New Hologram System Using Photochemical Holeburning Phenomena

1.导论近年来，基于持久光谱烧孔(PSHB)的光存储因其应用于高密度光存储的可能性而受到越来越多的关注。在聚合物中掺杂有机染料，在无机晶体或玻璃中掺杂稀土或过渡金属，观察到了有机染料的PSHB。掺Sm^&lt；2+&gt；的氟化物晶体和玻璃已经观察到了室温PSHB现象。然而，这些材料的伽马线宽(非均匀线宽)/伽马h(均匀线宽)是一个统一的数量级。对于PSHB材料在光存储中的应用，需要较高的工作温度和较大的伽马值。结果与讨论光化学烧孔技术可用于数据存储系统，也是研究光学中心周围局域结构的有力手段。我们研究了铝、镁、硅离子效应和碱离子效应对室温下出现PHB的硼酸盐玻璃烧孔和声子边带的影响。在Sm^&lt；2+&gt；的^5D_0-^7F_0跃迁和Eu^-lt；3+&gt；的声子边带谱上测量了烧孔。孔宽与局部结构变化密切相关，尤其是随着稀土离子周围产生的非桥氧的减少，孔宽似乎减小。在钠铝硼玻璃的情况下，孔宽随着氧化铝含量的增加而显著减小。在室温下，85B_2O_310Al_2O_35aN_2OlSm_2O_3玻璃的伽马&lt；ih&gt；/伽马_h约为80，这是目前报道的最大值。此外，通过对样品进行X射线辐照，大大提高了烧孔速度。

1.IntroductionThese days, the interests in optical memory based on persistent spectral hole burning (PSHB) are increased because of its possibility of the applicaton to high density optical memory. PSHB has been observed for an organic dye doped in polymer and rare earth or transition metal doped in inorganic cyrstal or glass. Room temperature PSHB phenomena have been already observed for Sm^<2+> doped fluoride crystal and glasses. However, these materials'GAMMA_<ih> (inhomogeneous line width)/GAMMA_h (homogeneous line width) which is the parameter of data multiplicity is an order of unity. For the application of PSHB materials to optical memory, high operating temperature and a large GAMMA_<ih>/GAMMA_h should be required. Therefore, in this study, the relationship between the optical hole and glass structure is examined.2.Results and Discussionphoto-chemical hole burning (PHB) can be applied for data storaging system as well as a powerful method for studying the local structure around optical centers. We have studied both aluminum, magnesium and silicon ion effects and alkali ino effects on the hole burning and phonon sideband for borate glasses which show up the PHB at room temperature. The hole burning was measured on ^5D_0-^7F_0 transition of Sm^<2+> and phonon sideband apectrum for ^5D_0-^7F_0 transition of Eu^<3+>. The hole width is closely related to the local structure change, especially, seems to deacrease with decreasing non-bridging oxygens produced around raee rarth ion. In the case of sodium alumino-borate glasses, the hole width decreases cosiderably with increasing alumina. The the ratio of GAMMA_<ih>/GAMMA_h of 85B_2O_310Al_2O_35aN_2OlSm_2O_3 glass is about 80 at room temperature, which is the largest value reported up to now. Moreover, the hole-burning speed has been drastically improved by means of the X-ray irradiation to the specimens.