UV photorefractive effect in Na~+-doped lithium niobate crystals

摘要

We studied the UV photorefractive effect and other optical properties of Na~+-doped lithium niobate crystals. The behavior of the photorefractive resistance in Na~+-doped lithium niobate crystals was found to be quite different from that in lithium niobate crystals doped with other well known optical-damage resistant metal ions, such as Mg~(2+), Zn~(2+), In~(3+) etc. It is also found that not only the defect structures but also the ratio of [Li]/[Nb] in our samples was changed by doping with Na~+ ions. We theoretically analysed our experimental results, based on the Li-vacancy model.