Unconditionally stable FDTD algorithm for 3-D electromagnetic simulation of nonlinear media

For the first time, an unconditionally stable finite-difference time-domain (FDTD) method for 3-D simulation of dispersive nonlinear media is presented. By applying a new adopted alternating-direction implicit (ADI) time-splitting scheme and the auxiliary differential equation (ADE) technique, the time-step in the FDTD simulations can be increased much beyond the Courant-Friedrichs-Lewy (CFL) stability limit. Thus, in comparison to the classical nonlinear FDTD method, the computational time for the proposed approach is decreased significantly while maintaining a reasonable level of accuracy. Numerical examples arc presented to demonstrate the validity, stability, accuracy and computational efficiency of the proposed method. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement