Soma Go, Komatsu Kento, Nakano Yoshiaki, Tanemura Takuo
School of Engineering, The University of Tokyo, Tokyo, Japan.
Nat Commun. 2025 Aug 25;16(1):7744. doi: 10.1038/s41467-025-62401-w.
Vectorial optical mode converters that can transform orthogonal sets of multiple input vector beams into other orthogonal sets are attractive for various applications in optics and photonics. While multi-plane light conversion (MPLC) and metasurface technologies have been explored to individually address multiple spatial mode conversion and polarization mode manipulation, there has been no universal methodology to simultaneously convert a set of multiple vectorial modes with spatially non-uniform wavefronts and polarizations. Here, we present a general device framework to achieve complete vectorial mode conversion based on the MPLC concept incorporating multi-layer metasurfaces. The effectiveness of our method is confirmed experimentally by demonstrating 6-mode (3 spatial modes × 2 polarization modes) multiplexer fabricated on a compact chip. Additionally, we apply it to design devices with more advanced functionalities: a mode-division-multiplexed dual-polarization coherent receiver and spatial-mode-multiplexed vectorial holography. The versatility of our protocol makes it a powerful tool for realizing universal optical mode converters.
能够将多个输入矢量光束的正交集转换为其他正交集的矢量光学模式转换器，在光学和光子学的各种应用中具有吸引力。虽然已经探索了多平面光转换（MPLC）和超表面技术来分别解决多个空间模式转换和偏振模式操纵问题，但还没有一种通用的方法能够同时转换一组具有空间非均匀波前和偏振的多个矢量模式。在此，我们提出了一个基于包含多层超表面的MPLC概念来实现完全矢量模式转换的通用器件框架。通过展示在紧凑型芯片上制造的6模式（3个空间模式×2个偏振模式）复用器，我们的方法的有效性得到了实验证实。此外，我们将其应用于设计具有更先进功能的器件：一个模式分割复用双偏振相干接收器和空间模式复用矢量全息术。我们方案的通用性使其成为实现通用光学模式转换器的强大工具。
