Sa. Tretyakov, UNIAXIAL OMEGA-MEDIUM AS A PHYSICALLY REALIZABLE ALTERNATIVE FOR THE PERFECTLY MATCHED LAYER (PML), Journal of electromagnetic waves and applications, 12(6), 1998, pp. 821-837
Perfectly matched layers suggested for the grid termination in FDTD nu
merical simulations are active media, thus physically non-realizable a
s composite materials with passive inclusions. In this paper we show t
hat spatially dispersive passive media can be in principle used instea
d 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 res
trictions apply to the permittivities and permeabilities of the materi
al.