This paper presents an approach to design the all-dielectric metasurface with multi-function in the near-infrared range of 1.5–1.6 µm. Based on the geometric phase principle, the all-dielectric metasurface is composed of the Si nanopillar and the ${\rm SiO}_2$ substrate as an emitter unit distributed in a ${21} \times {21}$ array. Under the incidence of the circularly polarized light at 1550 nm, the metasurface works as a vortex-beam generator with high performance which generates the vortex beam with topological charges of $\pm {1}$, and the mode purity of the vortex beam is 90.66%. Under the incidence of the linearly polarized light at 1550 nm, the metasurface also works as the azimuthally/radially polarized beam generator with high performance, and the purities of the azimuthally and the radially polarized beams are 92.52% and 91.02%, respectively. Moreover, the metasurface generates different output spots under the different incident lights which can be applied to optical encryption, and the metasurface with the phase gradient also can be used as the dual-channel encoder/decoder in optical communication. The simulated results are in good agreement with the theoretical derivation. The designed metasurface may become a potential candidate as a multi-function photon device in the integrated optical system in the future.

中文翻译：

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在近红外波段具有多功能的全介电超表面

本文提出了一种在1.5-1.6 µm的近红外范围内设计具有多功能的全介电超表面的方法。基于几何相位原理，全介电超表面由Si纳米柱和$ {\ rm SiO} _2 $衬底作为发射器单元组成，分布在$ {21} \ times {21} $阵列中。在1550 nm的圆偏振光的入射下，超颖表面可作为高性能的涡流束发生器，产生具有$ \ pm {1} $拓扑电荷的涡旋束。，涡旋光束的模纯度为90.66％。在1550 nm的线性偏振光入射下，超颖表面也可以用作高性能的方位/径向偏振光束发生器，方位和径向偏振光束的纯度分别为92.52％和91.02％。而且，超表面在不同的入射光下会产生不同的输出光斑，可以应用于光学加密，具有相位梯度的超表面也可以用作光通信中的双通道编码器/解码器。仿真结果与理论推导吻合良好。将来，设计的超表面可能会成为集成光学系统中多功能光子设备的潜在候选者。