PHOTOACOUSTIC GENERATION IN LIQUIDS WITH LOW OPTICAL-ABSORPTION

Short laser pulses (250 ns) from a 1064 nm Nd:YAG laser have been used to generate acoustic waves in distilled water and methanol. The mechanism of this process has been studied both experimentally and theoretically with good overall agreement. The measurement of the acoustic signal utilized a small wideband (0.1-20 MHz) piezoelectric hydrophone. The advantages of this detector in the measurement of photoacoustically induced ultrasonic waves in liquids with low optical absorption are discussed.