A STUDY OF OPTOACOUSTIC SIGNAL AMPLITUDE IN WEAKLY ABSORBING FLUIDS

The optoacoustic effect has been experimentally studied. These results have been compared to existing theoretical predictions based upon linear thermal expansion. The dependence of optoacoustic amplitude on the coefficient of thermal expansion, propagation distance, and laser pulse energy was measured. The experimental observations were found to be in agreement with theory. The signal amplitude was also measured as a function of optical absorption coefficient. It was found that the observed signal agreed with theory so long as the absorption coefficient was small. The absolute magnitude of the optoacoustic signal was also measured and compared to theory. PACS numbers: 43.35.Ud. © 1990, Acoustical Society of America. All rights reserved.