Im Sande Sören, Bozhevolnyi Sergey I, Ding Fei
Centre for Nano Optics, University of Southern Denmark, Campusvej 55, Odense M DK-5230, Denmark.
Nanophotonics. 2023 Jan 9;12(8):1363-1371. doi: 10.1515/nanoph-2022-0535. eCollection 2023 Apr.
Metasurface-generated holograms have emerged as a unique platform for arbitrarily shaping the reflected/transmitted wavefronts with the advantages of subwavelength large pixel sizes and multiple information channels. However, achieving multiple holographic images with large operation bandwidths is a rather complicated and arduous issue due to the dissimilar dispersion of all meta-atoms involved. In this work, we design and experimentally demonstrate single-celled metasurfaces to realize broadband and spin-multiplexed holograms, whose phase modulation is based only on the geometric phase supplied by a judiciously designed high-performance nanoscale half-wave plate operating in reflection. Four different multiplexing strategies are implemented, and the resulting holograms are systemically assessed and compared with respect to background levels, image fidelities, holograms efficiencies, and polarization conversion ratios. Our work complements the methodologies available for designing multiplexed meta-holograms with versatile functionalities.
超表面生成的全息图已成为一个独特的平台，可用于任意塑造反射/透射波前，具有亚波长大像素尺寸和多信息通道的优势。然而，由于所有涉及的超原子的色散不同，实现具有大操作带宽的多个全息图像是一个相当复杂和艰巨的问题。在这项工作中，我们设计并通过实验证明了单细胞超表面，以实现宽带和自旋复用全息图，其相位调制仅基于由精心设计的高性能纳米级反射式半波片提供的几何相位。实施了四种不同的复用策略，并对所得全息图的背景水平、图像保真度、全息图效率和偏振转换率进行了系统评估和比较。我们的工作补充了用于设计具有多种功能的复用超表面全息图的方法。
