Parametric hybrid scattering from light-induced ferroelectric and photorefractive structures.

Processes of photo-induced light scattering are studied in single crystals of LiNbO(3):Fe to uncover the origin of a new part of the entire scattering pattern which can be observed on a viewing screen. The new scattering manifests itself as two arcs enclosing the directly transmitting pump beam. It is shown that this type of scattering is due to a parametric wave-mixing process of coherent optical noise and a pump beam on a combination of photorefractively recorded phase-gratings and photo-induced ferroelectric structures. Phase-matching conditions corresponding to the new scattering are introduced. All photo-induced scattering phenomena contributing to the total scattering pattern are discussed, compared and classified.