Properties of a one-dimensional metallophotonic crystal

We analyze the structure of a periodic arrangement of optically thick metallic gratings that have very narrow slits. This structure permits perfect transmission of light in some frequency range and is analogous to a one-dimensional all-dielectric photonic crystal. Our study shows this structure has many unusual features due to evanescent modes. One of these is that its band diagram has flat bands at long wavelengths. Another feature is that this structure can enhance the fields locally. More significantly, we show that a manipulation of the positions of the slits on adjacent metal films produces lateral displacement along the grating surface for a transmitted beam of finite cross section. This shift is similar to the birefringence in crystal optics.