  We propose the use of a left-handed material in an optical waveguide
structure to reduce its thickness well below the wavelength of light. We
demonstrate that a layer of left-handed material, added to the cladding of a
planar waveguide rather than to its core, allows for good light confinement in
a subwavelength thin waveguide. We attribute the observed behavior to the
change in phase evolution of electromagnetic waves in the guide. This technique
can be used for the miniaturization of photonic integrated circuits.
