LiNbO_3∶Ce∶Cu晶体中绿光非挥发全息记录优化

Optimization of Nonvolatile Holographic Recording in LiNbO_3∶Ce∶Cu with Green Light

为了对在LiNbO3∶Ce∶Cu晶体中绿光作为记录光的非挥发全息记录进行优化,联立求解了双中心物质方程和双光束耦合波方程,数值分析了平均空间电荷场(SCF)和衍射效率随晶体的氧化还原态、记录光与敏化光的光强比以及深浅中心的掺杂浓度的变化。结果表明,采用绿光作为记录光在LiNbO3∶Ce∶Cu晶体中进行非挥发全息记录,可以记录得到强光折变光栅,其空间电荷场高达107V/m;获得高达80%以上的固定衍射效率,各相关参量都有较大的优化空间。

In order to optimize the nonvolatile holographic recording in LiNbO3：Ce：Cu crystal with green light, we solved the joint two-center material equations and the coupled wave equations. Variations of parameters were analyzed, such as average space charge field （SCF） and the diffraction efficiency with the crystal annealing state, the intensity ratio of green-to-ultraviolet （UV）, and the concentration of shallow and deep traps in oxidized LiNbO3 ： Ce ：Cu crystal. The results show that strong photorefractive grating with the averaged space-charge field as high as 107 V/m and 80% high fixed diffraction efficiency can be obtained in LiNbO3 ：Ce： Cu with green light recording. And much better performance can be obtained by changing the corresponding parameters.