Full‐Stokes Polarimetry Metasurface‐Enabled Single‐Shot Measurement of the Spin Hall Effect of Light

ABSTRACT Spin Hall effect of light (SHEL) manifests as a transverse displacement of light into two circularly polarized components upon reflection or refraction at a planar interface. The shift delivers information about the interface in a nondestructive way, but its direct observation remains challenging due to its subwavelength scale. Stokes polarimetry measurement, one experimental approach to quantify the shift by characterizing the polarization state of the spin Hall shifted light, offers distinct advantages, such as robustness against environmental fluctuations and applicability to arbitrary polarization. However, it requires six intensity measurements using multiple optical components, leading to bulky setups and time‐consuming procedures. Here, we propose a single‐shot measurement of the SHEL using metasurface‐based full‐Stokes polarimetry, which spatially separates the spin Hall shifted beam into distinct focal spots by polarization. Our metasurface provides complete information required for evaluating the SHEL from a single image, eliminating the need for repetitive measurements. We validate this approach by quantifying the SHEL at both lossless and lossy interfaces. This single‐shot measurement not only overcomes the limitations of conventional Stokes polarimetry but also extends SHEL metrology to arbitrary incident polarizations and complex media, paving the way for integrated photonic devices for sensing and polarization detection.