Polarization-Encoded Multi-Focus Stitched Imaging Based on All-Dielectric Metasurface Engineering

Conventional optical imaging systems rely on complex lenses and polarizing structures to achieve imaging of microscopic objects and field-of-view expansion, resulting in bulky system volumes and intricate designs. This paper proposes a polarization-encoded multi-focus stitching imaging method based on all-dielectric metalenses to overcome the aforementioned limitations. We design a polarization-multiplexed metalens that enables dynamic multi-focus modulation depending on the incident polarization state. Under right-handed circularly polarized light incidence, eight focal spots are generated; under left-handed circularly polarized light, four focal spots are generated; and under linearly polarized light incidence, all twelve focal spots are activated simultaneously. By employing this metalens for multi-focus stitching imaging of a resolution target, its capability to enhance the field of view and imaging quality is verified. Finally, as a proof of concept, we digitally process the captured information using computational imaging algorithms such as convolution and stitching to reconstruct a fundus blood vessel image. Simulation results validate the feasibility of the proposed approach for large field-of-view, high-resolution biological imaging. This work demonstrates the significant potential of polarization-multiplexed metasurfaces in the field of integrated, high-performance computational imaging.