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. Computer simulations demonstrate that this technique is more convenient in the recording process and can improve the precision of the reconstructed wavefront by more than one order of magnitude after considering the real reference amplitude. Optical experiment results show the feasibility and effectiveness of this method.