Nonlocal Metasurfaces for Optical Signal Processing
Nonlocal Metasurfaces for Optical Signal Processing
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DOI：
10.1103/physrevlett.121.173004
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发表时间：
2018-10-24
影响因子：
8.6
通讯作者：
Alu, Andrea
中科院分区：
文献类型：
--
作者：
Kwon, Hoyeong;Sounas, Dimitrios;Alu, Andrea
光模拟信号处理作为一种克服数字技术的速度和能量限制的方法已经获得了极大的关注。超表面为实现这一目标提供了一条有希望的途径，因为它们可以有效地处理深度亚波长体积上的光信号。迄今为止，超表面已被提出用于在空间域中转换信号，例如，用于光束转向，聚焦或全息，其中角相关响应或非局域性是必须避免或减轻的不需要的特征。在这里，我们证明了超表面非局部性可以被设计成在超薄平台上的动量域中进行信号操纵。我们探索执行基本数学运算的非局部超表面，为边缘检测和光学图像处理的快速和节能超薄设备铺平道路。
Optical analog signal processing has been gaining significant attention as a way to overcome the speed and energy limitations of digital techniques. Metasurfaces offer a promising avenue towards this goal due to their efficient manipulation of optical signals over deeply subwavelength volumes. To date, metasurfaces have been proposed to transform signals in the spatial domain, e.g., for beam steering, focusing, or holography, for which angular-dependent responses, or nonlocality, are unwanted features that must be avoided or mitigated. Here, we show that the metasurface nonlocality can be engineered to enable signal manipulation in the momentum domain over an ultrathin platform. We explore nonlocal metasurfaces performing basic mathematical operations, paving the way towards fast and power-efficient ultrathin devices for edge detection and optical image processing.