Khonina Svetlana N, Golub Ilya
Opt Lett. 2022 May 1;47(9):2166-2169. doi: 10.1364/OL.457507.
The spin Hall effect of light is a manifestation of angular momentum conservation in the process of spin-orbit interaction of light. This optical Hall effect is exhibited in tight focusing of a circularly polarized asymmetric input beam as a shift of the center of gravity of the focal spot in the transverse plane, perpendicular to the direction/axis of symmetry breaking. It is commonly established that the direction of this shift depends on the sign of the spin. Here we show, for the first time, to the best of our knowledge, both analytically and by numerical simulation, that different Cartesian components of an asymmetric circularly polarized focused beam shift in opposite directions by different amounts. Moreover, these shifts depend on the type and degree of the asymmetry and thus can be tuned/controlled. We show how these field components' shifts are related to spin and orbital angular momentum shifts. These findings shed new light on the spin optical Hall effect, facilitate new/simpler ways to measure it, and may broaden the gamut of its applications in manipulation and trapping of particles by light and precision metrology.
光的自旋霍尔效应是光的自旋 - 轨道相互作用过程中角动量守恒的一种表现。这种光学霍尔效应在圆偏振非对称输入光束的紧聚焦中表现为焦斑重心在垂直于对称破缺方向/轴的横向平面内的移动。通常认为这种移动的方向取决于自旋的符号。据我们所知，在此我们首次通过解析和数值模拟表明，非对称圆偏振聚焦光束的不同笛卡尔分量会沿相反方向以不同量移动。此外，这些移动取决于非对称的类型和程度，因此可以进行调谐/控制。我们展示了这些场分量的移动如何与自旋和轨道角动量的移动相关。这些发现为自旋光学霍尔效应带来了新的认识，促进了测量它的新的/更简单的方法，并可能拓宽其在光对粒子的操控和捕获以及精密计量中的应用范围。
