Broadband Full Polarization Control Using a Staggered Arrangement of Metamolecules

Metasurfaces show an extraordinary ability for polarization control, despite the limitations imposed by their working bandwidth and complex meta-atom designs. Here, we present a strategy for generating arbitrary polarization in the broadband, relying solely on the Pancharatnam-Berry phase. The proposed metasurface design comprises two metamolecules arranged in a staggered configuration. Importantly, the orientation of the two metamolecules provides a new degree of freedom to control both the amplitude and phase of right- and left-circular polarization components. We experimentally demonstrated that the polarization of the scattered light can cover the entire Poincaré sphere by merely tuning the metamolecule orientation. These results provide a unique approach for fabricating ultracompact photonic devices and integrated quantum optical systems.