  Engineering plasmonic metamaterials with anisotropic optical dispersion
enables us to tailor the properties of metamaterial-based waveguides. We
investigate plasmonic waveguides with dielectric cores and multilayer
metal-dielectric claddings with hyperbolic dispersion. Without using any
homogenization, we calculate the resonant eigenmodes of the finite-width
cladding layers, and find agreement with the resonant features in the
dispersion of the cladded waveguides. We show that at the resonant widths, the
propagating modes of the waveguides are coupled to the cladding eigenmodes and
hence, are strongly absorbed. By avoiding the resonant widths in the design of
the actual waveguides, the strong absorption can be eliminated.
