School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT, UK.
College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073, China.
Nat Commun. 2016 Jun 16;7:11930. doi: 10.1038/ncomms11930.
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.
超表面作为超材料的超薄版本，由于其在控制光的相位、幅度和偏振态方面的卓越能力而引起了越来越多的关注。在各种类型的超表面中，将几何或潘查拉瓦 Berry 相位编码到组成元原子的取向角中的几何超表面在线性和非线性光学领域中都显示出了控制光的巨大潜力。几何相位的稳健性和无色散性极大地简化了波的操控。得益于连续的相位控制，超表面全息术在具有离散相位级别的传统深度控制全息术中表现出了优势。在这里，我们报告了自旋和波长复用的非线性超表面全息术，它允许构建多个目标全息图像，这些图像由不同自旋的基频和倍频产生的波独立携带。这些非线性全息图为全息复用和多维光数据存储、防伪和光学加密提供了独立、无弥散和无串扰的后选择通道。
