Broadband terahertz reflective linear polarization convertor

A broadband terahertz reflective linear polarization convertor is proposed. The structure is composed of a metallic disk and split-ring resonators in proximity to a ground plane. It is found that the structure exhibits three neighboring resonances, from which the linear polarization of incident light can be rotated to its orthogonal counterpart after reflection. Both simulated and experimental results exhibit that the polarization conversion ratio is greater than 80% in the range of 0.53-1.34 THz, equivalent to 82.1% relative bandwidth. This presented design for enhancing efficiency of polarization conversion has potential applications in the area of terahertz spectroscopy, imaging, and communications.