数字全息术测定涡旋光束拓扑电荷数∗

摘要

提出了一种基于数字全息技术测定涡旋光束拓扑电荷数的方法。该方法通过数字全息技术获取涡旋光束和参考光的全息图并重构出涡旋光束的波前相位，判定相位围绕相位奇点的周期性分布来测定涡旋光束的拓扑电荷数。在拓扑电荷数取值分别为整数和分数的情况下，通过对数值模拟和实验结果的比较，表明该方法能够较准确地测定出拓扑电荷数。%In this paper we propose a method to detect the topology charge of vortex beam using digital holography. Hologram of vortex beam interference with reference beam is recorded, and the phase of vortex beam is reconstructed. The topology charge can be accurately determined by judging the periodicity of reconstructed phase distribution around the phase singularity. The phases of vortex beams generated by numerical simulation and those obtained by experiment of vortex beams with integral and fractional topology charges are compared with each other. The feasibility of the method of detecting the topology charge of vortex beam using digital holography is proved by comparing the results.