Scattering of light from solids with incident frequency above the band gap is shown to occur as a cascade process in which the electron (hole) makes successive transitions between real states with a small probability of radiative recombination at each step. This gives rise to multiple LO-phonon Stokes-shifted lines in agreement with experimental results.

• Received 10 March 1971

DOI:https://doi.org/10.1103/PhysRevLett.26.1241