UNIAXIAL OMEGA-MEDIUM AS A PHYSICALLY REALIZABLE ALTERNATIVE FOR THE PERFECTLY MATCHED LAYER (PML)

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.