Photoacoustic spectroscopy is a useful noninvasive technique for monitoring chemical composition in liquid. The resolution capability of photoacoustic methods is limited due to the low absorbance factor of some liquid. To increase effective absorbance distance of laser beams, two novel photoacoustic cell structures are introduced, in which multi-beam photoacoustic sources are produced respectively by zigzag reflection and inner-circle reflection of a single incident laser beam. Approximate surface acoustic waves can be produced in the two cell structures. The mathematical models are also labored, which can provide preliminary simulation results. Using which, A conclusion can be drawn that the acoustic pressure produced by the zigzag reflecting multi-beam acoustic source can reach at about 500 times than that produced by single-beam source with same incident laser power. A rough estimate can also be made that with a large number of reflecting, the acoustic pressure produced by the inner-circle reflecting multi-beam source can easily reach 50 times than that produced by single-beam source with same incident laser power.

Date Published: 24 January 2008
PDF: 8 pages
Proc. SPIE 6829, Advanced Materials and Devices for Sensing and Imaging III, 68291X (24 January 2008); doi: 10.1117/12.757794

Published in SPIE Proceedings Vol. 6829:
Advanced Materials and Devices for Sensing and Imaging III
Anbo Wang; Yimo Zhang; Yukihiro Ishii, Editor(s)