Complex amplitude extraction from a set of interferograms by simultaneous modulation of amplitude and phase steps

Abstract

The measurement of an optical field arises in various fields of science and engineering, including holography, crystallography, microscopy, and many others. Nowadays, there are several methods to estimate amplitude and phase including Shack–Hartman wavefront sensor, algorithms type Gerchberg–Saxton, algorithm-based on the transport of irradiance equation, holographic, interferometric, among others. This paper introduces an interferometric method for retrieving the complex amplitude from a set of interferograms modulated simultaneously in visibility and phase steps. Instead of phase only as the method of so-called phase-shifting interferometry. This approach is based on the modulation of amplitude and phase steps and is presented for the case of synchronous detection and coherence light. It is validated with a numerical noise study, turning out to be accurate and robust to detuning errors, with low distortion, and a very high signal-to-noise. The experiment is carried out on a Mach–Zehnder interferometer adapted to modulate the reference amplitude, and the phase steps by modulation of polarization, instead of phase steps only as in phase-shifting interferometry.