Resonant transparency of materials with negative permittivity

It is shown that the transparency of opaque material with negative permittivity exhibits resonant behavior. The resonance occurs as a result of the excitation of the surface waves at slab boundaries. Dramatic field amplification of the incident evanescent fields at the resonance improves the resolution of the sub-wavelength imaging system (superlens). At the resonance, two evanescent waves have a finite phase shift providing non-zero energy flux through the non-transparent region. It is also shown that the resonant excitation of a surface mode creates a condition for the total transparency of a finite thickness slab to a p-polarized obliquely incident electromagnetic wave for resonant values of the incidence angle and wave frequency.