Photoinduced domain origin in lithium niobate crystals

Light influence on LiNbO3:Fe crystals has been found to induce appearance of needle-like microdomains with average length of 1 - 2 mm and diameter of 1 micrometer. Light scattering by photoinduced microdomain array has been investigated and found to be a seeding source of polarizationally anisotropic photorefractive light scattering. The effect of unlocality of forming the microdomains has been revealed. Photoinduced charge redistribution at the crystal surface has been found to cause the domain formation and rebuilding the crystal structure.