Planar metasurface retroreflector
Planar metasurface retroreflector
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DOI：
10.1038/nphoton.2017.96
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发表时间：
2017-07-01
期刊：
影响因子：
35
通讯作者：
Faraon, Andrei
中科院分区：
文献类型：
--
作者：
Arbabi, Amir;Arbabi, Ehsan;Faraon, Andrei
超颖表面是控制光波传播的亚波长散射体的二维排列（1-3）。在这里，我们展示了级联的元表面，每个元表面执行预定义的数学变换（4），提供了一个新的光学设计框架（5），该框架实现了单个元表面尚未展示的新功能。具体来说，我们证明了可以通过两个垂直堆叠的平面元表面来实现逆反射，第一个执行空间傅里叶变换及其逆变换，第二个向入射光的傅里叶变换赋予空间变化的动量。利用这一概念，我们制作并测试了一个由两层硅纳米柱组成的平面单片近红外后向反射器，该后向反射器可将光沿着其入射方向反射，法向入射效率为78%，半焦度大视场为60 °。超表面回射器展示了级联超表面用于实现新型高性能组件的潜力，并实现了低功率和低重量的无源光发射器（6-8）。
Metasurfaces are two-dimensional arrangements of subwavelength scatterers that control the propagation of optical waves(1-3). Here, we show that cascaded metasurfaces, each performing a predefined mathematical transformation(4), provide a new optical design framework(5) that enables new functionalities not yet demonstrated with single metasurfaces. Specifically, we demonstrate that retroreflection can be achieved with two vertically stacked planar metasurfaces, the first performing a spatial Fourier transform and its inverse, and the second imparting a spatially varying momentum to the Fourier transform of the incident light. Using this concept, we fabricate and test a planar monolithic near-infrared retroreflector composed of two layers of silicon nanoposts, which reflects light along its incident direction with a normal incidence efficiency of 78% and a large half-power field of view of 60 degrees. The metasurface retroreflector demonstrates the potential of cascaded metasurfaces for implementing novel high-performance components, and enables low-power and low-weight passive optical transmitters(6-8).