Wave front sensing of an optical vortex

The sensing of phase front of the vortex laser beam has been carried out with the help of a Hartmann-Shack sensor. The vortex beam is generated in the form of a Laguerre-Gaussian beam ( LG 0 1 mode) with the help of the special helicoidal phase plates manufactured by the kinoform technology. The measured shifts of focal spots on the hartmannogram are compared with the calculated shifts. From the measured wave front tilts the reconstruction of singular phase surface has been performed.