Laser-generated nonlinear Rayleigh waves with shocks

Intense laser radiation was used to generate a Rayleigh wave pulse of finit e amplitude in fused quartz, Measurements of the pulse at two locations alo ng the propagation path reveal the formation of well-defined shocks in the horizontal (in-plane) velocity waveform. As the pulse propagates, the diffe rent propagation speeds of the head and tail shocks lead to a considerable increase in the duration of the pulse. Theoretical predictions based on non linear spectral evolution equations are in close agreement with the observe d waveform distortion and shock formation. (C) 1999 Acoustical Society of A merica. [S0001-4966(99)03704-2].