Ultra-broadband and high-efficiency terahertz reflective metamaterials polarization converter

The paper presents an ultra-broadband and high-efficiency terahertz (THz) reflective metamaterials polarization converter (PC). It consists of the gold (Au) pattern layer, the dielectric layer inlaid with an Au frame and the Au substrate layer. Based on the full vector finite element method, the polarization conversion properties, physical mechanism and the effects of device parameters are studied theoretically. The results show that the PC can realize linear and circular polarization conversion within the range of center frequency 7.5 THz and bandwidth 5.0 THz, and the polarization conversion rate (PCR) is greater than 99%. They are clearly superior to what has been reported. Meanwhile, it can maintain good polarization conversion properties when the incident angle of THz wave is less than 30 & DEG;. The proposed PC has potential application prospects in THz polarization imaging and communication fields.