We studied the changes of the pulse shape and the phase of the spectral components in converging-surface acoustic wave pulses. These pulses were excited with a femtosecond laser by a thermoelastic mechanism. To produce converging acoustic pulses, the laser beam was focused with an axicon in a circle on the surface of an aluminum sample. During propagation through the focus, the shape of the pulses of the normal surface velocity changed from two to three polar. The absolute value of the phase of the spectral components experienced a change close to rad (Gouy phase shift) after passage of the focal region. These observations were confirmed by analytical and numerical calculations based on the two-dimensional wave equation for surface acoustic waves.
© 2005 Optical Society of AmericaFull Article | PDF Article
More Like This
T. Tritschler, K. D. Hof, M. W. Klein, and M. Wegener
Opt. Lett. 30(7) 753-755 (2005)
Opt. Lett. 37(5) 924-926 (2012)
Miguel A. Porras, Carlos J. Zapata-Rodríguez, and Isabel Gonzalo
Opt. Lett. 32(22) 3287-3289 (2007)