At&t Bell Laboratories

William A Vicory

James A Aberson

Calvin M Miller

David N Ridgway

Jane B Clayton

Raymond P DeFabritis

Jane F Kuhl

Eugene Halupke

A low loss, tunable optical filter (20) comprises two ferrules (24-24) which are aligned axially with each of two adjacent end faces being provided with a wafer (30). A mirror (40) is embedded between each end face and its associated wafer, the wafer being bonded to the end face of its associated wafer. Optical fiber is disposed in a passageway which extends through each ferrule and through the associated wafer. The ferrules and associated wafers are supported to cause adjacent exposed faces of the wafers to be in predetermined spatial relation to each other. Any gap therebetween may be fixed or may be adjusted by a piezoelectric transducer system (44). The disclosed filter provides rejection ratios which are sufficiently high for frequency discrimination in frequency shift keying systems and for channel selection or switching in wave division multiplexer applications.

Methods of making an optical fiber filter

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

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

High-strength, low-loss splices of optical fiber can be produced by fusion splicing the fiber with a D.sub.2 -O.sub.2 flame. According to the invention, the deuterium concentration in the gas mixture used to produce the flame is at least 10% by volume of the reducing gas present in the mixture. Preferably, substantially all of the reducing gas in the mixture is deuterium, with oxygen the oxidizing gas species.

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Duluth, GA, United States of America

William A Vicory