  Influence of hole shape on extraordinary optical transmission was
investigated using hole arrays consisting of rectangular holes with different
aspect ratio. It was found that the transmission could be tuned continuously by
rotating the hole array. Further more, a phase was generated in this process,
and linear polarization states could be changed to elliptical polarization
states. This phase was correlated with the aspect ratio of the holes. An
intuitional model was presented to explain these results.
