Shi R, Gao D L, Hu H, Wang Y Q, Gao L
Opt Express. 2019 Feb 18;27(4):4808-4817. doi: 10.1364/OE.27.004808.
Spin-orbit interaction of light is ubiquitous in any optical system. However, the relevant spin Hall effects are usually weak for the light scattering from nanoparticles, making it challengeable to detect directly in experiment. In this paper, we demonstrate enhanced broadband spin Hall effects by using core-shell nanoparticles. The electric and magnetic dipoles can be tuned by the core-shell nanostructure with great freedom, and are excited simultaneously in a broadband spectrum, resulting in robust enhanced spin Hall shifts. Moreover, the coupling of the electric dipole and electric quadrupole gives rise to enhanced spin Hall shifts at both forward and backward directions. Numerical results from far-field and near-field verify the strong spin-orbit interaction of light. Our work offers a new way to exploit spin Hall effects in superresolution imaging and spin-dependent displacement sensing.
光的自旋 - 轨道相互作用在任何光学系统中都普遍存在。然而，对于从纳米颗粒散射的光而言，相关的自旋霍尔效应通常很微弱，这使得在实验中直接检测具有挑战性。在本文中，我们展示了通过使用核壳纳米颗粒增强的宽带自旋霍尔效应。电偶极子和磁偶极子可以通过核壳纳米结构进行高度自由地调节，并在宽带光谱中同时被激发，从而产生稳健增强的自旋霍尔位移。此外，电偶极子和电四极子的耦合在向前和向后方向上都产生了增强的自旋霍尔位移。远场和近场的数值结果验证了光的强自旋 - 轨道相互作用。我们的工作为在超分辨率成像和自旋相关位移传感中利用自旋霍尔效应提供了一种新方法。
