Multi-focal lenses are widely applied in zoom imaging, parallel laser processing, 3D displays, among others. However, conventional refractive or diffractive elements cannot realize independently switchable multi-focal points at arbitrary spatial positions. The ultra-thin metasurface provides a compact solution while the commonly used interleaved meta-units scheme deteriorates the performance of the meta-devices. Here the authors propose all-dielectric noninterleaved metalenses with polarization-switchable multi-focal points. By fully using the degrees of freedom of the single rectangular nanopillar, up to three independently switchable focal points at any spatial position can be realized in a metalens with a single-structure lattice. With the near-zero crosstalk between orthogonal polarization channels, polarization detection, zoom imaging, variable-parameter phase detection, and parallel laser lithography are demonstrated. The multichannel scheme by fully utilizing the polarization freedom paves the way for various multifunctional components.

中文翻译：

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可见光中的宽带偏振可切换多焦点非交错超透镜

多焦镜头广泛应用于变焦成像、平行激光加工、3D显示等领域。然而，传统的折射或衍射元件无法在任意空间位置实现独立可切换的多焦点。超薄超表面提供了一种紧凑的解决方案，而常用的交错元单元方案会降低元器件的性能。在这里，作者提出了具有偏振可切换多焦点的全介电非交错超透镜。通过充分利用单个矩形纳米柱的自由度，可以在具有单结构晶格的元透镜中实现任意空间位置上多达三个独立可切换的焦点。正交偏振通道之间的近零串扰、偏振检测、变焦成像、展示了可变参数相位检测和并行激光光刻。充分利用极化自由度的多通道方案为各种多功能组件铺平了道路。