Optical Vortex Transmutation with Geometric Metasurfaces of Rotational Symmetry Breaking
Optical Vortex Transmutation with Geometric Metasurfaces of Rotational Symmetry Breaking
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DOI：
10.1002/adom.201901152
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发表时间：
2019-08
影响因子：
9
通讯作者：
Yuchao Zhang;Jie Gao;Xiaodong Yang
中科院分区：
文献类型：
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作者：
Yuchao Zhang;Jie Gao;Xiaodong Yang
利用几何等离子体超颖表面实现了自由空间光学涡旋的嬗变，所设计的非正则涡旋相位轮廓具有有限阶的离散旋转对称性。基于超颖表面中连续到离散的旋转对称破缺，在自由空间中观察到超颖表面后从近场到远场衍射的涡旋嬗变现象。近场光束轮廓表示输入涡旋，而在远场中，输入涡旋被衍射到具有由嬗变规则确定的拓扑电荷的中心输出涡旋和具有从输入涡旋分叉的单位拓扑电荷的对称分布的离轴涡旋中，其中总轨道角动量守恒。所展示的自由空间光学涡旋变换将有望在光通信、粒子操纵和量子信息处理等方面获得许多潜在的应用。
The free‐space optical vortex transmutation is realized by using geometric plasmonic metasurfaces with the designed noncanonical vortex phase profiles possessing discrete rotational symmetries of finite order. Based on the introduced continuous‐to‐discrete rotational symmetry breaking in metasurfaces, the vortex transmutation phenomena are observed behind the metasurfaces from the near‐field to far‐field diffraction in free space. The near‐field optical beam profile represents the input vortex, while in the far field the input vortex is diffracted into the central output vortex with topological charge determined by the transmutation rule and the symmetrically distributed off‐axis vortices with unity topological charge bifurcating from the input vortex, with the total orbital angular momentum conserved. The demonstrated free‐space optical vortex transformation will promise many potential applications related to optical communication, particle manipulation, and quantum information processing.