Analysis of a metallic nano-rod polarizer using finite-difference-time-domain method.

The polarization behavior of metallic nano-rods has been analyzed by means of the finite-difference-time-domain method. When the average spacing between the nano-rods is less than a half wavelength, the layer reflects the light polarized parallel to the nano-rods, as in a nano-slit. However, when the spacing is larger than a half wavelength, the metallic surface absorbs the light, polarized perpendicular to the rods, leading to a polarization switching. Multiple layers of nano-rods can make a polarizer with a high extinction ratio and good transmittance.