Radiation Modification of Optical Characteristics of LiNbO3:Zn and LiNbO3:Mg Crystals

The modification of the optical characteristics of LiNbO3:Zn and LiNbO3:Mg crystals grown by the Czochralski method was investigated using β and γ radiation. The photorefractive effect was found to be inhibited by ionizing radiation in the LiNbO3:Zn ([ZnO] ≈ 2.1 mol%) crystal, which belonged to a below-threshold concentration range. The inhibition was attributed to a stepwise radiation annealing of charged defects. Ionizing radiation increased the general optical uniformity of above-threshold crystals LiNbO3:Zn ([ZnO] ≈ 5.9 mol%) and LiNbO3:Mg([MgO] ≈ 5.6 mol%). In addition, we determined that radiation annealing substantially influenced photorefraction dynamics in lightly doped LiNbO3:Zn ([ZnO] ≈ 0.1 mol%) crystals, which widens their application areas