Stokes modulated THz radiation from non-chiral perovskite emitters

Chiral terahertz (THz) radiation plays a vital role in advanced optoelectronic applications, yet its efficient generation and flexible control remain challenging. Here, we demonstrate a simple and efficient method for generating chiral terahertz (THz) radiation using solution-processed polycrystalline halide perovskite films. Through the photon-drag effect, we achieve fully polarization-tunable THz emission controlled solely via the optical Stokes parameters of the pump beam—without external bias or crystalline anisotropy. We reveal an inherent time-domain integral relationship between polarization-independent and polarization-dependent photocurrent components that naturally induces a π/2 phase shift, enabling switchable THz waveforms (left-handed, linear, and right-handed elliptical) with high ellipticity up to ±0.7. These results demonstrate that metal-halide perovskites serve as a “plug-and-play”, easy-to-integrate, and low-cost material platform, establishing them as a compelling choice for cost-effective, alignment-free, and all-optically controlled chiral THz emission sources, offering a promising pathway toward miniaturized and integrable THz emitters for on-chip applications.