[OPTICAL REVIEW Vol. 19, No. 6 (2012) 366-370]
© 2012 The Japan Society of Applied Physics

Parallel Phase-Shifting Dual-Illumination Phase Unwrapping

Tatsuki TAHARA1,2, Akifumi MAEDA3, Yasuhiro AWATSUJI1*, Kenzo NISHIO4, Shogo URA1, Toshihiro KUBOTA5, and Osamu MATOBA6

1Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
2Research Fellow of the Japan Society for the Promotion of Science, Chiyoda, Tokyo 102-7472, Japan
3School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
4Advanced Technology Center, Kyoto Institute of Technology, Kyoto 606-8585, Japan
5Kubota Holography Laboratory Corporation, Uji, Kyoto 611-0042, Japan
6Graduate School of System Informatics, Kobe University, Kobe 657-8501, Japan

(Received June 22, 2012; Accepted September 12, 2012)

We propose a single-shot phase unwrapping technique using a single wavelength and parallel phase-shifting interferometry. In the proposed technique, an object is illuminated by two laser beams, which are emitted from the same laser, and have different illumination angles and polarizations. Two types of object waves generated by the two beams are separately and simultaneously recorded by a polarization-imaging camera. In the path of the reference wave, an array of phase retarders is placed to implement the parallel phase-shifting technique. A highly accurate three-dimensional shape is reconstructed from a single hologram. We numerically simulated the proposed technique and conducted a preliminary experiment to verify its effectiveness. It was confirmed that millimeter-order height, which was several thousand times the wavelength of the laser, can be reconstructed by the proposed technique without wrapping.

Key words: phase unwrapping, digital holography, three-dimensional imaging, phase-shifting interferometry, holography

*E-mail address: awatsuji@kit.ac.jp