Efficient and broadband terahertz polarization convertor enabled by an all-metal stereo reflective metasurface

The pursuit of novel concepts and design schemes for metasurfaces to develop Terahertz (THz) polarization-related devices with exceptional performance is an ongoing and highly demanding project. Here, A new all-metal stereo U-shaped meta-atom based design scheme for manipulating terahertz polarization is proposed. The design functions as an efficient and broadband THz waveplate with tailorable birefringence by controlling sunken depth. The polarization conversion ratio (PCR) is >90% with 69% relative bandwidth and 85 degrees angle tolerance. The proposed meta-grating based on Pancharatnam-Berry (PB) phase method is also demonstrated, enriching design degrees of freedom for metasurfaces and offering potential for various functional devices.