Comparison of phase reconstruction algorithms when branch points are present

In general case it is appropriate to represent the phase gradient fields g(r) measured by wave front sensor as a sum of potential gp and .g = gp + gs. The phase is separable into two parts. One of them, the potential phase corresponds to the gradient component gp and is successfully reconstructed by the least squares technique. To reconstruct the other part, so called hidden phase or slope discrepancy component of the phase, the two approach can be used. One of them is associated with detection of branch points and consequent calculation of the hidden phase. The other is based on reconstruction of the hidden phase directly from the measured phase gradient. In the paper we compare both approach to the reconstruction of the phase of optical wave propagating in a turbulent atmosphere under conditions of strong scintillation. We study their effectiveness in dependence on strength of optical turbulence for two different type of adaptive systems.