Generation and propagation of coherent phonon beams
D. J. Dieleman, E. P. N. Damen, A. F. M. Arts, and H. W. de Wijn
Faculty of Physics and Astronomy, and Debye Research Institute, Utrecht
University, P.O. Box 80.000, 3508 TA Utrecht, The Netherlands
Narrow coherent beams of longitudinal acoustic waves are injected into a
single crystal of PbMoO4 at gigahertz frequencies, and observed
by means of Brillouin scattering. The waves are generated via the
thermoelastic strain that results from periodic thermomodulation of a thin
metallic transducer by interfering cw dye lasers.