Intensities of resonant brillouin scatterings from multicomponent exciton-polaritons

To reduce the arbitrariness in the current analysis of resonant Brillouin scattering (RBS) from multicomponent polaritons, the intensities of scattering peaks are theoretically studied. The interaction among the multicomponent excitons may contain linear and quadratic terms in translational wave vector, electron-hole exchange interaction, and any other terms that retain translational symmetry. As the scattering mechanisms due to TA and LA phonons, we consider various deformation and piezoelectric potentials. In certain cases, this theory leads to a “selection rule”, which can solve the controversy between the two different dispersion curves for CuBr obtained from RBS and two photon resonant Raman scattering, in favor of the latter. The theory also provides a basis to discuss the problem of additional boundary conditions for multicomponent polaritons in terms of the relative intensities of scattering peaks.