(Ce,Cu)∶LiNbO₃晶体非挥发全息记录理论研究与优化

根据双中心带输运模型,对(Ce,Cu)∶LiNbO3晶体双中心非挥发全息记录进行了理论研究与优化。推导了(Ce,Cu)∶LiNbO3晶体的微观参量,采用数值方法通过严格求解模拟双中心带输运方程来模拟全息记录过程。分析了记录过程中,记录与敏化光强、Ce和Cu掺杂浓度以及晶体微观参量对(Ce,Cu)∶LiNbO3晶体双中心全息记录的影响。发现(Ce,Cu)∶LiNbO3晶体非挥发全息记录中实现高衍射效率与固定效率的主导因素是深中心Cu,在记录过程中,深中心Cu建立起了很强的空间电荷场。数值模拟的结果经过实验验

Based on the band transport model, the two-center nonvolatile holographic recording in (Ce,Cu)∶LiNbO3 has been theoretically investigated and optimized. Microphysical parameters of (Ce,Cu)∶LiNbO3 crystal are obtained and used to rigorously solve two-center band transport equations by numerical algorithm. The effects of recording and sensitizing intensities, dopant concentration of Ce and Cu, and microphysical parameters on recording performance of two-center holographic recording have been analyzed. And the characteristic of two-center recording in (Ce,Cu)∶LiNbO3 crystal has been found, that the deep center Cu plays a key role in the recording process and a strong space-charge field has been built in Cu traps, so a high diffraction efficiency and fixing efficiency can be achieved. Numerical results have been verified by experiments. The highest saturation and fixing diffraction efficiencies achieved are 60.5% and 53.8%, respectively.