An efficient scheme of split-step Fourier method for fiber optic communication systems

Nonlinear Schrödinger equation (NLSE) is solved using different split-step Fourier methods (SSFM). The uniform step size distribution is traditionally utilized and the efficiency of the scheme can be improved by using the adaptive step sizes. One scheme of using the adaptive step size is the local error method, which updates the step size based on the local error of the current step. In this paper, a novel scheme which combines the minimum area mismatch (MAM) and the local error method is proposed. The MAM method can be used to find the optimal step size distribution based on minimizing the area mismatch between the ideal effective nonlinear coefficient curve and its stepwise approximation. The local error is a criterion to choose the total number of steps per span. The simulation results show that the proposed scheme outperforms the schemes using uniform step size and adaptive step size.