【作者】 王艳；

【导师】 黄明举；

【作者基本信息】 河南大学 ， 光学， 2010， 硕士

【摘要】 光致聚合物材料以其卓越的光化学特性已成为目前超高密度数字全息记录材料的研究热点。但常用的光致聚合物材料具有曝光缩皱性和折射率调制度有限等不足,影响其全息存储的读写性能。本文利用有机/无机复合材料具有抗缩皱性且能够增加材料的折射率调制度等优点,在高效光致聚合物全息记录材料中掺入纳米SiO₂粒子,并对其制备条件、相关的物理和化学机理及全息记录性能进行了较深入的研究。本文主要包含以下几方面的工作:1.制备了掺杂有水溶性纳米SiO₂粉体的丙烯酰胺/聚乙烯醇复合的光致聚合物全息存储材料。通过对聚合物样品制备过程的改进,使纳米SiO₂粉体能够均匀分散在聚合物体系中。2.用迈克尔逊干涉法测试样品中形成的纳米粒子/聚合物复合全息光栅的折射率的方法,分析不同折射率的分布情况,证明了样品内部的光栅形成过程中,纳米粒子与单体是相对扩散的。3.研究了不同曝光条件下材料的全息性能,通过对全息特性参数的分析,得到了一个优化的曝光方案。4.制备了含有不同浓度纳米SiO₂的聚合物样品。在最佳的曝光方案下实验测试并结合理论分析了各样品的布拉格偏移情况,计算了材料的曝光缩皱率。研究发现,纳米粒子的加入确实能够提高样品曝光过程的维度稳定性,有利于增加信息记录和读出的可靠性;同时通过分析透过率随曝光时间的变化曲线研究了该光致聚合物样品的成膜均匀性。5.实验分别测试了含有不同浓度纳米SiO₂聚合物样品的衍射效率、折射率调制度、感光灵敏度等静态参数随纳米SiO₂浓度以及曝光时间的变化曲线,解释了变化原因,最终得到一个优化的SiO₂浓度全息光致聚合物配置方案。更多还原

【Abstract】 The excellent photochemical properties of photopolymer material have made them become the hot spot of current research on ultra-high density holographic recording material. However, the shortcomings of common photopolymer materials such as exposure shrinkage and limited refractive index modulation affect the reading and writing properties of their holographic storage. This thesis, built on the theoretical basis of the fact that organic/inorganic composite materials possess the advantages of anti-shrinkage and increasing the refractive index modulation of materials, mainly carries out work on organic/inorganic photopolymer materials blended with SiO₂-nanoparticles from the following aspects:1. The material of acrylimide/polyvinyl alcohol blended with hydrophilic SiO₂-nanoparticles for holographic storage is fabricated. Through improvement on the preparing process of photopolymer film, these SiO₂-nanoparticles are evenly dispersed in the polymer system.2. By testing the refractive index of nanoparticle/polymer composite hologram through Michelson interferometry, it analyzes the distribution of different refractive indexes and proves the counter diffusion exists in the forming process of the grating of nanoparticles and monomer within the sample.3. The holographic properties of the materials under different exposure conditions are studied. By analyzing the parameters of holographic properties, an optimum exposure intensity is found out.4. The polymer samples doped with different density of SiO₂-nanoparticles are prepared. Under the optimum exposure scheme, the bragg-mismatch and shrinkage ratio of all samples is analyzed, combining experimental tests and theories and comes to a conclusion: adding those nanoparticles increases the dimensional stability of the samples during the exposure process. Also, though analyzing the curve of transmittance changing against exposure time, the homogeneity of such photopolymer film is demonstrated.5. The curves of diffraction efficiency, refractive index modulation, exposure sensitivity and other static parameters changing against the density of SiO₂-nanoparticles and exposure time of the samples blended with SiO₂-nanoparticles of different density are tested, and explain the causes of these changes. Finally, it works out an optimum plan of SiO₂-nanoparticles density, which allows all holographic properties to attain the ideal value.更多还原