American Telephone & Telegraph Co., At&t Bell Laboratories

At&t Bell Laboratories

Lucent Technologies Inc.

Bruce V Darden

Thomas C Cannon, Jr

Jerry Max Anderson

Arthur Wallace Carlisle

Clyde J Myers

Norman Roger Lampert

George Edwin Mock

Stephen Clement Mettler

Dean R Frey

Donald T Smith

Vasilios E Kalomiris

Bruce B Boehlke

Glenn A Thaller

The apparatus of this invention includes a macrobend/microbend unit which imposes first and second macrobends, and microbends between the first and second macrobends, on an optical fiber under analysis. If light is travelling in one direction on the optical fiber, the bending of the optical fiber is such that some light will escape from the core of the optical fiber at the first macrobend. A first photodetector is arranged to receive light emitted from the first macrobend, and generates a signal indicative of whether light is present at the first macrobend. If light is travelling in the optical fiber in the other direction, the second macrobend causes some light to be emitted. A second photodetector arranged to receive light from the second macrobend, generates a signal indicative of whether light is present at the second macrobend. The apparatus includes a display, generated based on the signals from the photodetectors, indicating the optical fiber status including information such as whether light is travelling in the optical fiber in one direction or the other, whether the optical fiber is live or dead, and/or whether the light emitted from the optical fiber includes a tone signal of fixed frequency. For example, the apparatus can be used to aid a repair technician in quickly determining the optical fibers in need of repair in a damaged optical fiber cable containing many optical fibers. The invention also includes a related method.

Optical fiber status analyzer and related methods

A single optical fiber hermaphroditic connector (20) includes a ferrule or plug (90) of a subassembly which terminates an optical fiber (22) of a cable (24) and an end of which is received in a cavity of a housing (83). Furcations (102,102) of a bifurcated member extend beyond a free end of the ferrule. An end of the housing is supported from one free end of a tubular member (70) such that a compression spring (106) disposed about the housing causes the ferrule to be biased outwardly. An opposite end of the tubular member is connected to a bushing and tapered plug arrangement which is effective to transfer forces from strength members of the cable to the connector to prevent the forces from being applied to the connection. The subassembly is received in a sleeve (50) having a small diameter threaded end adjacent to the force transfer arrangement and an enlarged diameter, externally threaded end which encloses the housing and the bifurcated member. A coupling nut (150) having an internally threaded end is disposed about the sleeve and is adapted to receive a free end of another single fiber hermaphroditic connector such that the internally threaded free end of the coupling nut is turned into engagement with the externally threaded enlarged end of the sleeve of the other connector to hold together the connectors.

Hermaphroditic connector for single fiber optical cable

In a hermaphroditic biconic connector (20), an optical fiber cable (24) extends through a cap (46) into a tapered passageway of a flanged bushing. Optical fibers extend from the cable through a bore in a wedge (65) having a truncated conical shape and being received in the bushing. Portions of a strength member system (28) of the cable in the form of non-metallic filamentary strand material are captured between a wall which defines the tapered passageway and an outer surface of the wedge. The surfaces between which the strength members become locked are substantially smooth to avoid damage to the strength members. Forces applied to the cable and hence to the strength members cause the wedge to be seated further in the bushing. Also, the included angle between diametrically opposite lines on the surface of the wedge that lie in a plane that passes through the longitudinal axis of the wedge enhances the locking features of the connector. The fibers also extend through a retention nut (70) which is turned threadably over a threaded portion of the bushing and each fiber is connected to a truncated, conically shaped plug (94). The plugs are mounted adjacent to an end of the connector with one plug being received in an alignment sleeve (130). A sleeve retainer (140) is disposed over the sleeve and the other plug and includes alignment posts (145--145) so that when another connector is assembled thereto, a plug of the other connector is received in the unused end of the sleeve and a sleeve extending from another plug of the other connector receives the other plug of this connector.

Connector for optical fiber cable

In a hermaphroditic connector (20), an optical fiber cable (24) extends through a cap (46) into a tapered passageway of a flanged bushing. Optical fibers extend through a bore in a wedge (65) having a truncated conical shape and being received in the bushing. Portions of non-metallic filamentary strength member (28) of the cable are captured between surfaces of a wall of the tapered passageway and the wedge which are substantially smooth to avoid damage to the strength members. Forces applied to the cable cause the wedge to be seated further in the bushing. The included angle between diametrically opposite lines on the wedge surface that lie in a plane passing through the longitudinal axis of the wedge enhances the locking features. The fibers also extend through a retention nut (70) which is turned threadably over a portion of the bushing and each fiber is connected to a plug (94) mounted adjacent to an end of the connector with one plug being received in an alignment sleeve (130). A retainer (140) is disposed over the sleeve and the other plug and includes alignment posts (145--145). When another connector is assembled hereto, a plug of the other connector is received in the unused end of the sleeve and a sleeve extending from another plug of the other connector receives the other plug of this connector.

An optical fiber connector (20) includes two plug assemblies (37--37) each including a cylindrically shaped plug (40) extending from within a cap (70). An end of each cap is adapted to be secured to a coupling housing (92) to cause the plug which extends from the cap to be received in a sleeve (105) disposed in the housing. An optical fiber cable (22) extends through a cable entrance end of the cap and has an end portion of its optical fiber terminated by theplug. An extender(85) of the cap is secured thereto and extends along the cable a distance to a location where portions (91--91) thereof are closely adjacent to the cable. Bending forces applied to the cable are transferred at the location to the extender and then to the cap. This avoids the transfer of those forces to the plug which otherwise could cause the plug to turn pivotally about an interior lip of the cap and result in an optical disconnection of the plug from the other plug in the sleeve.

Optical fiber connector

In an optical fiber connector (20), an alignment sleeve (66) for holding two conically shaped portions (30-30) of plugs (24-24) each of which terminates an optical fiber (25) includes two conically shaped cavities (68,70) communicating through a common plane (72). A peripheral end portion of at least one end of the sleeve is provided with a notch (86). The notch is adapted to receive a key (43) which projects from a plug as the plug is inserted into the sleeve cavity. This locks the plug in the sleeve and prevents unintended rotation of the plug relative to the sleeve which could abrade opposing end faces of the fibers when a threaded cap in which the plug is mounted is turned into a coupling housing (57) which supports the sleeve and which already has another plug mounted therein. This connector improves insertion loss and performance repeatability by causing fiber core centroids (170,173) of optical fibers terminated by plugs received in the housing to be disposed in a common plane which extends radially from a longitudinal axis of the connector.

A duplex optical fiber connector (20) includes a housing (21) having a cable entrance end and a plug end. At the cable entrance end, an optical fiber cable (23) which includes two individually buffered optical fibers (25--25), strength member yarn (29) and a plastic jacket is routed into a flanged end of a bushing (45) having a tapered passageway therethrough. The bushing is supported in a base (22) of the housing. The jacket is removed from the portion of the cable which extends from the cable entrance end to the plug end and the yarn is positioned between two conformable, truncated conically shaped, substantially smooth surfaces which define the passageway of the bushing and a truncated conically shaped wedge (50) which is received in the passageway. The wedge includes a bore through which the optical fibers extend. This locking arrangement in which the yarn makes no retroflexed turns is self-enhancing when tensile forces are applied to the cable. At the plug end are secured two plugs (70--70) each terminating one of the optical fibers. Each plug is spring-loaded and further, end portions of the plugs which protrude beyond the connector housing are protected by a bumper (90) which also is spring-loaded and which is moved inwardly when the connector is assembled to another. A cover (52) is assembled to the base to complete the housing and to secure the force-transfer facilities and plugs therein.

Duplex optical fiber connector

A solderless in-line connector has a U-shaped slotted contact member, with the slots extending the length of the respective upright portion of the member and into the base portion. This contact member geometry results, upon insertion of a wire into the slot, in elastic torsional as well as bending deformation of the contact member, which in turn permits accommodation of a wide range of wire sizes in a low profile connector. Further desirable features of the connector are the possibility of installation without use of special tools, and the possibility of sequential contact formation. The connector can advantageously be used for splicing small pair count cables, but it can also be adapted for making half taps.

Solderless electrical connector

An optical fiber connector comprising a fiber terminus piece with a longitudinal bore through which a bare fiber is inserted. The fiber terminus piece with an appropriately prepared fiber therein is held coaxially aligned with a mating terminus piece. The fiber terminus piece comprises, on its mating face, a 'pedestal,' typically having truncated-cone shape, extending outwardly from the plane of the face, with the fiber terminating within the face of the pedestal, whereby the area of potential contact between the mating terminus pieces is substantially reduced. The pedestal material advantageously is somewhat compliant, of compressive modulus between about 10.sup.4 and 10.sup.6 psi at 25.degree. C., preferably between about 10.sup.5 and 5.10.sup.5 psi. The novel geometry results in improved performance, as compared to prior art connectors having flat mating faces. Disclosed are also connectors comprising advantageous means for transferring axial loads from a cable strength member to the connector body.

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Lawrenceville, GA, United States of America

Bruce V Darden