Zhang Yuchao, Gao Jie, Yang Xiaodong
Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO, 65409, USA.
Sci Rep. 2019 Jul 10;9(1):9969. doi: 10.1038/s41598-019-46433-z.
The spatial variation of vector vortex beams with arbitrary polarization states and orbital angular momentum (OAM) values along the beam propagation is demonstrated by using plasmonic metasurfaces with the initial geometric phase profiles determined from the caustic theory. The vector vortex beam is produced by the superposition of deflected right- and left-handed circularly polarized component vortices with different helical phase charges, which are simultaneously generated off-axially by the single metasurface. Besides, the detailed evolution processes of intensity profile, polarization distribution and OAM value along the beam propagation distance is analyzed. The demonstrated arbitrary space-variant vector vortex beam will pave the way to many promising applications related to spin-to-orbital angular momentum conversion, spin-orbit hybrid entanglement, particle manipulation and transportation, and optical communication.
利用具有由焦散理论确定的初始几何相位分布的等离激元超表面，展示了具有任意偏振态和轨道角动量（OAM）值的矢量涡旋光束沿光束传播方向的空间变化。矢量涡旋光束由具有不同螺旋相位电荷的右旋和左旋圆偏振分量涡旋的叠加产生，这些涡旋由单个超表面同时非轴向产生。此外，还分析了强度分布、偏振分布和OAM值沿光束传播距离的详细演化过程。所展示的任意空间变体矢量涡旋光束将为许多与自旋到轨道角动量转换、自旋-轨道混合纠缠、粒子操纵与传输以及光通信相关的有前景的应用铺平道路。
