研究了平面波经过螺线型相位板后产生的涡旋光束, 经双缝干涉后在干涉场中干涉条纹的分布情况。详细介绍了涡旋光束的拓扑荷数对干涉条纹分布的影响。发现同平面波的竖直干涉条纹相比较, 涡旋光束的干涉条纹, 从顶部向底部看去, 沿着横向出现移动, 并且移动的大小和方向与拓扑荷数的取值有关。通过观测干涉条纹, 可以得到涡旋光束的拓扑荷数。涡旋光束由于携带轨道角动量可应用于新型的光信息编码与传输, 研究结果可望在这种新型的光信息编码与传输中得到应用。

The distribution of interference pattern in Young’s double-slit experiment of vortex beam, which was generated by passing a plane beam through a spiral phase plate, was investigated. It is found that topological charge of vortex beam influences the interference pattern, i.e., by compared with the straight interference pattern of plane wave, the interference pattern of vortex beam is shifted in the transverse direction as we look from the top of the interference to the bottom, and the magnitude and direction of shift are related to the topological charge. The topological charge of vortex beam can be derived from the interference pattern. Vortex beams carrying orbital angular momentum may find applications in information encoding and transmission. Therefore our research results may be applied to this new kind of information encoding and transmission.