Finite-difference time-domain simulation of dispersive features smaller than the grid spacing

✍ Scribed by W. H. P. Pernice; F. P. Payne; D. F. G. Gallagher

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 256 KB
• Volume: 20
• Category: Article
• ISSN: 0894-3370
• DOI: 10.1002/jnm.648

✦ Synopsis

Abstract

A novel approach for the interpolation of dispersive materials for use in the finite‐difference time‐domain (FDTD) method is presented. The method allows for the simulation of geometrical structures that cannot be aligned to the discretized grid. Materials overlapping multiple cells are described by averaging flux densities in the cells concerned. This method provides an efficient way to simulate structures that are smaller than the minimum grid size. A formulation for an absorbing boundary condition using the uniform perfectly matched layer approach is given for the complex dispersive material model. The approach is validated by analysing reflection from metal sheets extending into multiple grid cells and two‐dimensional photonic crystals. Excellent agreement between analytical calculations and FDTD simulations is obtained for the simulation of real metal structures. Copyright © 2007 John Wiley & Sons, Ltd.