Based on the non-coaxial interference of Bessel–Gaussian (BG) beams, a new complex-structured light field is formed. By varying the off-axis distance, phase difference, separation angle, and topological charges (TCs) of the component beams, we observed the splitting, generation, and annihilation of phase singularities. The net TCs of the composite light field is not always equal the sum of the TCs of the original beams. Different from the general single-ringed vortex beams, because BG beams have infinitely many rings, alternately positive and negative unit vortex chains arise in the interference region. Furthermore, the edge dislocations are unstable, by modulating the phase difference and separation angle, we observe controllable transitions between edge dislocations and vortex singularities. Beyond providing an effective method for studying composite vortex beam interference, our results are significant for laser calibration and complex particle manipulation.

基于贝塞尔-高斯 (BG) 光束的非同轴干涉，形成了新的复杂结构光场。通过改变分量光束的离轴距离、相位差、分离角和拓扑电荷 (TC)，我们观察到了相位奇点的分裂、产生和湮灭。复合光场的净 TC 并不总是等于原始光束的 TC 之和。与一般的单环涡旋光束不同，由于BG光束有无限多个环，在干涉区产生交替的正负单位涡链。此外，边缘位错是不稳定的，通过调制相位差和分离角，我们观察到边缘位错和涡旋奇异点之间的可控转变。