Resonant Raman Scattering in a Semiconductor Superlattice

We report the observation of enhancement in the Raman cross section for photon energies near electronic resonance in $\mathrm{GaAs}{\mathrm{Ga}}_{1-x}{\mathrm{Al}}_x\mathrm{As}$ superlattices of a variety of configurations. Both the energy positions and the general shape of the resonant curves agree with those derived theoretically based on the two-dimensionality of the quantum states in such superlattices. Polarization studies indicate a major contribution to the scattering from forbidden processes.