Influence of a laser beam's frequency stability on dislocation of vortex points in an optical vortex interferometer

New applications for optical vortex interferometers (OVIs) are under investigation. The precision of the OVI depends strongly on the accuracy of positioning of the vortex points, which requires more than one interferogram (fringe pattern), so the influence of the laser beam's frequency stability is important. We present an analysis of the influence of the laser beam's frequency stabilization on the accuracy of methods locating vortex points relative to dimensions in optical arrangements of OVIs.