Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling Wetter, Helene Wingenbach, Jan Rehberg, Falk Gao, Wenlong Schumacher, Stefan Zentgraf, Thomas Metasurfaces are powerful tools for manipulating light using small structures on the nanoscale. In most metasurfaces, near-field couplings are treated as being unfavorable perturbations. Here, we experimentally investigate a structure consisting of sinusoidally modulated silicon waveguides where near-field coupling of local resonances leads to negative coupling, i.e., a negative coupling constant. This gives rise to wave-vector-dependent eigenstates of elliptical, linear, and circular polarizations. In particular, fully circular polarization states are not only present at a single point in momentum space (k-space) but also along a line. This circular polarization line, as well as a linear polarization line, emanates from a polarization degeneracy at the Dirac point. We experimentally validate the existence of these eigenstates and demonstrate the energy-, polarization-, and wave vector dependence of this metasurface as well as its sensitivity to fabrication tolerances. By tuning the incident k-vector, certain polarization-energy eigenstates are strongly reflected, allowing for uses in angle-tunable polarization filters and light sources. American Chemical Society (ACS) 2026 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/65316 Wetter H, Wingenbach J, Rehberg F, Gao W, Schumacher S, Zentgraf T. Polarization- and Wave-Vector Selective Optical Metasurface with Near-Field Coupling. <i>ACS Photonics</i>. Published online 2026. doi:<a href="https://doi.org/10.1021/acsphotonics.5c02865">10.1021/acsphotonics.5c02865</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1021/acsphotonics.5c02865 info:eu-repo/semantics/altIdentifier/issn/2330-4022 info:eu-repo/semantics/altIdentifier/issn/2330-4022 info:eu-repo/semantics/altIdentifier/arxiv/2512.14452 info:eu-repo/semantics/openAccess