Xie Jianfeng, Guo Hanming, Zhuang Songlin, Hu Jinbing
Opt Express. 2021 Feb 1;29(3):3081-3089. doi: 10.1364/OE.413573.
A perfect vortex beam has been attracting tremendous attention due to the fact that its ring radius is independent of the topological charge. Taking advantage of the superposition principle of phase in Fourier space, we proposed to generate perfect vortex beam using propagation-phase-based dielectric metasurface, which exhibits production efficiency larger than 83.5%. Due to the sensitivity of propagation phase to the polarization of incident beam, two sets of phase profiles can be imposed on a single dielectric metasurface, enabling the simultaneous generation of dual perfect vortex beams. Based on this property, convenient control to the radius and/or topological charge of perfect vortex beam is achieved by switching the incident polarization between two orthogonal polarizations, without redesigning metasurface or changing optical path. What's more important, the crosstalk of these two channels is low, less than 4%. Thus, the propagation-phase method of producing perfect vortex beam will find significant applications in optical communication, particle trapping, particle manipulation and holographic display.
一种完美涡旋光束因其环形半径与拓扑电荷无关而备受关注。利用傅里叶空间中的相位叠加原理，我们提出使用基于传播相位的介质超表面来产生完美涡旋光束，其产生效率大于83.5%。由于传播相位对入射光束偏振的敏感性，可以在单个介质超表面上施加两组相位分布，从而能够同时产生双完美涡旋光束。基于这一特性，通过在两个正交偏振之间切换入射偏振，无需重新设计超表面或改变光路，就能方便地控制完美涡旋光束的半径和/或拓扑电荷。更重要的是，这两个通道的串扰很低，小于4%。因此，产生完美涡旋光束的传播相位方法将在光通信、粒子捕获、粒子操纵和全息显示等方面找到重要应用。
