Coupling Effects Among Degenerate Modes in Multimode Optical Fibers

Multimode optical fibers have recently received revived attention in the framework of space-division multiplexed systems, where the spatial diversity of fiber modes is exploited to increase transmission capacity. The complexity of these systems strongly depends on the coupling characteristic of the fiber. Therefore, a better description of coupling effects may lead to the more accurate modeling of the system and to an optimized design of multimode fibers. In this paper, we analyze coupling among (quasi) degenerate modes as a consequence of different kinds of coupling sources.