Abstract-We analyze the transverse-electric wave propagation through lossless trilayer stacks containing single-negative (SNG) materials in which only one of the two material constants, permittivity (epsilon) or permeability (mu), is negative. We consider the following combinations: ENG/MNG/ENG, ENG/DPS/MNG, DPS/ENG/DPS, and ENG/DPS/ENG, where ENG refers to epsilon-negative, MNG to mu-negative, and DPS to double-positive media. The transfer matrix formalism is applied. Although the waves are evanescent in the SNG media, combining the SNG layers or the SNG and DPS layers, leads to some unusual features, such as the complete tunneling. Since the symmetrical trilayer is equivalent to a single homogeneous layer, the complete tunneling conditions are easily predicted analytically for the trilayer stacks, and we show that in most of cases, they are rather well applicable to the respective bilayer stacks. The field and the Poynting vector distributions are studied in different trilayers and, in some cases, in the respective bilayers. In particular, we show that the complete tunneling is facilitated theoretically in the electrically thin stacks. Similar results could be obtained for the transverse-magnetic waves and the respective dual combinations by using the duality principle.

We comparatively investigate Dyakonov surface waves (DSWs) traveling along the plane interface between a dielectric isotropic medium and a lossless anisotropic uniaxial medium with the optic axis (OA) parallel to the interface, when the principal permittivities of the uniaxial medium are both positive (elliptic medium) and of opposite signs (hyperbolic medium). New insights concerning the DSWs are given by analyzing the behavior of the Poynting vector (PV) components. Thus, singularity points at which the PV of the DSW vanishes can exist at the dielectric-elliptic media interface. The range of angles with respect to the OA, which is determined both for the wave vector and the respective PV, can be larger for the DSWs at the dielectric-hyperbolic media interface.Extremely high values of the wave vector and the PV components of the DSWs can be attained at the dielectrichyperbolic media interface.

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Periodic and quasi-periodic Cantor-like bandgap structures that bordered upon a medium of refractive index n(0) are analyzed. An immersion model is used with the assumption that each layer is embedded between two identical regions of refractive index n(0) and thickness d(0), where d(0) is set equal to zero. Transmittance and group velocity are determined. Their dependence on n(0) is emphasized. Relations for the midgap value of the normalized group velocity are given. By use of these relations, diagrams are completed at different values of n(0), showing the pairs of quarter-wave-layer refractive indices at which there is an apparent superluminal tunneling through the finite periodic and quasi-periodic Cantor-like bandgap structures.