Polarization Beam Splitting with Gauge Field Metamaterials

Abstract By designing a microwave metamaterial with biaxial dielectric constants, a 2D polarization‐dependent effective gauge field is experimentally realized for electromagnetic waves. Such an effective gauge field is manifested by the oppositely shifted circular dispersions for two polarizations in k‐space. A polarization beam splitter is experimentally demonstrated as an immediate application of the effective gauge field. Rather than the conventional horizontal |H〉 and vertical |V〉 basis, it allows polarization beam splitting into the |H + V〉 and |H − V〉 basis in the transmission regime and works for a large span of incidence angles, and thus provides additional degrees of freedom in optical signal processing. The implementation has proved that biaxial dielectrics can be a straightforward approach to construct gauge‐field‐driven devices and the same design principle can be further extended to the optical regime.