Location

La Jolla, CA

Start Date

1-1-1998 12:00 AM

Description

Shearography, introduced in 1973 by both Hung & Taylor [1] and Leendertz & Butters [2], was developed from speckle pattern interferometry. Both methods are full- field optical techniques which generate interference patterns by combining a reference beam with the reflected light from a diffusive surface. However, a significant difference exists between the manner in which these two methods form their resulting interferograms. Shearography is a common path intereferometer; the reference beam is derived from the same beam as that used to probe the object. This distinction has a number of advantages including tolerance to rigid body motions, reduced laser coherence requirements, compact design, convenient sensitivity adjustment, and direct measurement of differential displacement. The advent of modern video cameras has allowed designers to build upon these intrinsic advantages producing a portable low-cost sensor. In this configuration, (electronic) shearography has gained acceptance as a nondestructive inspection technique [3–5], which is commonly used on aerospace structures and materials [6–10].

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

17B

Chapter

Chapter 7: New Inspection/Control Procedures

Section

New Techniques

Pages

1729-1736

DOI

10.1007/978-1-4615-5339-7_224

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Wide-Area Imaging of Ultrasonic Fields by Digital Phase-Stepping Shearography

La Jolla, CA

Shearography, introduced in 1973 by both Hung & Taylor [1] and Leendertz & Butters [2], was developed from speckle pattern interferometry. Both methods are full- field optical techniques which generate interference patterns by combining a reference beam with the reflected light from a diffusive surface. However, a significant difference exists between the manner in which these two methods form their resulting interferograms. Shearography is a common path intereferometer; the reference beam is derived from the same beam as that used to probe the object. This distinction has a number of advantages including tolerance to rigid body motions, reduced laser coherence requirements, compact design, convenient sensitivity adjustment, and direct measurement of differential displacement. The advent of modern video cameras has allowed designers to build upon these intrinsic advantages producing a portable low-cost sensor. In this configuration, (electronic) shearography has gained acceptance as a nondestructive inspection technique [3–5], which is commonly used on aerospace structures and materials [6–10].