Geometric Phase Control of Surface Plasmons by Dipole Sources
Geometric Phase Control of Surface Plasmons by Dipole Sources
复制标题
偶极源对表面等离子体的几何相位控制
DOI：
10.1002/lpor.202200948
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发表时间：
2023-04-11
影响因子：
11
通讯作者：
Zhang, Weili
中科院分区：
文献类型：
--
作者：
Jiang, Xiaohan;Xu, Quan;Zhang, Weili
几何相位元表面作为元光学的一个重要分支，在过去的二十年里引起了人们极大的兴趣。近年来，通过旋转一组亚波长偶极子源，几何相位的概念被扩展到近场区域，用于表面等离子体激元的控制。尽管取得了这些进展，但仍然存在一些问题和不足：奇怪的是，对于SP控制，几何相位等于偶极子源旋转角的一倍和两倍都有报道，并且迄今为止所研究的控制策略仅适用于单个波长。据此，对圆偏振照明下偶极源的SP激发进行了严格的推导，阐明了SP几何相位控制的旋转依赖性和面内坐标相关性。此外，全息的方法提出了实现多路复用的几何相位控制，实验证明几个超透镜，可以耦合和转向的四个波长和两个自旋方向的入射圆偏振到不同的SP聚焦光束。这项工作将铺平道路的综合和多路复用SP设备的发展。
Geometric phase metasurfaces, as one of the main branches of meta-optics, have attracted enormous interest in the last two decades. Recently, through rotating a set of subwavelength dipole sources, geometric phase concept has been extended to near-field regime for the control of surface plasmons (SPs). Despite this progress, puzzles and shortcomings still exist: it is curious that geometric phases equal to once and twice the rotation angle of dipole source are both reported for SP controls, and the control strategies examined thus far only work for a single wavelength. Hereby, a rigorous derivation of the SP excitation of dipole sources upon circularly polarized illumination is performed, and the rotation dependence and in-plane coordinate correlation of geometric phase control of SPs is clarified. Moreover, a holographic approach is proposed to implement multiplexed geometric phase control, experimentally demonstrating several metalenses that can couple and steer the incident circular polarizations of four wavelengths and two spin directions to different SP focusing beams. This work will pave an avenue toward the development of integrated and multiplexed SP devices.