Liquid-crystal phase-shifting lateral shearing interferometer with improved fringe contrast for 3D surface profilometry
IR@NPL: CSIR-National Physical Laboratory, New Delhi
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| Title |
Liquid-crystal phase-shifting lateral shearing interferometer with improved fringe contrast for 3D surface profilometry
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| Creator |
Mehta, Dalip Singh
Inam, Mohammad Prakash, Jai Biradar, A. M. |
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| Subject |
Optics
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| Description |
We report the development of a common-path and nonmechanical scanning phase-shifting lateral shearing interferometer based on a homogeneous gap and wedge-shaped gap liquid-crystal (LC) cell. The modified cell consists of semi-reflecting and fully reflecting glass plates with LC material sandwiched between them so that the amount of reflected light from both the surfaces is nearly equal, thus generating high contrast interference fringes. The thickness of the LC cell was maintained at similar to 3 mu m uniformly for a homogeneous gap and a varying wedge gap was also introduced between two glass plates. Phase-shifting linear fringe patterns of high contrast were generated. The phase-shifted interferograms were projected onto an object and the distorted interferograms were recorded by a CCD camera. The phase-shifting fringe analysis technique was used to reconstruct the 3D shape of the object. The present system is compact and low cost.
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| Publisher |
Optical Society of America
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| Date |
2013-09-01
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://npl.csircentral.net/3145/1/Liquid-crystal%20phase-shifting.pdf
Mehta, Dalip Singh and Inam, Mohammad and Prakash, Jai and Biradar, A. M. (2013) Liquid-crystal phase-shifting lateral shearing interferometer with improved fringe contrast for 3D surface profilometry. Applied Optics, 52 (25). pp. 6119-6125. ISSN 1559-128X |
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| Relation |
http://npl.csircentral.net/3145/
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