title: Effective permittivities with exact second-order accuracy at inclined dielectric interface for the two-dimensional finite-difference time-domain method.
abstract: Accuracy degradation at a dielectric interface in simulations using the finite-difference time-domain method can be prevented by assigning suitable effective permittivities at the nodes in the vicinity of the interface. The effective permittivities with exact second-order accuracy at the interface inclined to the Yee-lattice axis are analytically derived for what we believe to be the first time. We discuss two interfaces with different inclined angles between their normal and the Yee-lattice axis in the case of two-dimensional TE polarization. The tangent of the angle is 1 for one interface and 1/2 for the other. With the derived effective permittivities, reflection and transmission at the interface are simulated with second-order accuracy with respect to cell size. The accuracy is demonstrated by numerical examples.
authors.affiliation: NTT Photonics Laboratories, NTT Corporation, 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198, Japan. hirono-takuo@ntt-el.com
authors.forename: Takuo
authors.initials: T
authors.lastname: Hirono
authors.forename: Yuzo
authors.initials: Y
authors.lastname: Yoshikuni
authors.forename: Takayuki
authors.initials: T
authors.lastname: Yamanaka