Spintronic terahertz emitter integrated multiple metasurface pattern for terahertz polarization modulation

Compact, broadband, and on-chip terahertz (THz) polarization control is still constrained by bulky free-space components and resonance-limited metasurfaces that add integration complexity and coupling loss. In this paper, spintronic THz emitter with metasurface pattern is proposed for polarization-control performance. We benchmark strip and hexagon geometries pattern by rotating magnetic field direction to investigate the modualtion difference. Key results: strip pattern array produces predominantly linear trajectories with very low ellipticity, highlighting high-purity linear emission along a preferred axis. In contrast, hexagon pattern yields stable closed ellipses with axis ratios ∼0.3-0.8 and fourfold symmetry, the principal component peaks are consistently ∼±1.0 (normalized), while off-axis components remain robust at ∼±0.6, enabling near-isotropic, multidirectional polarized emission. The spintronic terahertz emitter integrated microdevice opens a route to scalable, on-chip THz polarization functionality and can be extended with programmable magnetic biasing and active metasurfaces toward reconfigurable vector imaging, chiral sensing, and secure communication.