Low-Loss Splices in Optical Fibers

Several methods have been demonstrated for making splices in optical fibers. These have included fused b u t t joints, 1 ' 2 sandwiching of the fiber ends between grooved lucite blocks, 3,4 and mounting in a snug-fitting sleeve. 5 These techniques have been applied to multimode and single-mode fibers. The most desirable splice in an optical fiber would be one which can be made quickly and simply, causes negligible loss at the junction, and does not have a bulky connector at the junction. Furthermore, it should be made with a technique which is applicable to simultaneous splicing of a number of fibers in a bundle. As a step toward this goal, we have constructed a splicing device which has been used to make several types of splices in multimode optical fibers. It can be used to make splices in both solid-core and liquid-core optical fibers, although we have demonstrated its use here only for liquid-core fibers. Its extension to simultaneously splicing a number of fibers is obvious and a feature to permit this has been included, although not demonstrated. Our best results, which have been obtained repeatedly, are 0.4 dB loss in the splice.