Image recording in doped crystals of lithium niobate

In lithium niobate crystals doped with iron, copper, rhodium, and ruthenium ions, the optical image recording is feasible when the illumination gradient is directed parallel to the polar axis of the crystal. Depending on the dopant type, the doping level, and external conditions (for instance, the recording time), the storage time of the image can reach 60 days. The effect of polarization of recording radiation on the contrast of the recorded image is investigated.