Pulse Propagation in a Short Nonlinear Graded-Index Multimode Optical Fiber

We present a detailed analysis of the modal properties, dispersive behavior, and nonlinear mode coupling in graded-index multimode fibers (GIMFs), and lay out a simplified form of a generalized nonlinear Schrödinger equation, which can be used to explore the rich nonlinear dynamics related to the propagation and interaction of light pulses in GIMFs in a tractable manner. We also briefly discuss an application of the presented formalism in the study of four-wave mixing in these fibers. While the reported formalism is fairly general, our presentation is mainly targeted at device applications in which short segments of GIMFs are used.