Wang Yuzhong, Wang Yifei, Yu Axiang, Hu Mingshuang, Wang Qiming, Pang Cheng, Xiong Huimin, Cheng Yayun, Qi Jiaran
Department of Microwave Engineering, School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin, 150001, China.
Adv Mater. 2025 Feb;37(8):e2408978. doi: 10.1002/adma.202408978. Epub 2024 Nov 25.
Characterization of electromagnetic wave polarization states is critical in various applications of materials, biomedical, and imaging. The emergence of metasurfaces opens up the possibility of implementing highly integrated full-Stokes imagers. Despite rapid development, prevailing schemes on metasurface-based full-Stokes imagers require interleaved or cascaded designs, inevitably resulting in performance deterioration, bulky size, and complicating the imaging procedure due to misalignment. To overcome these challenges, a non-interleaved shared-aperture full-Stokes metalens enabled by the prior-knowledge-driven inverse design methodology is proposed. The metalens can be directly deployed into imagers, performing high-accuracy diffraction-limited full-Stokes imaging without other ancillary components, breaking intrinsic constraints of efficiency and resolution in interleaved design. To demonstrate this, the metalens is integrated into the W-band passive imaging system, as an alternative solution, to perform polarimetric imaging, which reduces the reliance on the high cost and high complexity of the ortho-mode transducer and broadband correlator in traditional polarimetric radiometers. Furthermore, with the assistance of a 3D reconstruction method, the feasibility of multi-polarization information for contactless surface slope measurements is explored. This work may open new paradigms for the full-Stokes imager designing and broaden the applications of metasurface polarimetric imaging.
电磁波偏振态的表征在材料、生物医学和成像等各种应用中至关重要。超表面的出现为实现高度集成的全斯托克斯成像仪开辟了可能性。尽管取得了快速发展，但基于超表面的全斯托克斯成像仪的主流方案需要交错或级联设计，不可避免地会导致性能下降、尺寸庞大，并且由于对准误差而使成像过程复杂化。为了克服这些挑战，提出了一种由先验知识驱动的逆向设计方法实现的非交错共享孔径全斯托克斯超透镜。该超透镜可以直接部署到成像仪中，无需其他辅助组件即可进行高精度衍射极限全斯托克斯成像，突破了交错设计中效率和分辨率的固有限制。为了证明这一点，该超透镜被集成到W波段被动成像系统中，作为一种替代解决方案来进行偏振成像，这减少了对传统偏振辐射计中正交模变换器和宽带相关器的高成本和高复杂性的依赖。此外，借助三维重建方法，探索了多偏振信息用于非接触式表面斜率测量的可行性。这项工作可能为全斯托克斯成像仪设计开辟新的范式，并拓宽超表面偏振成像的应用。
