Uniaxial omega medium as a physically realizable alternative for the perfectly matched layer (PML)

Perfectly matched layers suggested for the grid termination in FDTD numerical simulations are active media, thus physically non-realizable as composite materials with passive inclusions. In this paper we show that spatially dispersive passive media can be in principle used instead of the active PML. In that case, ideal matching can be achieved with physically-realizable material parameters for the normal incidence on the interface. To achieve uniform absorption effectiveness at oblique incidence angles, the use of higher-order spatial dispersion effects is suggested. With more material parameters available, less severe restrictions apply to the permittivities and permeabilities of the material.