Guided Modes in Negative Refractive Index Waveguides
  We study linear guided waves propagating in a slab waveguide made of a negative-refraction- index material, the so-called left-handed waveguide. We reveal that the guided waves in left-handed waveguides possess a number of peculiar properties, such as the absence of the fundamental modes, mode double degeneracy, and sign-varying energy ux. In particular, we predict the existence of novel types of guided waves with a dipole-vortex structure of the Pointing vector. 
Ilya V. Shadrivov, Andrey A. Sukhorukov, and Yuri S. Kivshar