  We present a detailed study of oscillating modes in a slab waveguide with air
core and anisotropic metamaterial cladding. It is shown that, under specific
dielectric configurations, slow and even stopped electromagnetic wave can be
supported by such an air waveguide. We propose a linearly tapped waveguide
structure that could lead the propagating light to a complete standstill. Both
the theoretical analysis and the proposed waveguide have been validated by
full-wave simulation based on finite-difference time-domain method.
