Surface modes of the sandwhich structure containing indefinite metamaterials

The surface modes of an indefinite mo ta ma to rial (IMM) sandwiched between isotropic mediums are studied. Four cases for the IMMs, including cutoff, always-cutoff, never-cutoff, and anticutoff media, are considered. It is shown that two branches of TE surface modes and two branches of TM surface modes are found to exist. The surface modes can exist in the same frequency region or different frequency region, the double TE(TM) surface modes degenerate with the thickness of the central IMM layer. The resonance excitation of the surface modes are also studied by using the attenuated total reflection (ATR). The calculated reflectance spectra in an ATR configuration shows that different incident angles and gap width between the prism and the IMM can excitated different surface modes. The gap width has some influence on the location and the magnitude of the reflectance minimum.