Characterizing the topological charges distribution of the elliptical beams with vortex lattices

A new numerical approach is proposed to analyze the topological charges distribution of elliptical beams with vortex lattices generated from the astigmatic transformations of Hermite–Gaussian beams. The birth and death of the topological charges for elliptical beams are thoroughly verified by continuously changing the astigmatic strength. The theoretical explorations are exploited to make a complete comparison with experimental measurements which are obtained from an off-axis pumped solid-state laser with an external astigmatic mode converter and a Mach–Zehnder interferometer. The good agreement between the theoretical and experimental results provides the feasibility to flexibly manipulate the topological charges of vortex lattices in further applications.