Convolution PML (CPML): An efficient FDTD implementation of the CFS–PML for arbitrary media

TLDR

The paper introduces a novel PML implementation for terminating FDTD lattices. It uses a stretched‑coordinate PML with recursive convolution and complex‑frequency‑shifted parameters. The CPML is media‑independent, highly absorptive of evanescent modes, and yields significant memory savings for complex geometries. © 2000 John Wiley & Sons, Inc., Microwave Opt Technol Lett 27:334–339.

Abstract

A novel implementation of perfectly matched layer (PML) media is presented for the termination of FDTD lattices. The implementation is based on the stretched coordinate form of the PML, a recursive convolution, and the use of complex frequency, shifted (CFS) PML parameters. The method, referred to here as the convolutional PML (CPML), offers a number of advantages over the traditional implementations of the PML. Specifically, the application of the CPML is completely independent of the host medium. Thus, no modifications are necessary when applying it to inhomogeneous, lossy, anisotropic, dispersive, or nonlinear media. Secondly, it is shown that the CFS–PML is highly absorptive of evanescent modes and can provide significant memory savings when computing the wave interaction of elongated structures, sharp corners, or low-frequency excitations. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 334–339, 2000.