双掺杂Fe:Mn:LiNbO_3晶体双色全息存储性能分析

Analysis on Performance of Two-Color Holographic Storage Based on Fe:Mn:LiNbO_3 Crystal

基于带输运模型建立双掺杂Fe:Mn:LiNbO3晶体双色全息存储的耦合微分方程组,在此基础上用数值求解的方法讨论用锰多铁少型双掺杂铌酸锂晶体进行双色全息存储的时间动态过程,分析此种晶体氧化还原态对晶体内建空间电荷场的影响。只有氧化的Fe:Mn:LiNbO3晶体能通过双色存储实现全息图的非破坏性读出,氧化的Fe:Mn:LiNbO3晶体红光擦除后所保留的衍射效率随氧化而提高。在实验方面用同种杂质浓度的四种不同氧化还原态的晶体,进行了还原晶体之间、氧化晶体之间二波耦合对比实验,实验结果和理论分析的结果一致,同时利用实验曲线定量地计算了氧化晶体的全息动态范围参量M/#和各个晶体的记录灵敏度,得到了较大的M/#的值为5.03(非寻常光,激光波长,632 nm),但是以较低的灵敏度为代价的。

The paper established the coupling differential equations using the band-transport model. Using practical experiment＇s parameters,we numerically calculated and explained the time-dynamic developing process of the holographic storage,and analyzed how the oxidation-reduction degree of the crystal affects the space charge field within the crystal. Only the oxidative crystals can accomplish nonvolatile holographic storage,which its diffraction efficiency after red-light read-out increases with the increase of oxidative degree. Further more we measured the diffraction efficiencies of four specimens with different degree of oxidation-reduction and did comparable experiments of two-wave coupling between reductive crystals and oxidative crystals. The experimental results coincided with the theoretical analysis very well. At the same time,holographic dynamic range M/# and recording sensitivity of oxidative crystal was quantitatively calculated by using experimental curve in which value of M/# equaled to 5.03 （extraordinary light,wavelength,632 nm）,but trade off with lower sensitivity.