An Expedient Approach to FDTD-Based Modeling of Finite Periodic Structures

This article proposes an efficient finite-difference time-domain (FDTD) technique for determining electromagnetic fields interacting with a finite-sized 2-D and 3-D periodic structures. The technique combines periodic boundary conditions-modeling fields away from the edges of the structure-with independent simulations of fields near the edges of the structure. It is shown that this algorithm efficiently determines the size of a periodic structure necessary for fields to converge to the infinitely periodic case. Numerical validations of the technique illustrate the savings concomitant with the algorithm.