Theory of Raman scattering on polar phonons

Raman scattering (RS) on dipole‐active phonons in crystals of all kinds of symmetry is investigated for the case of arbitrary direction of a vibrational wave vector. The explicit form of RS tensor associated with electrooptic scattering mechanism is obtained. A comparison is made with the tensor obtained within the framework of polarizability theory. The electrooptic mechanism is shown to contribute to the scattering intensity on transverse phonons which is caused by local fields generated by dipole vibrations. The violation of selection rules due to the dipole vibration macroscopic field is investigated. It is shown how electrooptic mechanism contribution to scattering intensity can be separated in the explicit form in all anisotropic crystals. [Russian Text Ignored].