Transmission of coherent phonons through a metallic multilayer
D. J. Dieleman, A. F. M. Arts, and H. W. de Wijn
Faculty of Physics and Astronomy, and Debye Institute, Utrecht
University, P.O. Box 80.000, 3508 TA Utrecht, The Netherlands
The transmission of a coherent beam of longitudinal acoustic phonons
through a twelve-layer Ag-Au superlattice is measured at gigahertz
frequencies. The acoustic wave is generated by laser-induced
thermomodulation, and detected with Brillouin scattering in the The
transmission of a coherent beam of longitudinal acoustic phonons through a
twelve-layer Ag-Au superlattice is measured at gigahertz frequencies. The
acoustic wave is generated by laser-induced thermomodulation, and detected
with Brillouin scattering in the PbMoO4 single-crystalline
substrate after passage through the superlattice. The transmission is
found to drop to order one percent in well defined stop bands.
Calculations based on wave equations reproduce the stop bands as well as
the transmission at intermediate frequencies.