Ultra-wideband terahertz reflective polarization conversion based on anisotropic meta-mirror with interlaced-parallel-dipole metasurface

An ultra-wideband, high efficiency, and wide angle terahertz reflective polarization converter (RPC) using interlaced-parallel-dipole metamaterial (IPDMM) is theoretically demonstrated in this paper. Illuminated by linearly polarized (LP) wave, the proposed polarizer performances an excellent 90° linear polarized conversions at three resonance frequencies, and pure circularly polarized (CP) conversion at two resonance frequencies. Remarkably, due to the enhanced inductive-capacitive (LC) resonances by the IPDMM using double-parallel cut-wire particles, 99% ultra-broadband width of triple-band overlapping over 75% and 0.99 highest power conversion efficiency are obtained numerically. Furthermore, the excellent cross-polarization conversion sustains when the incidence is a CP wave. In addition, the proposed polarizer obtains 80% relevant bandwidth over 70% reflective polarization conversion power with incident angle up to 45°. The physical mechanism of the polarization conversion is elucidated by analysis of the surface current distributions of the polarizer. The merits of broadband, high efficiency and widely incident angles could benefit the potential applications in THz regime.