Optical fiber end preparation for low-loss splices

Cables made from brittle materials like glass require new techniques of end preparation for the purpose of splicing, especially if such splices are to be made in the field. We report here on a method of breaking fibers in a way which invariably produces flat and perpendicular end faces. We explain the underlying theory and derive optimal parameters that permit the design of a simple breaking tool. Experiments with a tool of this kind show that the tolerances for successful fracture are not critical. Laboratory splices of multimode fibers prepared by this method exhibited losses of less than 1 percent (0.04 dB) when joined in index-matching fluid.