Direct all-electrical decoding of vector vortex beams on chip.

Vector vortex beams, structured light fields characterized by polarization and phase singularities, offer substantial promise for next-generation photonic technologies. While the detection of scalar vortex beams has been investigated, the direct, all-electrical, and filter-free detection of vector vortex beams has remained a challenge. Here, we demonstrate an on-chip, all-electrical detection platform capable of simultaneously resolving the orbital angular momentum (OAM) order and polarization state of incident vector vortex beams. This functionality is achieved by coupling van der Waals layered thermoelectric materials with a phase-gradient metagrating, which spatially maps OAM and polarization information onto surface plasmon polariton intensity distributions, thereby inducing directionally modulated photothermoelectric responses. Leveraging these distinctive photoresponses, we demonstrate a proof-of-concept two-dimensional encrypted optical communication protocol. Our platform establishes a scalable approach for high-dimensional light field detection and lays the groundwork for advanced optoelectronic systems spanning secure communications, quantum information, optical manipulation, and high-resolution imaging.