Formation of ordered defect structures in lithium niobate crystals of different chemical composition at non-equilibrium processes of different nature

Abstract Ordered defective structures in lithium niobate crystals have been established. The phenomenon is a result of non-equilibrium processes of a different nature: photo-induced light scattering, laser ablation, and creation of cracks during relieving mechanical stresses. The shape of such structures depends on the nature and energy that affect a crystal. A number of concentric areas with a different density of laser-induced defects with a changed refractive index appear during photoinduced light scattering. Concentric clusters of microdomains appear in a macrodomain of another sign at laser ablation as a result of local switching under impulse laser radiation. A number of microcracks with a fractal structure appear near main macro-crack during cracking under mechanical stress. Thus, appearance of ordered defective structure occurs not only in the local spot of direct exposure to laser radiation, mechanical stress, etc., but also in some volume of a crystal around it.