A Real-Time Automated System for Dual-Aperture Common-Path Interferometer Phase-Shifting

• Main Authors: Antonio Barcelata-Pinzón, Ricardo Iván Álvarez-Tamayo, Patricia Prieto-Cortés
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Applied Sciences
• Subjects: generalized phase shifting interferometry; dual-aperture common-path interferometer; real-time optical instrumentation; optomechatronic systems
• Online Access: https://www.mdpi.com/2076-3417/11/16/7438

We report a novel fully real-time automatized optomechatronic dual-aperture common-path interferometer system for obtaining the phase difference between two interferograms by using the technique of phase-shifting interferometry. A motorized system is used to shift an additional phase transversally to the optical axis by ruling translation. For each high-resolution ruling displacement step of 0.793 μm, an interferogram is recorded by a CCD camera. The phase difference between the two successive recorded interferograms is then automatically calculated by computational self-calibrated algorithms. The proposed device provides more accurate measuring than typically used manual processes. Real-time phase differences are obtained from a robust low-cost optomechatronic system. Analytical calculation of the phase is performed automatically without the requirement of additional or external tools and processes, reducing the significant rework delay. A set of 47 interferograms were captured in real time then recorded and analyzed, obtaining an average phase shifting of 2.483 rad. Analytic explanation and experimental results are presented.