Raman Scattering by Coupled LO Phonon-Plasmon Mode in <i>n</i>-GaAs

Abstract

Recent experimental results of Raman spectra in gallium a arsenide are analyzed on the basis of a non-local theory of the coupling between plasmons and longitudinal optical (LO) phonons. A formula is derived which gives the efficiency for the Raman scattering by a coupled LO phonon-plasmon (LO-PL) mode in an absorptive medium. The finiteness of the wave number of the scattering mode and the attenuation of light in the medium are explicitlv taken into account. An analysis of the GaAs Raman spectra obtained recently Murase et at . shows that the theory reproduces the experimental results fairly well. It also explains the characteristic features of the spectra. The integrated efficiency from the LO-PL mode in GaAs is estimated to be of the order of 10 -11 .