(Top) Light-bending behaviors in materials with positive, near-zero, and negative indices of refraction. In the index-near-zero medium, the electromagnetic fields become homogeneous with a uniform phase distribution. (Bottom) The dispersion relations of a dielectric strip waveguide with an air cladding (green) and a plasmonic waveguide with a dielectric core surrounded by a metallic cladding (red). The black circles indicate the cutoff conditions. The two straight lines correspond to the light lines of vacuum () and glass (), respectively, and the dashed line represents the dispersion curve of surface plasmons. The inset shows the electric field (arrows) and magnetic field (color map) of the zero-index mode at the cutoff frequency.