Distinguishing orbital angular momenta and topological charge in optical vortex beams

摘要

In this work we discuss how the classical orbital angular momentum (OAM) andtopological charge (TC) of optical beams with arbitrary spatial phase profilesare related to the local winding density. An analysis for optical vortices (OV)with non-cylindrical symmetry is presented and it is experimentally shown forthe first time that OAM and TC may have different values. The new approach alsoprovides a systematic way to determine the uncertainties in measurements of TCand OAM of arbitrary OV.