Polarization sensitive sub-wavelength metallic structures: toward near-field light confinement control

In this paper, we seek to demonstrate spatial near field light confinement with a truly sub-wavelength resolution in the visible range. For that purpose, an opaque metallic screen is pierced with an array of rectangular nano-apertures which support polarization sensitive guided modes. We show that it is possible to switch on and off sub-wavelength apertures about only 200 nanometers away. Theoretical results have been performed (3D-FDTD home-made code) and are in good agreement with the experimental results. These kinds of nano-structures might offer a convenient and versatile way to sub-wavelength light addressing, optical trapping, molecular, or nano-probing, non-linear spectroscopy.