Optical Spin–Orbit Superposition State Hall Effect

ABSTRACT

We report the first demonstration of the optical spin–orbit superposition state Hall effect (HE), a new member of the optical HE family. In contrast to all previous HEs—which rely on the splitting of angular momentum (AM) eigenstates or their product states (spin, orbital, and spin–orbit AM eigenstates)—our effect separates orthogonal spin–orbit AM superposition states. As a proof of concept, we experimentally show that the spin–orbit superposition state HE can be controlled by using a simple uniaxial crystal system. Moreover, we demonstrate that this effect can be harnessed to generate and tailor optical skyrmions. Importantly, because the uniaxial crystal supports electro‐optic modulation at tens of GHz, our result theoretically provides a pathway for high‐speed switching of skyrmion number and texture. This work not only deepens the understanding of optical Hall physics but also opens new routes for dynamic control of topological light fields, with promising applications in particle manipulation, information processing, and spin–orbit photonics.