Polariton Theory of Resonance Raman Scattering in Insulating Crystals

摘要: A multibranch polariton theory of Raman scattering in insulators is presented; actual calculations the resonance cross section are carried out for an undamped two-branch model, various values photon-exciton coupling and background dielectric constant, including appropriate to CdS. One obtains a double peaking with incoming photon frequency, corresponding experimentally observed in- out-going resonances. Comparison bare- generalized-exciton computations shows that results three theories nearly same "smaller" couplings, as CdS, except immediate region higher-energy peak; increases from near those predictions begin differ more substantially. When exciton continuum included by perturbation theory, similar theories, frequencies below bare-exciton agreement experimental data on LO-phonon