<title>Resonant modes in nested diffraction gratings</title>

Abstract

The diffraction problem of a plane wave impinging on a grating formed by nested cavities is presented. The nested cavities are formed by layers of perfectly conducting sheets that describe rectangular profiles. The problem is solved by means of the modal method, for s and p polarization modes. The electromagnetic response of the grating is analyzed, paying particular attention to the generation of resonances within the structure. The dependence of the resonances on the geometrical parameters of the grating is studied, and results of far and near field are shown. The results were checked and found in good agreement with those available in the literature for certain limit cases.