An Artificially-Synthesized Absorbing Medium for the Truncation of FDTD Lattices

An artificially-synthesized absorbing material composed of a doubly-periodic array of lossy electric and magnetic media (i.e., an ε and μ checkerboard) is presented for the truncation of Finite-Difference Time-Domain (FDTD) lattices in waveguide simulations. It is shown numerically that this artificially-synthesized material exhibits excellent absorption properties when used in waveguide simulations. However, unlike the Perfectly Matched Layer (PML) absorbing medium, the artificially-synthesized medium presented in this letter does not require any modification of the standard FDTD formulation. Numerical examples demonstrate that the FDTD implementation of the artificially-synthesized absorbing medium is stable as well as computationally efficient.