A COMPARISON BETWEEN RESONANT RAMAN-SCATTERING IN TYPE-II GAAS ALAS SUPERLATTICES AND SINGLE GAAS QUANTUM-WELLS/

We present a comparison between resonant Raman scattering experiments on a type II GaAs/AlAs superlattice of short period and a single GaAs quantum well. Under resonant excitation, a continuous emission is obse rved in the low-frequency range of the two heterostructure Raman spect ra. This scattering is analyzed in terms of breakdown of the wavevecto r conservation law due to single quantum-well effects. In the optical regions, strong similarities are also observed. Doubly resonant Raman scattering processes of symmetric and antisymmetric interface modes ar e specified and discussed within disorder effects. Finally, lateral ex tents of in-plane microroughnesses detected by acoustic and interface phonons, are estimated.