Engineering the Optical Transmission Enhancement through the Air Holes in a Metallic Film

Optical transmission enhancements of the metallic film with air holes are studied. The results show that the location of the resonant peak wavelengths are sensitive to the length of array´s periodicity, while the width of the extraordinary transmission wavelength region can be adjusted by altering the side length of square holes. The light intensity distributions through the air holes indicate that the near-field intensity is greatly enhanced. When the shape of the air holes is changed from a square to a rectangle, the transmission efficiency is quite sensitive to the direction of the incident electric field´s polarization, which can be used as a simple optical polarization-choosing device.