激光与光电子学进展, 2019, 56 (14): 140501, 网络出版: 2019-07-12
环形渐变型光栅用于涡旋光束拓扑荷数测量的研究 下载: 1354次
Measurement of Topological Charges for Vortex Beams using Gradually-Changing-Period Annular Gratings
摘要
涡旋光的拓扑荷数测量是涡旋光应用不可或缺的关键技术。将周期渐变型光栅的渐变性与环形光栅的完全对称性相结合,对环形光栅的结构附加周期渐变性并进行优化,研制了一种用于涡旋光束高阶拓扑荷数测量的新型环形渐变型光栅。经过数值模拟与实验测试,涡旋光束准直投射至环形渐变光栅形成远场衍射图案,其变化规律精准地对应涡旋光束轨道角动量状态。实验测量拓扑荷数达±30。该研究为涡旋光束的测量应用提供了新方法。
Abstract
Measurement of topological charges (TC) for vortex beams is a key technology for the practical application of vortex beams. Herein, combining the gradual change of the gradually-changing-period grating with the complete symmetry of the annular grating, a new type of gradually-changing-period annular grating for measuring higher-order TC of vortex beams is developed by optimizing the structure of the ring grating with an additional periodic gradient. Numerical and experimental results demonstrate that a far-field diffraction pattern is formed by collimating the vortex beam onto the ring grating. The results demonstrate that the variation of the patterns accurately corresponds to the orbital angular momentum states of the vortex beams. Consequently, the number of TCs measured in the experiment is ±30. It provides a new measurement method for vortex beams.
邹文康, 杨春勇, 侯金, 龙浩, 陈少平. 环形渐变型光栅用于涡旋光束拓扑荷数测量的研究[J]. 激光与光电子学进展, 2019, 56(14): 140501. Wenkang Zou, Chunyong Yang, Jin Hou, Hao Long, Shaoping Chen. Measurement of Topological Charges for Vortex Beams using Gradually-Changing-Period Annular Gratings[J]. Laser & Optoelectronics Progress, 2019, 56(14): 140501.