Observation of optically excited near-zone-edge phonons in GaAs by diffuse x-ray scattering

Abstract
We report on the use of diffuse x-ray scattering as a probe of nonequilibrium phonon excitations generated optically in GaAs at T1.5 K. The measurements show a substantial athermal population of TA phonons near the [111] zone boundary consistent with a lifetime of microseconds.