Investigation of a Multimode Fiber Optic Coupler.

摘要

The operation of a three-fiber multimode fiber optic coupler was experimentally investigated for the dependence of the forward coupling ratio upon surface conditions of the aligning rods, stress on the fibers, length of the aligning rods, mode distribution in the main fiber, make of fiber, and length of input fiber. An explanation of the discrepancies between theory and experiment was also sought. The forward coupling was found to increase for gross perturbations of the surface of the alignment rods, increase for increased stress on the fibers, increase with length of the aligning rods, increase with increasing number of higher order modes, depend strongly on type of fiber, and decrease with input fiber length. Further, the directivity of the coupler was increased greatly by reducing reflections from the ends of the fibers. (Author)