Location

La Jolla ,CA

Start Date

1-1-1989 12:00 AM

Description

A sensor for detecting low-amplitude acoustic displacements is described. This instrument is based on a stabilized helium-neon laser and is capable of measuring submicron displacements of diffuse surfaces at distances of up to 10 m and with a bandwidth between 0.2 and 100 kHz. The potential for extension of the technique to higher frequencies is discussed. The sensor uses the inherent sensitivity of an alternate-mode balanced, frequency-stabilized laser to small amounts of retroreflected light. Applications of the sensor include a study of bonding flaws in complex multilayer materials, such as the thermal protection tiles on the Space Shuttle Orbiter and in graphite epoxy laminar composites.

Book Title

Review of Progress in Quantitative Nondestructive Evaluation

Volume

8A

Chapter

Chapter 2: Advanced Techniques

Section

Laser Ultrasonics

Pages

543-549

DOI

10.1007/978-1-4613-0817-1_68

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Laser Detection of Acoustic Displacements by Destabilizing a Frequency Stabilized Helium Neon Laser

La Jolla ,CA

A sensor for detecting low-amplitude acoustic displacements is described. This instrument is based on a stabilized helium-neon laser and is capable of measuring submicron displacements of diffuse surfaces at distances of up to 10 m and with a bandwidth between 0.2 and 100 kHz. The potential for extension of the technique to higher frequencies is discussed. The sensor uses the inherent sensitivity of an alternate-mode balanced, frequency-stabilized laser to small amounts of retroreflected light. Applications of the sensor include a study of bonding flaws in complex multilayer materials, such as the thermal protection tiles on the Space Shuttle Orbiter and in graphite epoxy laminar composites.