Souza C E R, Huguenin J A O, Khoury A Z
J Opt Soc Am A Opt Image Sci Vis. 2014 May 1;31(5):1007-12. doi: 10.1364/JOSAA.31.001007.
The topological phase acquired by vector vortex optical beams is investigated. Under local unitary operations on their polarization and transverse degrees of freedom, the vector vortices can only acquire discrete geometric phase values, 0 or π, associated with closed paths belonging to different homotopy classes on the SO(3) manifold. These discrete values are demonstrated through interferometric measurements, and the spin-orbit mode separability is associated to the visibility of the interference patterns. The local unitary operations performed on the vector vortices involved both polarization and transverse mode transformations with birefringent wave plates and astigmatic mode converters. The experimental results agree with our theoretical simulations and generalize our previous results obtained with polarization transformations only.
研究了矢量涡旋光束所获得的拓扑相。在对其偏振和横向自由度进行局部幺正操作时，矢量涡旋只能获得与属于SO(3)流形上不同同伦类的闭合路径相关的离散几何相值，即0或π。这些离散值通过干涉测量得到证明，并且自旋 - 轨道模式可分离性与干涉图样的可见度相关。对矢量涡旋执行的局部幺正操作涉及使用双折射波片和像散模式转换器进行的偏振和横向模式变换。实验结果与我们的理论模拟相符，并推广了我们之前仅通过偏振变换获得的结果。
