Under the government of Malus’s law, metasurfaces composed of anisotropic nanostructures acting as nano-polarizers have shown their precise optical manipulation of polarization profile of incident light at the nanoscale. The orientation degeneracy implied in Malus’s law provides a new design degree of freedom for polarization multiplexing, which can be employed to design amplitude-modulated multiplexing meta-devices. Herein, we experimentally demonstrate this concept by encoding two independent amplitude profiles into a single metasurface under different polarization controls, merely with a single-size nanostructure design approach. Hence, the multiplexing metasurface functions as two independent fork gratings to generate two vortex beams with different topological charges, and the two channels can be readily switched by rotating the metasurface sample around its optical axis from 0° to 45° or vice versa. The proposed metasurface for vortex beam generation enjoys advantages including high resolution, ultracompactness, dual-channel information capacity, and ultrasimple nanostructures, and it can be extended to a variety of practical applications in information multiplexing, orbital angular momentum (OAM) multiplexing communication, quantum information processing, etc.

中文翻译：

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用于双通道涡旋束生成的单尺寸纳米结构超表面。

在马卢斯定律的统治下，由各向异性的纳米结构充当纳米偏振器的超颖表面已显示出它们在纳米级对入射光的偏振分布的精确光学操纵。马卢斯定律中隐含的取向简并性为极化复用提供了新的设计自由度，可用于设计调幅复用元设备。在这里，我们仅通过单一尺寸的纳米结构设计方法，通过将两个独立的振幅分布图编码到不同极化控制下的单个超表面中，以实验方式证明了这一概念。因此，多路复用超表面起两个独立的叉状光栅的作用，以产生具有不同拓扑电荷的两个涡旋光束，并且通过将超表面样品绕其光轴从0°旋转到45°或反之亦然可以轻松切换两个通道。提出的用于涡流束产生的超颖表面具有高分辨率，超紧凑性，双通道信息容量和超简单纳米结构等优点，并且可以扩展到信息复用，轨道角动量（OAM）复用通信，量子信息处理等