Polarimetry of transmission gratings.

We have investigated the polarizing properties of gold wire gratings in the resonance domain. The partial polarizing properties of 1-μm period gratings in the near IR are then used to orient the wire structure of transmission grating facets parallel to each other by means of an alignment polarimeter technique. The absolute alignment accuracy for these gratings is limited by the influence of the support structure on the orientation of the polarization ellipse. If the polarizing properties of this perturbative component are known, the accuracy can be enhanced by treating the polarization by means of the Mueller calculus.