Noncontact continuous wavefront diffractive acoustic elements for Rayleighwave control

A laser is used to excite Rayleigh waves on a sample. The optical distribut ion of the laser energy as it strikes the sample is controlled using a comp uter generated hologram-this optical distribution determines the initial ac oustic wavefront and hence the acoustic amplitude distribution. In this let ter, we present two designs of acoustic elements which use diffraction of t he Rayleigh waves as a means of controlling the acoustic amplitude distribu tion. (c) 1999 American Institute of Physics. [S0003-6951(99)02824-7].