T.J. Watson Laboratory of Applied Physics, California Institute of Technology, 1200 E California Boulevard, Pasadena, California 91125, USA.
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
Nat Nanotechnol. 2015 Nov;10(11):937-43. doi: 10.1038/nnano.2015.186. Epub 2015 Aug 31.
Metasurfaces are planar structures that locally modify the polarization, phase and amplitude of light in reflection or transmission, thus enabling lithographically patterned flat optical components with functionalities controlled by design. Transmissive metasurfaces are especially important, as most optical systems used in practice operate in transmission. Several types of transmissive metasurface have been realized, but with either low transmission efficiencies or limited control over polarization and phase. Here, we show a metasurface platform based on high-contrast dielectric elliptical nanoposts that provides complete control of polarization and phase with subwavelength spatial resolution and an experimentally measured efficiency ranging from 72% to 97%, depending on the exact design. Such complete control enables the realization of most free-space transmissive optical elements such as lenses, phase plates, wave plates, polarizers, beamsplitters, as well as polarization-switchable phase holograms and arbitrary vector beam generators using the same metamaterial platform.
超表面是一种平面结构，可在反射或透射过程中局部改变光的偏振、相位和幅度，从而实现具有由设计控制的功能的光刻图案化平面光学元件。透射超表面尤其重要，因为实际中使用的大多数光学系统都在透射模式下工作。已经实现了几种类型的透射超表面，但它们要么传输效率低，要么对偏振和相位的控制有限。在这里，我们展示了一种基于高对比度介电椭圆纳米柱的超表面平台，该平台具有亚波长空间分辨率和实验测量效率在 72%至 97%之间（具体取决于设计），可实现对偏振和相位的完全控制。这种完全控制可以使用相同的超材料平台实现大多数自由空间透射光学元件，如透镜、相位板、波片、偏振器、分束器，以及偏振可切换相位全息图和任意矢量光束发生器。
