Title :
A 2D FDTD Algorithm for Whole-Hemisphere Incidence on Periodic Media
Author :
Miskiewicz, Matthew ; Schmidt, Signe ; Escuti, Michael
Author_Institution :
Dept. of Electr. & Comput. Eng., North Carolina State Univ., Raleigh, NC, USA
Abstract :
We present a modified version of the 2D split-field finite difference time domain (FDTD) method which enables efficient simulation of periodic structures. Our algorithm allows for broadband, whole-hemisphere oblique incidence sources with structures that are inhomogeneous in permittivity, conductivity, and permeability. The structures considered are of finite extent in one dimension, periodic in a second orthogonal dimension, and uniform (or homogeneous) in a third dimension. With prior FDTD methods, this required a full 3D simulation space. In this work, we reduce the modeling space from a 3D grid to a 2D grid, while still allowing incident waves to be oblique with respect to that dimension. We derive this new algorithm beginning with a complete source definition that allows for arbitrary polarization and incidence direction. The key update equations are found, and we also give a method for finding the full vectorial far-field orders from the simulation output. We validate the method by simulating an etalon, a Bragg grating, and a photonic band gap structure.
Keywords :
Bragg gratings; finite difference time-domain analysis; optical materials; periodic structures; permeability; permittivity; photonic band gap; 2D FDTD algorithm; 2D split-field finite difference time domain; 3D grid; Bragg grating; FDTD methods; arbitrary polarization; broadband oblique incidence sources; complete source definition; full vectorial far-field orders; periodic media; periodic structures; permeability; permittivity; photonic band gap; second orthogonal dimension; whole-hemisphere incidence; whole-hemisphere oblique incidence sources; Equations; Finite difference methods; Mathematical model; Periodic structures; Standards; Three-dimensional displays; Time-domain analysis; Diffraction; far-field; finite difference time domain (FDTD); oblique; periodic; polarization;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2013.2296302