Amplification of the surface elastic wave in a solid tracked by a laser beam

It has been predicted theoretically in an earlier study (Dykhne and Rysev, 1983) that surface elastic waves can be excited in a solid by a laser beam focused on the surface of the solid and scanned at a velocity equal to that of the surface waves. A study is reported here in which the above effect has been observed experimentally. When the velocities of the source and of the wave are at resonance, the amplitude increases linearly with time.