Development of a Wollaston phase grating polarized interferometer for simultaneous generation of interferograms

• Published in: Optics and lasers in engineering 2025-03, Vol.186, p.108739, Article 108739
• Main Authors: Reyes, A.K., Rodríguez-Zurita, Gustavo, Montes-Pérez, A., Sánchez-Aguilar, J.R., García-Lechuga, L., Toto-Arellano, Noel-Ivan
• Format: Article
• Language: English
• Subjects: Dynamic measurement, Interferometry; Optical Metrology; phase-shifting technique; Polarization
• ISSN: 0143-8166
• DOI: 10.1016/j.optlaseng.2024.108739

•Implemented a 4f imaging system with a 2D phase grating at the Fourier plane to generate n-polarized interferograms.•Achieved the simultaneous generation of multiple interferograms, with up to 16 interference patterns observed in a single frame.•Demonstrated the system's stability and repeatability, with minimal discrepancies in mean phase values and smooth data distributions.•Validated the feasibility and utility of the interferometric technique for efficient and cost-effective optical phase imaging of dynamic phenomena.•Demonstrated the system's capability to analyze both static and dynamic phase objects, showcasing its versatility. Wollaston phase-grating interferometer is introduced to measure of the optical phase across various samples. The system employs a Wollaston prism to create two angularly separated beams and with orthogonal linear polarizations. Working as a quasi-common-path interferometer, one of these beams serves as a reference while the other acts as the sample. Circular polarization states are induced in each beam using a quarter-wave plate. Both beams are directed onto a 4-f imaging system, within which a 2D phase grating is positioned at the Fourier plane. This 2D grating enables the superposition of the two beams, generating a polarized interferogram. The characteristics of the diffractive elements cause the grating to produce replicas of interference patterns, which are centered around the diffraction orders of the 2D phase grating itself. Due to the presence of interference patterns with inherent π phase shifts, this configuration reduces the number of polarizers needed to implement phase shifting methods. It is shown that by using two polarizers it is possible to generate four phase shifts. A polarizer oriented at 0° covers two of the replicas and another polarizer oriented at π/4 covers the remaining interferograms. This configuration introduces phase shifts of ξ1 = 0, ξ2 = π/2, ξ3 = π and ξ4 = 3π/2. Results obtained for static and dynamic samples are presented, as well as the corresponding statistics on the repeatability of the configuration.