Share Email Print

Proceedings Paper

Application Of Laser Speckles To Nondestructive Evaluation
Author(s): F. P. Chiang
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

When an optically rough surface is illuminated by a coherent laser beam, speckles are created due to multiple interference of the reflected (or transmitted) wavelets. They fill a volume in front of the illuminated surface. By suitably choosing a "plane" of speckles to photograph before and after they are displaced by the surface deformation via double exposure or time-average, the resulting speckle interferogram can yield a variety of information for engineering measurement. Speckles can also be created in the interior of a body by scattered light if it is made of transparent material and a laser beam is sent through it. In this way one can also probe the stress distribution inside a general three dimensional object. In this presentation two types of applications of the basic principle of one-beam laser speckle interferometry will be discussed: one is in the realm of nondestructive quantitative evaluation such as stress analysis of plane problems of elasticity, flexure of plates, vibration, and general three-dimensional problems; and the other is qualitative evaluation such as detection of crack in structure and debonding of laminated composites.

Paper Details

Date Published: 20 October 1977
PDF: 10 pages
Proc. SPIE 0122, Advances in Laser Engineering I, (20 October 1977); doi: 10.1117/12.955774
Show Author Affiliations
F. P. Chiang, State University of New York (United States)

Published in SPIE Proceedings Vol. 0122:
Advances in Laser Engineering I
Malcolm L. Stitch; Eric J. Woodbury, Editor(s)

© SPIE. Terms of Use
Back to Top