利用螺旋相位板获取涡旋光束的传播分析

Propagation characteristic analysis of vortex beams produced by spiral phase plate

为研究涡旋光束在空间中的传播特性,首先从理论上对利用螺旋相位板获取涡旋光束的基本原理进行了推导,并得出影响涡旋光束光斑半径尺寸的详细因素。然后基于设计好的螺旋相位板模型,对具有不同拓扑荷数涡旋光束的传播过程进行了细致的模拟分析和实验验证。结果表明,光斑半径会随着光束传输距离的增加而逐渐变大,并且随着拓扑荷数的增大光斑展宽程度也会相应明显。最后验证了基于螺旋相位板叠加获取新型拓扑荷数涡旋光束的实验方法。该结论为激光应用中实现不同性质微粒的微控制提供了具体的指导。

For studying and optimizing propagation characteristics of vortex beam,the fundamental theory for generating vortex beam with spiral phase plate is deduced,and the factors of affecting the radius and width of vortex beam spot are discussed in detail. Based on the designed model of spiral phase plate,the propagation process of vortex beam with different topological charges is simulated by the ray tracing software（ Trace Pro） and validated through the experimental platform. The results show that the radius and width of light spot are directly proportional to propagation distance of vortex beam. In addtion,the width can also increase with the increase of the topological charge. At the same time,a new method using the spiral phase plate superposing to get different topological charges of vortex beam is proposed. The theoretic analysis is consistent with the experimental results. The conclusion provides theoretical foundation and practical guidance for the application of optical micro manipulation technology and the obtaining of vortex beam with different topological charges in the experiment.