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.

传统光学成像系统依赖复杂透镜与偏振结构实现显微物体成像及视场拓展，却导致系统体积庞大、设计繁复。本文提出一种基于全介质超构透镜（all-dielectric metalens）的偏振编码多焦点拼接成像方法，以克服上述局限。我们设计了一款偏振复用超构透镜（polarization-multiplexed metalens），可根据入射偏振态实现动态多焦点调制：入射右旋圆偏振光时产生8个焦点，入射左旋圆偏振光时产生4个焦点，而入射线偏振光时12个焦点可同时被激发。通过将该超构透镜用于分辨率靶标的多焦点拼接成像，验证了其提升视场与成像质量的性能。最后，作为概念验证，我们采用卷积、拼接等计算成像算法对采集到的信息进行数字化处理，重构出眼底血管图像。仿真结果验证了所提方法在大视场、高分辨率生物成像场景中的可行性。本研究表明，偏振复用超构表面（polarization-multiplexed metasurfaces）在集成化、高性能计算成像领域具备显著应用潜力。