Ma Jingbo, Li Peng, Zhou Ziheng, Gu Yuzong
J Opt Soc Am A Opt Image Sci Vis. 2021 Jan 1;38(1):115-123. doi: 10.1364/JOSAA.412404.
Fork-shaped fringes are formed for off-axis interference between two oblique-incident vortex beams. New formulas considering various parameters [such as the angles between two vortex beams and their topological charges (TCs)] are established to describe all kinds of fork-shaped fringes. An improved Mach-Zehnder interferometer is employed to investigate these interference fringes. Experimental measurements are consistent with numerical simulations by using our formulas. Our results broaden the understanding of the off-axis interference between two vortex beams, and can be applied to detect the TCs' sign and value of an unknown vortex beam, especially large-value TCs.
对于两个斜入射涡旋光束之间的离轴干涉，会形成叉形条纹。建立了考虑各种参数（如两个涡旋光束之间的夹角及其拓扑电荷）的新公式来描述各种叉形条纹。采用改进的马赫-曾德尔干涉仪来研究这些干涉条纹。实验测量结果与使用我们的公式进行的数值模拟结果一致。我们的结果拓宽了对两个涡旋光束离轴干涉的理解，并且可应用于检测未知涡旋光束的拓扑电荷的符号和值，特别是大值拓扑电荷。
