Inelastic light scattering in the presence of uniaxial stresses

When a crystal is subject to a uniaxial stress, the Raman spectrum of various phonons may exhibit changes in the scattering intensity and also shifts of the frequencies and splittings of the degeneracies of the optical phonons. Valuable information can be obtained from such studies regarding the electronic band structure, the scattering mechanism, and the elastic and lattice‐dynamical properties of the material. The basic theoretical and experimental facts related to such effects are briefly reviewed in this contribution. Other possibilities are also discussed which demonstrate the usefulness of a uniaxial stress as a controlled perturbation in the study of crystalline matter by use of light scattering techniques.