Investigation on properties of transmission spectra for Bulls-eye structure based on CNT film

In order to present an exhaustive exploration of the optical properties of a Bulls-eye structure consisting of a circular annular aperture surrounded with several concentric periodic grooves in a conductor film, we calculated and analyzed a series of transmission spectra of the proposed structure in terahertz (THz) range and demonstrate that the number of grooves, the depth of grooves, the width of grooves and the conductivity of film material are several important factor of the peak value of transmission spectra. The results obtained not only describe the effect of the geometry parameters of Bulls-eye structures on the transmission properties in detail, but also point out the direction to further optimum design to get the most efficiency Bulls-eye structure.