光自旋霍尔效应中的自旋角分裂

Spin Angle Splitting in Spin Hall Effect of Light

理论研究了光自旋霍尔效应(SHEL)中的自旋角分裂现象。通过建立平行和垂直偏振两种情况下光束由玻璃到空气界面的全内反射传输模型,揭示了光自旋霍尔效应中的自旋角分裂与入射角、偏振态以及光束传播距离等因素的定量关系。研究发现只有当入射角大于全内反射角时,角移才会出现,且角移会随着入射角的增大而减小,同时随着光束传播距离的变化而变化。在垂直偏振光入射情况下,由于自旋角分裂的影响,横移会发生反转。光自旋霍尔效应中的自旋角分裂现象可以用菲涅耳反射系数平行与垂直分量相位差的变化来解释。预测光束在损耗介质和多层纳米结构中传输时也存在类似的自旋角分裂现象。

Spin angle splitting phenomenon in spin Hall effect of light （SHEL） is studied theoretically. The quantitative relationships of incident angle, polarization state and beam transmission distance upon the spin angle splitting of SHEL are revealed, by establishing horizontal polarization and vertical polarization transmission models of beam total internal reflection at the interface from glass to air. It is found that only when the incident angle is bigger than the critical angle, will the spin angle splitting phenomenon appear, or will there be only space shift in SHEL. The angle shift decreases with the increase of the incident angle, it also changes with the increase of transmission distance at the same time. Transverse shift will reverse because of the influence of spin angle splitting in the case of vertical polarization light. The spin angle splitting phenomenon of SHEL can be explained by the aspect of phase difference between parallel and vertical components of Fresnel reflection coefficient. It is predicted that the similar spin angular splitting would also exist in the cases of loss media and layer nanostructures.