Resonant 2D Wavefront Manipulation via Birefringent Guided‐Mode Resonances in Dielectric Phase Gradient Metasurfaces

Abstract Phase gradient metasurfaces based on guided‐mode resonances have emerged as a promising route to manipulate optical wavefronts with high resolutions in both spatial and spectral dimensions. However, optical responses in these resonant metasurfaces generally rely on the coherent interaction among many adjacent meta‐atoms across an extended spatial region, so that the neighboring interaction varies with the geometric parameters of nearby meta‐atoms, leading to distortion and low efficiency in the wavefront manipulation. In this work, the experimental demonstration is presented of dielectric phase gradient metasurfaces enabled by birefringent guided‐mode resonances, which are utilized to realize 2D wavefront manipulations such as anomalous beam deflection, beam focusing, and vortex beam generation. In this configuration, the two‐fold mirror symmetry of meta‐atoms enables birefringent guided‐mode resonances, giving rise to efficient cross‐polarization conversion and complete 2 π phase coverage via the geometric phase scheme with stable neighboring interactions. The results provide an effective strategy for realizing robust neighboring coupling effects, facilitating the development of resonant phase gradient metasurfaces.