Polarization-controlled diffraction from a quasicrystal nanohole array in a gold film

Optical transmission and diffraction of a two-dimensional quasicrystal nanohole array in a gold film is studied. Transmission spectrum peaks are observed with strong dependence on the dispersion of the metal in the optical regime, while not coinciding exactly with the surface plasmon polariton wavevectors of the quasicrystal. The diffraction pattern from the quasicrystal shows the expected tenfold rotational symmetry. Control of the diffraction pattern orientation is achieved by rotating the polarization of the incident light. This phenomenon arises from the surface wave nature of the extraordinary transmission phenomenon. The polarization dependence can be used to analyze the polarization of the incoming beam without any moving parts, or for polarization based beam-path switching.