Polarization control is shown to enhance functionalities of terahertz waves in various
applications. As a step toward introducing efficient practical devices operating in the
terahertz band, we propose and experimentally validate a free-standing three-layer
polarization converter operating in transmission. The device can efficiently convert a linearly
polarized terahertz wave to its orthogonal counterpart. Our device comprises split-ring and H-
shaped resonators inserted between two layers of orthogonal wire gratings. The sole …