以双中心模型为基础,在低光强连续光条件下研究了LiNbO3∶Fe∶Mn晶体在稳态情况下的非挥发双光双步全息存储性能。采用数值方法,通过比较双中心模型中深(Mn2+/Mn3+)、浅(Fe2+/Fe3+)能级之间所有可能的电子交换过程,发现由隧穿效应引起的深浅能级之间直接电子交换过程对LiNbO3∶Fe∶Mn晶体总的空间电荷场大小起着决定性的作用。同时,这一电子交换过程对晶体非挥发全息存储性能也起着至关重要的作用。此外,通过相同实验条件下LiNbO3∶Fe∶Mn晶体与近化学比LiNbO3∶Fe晶体总的空间电荷场的比较,显示LiNbO3∶Fe∶Mn晶体在低抽运光和高记录光光强条件下有着比近化学比LiNbO3∶Fe晶体更佳的全息存储性能。

Based on the two-center model, the steady-state nonvolatile two-step, two-color holographic recording performance with continuous-wave lights in the low intensity for LiNbO3∶Fe∶Mn is studied theoretically. By use of numerical method, through comparing the contributions to the space-charge fields from the different electron transfer processes between the deep-trap centers (Mn2+/Mn3+) and the shallow-trap centers (Fe2+/Fe3+), the direct electron exchange between the Mn2+/Mn3+ and the Fe2+/Fe3+ levels through the tunnelling effect dominates the amplitude of the total space-charge field. This direct electron transfer process plays a key role on the two-step, two-color holography performance also. In addition, by comparing the amplitudes of the space-charge fields of the LiNbO3∶Fe∶Mn with the near-stoichiometric LiNbO3∶Fe, the results show that the holographic recording performance in the LiNbO3∶Fe∶Mn is much better than that in the near-stoichiometric LiNbO3∶Fe at low intensity of gating light and high intensity of recording light.