Optical Fiber Connectors, Splices, and Jointing Technology

In recent years the state of the art of optical fiber technology has progressed to where the achievable attenuation levels for the fibers are very near the limitations due to Rayleigh scattering. As a result, optical fibers, and particularly single-mode fibers, can be routinely fabricated with attenuation levels of about 0.5 dB/km at 1300 nm and 0.25 dB/km at 1550 nm. Employing these fibers in lightwave systems requires precise jointing devices such as connectors and splices. Considering the small size of the fiber cores, less than 10 μm in diameter for single-mode fibers and less than 100 μm for multimode fibers, it is not surprising that these components can easily introduce high optical losses. Furthermore, since single-mode fibers have practically unlimited bandwidth, they have recently become the favorite choice for most of the lightwave systems presently being designed for telecommunication networks and in the future may be used in local area networks as well. To provide low-loss connectors and splices for these single-mode fibers, alignment accuracies in the submicrometer range are required, and these sub- micrometer alignments must be both reliable and cost-effective. Achieving these goals is presently the challenge facing the jointing technologist.