Dual-Mode Reflective-Transmissive Polarization Conversion by Symmetry Breaking in Stereometamaterials

The ability to control light polarization is vital for applications in imaging, communications, and beyond. This work reports a systematic approach using supercells of periodic stereometamaterials to achieve enhanced polarization control. The use of supercells, with identical resonators, provides enhanced parameter flexibility, enabling facile control over the phase and polarization of scattered beams through rotation, flipping, and shifting of the resonators. In particular, we show that by changing the symmetry of the system from reflection to inversion in a subwavelength two-layer supercell, a transmissive half-wave plate can be transformed into a reflective counterpart, both with near-unity polarization conversion ratios. This systematic use of supercells highlights their potential for advanced polarization manipulation in electromagnetic and optical devices.