Laser-induced bandgap collapse in GaAs.” In . Ultrafast Phenomena in Semiconductors. Publisher's VersionAbstract. 1994. “
We present recent time-resolved measurements of the linear dielectric constant of GaAs at 2.2 eV and 4.4 eV following femtosecond laser pulse excitation. In sharp contrast to predictions based on the widely-used Drude model, the data show an interband absorption peak coming into resonance first with the 4.4-eV probe photon energy and then with the 2.2-eV probe photon energy, indicating major changes in the band structure. The time scale for these changes ranges from within 100 fs to a few picoseconds, depending on the incident pump pulse fluence.