Single-layer metasurface for simultaneous Fourier-domain filtering and polarization-resolved edge imaging

Spatial Fourier processing is commonly implemented using 4f optical architectures, in which spatial filtering and imaging are carried out on physically distinct Fourier and image planes. Our work proposes a metasurface-based imaging system. By introducing a quadratic phase factor at the object plane to pre-modulate the optical field, and integrating a metasurface with a filtering function and a focusing phase profile at the spectral plane, the system simultaneously executes frequency-domain filtering and spatial-domain imaging. This enables four-channel (x, y, 45°, and 135°) polarization-resolved edge imaging in a single exposure. Finally, by capturing images from four polarization channels and employing the Stokes vector method for polarization-state retrieval, the system reconstructs the original polarization information. This synchronous tuning scheme for spatial-domain and Fourier-domain information offers a novel, to the best of our knowledge, solution for compact optical processors and on-chip polarization imaging.