Polarization dependence of transmission of terahertz radiation through periodic array of sub-wavelength rectangular holes

We experimentally investigated the polarization dependence of enhanced transmission of terahertz radiation through the periodic array of sub-wavelength rectangle holes. The array patterns of rectangle holes are fabricated by the cutting of YAG laser to the copper foils with 100 mu m thickness. These patterns are designed as different sizes and different shapes of rectangular holes on the copper foils. The optical transmission properties in terahertz; range are obtained by measuring terahertz time-domain spectra of these samples. Our results show that the transmission of periodic array of sub-wavelength rectangular holes proposes distinct frequency selectivity. The transmission peaks at the lower frequency increase with increasing of the angle of incident THz wave polarization relative to the long side of rectangle hole. The frequency locations of the transmission peaks do not change when the polarization of incident THz wave change. Our experimental results are going to be a important reference for developing photonic devices of THz frequency range.