Abstract

Surface phonons play a crucial role in the dynamics of surface chemical reactions because they mediate the flow of vibrational energy between the bulk and surface adsorbates. We have used ultrashort laser pulses to excite and detect coherent surface phonon waves on GaAs surfaces. This macroscopically large coherent excitation is significant because it not only allows us a new surface spectroscopic tool for measuring the phonon frequency and dephasing time (equivalent to linewidth) but also gives us the potential of exciting a single surface phonon and observing which degrees of freedom “receive” the energy.

© 1996 Optical Society of America