Influence of the Kerr-Nonlinearity in MDM Transmission Systems Scaling with the Number of Modes in Dependence of the Core Radius

Scaling the radius of graded-index multimode fibers, while keeping the refractive index difference between the core and the cladding constant, is a promising approach to adjust the number of modes in multimode fibers. With an increasing number of modes, more modes are involved in the nonlinear coupling induced by the Kerr-nonlinearity. This potentially increases the nonlinear impairments. However, the nonlinear coefficient g decreases at the same time due to increasing effective areas. We investigate by numerical simulations which one of the two effects is dominating and clarify if the nonlinear impairments are increased or even reduced with an increasing capacity.