Phase-shifted interferometry without phase unwrapping: reconstruction of adecentered wave front

We apply the method of the line integration of the phase gradient to determ ine unambiguously the phase from several phase-shifted interferograms (inte nsity fringe patterns) without phase unwrapping. The ambiguities introduced owing to the multiple values of the arctangent function and to the necessi ty to invoke a priori knowledge in the regions of high-intensity gradients are avoided. A decentered wave bent with circular boundaries is reconstruct ed fr om high-fringe-density interferograms with an error of less than 0.1 percent, thus demonstrating the feasibility of testing the off-axis optical elements with approximate reference components. (C) 1999 Optical Society o f America [S0740-3232(99)02203-6].