【作者】 赵磊；

【导师】 黄明举；

【作者基本信息】 河南大学 ， 物理电子学， 2011， 硕士

【摘要】 光致聚合物材料由于具有高衍射效率、高灵敏度、可并行读写、制作工艺简单和价格低廉等优点,已成为近年来研究的热点。然而聚合材料在记录过程中会使材料体积收缩,引起光栅读出时布拉格条件的变化,造成信息丢失,严重影响全息图的再现质量。本文利用有机/无机纳米复合材料具有抗缩皱和能够增加光致聚合物材料的折射率调制度等优点,在丙烯酰胺基的水溶性光致聚合物材料中掺入亲水性Mg（OH）₂纳米粒子,并对其制备条件、光栅记录机理及全息记录性能进行了较深入的研究,本文主要开展了以下几方面的工作:1.通过反沉淀法制得具有粒径小、分散性好、亲水性好的Mg（OH）₂纳米粒子,并制备了掺杂纳米Mg（OH）₂的丙烯酰胺基复合的光致聚合物全息存储材料。2.通过计算纳米粒子的扩散常数及利用方波粒度公式,证明了在样品内部的光栅形成过程中,纳米粒子与单体是相向扩散的。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,得到一个优化的曝光方案。4.制备了不同浓度的纳米Mg（OH）₂含量的聚合物样品。在最佳的曝光方案下,通过分析透过率随曝光时间的变化曲线研究光致聚合物样品的成膜均匀性。5.测试了样品的衍射效率、折射率调制度、感光灵敏度等静态参数随曝光时间和掺杂纳米粒子浓度的变化曲线,最终得到最优的掺杂Mg（OH）₂浓度配置方案。6.在最优化浓度配置条件下实验测试并结合理论分析了样品的布拉格偏移情况,并计算了材料的曝光缩皱率,证明了纳米粒子的加入的确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。7.在所制备的最优化浓度记录材料中存储了模拟全息图和由空间光调制器生成的数字化图像,存储性能稳定,并且再现效果较好,保真度高。更多还原

【Abstract】 Photopolymer materials have been becoming a hot spot of research on ultra-high density holographic recording material in recent years because of its many attractive features, such as high diffraction efficiency, high sensitivity, high data transfer rates, parallel processing characters, easy preparation and low cost. However, there were shortcomings of common photopolymer materials such as shrinkage induced by the exposure, and then the shinkage affects the quality of the reading in holographic storage. In this thesis, the hydrophilic Mg（OH）₂ nanoparticles were dispersed in acrylamide-based photopolymer. And we studied further on the preparation, holographic storage principle and characteristics of photopolymer. The mainly contents of this thesis were as follows:1. Mg（OH）₂ nanoparticles, which have the advantages of small size, good dispersion and hydrophilicity were fabricated, and the photopolymer of acrylimide/polyvinyl alcohol blended with hydrophilic Mg（OH）₂-nanoparticles, were also fabricated.2. By evaluating the diffusion coefficient D of nanoparticle/polymer composite hologram and using square-wave particle distribution function, it was proved that the counter diffusion exists in the forming process of the grating of nanoparticles and monomer within the samples.3. The holographic properties of the materials under different exposure conditions were studied. An optimum exposure intensity was found after analyzing the parameters of holographic properties.4. The photopolymer samples doped with different densities of Mg（OH）₂-nanoparticles were prepared. Under the optimum exposure scheme, through analyzing the curve of transmittance changing with exposure time, the homogeneity of such photopolymer film was demonstrated.5. The curves of diffraction efficiency, refractive index modulation, exposure sensitivity and other static parameters changing with the densities of Mg（OH）₂-nanoparticles and exposure time of the samples blended with Mg（OH）₂-nanoparticles of different density were tested. Finally, an optimum plan of Mg（OH）₂-nanoparticles density, which allows all holographic properties to attain the ideal value, was worked out.6. The Bragg-mismatch and shrinkage ratio of the optimum concentration of Mg（OH）₂-nanoparticles were analyzed. Combining experimental results and theories, we draw the conclusion that adding those nanoparticles can increase the dimensional stability of the samples during the exposure process.7. Two dimensional analog images and digital data pages modulated by the SLM（Spatial Light Modulator） were stored in the the optimum concentration of Mg（OH）₂-nanoparticles, and the reconstructed images or data pages have good fidelity.更多还原