Location

La Jolla, CA

Start Date

1-1-1993 12:00 PM

Description

In spite of its obvious advantages over conventional contact and immersion techniques, laser interferometry has not yet become a practical tool in ultrasonic nondestructive evaluation since its sensitivity is insufficient in most practical applications. Part of the problem is that the maximum signal-to-noise ratio often cited in scientific publications and manufacturers’ specifications cannot be maintained on ordinary diffusely reflecting surfaces. Although these surfaces reflect a fair amount (5–50%) of the incident laser light, this energy is randomly distributed among a large number of bright speckles. Unless the detector happens to see one of these bright speckles, the interferometer’s signal-to-noise ratio will be much lower than the optimum.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

12A

Chapter

Chapter 2: Emerging Inspection Technologies

Section

Laser-Based Ultrasonics

Pages

527-538

DOI

10.1007/978-1-4615-2848-7_67

Language

en

File Format

application/pdf

Share

COinS
 
Jan 1st, 12:00 PM

Improved laser interferometry for ultrasonic NDE

La Jolla, CA

In spite of its obvious advantages over conventional contact and immersion techniques, laser interferometry has not yet become a practical tool in ultrasonic nondestructive evaluation since its sensitivity is insufficient in most practical applications. Part of the problem is that the maximum signal-to-noise ratio often cited in scientific publications and manufacturers’ specifications cannot be maintained on ordinary diffusely reflecting surfaces. Although these surfaces reflect a fair amount (5–50%) of the incident laser light, this energy is randomly distributed among a large number of bright speckles. Unless the detector happens to see one of these bright speckles, the interferometer’s signal-to-noise ratio will be much lower than the optimum.