Realization of photonic spin Hall effect by breaking the rotation symmetry of optical field in light-matter interaction
Realization of photonic spin Hall effect by breaking the rotation symmetry of optical field in light-matter interaction
复制标题
打破光与物质相互作用中光场的旋转对称性实现光子自旋霍尔效应
DOI：
10.1016/j.optcom.2018.06.056
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发表时间：
2018
影响因子：
2.4
通讯作者：
Wen Shuangchun
中科院分区：
文献类型：
--
作者：
Liu Yuanyuan;Ling Xiaohui;Zhang Jin;Ke Yougang;Shu Weixing;Luo Hailu;Wen Shuangchun
光子自旋霍尔效应（SHE）表现为光束的自旋相关位移或分裂，它源自自旋轨道相互作用，可以通过打破光物质相互作用系统的旋转对称性来实现。在这里，我们通过打破光场的旋转对称性，同时保持非均匀波片的旋转对称性来演示光子 SHE 的观察。由介电纳米结构构建的非均匀波片向输入光束的两个自旋分量引入了自旋相关的 Pancharatnam-Berry 相，即左圆偏振分量和右圆偏振分量获得完全相反的涡旋相位。在光束传播期间，它们经历相反的方位角旋转，并在方位角方向上引起四瓣自旋相关分裂。此外，自旋相关的分裂在光束传播时变得更加明显，并且可以通过增加纳米结构的拓扑顺序来增强。为了进行比较，我们还检查了在保持入射光场的旋转对称性时，没有观察到自旋相关的分裂。
Photonic spin Hall effect (SHE) manifests itself as spin-dependent shift or splitting of a light beam, which is derived from spin–orbit interactions, and can be realized by breaking the rotation symmetry of light–matter interaction systems. Here, we demonstrate the observation of a photonic SHE by breaking the rotation symmetry of the optical field, while keeping the rotation symmetry of the inhomogeneous waveplate. The inhomogeneous waveplate constructed by dielectric nanostructures, introduces a spin-dependent Pancharatnam–Berry phase to the two spin components of the input beam, i.e., the left- and right-circular polarization components acquire exactly opposite vortex phases. During beam propagation, they experience opposite azimuthal rotations, and induce a four-lobe spin-dependent splitting in the azimuthal direction. In addition, the spin-dependent splitting becomes more evident upon beam propagation, and can be enhanced by increasing the topological orders of the nanostructures. For comparison, we also examine that no spin-dependent splitting can be observed when keeping the rotation symmetry of the incident optical field.