Wang Peiyao, Sun Xiudong, Liu Peng
School of Physics and Electronic Engineering, Sichuan Normal University, Chengdu 610101, China.
Institute of Modern Optics, School of Physics, Key Laboratory of Micro-Nano Optoelectronic Information System, Ministry of Industry and Information Technology, Key Laboratory of Micro-Optics and Photonic Technology of Heilongjiang Province, Harbin Institute of Technology, Harbin 150001, China.
Polymers (Basel). 2023 Dec 30;16(1):126. doi: 10.3390/polym16010126.
Polymer systems induced by the reaction between monomers and photo-initiators play a crucial role in the formation of volume-phase gratings. In this paper, we fabricated a dual-photo-initiator photopolymer by doping EY (Eosin Yellow) molecules into a TI (Titanocene, Irgacure 784@BASF) dispersed PMMA (poly-[methyl methacrylate]) substrate system, with the aim of promoting the diffusion and polymerization processes in volume holographic storage. The two-wave interference system is adopted to record a permanent grating structure in our materials. The temporal diffraction variations of photopolymerization (during the interference exposure) and dark diffusion (after the interference exposure) processes have been investigated and analyzed. Aiming to analyze the influence of EY doping ratios on holographic performances, some key parameters were examined in the experiment. We first measured the temporal evolution of diffraction efficiency, then an exponential fitting was adopted to obtain the response time. Finally, the angular selectivity was evaluated by the Bragg condition after holographic recording. Also, the temporal evolution of each component is described by the nonlocal polymerization-driven diffusion model with a dual-photo-initiator composition, theoretically. Furthermore, we experimentally achieved the holographic grating enhancement in both the dark diffusion and photopolymerization processes by doping appropriate EY concentrations, respectively. This work provides a foundation for the acceptability of TI&EY/PMMA polymers in further holographic storage research.
由单体与光引发剂之间的反应所诱导的聚合物体系在体相位光栅的形成过程中起着至关重要的作用。在本文中，我们通过将EY（曙红Y）分子掺杂到TI（二茂钛，巴斯夫公司的Irgacure 784）分散的PMMA（聚甲基丙烯酸甲酯）基底体系中制备了一种双光引发剂光聚合物，目的是促进体全息存储中的扩散和聚合过程。采用双波干涉系统在我们的材料中记录永久性光栅结构。研究并分析了光聚合过程（在干涉曝光期间）和暗扩散过程（干涉曝光之后）的时间衍射变化。为了分析EY掺杂比例对全息性能的影响，在实验中考察了一些关键参数。我们首先测量了衍射效率的时间演化，然后采用指数拟合来获得响应时间。最后，在全息记录之后通过布拉格条件评估角度选择性。此外，理论上用具有双光引发剂组成的非局部聚合驱动扩散模型描述了各组分的时间演化。而且，我们通过分别掺杂适当浓度的EY在实验上实现了暗扩散和光聚合过程中全息光栅的增强。这项工作为TI&EY/PMMA聚合物在进一步的全息存储研究中的可接受性提供了基础。
