Polarization-Controlled Broadband Accelerating Beams Generation by Single Catenary-Shaped Metasurface
Polarization-Controlled Broadband Accelerating Beams Generation by Single Catenary-Shaped Metasurface
复制标题
偏振——单悬链线控制宽带加速光束生成——异形超表面
DOI：
10.1002/adom.201900503
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发表时间：
2019-09-01
影响因子：
9
通讯作者：
Luo, Xiangang
中科院分区：
文献类型：
--
作者：
Guo, Yinghui;Huang, Yijia;Luo, Xiangang
自加速光束由于其无衍射和自愈的特性，在光学领域引起了极大的关注。传统上，这种光束的产生需要庞大的器件和较长的工作距离，这阻碍了光学系统的小型化。亚表面的最新进展使得用超薄和平面的纳米光学器件取代笨重的光学元件变得容易。然而，现有的大多数方法都存在着轨迹固定、操作带宽窄、效率低等问题。本文提出了一种基于几何光学和干涉理论的广义分析方法来产生任意轮廓的自加速光束。作为概念的证明，利用单个悬链线形状的亚曲面来产生立方相移，从而产生倒易的加速轨迹。空间连续和光谱无色散的悬链线纳米孔在带宽和效率方面比离散的悬链线纳米孔显示出巨大的优势。仿真和测量结果都验证了偏振控制的加速轨迹。所提出的紧凑而高效的波束发生器被认为在未来的片上和集成应用中具有广阔的前景。
Self-accelerating beams have drawn enormous attentions in optics owing to their nondiffracting and self-healing properties. Traditionally, the generation of such beams demands bulky devices and a long working distance, which impede the miniaturization of the optical system. Recent progresses in metasurfaces facilitate replacing cumbersome optical components by ultrathin and planar nano-optical devices. Nevertheless, most of the existing approaches suffer from fixed trajectories, narrow operation bandwidth and low efficiency. Here, a methodology is proposed to generate self-accelerating beams with arbitrary profiles by employing a generalized analysis based on geometric optics and interference theory. As a proof of the concept, single catenary-shaped metasurface is utilized to generate the cubic phase shift, which leads to a reciprocal accelerating trajectory. The spatially continuous and spectrally dispersionless catenary nanoapertures show great advantages in terms of bandwidth and efficiency over discrete counterparts. The polarization-controlled accelerating trajectories are demonstrated by both simulations and measured results. The proposed compact and efficient beam generators are believed to be promising for future on-chip and integration applications.