Polarization dependent light transmission through circular apertures of sub-wavelength dimensions

Recently the transmission of linearly polarized light through an array of nanoscopic holes is of increasing interest. The results demonstrate that this is higher than expected for this small dimensions to be. As a preliminary explanation the interaction of the field with surface plasmons enhances transmission through the apertures. As a consequence, it is expected to find a dependence on the polarization of the incoming beam. We investigate the transmission when illuminating with longitudinal and transverse fields. In our setup we prepare radially and azimuthally polarized light using a liquid crystal converter. These beams are focused by a microscope objective (NA 0.9) to illuminate single holes on a silver surface of thickness 150 nm immediately placed on the surface of a silicon diode for measuring transmission. The diameter of the holes range from 1000 nm down to 100 nm.