Nonlocal Huygens’ meta-lens for high-quality-factor spin-multiplexing imaging

作者：Jin Yao, Yubin Fan, Yunhui Gao, Rong Lin, Zhihui Wang, Mu Ku Chen, Shumin Xiao, Din Ping Tsai · 发表于：Light Science & Applications · 年份：2025 · DOI：10.1038/s41377-024-01728-3 · 被引用次数：57 · 研究领域：Metamaterials and Metasurfaces Applications、Orbital Angular Momentum in Optics、Plasmonic and Surface Plasmon Research

Combining bright-field and edge-enhanced imaging affords an effective avenue for extracting complex morphological information from objects, which is particularly beneficial for biological imaging. Multiplexing meta-lenses present promising candidates for achieving this functionality. However, current multiplexing meta-lenses lack spectral modulation, and crosstalk between different wavelengths hampers the imaging quality, especially for biological samples requiring precise wavelength specificity. Here, we experimentally demonstrate the nonlocal Huygens' meta-lens for high-quality-factor spin-multiplexing imaging. Quasi-bound states in the continuum (q-BICs) are excited to provide a high quality factor of 90 and incident-angle dependence. The generalized Kerker condition, driven by Fano-like interactions between q-BIC and in-plane Mie resonances, breaks the radiation symmetry, resulting in a transmission peak with a geometric phase for polarization-converted light, while unconverted light exhibits a transmission dip without a geometric phase. Enhanced polarization conversion efficiency of 65% is achieved, accompanied by a minimal unconverted value, surpassing the theoretical limit of traditional thin nonlocal metasurfaces. Leveraging these effects, the output polarization-converted state exhibits an efficient wavelength-selective focusing phase profile. The unconverted counterpart serves as an effective spatial frequency filter based on incident-angular dispersion, passing hig...