Volume 19, Issue 4 (July 1991)
Physical Acoustics: Vol. 18
It has been known for the more than a beam of light striking a material generates vibrations and acoustic waves in it. The common focus of this book is a review of the physics, measurement techniques and applications of recent developments of this phenomenon. Today, pulsed or modulated beams of lights or other radiations incident on a specimen are used to excite thermal or acoustic waves in the materials. In photothermal measurements the signals are detected by a sensor at the surface of the material, while in photoacoustic measurements the signals are detected by a sensitive microphone in the gas surrounding a specimen. The analysis of such thermally generated signals can be used to investigate the nature of the source, the material in the region of the source, or the material between the source and detector.