论文标题
用于光束塑形的Huygens元信息的基本限制
Fundamental limitations of Huygens metasurfaces for optical beam shaping
论文作者
论文摘要
预计由阵列纳米结构组成的光学介电元面积有望对具有下波长空间分辨率的入射波前进行任意空间控制。对于相位调制，通常会诉诸两种物理效应以实现2π相偏移。第一个效果依赖于高纳米级支柱的指导，第二个效果借鉴了纳米孔子剂具有两个退化的MIE共声。第一种方法需要高纵横比，而第二种方法（称为Huygens metasurfaces）则非常平坦，因此更容易制造。我们比较了两种方法，更多地关注概念性问题而不是技术问题，并确定后者的基本限制。我们解释了基于一般参数的局限性的起源，例如互惠，多模数/单模操作和对称性破坏。
Optical dielectric metasurfaces composed of arrayed nanostructures are expected to enable arbitrary spatial control of incident wavefronts with subwavelength spatial resolution. For phase modulation, one often resorts to two physical effects to implement a 2π-phase excursion. The first effect relies on guidance by tall nanoscale pillars and the second one exploits resonant confinement by nanoresonators with two degenerate Mie-resonances. The first approach requires high aspect ratios, while the second one, known as Huygens metasurfaces, is much flatter, and thus easier to manufacture. We compare the two approaches, more focusing on conceptual rather than technological issues, and identify fundamental limitations with the latter. We explain the origin of the limitations based on general arguments, such as reciprocity, multimode/monomode operation and symmetry breaking.
