ABSTRACT
Crossed gratings are periodic in two different directions, example, along the x-axis and z-axis, although the two directions are not necessarily perpendicular. Their electromagnetic study began at the end of the 1970s, in view of optimizing the performances of the surface of solar energy absorbers. The methods developed at that time mainly suffered from the limitations in the storage capacity of available computer memories. The discussion will be restricted to the case of a plane wave falling on a crossed grating under normal incidence, linearly polarized in an arbitrary direction. The resonant character of the extraordinary transmission is thus due to the fact that the channel resonantly excites surface Plasmon’s at the lower silver-glass interface to the crossed-grating periodicity. A phenomenological study using both complex poles of the scattering operator and complex zeros of the transmitted amplitude was able to account for this unexpected effect in both qualitative and quantitative ways.
