Full optical responses of one-dimensional metallic photonic crystal slabs

We reveal all the linear optical responses, reflection, transmission, and, diffraction, of typical one-dimensional metallic photonic crystal slabs (MPhCS) with the periodicity of a half micrometer. Maxwell equations for the structure of deep grooves are solved numerically with good precision by using the formalism of scattering matrix, without assuming perfect conductivity. We verify characteristic optical properties such as nearly perfect transmission and reflection. Moreover, we present large reflective diffraction and show that, in the energy range where diffraction channels are open, the photonic states in the MPhCS originate from surface plasmon polaritons.