光自旋霍尔效应中的交叉偏振特性研究

Cross-polarizaton characteristics in spin Hall effect of light

从光束角谱理论出发建立了描述光自旋霍尔效应的傍轴传输模型,利用这一模型分析了光自旋霍尔效应中的交叉偏振特性.通过分析交叉偏振效应强度和入射角变化的规律,发现交叉偏振效应越强,光自旋霍尔效应中的自旋分裂越大.为便于实验观察,将入射角选在光自旋霍尔效应较强的布儒斯特角附近,观测到了强的交叉偏振效应.增大交叉偏振分量的同时减小初始偏振分量,可显著增强光自旋霍尔效应.这一调控方法为研制基于光自旋霍尔效应的新型光子器件提供了理论基础.

From the angular spectrum theory of beam, we obtain a transmission model in the paraxial approximation which describes the spin Hall effect of light, and we use this model to analyze the cross-polarization characteristics in spin Hall effect of light. By analyzing the change of cross-polarization intensity and incident angles we find that the spin splitting in spin Hall effect of light becomes stronger when cross-polarization effect is stronger. In order to facilitate the experimental observation, we choose the incident angle near the Brewster angle where it＇s spin Hall effect of light is much more evident, and from where we observe a strong cross-polarization effect. If we increase the cross-polarization components and reduce the light of original polarization direction at the same time, the spin Hall effect of light can be greatly enhanced. This is a promising method to develop new optical devices based on spin Hall effect of light.