Application Of Laser Speckles To Nondestructive Evaluation

F. P. Chiang

doi:10.1117/12.955774

20 October 1977 Application Of Laser Speckles To Nondestructive Evaluation

F. P. Chiang

Proceedings Volume 0122, Advances in Laser Engineering I; (1977) https://doi.org/10.1117/12.955774
Event: 21st Annual Technical Symposium, 1977, San Diego, United States

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.

Citation Download Citation

F. P. Chiang "Application Of Laser Speckles To Nondestructive Evaluation", Proc. SPIE 0122, Advances in Laser Engineering I, (20 October 1977); https://doi.org/10.1117/12.955774

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available