异常涡旋光束的拓扑荷的测量

提出了一种测量异常涡旋光束的拓扑荷的方法。在接收孔径之前放置一个特殊样式的掩膜板,通过接收平面的光强图来分辨异常涡旋光束的拓扑荷值。首先采用理论推导的方法得出接收平面光强分布的解析式,然后通过数值仿真得出光强图。研究表明,接收平面上的强度分布图为多环结构,环数与异常涡旋光束的拓扑荷值有关,而与光束阶数无关。研究成果对于促进异常涡旋光束的应用具有重要意义。

Method for probing the topological charge of anomalous vortex beams

A method is proposed to measure the topological charge of an anomalous vortex beam.A mask is placed before the receiving aperture,and the topological charge of the anomalous vortex beam can be measured through analyzing the intensity distribution on the receiving plane.The analytical expression describing the intensity distribution of the anomalous vortex beams after passing through the mask is derived.Based on the expression,the intensity patterns are obtained through numerical simulating.It is shown that the intensity distribution on the receiving plane is a multi ring pattern,and the number of rings is related to the topological charge of the anomalous vortex beam,but not to the beam order.The results are of great significance to the application of anomalous vortex beams.