Single-Shot Imaging of Two-Wavelength Spatial Phase-Shifting Interferometry

• Published in: Sensors (Basel, Switzerland) Vol. 19; no. 23; p. 5094
• Main Authors: Jeon, Jun Woo, Joo, Ki-Nam
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 21.11.2019; MDPI
• Subjects: Color; Interference fringes; Interferometry; Light; Measurement techniques; one shot imaging; polarization pixelated camera; spatial phase shifting; Three dimensional imaging; two-wavelength interferometry; Visibility; two-wavelength interferometry; spatial phase shifting; polarization pixelated camera; one shot imaging
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s19235094

In this investigation, we propose an effective method to measure 3D surface profiles of specimens with single-shot imaging. Based on the two-wavelength interferometric principle and spatial phase-shifting technique using a polarization pixelated camera, the proposed system can not only rapidly measure the phase, but also overcome the 2π-ambiguity problem of typical phase-shifting interferometry. The rough surface profile can be calculated by the visibility of the interference fringe and can compensate for the height discontinuity by phase jumps occurring in a fine height map. An inclined plane mirror and a step height specimen with 9 μm were used for the validation of capability of measuring continuously smooth surface and large step heights. The measurement results were in good agreement with the results of typical two-wavelength interferometry.