Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group

Generating real-time curvature contours with shearing interferometry and Talbot effect

Open Access Open Access


In the small deflection theory of thin plates, the bending stress is directly proportional to the curvature of the deflected plate surface. Most optical methods, such as holographic interferometry and shadow moire, give deflection contours which have to be differentiated twice to yield curvature values. Since numerical differentiation is intrinsically error prone, it is important that it be avoided whenever possible. In this paper we present a technique whereby real-time curvature fringes of a mirrored specimen surface can be obtained with a simple Ronchi grating through the use of shearing interferometry and the Talbot effect. It is done by illuminating the deflected specimen surface with a coherent beam through the grating and observing the resulting wave at a certain distance away. If the distance between the specimen surface and the observation plane is one of the Talbot distances and the resulting wave is the sum of only zeroth-order and two first-order diffraction waves, a high quality fringe pattern representing curvature contours is obtained. A sensitivity of 2 × 10−6/mm/ fringe has been achieved. Both theoretical analysis and experimental demonstration are presented.

© 1985 Optical Society of America

PDF Article
More Like This
Application of the Talbot effect to moire methods

Fu-Pen Chiang, X. Yu, B. H. Dong, and D. Z. Yun
TUF7 OSA Annual Meeting (FIO) 1985

Real-time measurement of large surface deformation using a holographic shearing interferometer

Kiyofumi Matsuda, Tomoaki Aiju, and Shinya Watanabe
TUS3 OSA Annual Meeting (FIO) 1985

Curvature Measurement based on Talbot Effect and Image Moiré Interferometry

Yen-Chang Chu, Jing-Heng Chen, and Kun-Huang Chen
DTh3A.7 Digital Holography and Three-Dimensional Imaging (DH) 2015

Select as filters

Select Topics Cancel
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.