Metasurfaces, as the ultrathin version of metamaterials, have caught growing attention due to their superior capability in controlling the phase, amplitude and polarization states of light. Among various types of metasurfaces, geometric metasurface that encodes a geometric or Pancharatnam-Berry phase into the orientation angle of the constituent meta-atoms has shown great potential in controlling light in both linear and nonlinear optical regimes. The robust and dispersionless nature of the geometric phase simplifies the wave manipulation tremendously. Benefitting from the continuous phase control, metasurface holography has exhibited advantages over conventional depth controlled holography with discretized phase levels. Here we report on spin and wavelength multiplexed nonlinear metasurface holography, which allows construction of multiple target holographic images carried independently by the fundamental and harmonic generation waves of different spins. The nonlinear holograms provide independent, nondispersive and crosstalk-free post-selective channels for holographic multiplexing and multidimensional optical data storages, anti-counterfeiting, and optical encryption.

中文翻译：

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自旋和波长复用的非线性超表面全息术。

超表面作为超材料的超薄形式，由于其在控制光的相位，振幅和偏振态方面的卓越能力而受到越来越多的关注。在各种类型的超表面中，将几何或Pancharatnam-Berry相编码为组成亚原子的取向角的几何超表面在线性和非线性光学方案中都具有控制光的巨大潜力。几何相位的鲁棒性和无色散特性极大地简化了波的操纵。得益于连续的相位控制，超表面全息术已显示出优于具有离散相位水平的常规深度控制全息术的优势。在这里，我们报道了自旋和波长复用的非线性超表面全息技术，这样就可以构造由不同自旋的基波和谐波生成波独立携带的多个目标全息图像。非线性全息图为全息复用和多维光学数据存储，防伪和光学加密提供了独立，无色散和无串扰的事后选择通道。