To develop highly sensitive updatable hologram materials, an azobenzene monomer was synthesized herein that supports effective photoisomerization under visible green beam irradiation. Furthermore, an acetylene group was introduced via Sonogashira coupling for higher birefringence. Polymerization was performed on the synthesized azobenzene monomer and on the methyl methacrylate (MMA) monomer, which serves as the skeleton of the film. The structures of all molecules were characterized by nuclear magnetic resonance (NMR) spectroscopy, and UV-Visible absorption spectroscopy was performed to analyze their optical properties. The holographic writing and rewriting capabilities of the newly synthesized azobenzene side-chain polymer were characterized by using a green laser as a writing beam, which showed that a high diffraction efficiency was reliably achievable under low-energy laser irradiation when evaluated with a four-wave-mixing optical scheme. In this study, high birefringent acetylene group containing azobenzene-based polymers were synthesized as materials for rewritable green-laser holograms, and their properties were evaluated. Birefringence change of polymer, which has an absorption wavelength suitable for green laser (532 nm), is 0.018. The diffraction efficiency of polymer was 72% under low-energy irradiation (7 J/cm2). These results show that the hologram recording material made in this study with high birefringent azobenzene are stable, without undergoing decomposition even when repeated recording and rewriting were performed.

中文翻译：

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具有高双折射乙炔作为侧链的可光致异构偶氮苯的高灵敏度可更新绿色全息记录聚合物

为了开发高度敏感的可更新全息图材料，本文合成了一种偶氮苯单体，该单体支持在可见绿光束照射下的有效光异构化。此外，通过 Sonogashira 偶联引入乙炔基团以获得更高的双折射。对合成的偶氮苯单体和作为薄膜骨架的甲基丙烯酸甲酯 (MMA) 单体进行聚合。所有分子的结构均通过核磁共振 (NMR) 光谱表征，并进行紫外-可见吸收光谱分析其光学性质。新合成的偶氮苯侧​​链聚合物的全息写入和重写能力的特点是使用绿色激光作为写入光束，这表明当使用四波混合光学方案进行评估时，在低能量激光照射下可以可靠地实现高衍射效率。在这项研究中，合成了含有高双折射乙炔基的偶氮苯基聚合物作为可重写绿色激光全息图的材料，并评估了它们的性能。具有适合绿色激光（532 nm）的吸收波长的聚合物的双折射变化为0.018。在低能量照射（7 J/cm2）下聚合物的衍射效率为 72%。这些结果表明，本研究中制备的具有高双折射偶氮苯的全息记录材料是稳定的，即使在进行重复记录和重写时也不会发生分解。