Method for Increasing the Accuracy of Wavefront Reconstruction from a Set of Interferograms
A new approach to the wavefront (phase) reconstruction from interferograms is proposed based on the classical method of fringe tracing using a sample of interferograms with different numbers and orientations of interference fringes. Wavefronts reconstructed from individual interferograms are averaged, and the test surface quality is judged by the data obtained. Averaging the phase by several interferograms makes it possible to reduce the variance of the phase reconstruction error caused by random noise and inhomogeneities in aperture illumination and interference fringe distribution, as well as to reduce the effect of instability of external conditions.