ACOUSTIC AND FLEXURAL EXCITATION OF A FLOATING STRUCTURE BY A SINGLE LASER-PULSE

The acoustic and flexural vibrations of a small-scale floating structu re following irradiation by a pulsed Nd:glass laser are compared with a radiated underwater sound field. A single subablative laser pulse of 600-mu s duration was used both to bend and shock the floating struct ure at the irradiation site. The laser pulse caused the structure to f lex at at a frequency of approximately 1 kHz whereas relaxation oscill ations in the laser output simultaneously excited ultrasonic Lamb wave s within the material bulk. We present results to illustrate the broad bandwidth provided by this unusual form of excitation. (C) 1996 Optic al Society of America.