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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Abstract

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.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Optical Society of America.
Subjects:	Optics
Divisions:	UNSPECIFIED
Depositing User:	Users 27 not found.
Date Deposited:	27 Jul 2020 11:54
Last Modified:	27 Jul 2020 11:54
URI:	http://npl.csircentral.net/id/eprint/3145

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