Acoustic phonon pulse generation and detection in GaAs/Al0.3Ga0.7As quantumwells

摘要

Acoustic phonon pulse generation and detection are investigated in a sample with three embedded GaAs/AlGaAs quantum wells by an ultrafast optical pump and probe technique at the temperatures 20 K and 300 K. Scanning the pump photon energies around the hh1-e1 resonances we find a strong variation of the transient reflectance and phase changes. These changes are compared with a numerical simulation based on probe light scattering due to the inhomogeneous photoelastic effect.