Subpicosecond spectroscopy of excitons in GaAs/AlGaAs heterostructures

We study the dynamics of excitons in GaAs/AlGaAs quantum wells using time-resolved self-diffracted four-wave-mixing. We discuss two topics: First, we show that the decay of the diffracted signal is different for parallel and perpendicular polarization of the incident laser pulses, and second, we study the dephasing dynamics of a wavepacket in a coupled quantum well structure.