Photo-carrier dynamics in UV-visible pumped GaAs studied by time-resolved THz spectroscopy

We present a UV-visible pump/THz-probe study to determine the photo-carrier lifetime in GaAs. Three samples (<100>, <110> and <111> oriented) were pumped from 1.56 eV to 4.15 eV. For the three orientations we observed a strong unexpected peak of the carrier lifetime around 2.6 eV.