Reflective terahertz metasurfaces enabling multi-functional polarization modulation and beam deflection

Abstract Polarization manipulation and beam splitting are pivotal for advancing integrated photonic systems, yet conventional devices face challenges in miniaturization and dynamic control. This study introduces a spin-sensitive H-symmetry reflective metasurface that synergizes geometric and propagation phase modulation through subwavelength meta-atom engineering, enabling full polarization decoupling, arbitrary beam deflection and independent intensity control across multiple deflection channels. By combining multi-beam systems and Jones matrix theory, we can achieve efficient conversion from incident circularly polarized (CP) waves to orthogonally oriented states. Numerical simulations validate the metasurface’s capability to generate orthogonally polarized states under CP illumination, with dual-channel polarization conversion efficiencies exceeding 90% and triple-channel operation demonstrating programmable intensity ratios. This approach enables multifunctional metasurfaces platforms for reconfigurable radar and polarization-optimized imaging toward next-generation miniaturized photonic systems with enhanced integration.