Highly holographic diffraction efficiency and recording stable macromolecule photopolymer by introducing cross-linker vinyl-POSS

The cross-linked photopolymer vinyl-POSS (Vi-POSS)-phenanthraquinone doped poly methyl methacrylate (PQ/PMMA) was successfully fabricated via a one-pot free radical thermal polymerization technique by incorporating a Vi-POSS cross-linker into PQ/PMMA. The residual C=C bonds on the Vi-POSS branches after cross-linking significantly enhanced the holographic performance, achieving a high diffraction efficiency of 83% and a sensitivity of 0.49 cm J-1, while the cross-linked polymer matrix reduced volume shrinkage to 0.28% (compared to 64%, 0.33 cm J-1, and 0.39% for PQ/PMMA). Moreover, the Vi-POSS-PQ/PMMA sample exhibited excellent stability, with a bit error rate maintained at ∼0.5% over a broad holographic recording time range (3-13 s), demonstrating its suitability for data storage applications by mitigating the effects of laser power fluctuations or system instability. Further experimental analysis confirmed the synthesis of a 3D cross-linked macromolecular network with Vi-POSS as the core. The residual C=C bonds in the Vi-POSS-PQ/PMMA matrix originated primarily from Vi-POSS, and a hexatomic cyclic -C-O-C- structure formed between Vi-POSS and PQ upon beam exposure. In conclusion, this study not only elucidates the microphysical and chemical mechanisms underlying the enhanced holographic performance of Vi-POSS-PQ/PMMA but also proposes a novel strategy to optimize storage stability for holographic data storage applications.