Phase stitching and error correction in aperture synthesis for generalized phase-shifting interferometry.

An accurate aperture synthesis method in generalized phase-shifting interferometry is suggested to improve the quality of the reconstructed object wavefront by stitching both the phase and the real amplitude of the object wave on the recording plane. Since the phase distribution affects the reconstruction of the original object wavefront, phase stitching is also important in aperture synthesis. Double correlations are used to find the proper relative locations and correct the phase error of subwavefronts on the recording plane.

High-precision phase-shifting interferometry with spherical wavefront reference.

An advanced phase-shifting interferometry approach with a spherical wavefront reference is proposed to improve the quality of the holographic image by avoiding errors caused by noncollimated reference and lowering the resolution of the recording device. By considering not only the real amplitude but also the phase distribution of a spherical wavefront reference, a singular object-wave reconstruction formula is deduced. The suggested method here can work without using the collimator in the reference wave and can then remove all the errors incurred by it.

Phase shift selection for two-step generalized phase-shifting interferometry.

A phase shift selection method is proposed to design algorithms immune against phase shift errors in two-step generalized phase-shifting interferometry. A general formula for wavefront reconstruction error is derived, and its specific expressions for two common errors are also given. Calculation results suggest that the proper range of phase shift for general application is about from 0.