Optimized symplectic scheme for electromagnetic simulations

Classical finite-difference time-domain (FDTD) method has been widely used in computational electromagnetics, but for electrically large domains and for late-time analysis, FDTD method begins to show its limitations due to the accumulation of phase errors. To solve this problem, several methods have been proposed such as high-order schemes and four-stage Runge-Kutta integrator. Recently, the symplectic methods have been adopted for using in computational electromagnetics. In this paper, the concentration is on the derivation of an optimized fourth-order symplectic scheme in electromagnetic simulations.