Evanescent surface-wave modes in a slab with application to miniaturised waveguide components

Characteristics of surface-wave modes in a slab with either negative permittivity or negative permeability are considered. It is shown that this kind of slab is a monomode structure which supports TM mode when the permittivity is negative and TE mode when the permeability is negative. It is shown that tightly bound surface-wave modes exist, also backward waves, in a slab with small thickness. These surface-wave modes will certainly have applications in trying to miniaturise waveguide components in microwave techniques and in optics. As an example, characteristics for a planar plasma waveguide are given