Role of shape and periodicity in extraordinary transmission of periodic arrays at THz range

We investigated the transmission enhancement and the suppression in rectangular holes array at terahertz range. Experiments and simulations verified that the metal film perforated with rectangular holes array had the shape resonance and the Wood-Rayleigh anomalies. With the development of previously reported theory, we explored the contribution of the shape of single hole and the periodicity of array. The shape resonance caused by the geometry of structure leaded to the location of the resonance peak. The periodicity of array enhanced the peak and provided the minima in spectrum in the condition of the incident E-field parallel the direction of periodicity. This study contributed a better understanding of fundamental physics behind the extraordinary transmission of periodic arrays at THz range and provided a simple method for the THz devices designing.