Polarization-dependent transmission through a bull's eye with an elliptical aperture

Anisotropic transmission through a plasmonic bull's eye with an elliptical central aperture in a thin Au film is analyzed experimentally by changing the polarization. The light polarized along the minor axis of the elliptical aperture had a significantly larger enhanced optical transmission than the other orthogonal polarization, which agreed well with theoretical predictions. Spectral width of the output was narrowed, which indicates temporal elongation of pulse trains.