Polarization weighting of Fano-type transmission through bi-dimensional metallic gratings.

We demonstrate an approach allowing isolating effects of surface plasmon polariton mediated resonant transmission in a periodic grating by means of polarization rotation. The grating comprises a square array of cylindrical holes in an optically thick metallic film. Transmittance data for the co- and cross-polarized cases are described accurately with Fano-type and pure Lorentzian-type line shapes, respectively. This polarization control allows for changing the relative weights of resonant and non-resonant transmission mechanisms, thus controlling the shape and symmetry of the observed Fano-type line shapes.