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Proceedings Paper

Phase measurement algorithm without phase-unwrapping problem for phase-stepping interferometry
Author(s): Chunlong Wei; Mingyi Chen; Weidong Hou; Zhijiang Wang
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Paper Abstract

A new phase measurement algorithm without phase-unwrapping problem is presented. It is mainly applied in the interferograms of few and straight fringes with noise and corrupted regions. Existing phase-unwrapping algorithms for those interferograms are trivial and time-consuming. The new algorithm first searches N 'seeding pixels' in the interferograms according to the good modulation. The interferograms are then segmented into N parts by the 'seeding pixels'. The adjacent 'seeding pixels' phase difference is limited in the range. Because the phase measurement is relative, assuming one of the 'seeding pixels' phase is constant, other 'seeding pixels' phases can be easily obtained by the phase-stepping algorithm. Moreover, other pixels phases in the interferograms can be solved by the simple operation with the 'seeding pixels' phases by the phase-stepping algorithm. The procedure of calculating phase is straightforward. The operation of plus or minus 2(pi) is unnecessary. So the phase unwrapping problem is avoided. A smooth flat mirror is measured in a Linik interference microscope. The interferograms are corrupted with many dirty spots or regions. The experimental result confirm that our new algorithm is fast and robust.

Paper Details

Date Published: 30 June 1998
PDF: 6 pages
Proc. SPIE 3478, Laser Interferometry IX: Techniques and Analysis, (30 June 1998); doi: 10.1117/12.312962
Show Author Affiliations
Chunlong Wei, Shanghai Univ. (China)
Mingyi Chen, Shanghai Univ. (China)
Weidong Hou, Shanghai Univ. (China)
Zhijiang Wang, Shanghai Institute of Optics and Fine Mechanics (China)


Published in SPIE Proceedings Vol. 3478:
Laser Interferometry IX: Techniques and Analysis
Malgorzata Kujawinska; Gordon M. Brown; Mitsuo Takeda, Editor(s)

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