Strong polarization dependence in the optical transmission through a bull's eye with an elliptical sub-wavelength aperture.

Strong polarization dependence in the optical transmission through a bull's eye with a central elliptical aperture in a thin Au film is analyzed numerically by finite difference time domain (FDTD) method. Focusing on the impacts of the structural anisotropy, detailed investigation of polarization dependent enhanced optical transmission (EOT) of light is discussed in terms of the resonance intensity variations caused by the incident light polarization and the geometrical parameters of bull's eye. We found that the light polarized along the minor axis of the elliptic aperture has significantly larger EOT by more than three orders of magnitude than the other orthogonal polarization, which can be further utilized in polarized EOT devices.