Phonon avalanches in an acoustic cavity
L. G. Tilstra, 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
Avalanches of resonant acoustic phonons are observed following localized
population inversion of the Zeeman-split E(2E)
doublet in dilute ruby by selective optical pumping. The avalanches are
observed to engage in repeated passage through the active zone, with the
crystal acting as acoustic cavity.