LiNbO_3:Fe:Cu晶体全息时间常数的理论研究

Theoretical investigation of holography time constants in LiNbO_3:Fe:Cu crystals

根据双中心全息存储的理论模型,采用Runge-Kutta数值方法拟合了双中心全息存储的记录过程和紫外光擦除过程的时间常数,研究了双掺杂LiNbO3:Fe:Cu晶体的浅能级掺杂浓度、深能级掺杂浓度和光束比IR/IUV对记录时间常数和紫外光擦除时间常数的影响。结果表明,在双掺杂LiNbO3晶体的全息复用中,为了同时得到小的记录时间常数和大的紫外光擦除时间常数,可选用深能级掺杂浓度较小的晶体,采用大的光束比进行复用存储。

Based on the two-center model,the recording time constant and the erasure time constant with UV beam are fitted with the MATLAB programmes,and the effects of the Fe concentration,the Cu concentration and intensity ratio IR/Iuv on the recording time constant and erasure time constant in doubly doped LiNbO3：Fe：Cu crystals are studied by using the Runge-Kutta method.The results show that,to achieve the smaller recording time constant and the larger erasure time constant simultaneously,it is available to use the lower Cu concentration and the larger intensity ratio IR/IUV when holograms multiplexing.