Wavefront registration of an optical vortex generated with the help of spiral phase plates

The phase front measurements of a vortex laser beam have been carried out with the help of a Shack-Hartmann sensor. The vortex beam is generated in the form of a Laguerre-Gaussian beam ( LG 0 1 mode) with the help of the special spiral phase plates manufactured by the kinoform technology. The measured shifts of focal spots on the hartmanogram are compared with the calculated shifts.