Accurate modeling of dielectric interfaces by the effective permittivities for the fourth-order symplectic finite-difference time-domain method

摘要

The fourth-order finite-difference time-domain (FDTD) method using a symplectic integrator propagator can calculate the propagation of the electromagnetic waves with very low dispersion error in the region of a constant or smoothly varying index profile. An additional technique is required for the problem with the discontinuous dielectric interfaces. We derived the third-order effective permittivities at dielectric interfaces for the fourth-order FDTD method in the case of 2D TE polarization. As the required accuracy level is increased, the memory resources used by the fourth-order FDTD method with the effective permittivities are reduced severalfold or more compared with the standard FDTD method. The accurate performance of the proposed method is demonstrated through numerical examples.