含氟丙烯酸酯光致聚合物的全息特性研究

Holographic Performance of Fluorinated Acrylate Photopolymer

提高记录单体在成膜物中的迁移速率,加大记录单体与成膜物的折射率差,可以实现光致聚合物的折射率空间调制最大化.本工作以高折射率的超支化聚酯(折射率1.586)为成膜树脂,利用超支化聚合物分子结构疏松、便于小分子在其间扩散的特性,同时以低折射率的单官能团含氟丙烯酸酯(折射率1.372)和高活性的双官能团丙烯酸酯(折射率1.457)为记录单体制备了光致聚合物全息膜,以衍射效率为指标优化单体构成和全息膜的厚度,研究了该全息膜的衍射效率、空间分辨率、折射率调制度等性能.该光致聚合物全息材料的折射率调制度为4.82×10-3,衍射效率达到99.4%,在空间分辨率3750 lp/mm的衍射效率仍然达到85.6%,感光灵敏度56 mJ/cm2.

By enhancing the diffusion of monomer, and by increasing the difference of refractive index between the recording monomer and the binder resin, modulation of refractive index of photopolymer for holographic recording will be greatly realized. Hyperbranched polyester （refractive index 1. 586）, with the loosely packing molecular structure that makes the monomer transport easily, and fluorine-containing acrylate （refractive index 1. 372） combining with highly reactive diaerylate （refractive index 1. 457） were used in this work as the binders and monomer, respectively, of photopolymer for holographic recording. The effects of composition and film thickness on diffraction efficiency of holographic recording were studied, as well as the characteristic space resolution and refractive-index modulation of the new holographic recording material. The photopolymer exhibited excellent performance of holographic recording with modulation of refractive index about 4.82 × 10^-3, photosensitivity 56 mJ/cm^2, diffraction efficiency up to 99.4 %, and 85.6 % even at resolution as high as to 3754 lp/mm.