As an inherent characteristic of light, polarization plays important roles in information storage, display and even encryption. Metasurfaces, composed of specifically designed subwavelength units in a two-dimensional plane, offer a great convenience for polarization manipulation, yet improving their integrability and broadband fidelity remain significant challenges. Here, based on the combination of various subwavelength cross-nanofins (CNs), a new type of metasurface for multichannel hybrid polarization distribution in near-field is proposed. Sub-wavelength CN units with various waveplate (WP) functionalities, such as frequency-division multiplexing WP, half-WP and quarter-WP are implemented with high efficiency in broadband. High-resolution grayscale image encryption, multi-image storage and rapid polarization detection are demonstrated by encoding the WP pixels into single, double and four channels, respectively. All these applications possess good fidelity in an ultrabroad wavelength band from 1.2 to 1.9 µm, and the high degree of integrability, easy fabrication and multifunction make the CN-shaped WP pixels a promising candidate in optical device miniaturization, quantum applications and imaging technologies.

中文翻译：

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基于交叉纳诺芬的波片像素在近场中的宽带混合极化编码

作为光的固有特性，偏振在信息存储，显示甚至加密中起着重要作用。由二维平面中专门设计的亚波长单元组成的超颖表面为偏振操作提供了极大的便利，但如何提高其可集成性和宽带保真度仍然是重大挑战。在此，基于各种亚波长交叉纳米蛋白（CN）的组合，提出了一种用于近场多通道混合极化分布的新型超颖表面。具有各种波片（WP）功能的亚波长CN单元，例如频分复用WP，半WP和四分之一WP，在宽带中得到了高效实现。高分辨率灰度图像加密，通过将WP像素分别编码为单通道，双通道和四个通道，证明了多图像存储和快速偏振检测。所有这些应用在1.2至1.9 µm的超宽波长带中都具有良好的保真度，并且高度的可集成性，易于制造和多功能性使得CN形WP像素成为光学器件小型化，量子应用和成像技术中的有希望的候选者。