Analytical Description of Cross-Modal Nonlinear Interaction in Mode Multiplexed Multimode Fibers

In this letter, we present a semianalytical approach to calculate the nonlinear interference between mode-multiplexed signals that are transmitted over the eigenmodes of a multimode fiber (MMF). We point out the influence of several fiber parameters on nonlinear mode interaction using four-wave mixing concepts. Finally, we apply the presented theories on a mode-division multiplexed transmission link, which uses a graded index multimode fiber. It is shown, in a configuration, that each of the MMFs 55 modes achieves an optical signal to noise ratio at the receiver at least as high as a standard single-mode fiber, resulting in a higher overall capacity than 55 single-mode fibers.