Li Zile, Ren Renyuan, Deng Juan, Deng Liangui, Li Gongfa, Zheng Guoxing
Opt Express. 2021 Jan 4;29(1):134-144. doi: 10.1364/OE.415403.
Metasurface based polarization multiplexing is usually conducted in two orthogonal-polarization states, e.g., linearly polarized along x/y axes, left/right-handed circularly polarized states, etc. Herein, we show metasurfaces can be employed to implement tri-channel polarization multiplexing in three non-orthogonal-polarization states, merely with a single-size nanostructure design approach. Specifically, nanostructured metasurfaces acting as nano-polarizer arrays can modulate the incident light intensity pixel-by-pixel by controlling the orientation angles of nanostructures, governed by Malus's law. Hence, by inserting a metasurface between a bulk-optic polarizer and an analyzer, and elaborately controlling their polarization combinations, we show that the Malus-assisted metasurface can simultaneously record a continuous gray-image and two independent binary-patterns in three different information channels. We experimentally demonstrate this concept by recording three independent gray-images right at the metasurface surface. With the advantages of high information density, high security, high compatibility and ultracompactness, the proposed gray-imaging meta-device can play a significant role in the field of optical storage, anti-counterfeiting, and information multiplexing, etc.
基于超表面的偏振复用通常在两个正交偏振态下进行，例如沿x/y轴的线偏振、左旋/右旋圆偏振态等。在此，我们展示了超表面可以仅采用单一尺寸的纳米结构设计方法，在三种非正交偏振态下实现三通道偏振复用。具体而言，作为纳米偏振器阵列的纳米结构化超表面可以通过控制纳米结构的取向角，逐像素地调制入射光强度，这由马吕斯定律决定。因此，通过在体光学偏振器和检偏器之间插入一个超表面，并精心控制它们的偏振组合，我们表明马吕斯辅助超表面可以在三个不同的信息通道中同时记录一幅连续灰度图像和两个独立的二值图案。我们通过在超表面表面直接记录三个独立的灰度图像，对这一概念进行了实验验证。所提出的灰度成像超器件具有高信息密度、高安全性、高兼容性和超紧凑性等优点，在光存储、防伪和信息复用等领域可发挥重要作用。
