Topological charge of two parallel Laguerre-Gaussian beams

Abstract

We analytically, numerically, and experimentally determine a topological charge (TC) of the sum of two axisymmetric off-axis Laguerre-Gaussian (LG) beams with the indices (0, m ) and (0, n ). In particular, we find that at m = n , the combined beam has TC = n , which suggests that the sum of two identical off-axis LG beams has the TC of an individual constituent LG beam. At m