Brillouin scattering of exciton polaritons and additional boundary conditions

The importance of exciton damping, γ, on the Brillouin scattering efficiencies is pointed out. Brillouin scattering efficiencies have been calculated as a function of γ using two different additional boundary conditions (ABC). For γ larger than some value γC, as assumed in an earlier calculation of Brenig, Zeyher and Birman, the dependence of the scattering efficiencies on incident photon energy is rather insensitive to the ABC used. However, for γ small compared with γC the scattering efficiencies calculated with different ABC's show qualitative differences. © 1979.