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Proceedings Paper

Measurement for thickness variation of a latex membrane by ESPI method
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Paper Abstract

A simple and unique ESPI based system for real-time monitoring and measuring of thickness variation of semi-transparent membrane with an 'optically rough surface' is described in this paper. When membrane or film is illuminated by a coherent beam, a speckle pattern is produced on its rough surface. Reflected beams from both the bottom and top surfaces of the membrane combine and form a speckle interferometric pattern, which can be captured by CCD camera. Subtraction of sequentially captured images result in correlation fringes corresponding to thickness variation of the specimen. The beams reflected from both bottom and top surfaces serve as 'reference' beam for each other mutually. All the beams coming from the tested object possess an auto-reference feature and this makes the system more stable and simple.

Paper Details

Date Published: 7 May 1999
PDF: 4 pages
Proc. SPIE 3740, Optical Engineering for Sensing and Nanotechnology (ICOSN '99), (7 May 1999); doi: 10.1117/12.347771
Show Author Affiliations
Anand Krishna Asundi, Nanyang Technological Univ. (Singapore)
Lijun Jiang, Nanyang Technological Univ. (Singapore)


Published in SPIE Proceedings Vol. 3740:
Optical Engineering for Sensing and Nanotechnology (ICOSN '99)
Ichirou Yamaguchi, Editor(s)

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