Symmetric array of off-axis singular beams: spiral beams and their critical points

Yana Izdebskaya, Vladlen Shvedov, Alexander Volyar
2007 Optical Society of America. Journal A: Optics, Image Science, and Vision  
We consider conditions of structural stability under which the array of singular beams preserves its topological structure and intensity distribution while slightly perturbing its intrinsic parameters. The orbital angular momentum of the array as a function of the array parameters is a characteristic function, and its extreme points correspond to stable and unstable array states.
doi:10.1364/josaa.25.000171 pmid:18157224 fatcat:727gdkemafdgvgg6jey3qajaz4