Polarization-sensitive terahertz frequency-selective surface based on a laser-cutting technique [Invited]

In this study, we experimentally and simulatively investigated the characteristics of two distinct frequency-selective surfaces (FSS) sensitive to terahertz (THz) wave polarization. These structures were fabricated using a laser-cutting technique on stainless steel. The unit cells of the two studied FSS are rectangular-slot and C-slot, respectively. Analysis of the azimuthal dependence from 0° to 90° of the C-slot array FSS confirms the shift of the peak center frequency of the normalized transmission toward a higher value, and with an intermediate condition between its two modes of operation for the median values, enabling dual-frequency operation with high polarization selectivity. In contrast, for the rectangular-slot array FSS, no frequency shift was observed as a function of rotation angle, only an attenuation of transmission at peak center frequency, similar to the response of a frequency-selective polarizer. This study identifies potential candidates for polarization-dependent detection applications, such as THz multi-spectral polarimetry and THz polarimetric imaging.