LiNbO_3:Cu:Ce晶体非挥发全息存储性能的理论研究

Theoretical studies on nonvolatile holographic recording for LiNbO_3:Cu:Ce crystals

以双中心模型为基础,理论研究了LiNbO_3:Cu:Ce晶体在稳态情况下的非挥发双光双步全息存储性能.研究中考虑了在晶体深能级中心Cu^+/Cu^(2+)与浅能级中心Ce^(3+)/Ce^(4+)之间由隧穿效应引起的电荷直接交换过程.结果表明,总的空间电荷场大小主要由深能级上的空间电荷场所决定,并且非挥发全息存储性能主要由隧穿效应引起的深能级中心Cu^+/Cu^(2+)与浅能级中心Ce^(3+)/Ce^(4+)之间的电荷直接交换过程所决定.与隧穿效应相关的材料参数对于非挥发双光双步全息存储的性能起到了至关重要的作用.

The steady-state nonvolatile two-step, two-color holographic recording performance is studied theoretically for LiNbOa：Cu：Ce based on the two-center model, with taking into account the direct electron transfer between the deep-trap center Cu＋/Cu2＋ and the shallow-trap center Cea＋/Ce4＋ due to the tunneling effect. The results show that the total space-charge field is determined by the space-charge field on the deep-trap center, and the direct electron exchange between the Cu＋/Cu~＋ and the Ce3＋/Ce4＋ levels through the tunneling effect dominates the charge-transfer process in the two-step, two-color holographic recording. Therefore, the material parameters related to this direct tunneling process play a key role in the two-step, two-color holography performance.