Study on non-phase-shifting phase retrieval methods for interferogram with large phase gradient

As a non-contact, high-precision optical component testing method, interferometry performs the measurement by solving the interferogram containing the phase information of the object to be measured. The non-mechanical-phase-shifting phase retrieval method based on single or two interferograms has the advantages of good vibration resistance, fast speed and simple system, which can meet the increasingly urgent online and on-site detection requirements. Aiming at the large gradient phase detection requirements in processing, this paper compares the accuracy of typical non-mechanical-phaseshifting interferometric phase retrieval methods, including carrier Fourier method, digital moiré interferometry (DMI), and two DMI-based methods, namely two-step carrier stitching method and DMI combined with Newton iterative algorithm proposed by the authors. In this paper, the influences of the magnitude of the phase gradient and the noise of the interferogram on the phase retrieval accuracy of the above methods are analyzed. The simulation results in this paper will provide a theoretical basis for the selection of algorithms for in situ interferometry.