At&t Bell Laboratories

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

James A Aberson

George F DeVeau

William A Vicory

Calvin M Miller

Ian A White

Terry D Mathis

David N Ridgway

Scott Thomas Davies

Raymond P DeFabritis

Kenneth Michael Yasinski

Joseph K Lo

Eugene Halupke

In order to restore quickly service which has been interrupted by damage in at least a portion of a cable, ends of optical fibers on one side of a damage location are spliced to optical fiber end portions of a restoration cable (70) within first and second closures (22,23) of a restoration kit (20). The first closure is attached to a foamed polymeric mounting pad attached to one flange of a deployment reel (100) mounted rotably on a payout spindle (135) which extends normally from one portion of a carrying case (21). Optical fibers of each end of the restoration cable are connected to splicing devices mounted in splicing modules (40,40) in the first and second closures. The second closure is moved from the case toward an opposite side of the damage location whereat fibers of the damaged cable on the other side of the damage location are extended into the second closure and spliced to the restoration cable therein. Because the first closure is attached to the deployment reel, the first closure turns with the reel as the reel is turned rotatably during payout of the restoration cable.

Restoration kit for communications cable

An optical fiber splicing device (20) includes a glass cylindrically shaped capillary tube member (24) having a passageway formed therethrough eccentrically of the longitudinal axis of the capillary tube member. The capillary tube member is provided with a slot (86) such that a portion of the passageway in the form of a groove (88) extends across a planar surface (87) formed by the slot. The capillary tube member is mounted in a housing (22) which is made of a material and formed to provide a lens opposite to the slot to facilitate visual inspection of ends of end portions of two optical fibers which are positioned in the groove. A spring clamp (26) is mounted to the housing in a first position spaced from the planar surface to allow insertion of fiber end portions into the groove. The clamp is moveable to a second position where it is secured to the housing in a position which causes a portion of the clamp to engage the fiber end portions along at least a portion of the planar surface to hold the fiber end portions in secured alignment with each other.

Optical fiber splicing device

Optical fiber repair splices are effected by mating two fiber ends in an elongate open-sided housing containing a fiber-receiving capillary tube. The tube may be factory-inserted to achieve a predetermined alignment of the tube with the fiber guide-way axis of the housing. A stepping fiber passage in the housing guides the fiber end into the tube. The fiber progresses to a point in the tube's interior where the capillary track is visible through a slot in the tube. The splicer visually observes mating of the fiber ends through the slot. The tube slot also permits application of index-matching material and adhesive to the mated fiber ends. During splicing, a mounting jig holds the underside of the housing, freeing the splicer to manipulate and view the fibers.

Optical fiber splice

In an optical fiber connector in which each of two optical fibers (21-21) is terminated by a plug (40) having a passageway (41) for receiving an end portion of the optical fiber, eccentricity of one fiber end relative to the other is reduced by causing each optical fiber to be mounted in a specified orientation with respect to its associated plug passageway. In one embodiment, because the two cylindrical plugs which are used in the connector are derived from contiguous segments (111-111) of length of tubular stock, because the plugs are arranged so that the contiguous ends of the plugs before separation from the stock become the mating ends in the connection and because the plugs after separation from each other have the same rotational orientation with respect to each other as before, the predetermined orientation of the fiber ends in the plug passageways of the two adjoining plugs prior to separation of the segments from the stock reduces substantially any eccentricity which otherwise would be caused by the random mounting of the fibers in the associated passageways.

Optical fiber connector and methods of making

Optical radiation can be efficiently removed from, or injected into, single mode optical fiber at an intermediate point along the fiber, by causing quasi-resonant coupling of the guided mode LP.sub.01 to an appropriate tunneling leaky (TL) mode, e.g., LP.sub.11. Such coupling is caused by means of a 'grating' in the fiber, with the grating being formed by impressing a periodic (or pseudo-periodic) modulation on the fiber, or by causing a periodic (or pseudo-periodic) variation of the refractive index of the fiber by means of the photoelastic or the photorefractive effect. The nominal grating spacing .LAMBDA.(z) is chosen such that .OMEGA..sub.o =(2.pi./.LAMBDA.)&gt;.beta..sub.01 -2.pi.n.sub.cl /.lambda..sub.o, where .LAMBDA. is the average grating spacing, .beta..sub.01 is the propagation constant of the LP.sub.01 mode, n.sub.cl is the refractive index of the fiber cladding, and .lambda..sub.o is the wavelength of the radiation to be coupled from or into the fiber. Furthermore, .LAMBDA.(z) is to be chosen such that .OMEGA..sub.o .about..beta..sub.01 -.beta..sub.rs, where .beta. .sub.rs is the propagation constant of the selected TL mode. In order for the coupling to be quasi-resonant, it is necessary that .alpha..sub.rs, the attenuation constant of the selected TL mode, be relatively small, typically &lt;1 dB/cm. By appropriately choosing .LAMBDA.(z) and/or the amplitude function of the grating, it is possible to increase the coupling efficiency above what is possible with a constant spacing, constant amplitude grating. Devices according to the invention can be advantageously used not only as radiation couplers but also as filters and, if they are of the photorefractive type, as amplitude modulators.

Device for tapping radiation from, or injecting radiation into, single

In a plug-type optical fiber connector low loss can be achieved, without any active alignment of the fiber cores, if the two cylindrical plugs used in the connector are 'contiguous' plugs, i.e., derived from contiguous segments of the tubular stock from which the plugs are produced, and if the plugs are arranged such that the 'contiguous' ends of the plugs are the mating ends, and such that the rotational relationship between the plugs is substantially the one that existed prior to sectioning. The inventive connector comprises two contiguous plugs and includes features that permit identification of the contiguous ends and of the rotational relationship. In a preferred embodiment, the tubular stock is drawn glass stock, the two contiguous segments are left joined but scored circumferentially to permit easy separation in the field, with a longitudinal groove in the outer cylinder surface of the contiguous segments identifying the original rotational relationship. The plugs are to be inserted into an alignment sleeve, or into, e.g., three-rod alignment means. Disclosed is also a novel corrugated tube alignment sleeve that has general applicability in plug and sleeve-type connectors.

Growing community of inventors

Atlanta, GA, United States of America

James A Aberson