TIME-RESOLVED INTERFERENCE OF COHERENT POLARIZATION-WAVES IN SEMICONDUCTORS

We experimentally show that coherent transients can be investigated in any kind of material systems by means of simple interferometric techn ique with a time resolution limited only by the pulse duration. The me asurement, as a function of the time delay between two excitation puls es, of the time-integrated signal related either to the absorbed energ y or to the resonant elastic light scattering allows a straightforward determination of the coherence status of the system. Demonstrative ex periments in GaAs bulk samples and in GaAs/AlGaAs quantum well structu res are reported.