (28,29) to be spliced extend. One of the end plates supports a frame (101) which supports a plurality of optical fiber splicing trays (120--120). Adjacent end portions of the trays are staggered and hinged so that some trays may be moved pivotally to expose others. Optical fibers from each incoming cable are routed in individual tubes (115--115) from an optical fiber breakout (110) mounted in the framework to selected ones of the trays. Hinge lock plates (130--130) which complete a hinge for each tray also serve to clamp the tubes incoming to each tray to prevent unintended movement.

Abstract: A mechanical connection arrangement for two polarization-maintaining optical fibers (20--20) includes two ferrules (40--40). Each of the optical fibers to be connected includes an outer cladding layer (23) having a hybrid cross section transverse to a longitudinal axis of the fiber. The hybrid cross section is defined by two parallel sides and by two generally arcuate end portions. One of the polarization axes of the fiber is parallel to the parallel sides of the fiber. The ferrules were adjacent portions in a length (110) of stock material and are positioned in support means such that end faces of the ferrules which were contiguous to each other prior to the ferrules being separated from the length of material are adjacent to each other in the connection arrangement. Each ferrule prior to separation has a tab (126) associated therewith such that the tab of the adjacent portions are aligned longitudinally.

Abstract: An optical fiber cable includes a core (22) comprising optical fibers (24-24) in ribbon or single fiber form and a sheath system (50) which provides flexibility for ease of handling and installation, strength to resist tensile and torsional stresses and rodent and/or lightning protection. The core is enclosed by a tube (28) wich is made of a plastic material, a shield system (52) and outer plastic jacket (54). The shield system provides rodent and/or lightning protection. Strength is provided by a plurality of longitudinally extending strength members (58-58) which are disposed in a single layer concentric with the core and which in a preferred embodiment are disposed adjacent to an outer surface of the shield and with substantial portions of their perpheries embedded in the plastic of the outer jacket.