Photon–Phonon Interaction

Abstract

The interaction of photons with solids comprises ionic and electronic oscillations; this chapter focuses on lattice vibrations. The dielectric polarization is related to the atomic polarizability. The dynamic response of the dielectric function on electromagnetic radiation can be described classically by elementary oscillators, yielding strong interaction of photons and TO phonons with a resulting large Reststrahl absorption in the IR range. The dispersion is described by a phonon-polariton, which is observed in inelastic scattering processes. Brillouin scattering at acoustic phonons and Raman scattering at optical phonons provide direct information about the spectrum and symmetry of vibrations in a semiconductor.