可擦写俘精酸酐/PMMA薄膜的全息记录特性研究

Holographic Recording Characteristics of a Rewritable Fulgide / PMMA Film

对一种新型可擦写有机光致变色材料—吡咯俘精酸酐的光全息记录特性进行了实验研究 .用涂布法制成厚度约 10 μm的吡咯俘精酸酐 /PMMA聚合物薄膜 .样品无色态吸收峰在 373nm处 ,经紫外光照射发色后 ,变为呈色态 ,其吸收峰移动到 6 2 6nm处 ,呈色态在氦氖激光照射下可以重返为无色态 .无色态和呈色态在室温下都是稳定的 .以呈色态吡咯俘精酸酐 /PMMA薄膜作为记录材料 ,以氦氖激光作为记录光 ,分别建立了双光束干涉衍射记录装置和四波耦合实验系统 .实验测得该薄膜的空间分辨率至少可以达到 16 80lines/mm ,一级衍射效率大于 2 % ,全息记录中的最佳曝光量约为 1J/cm2 .实验测量了衍射效率与曝光量的特性曲线 ,分析了衍射光强度和光斑模式随曝光时间的变化关系 .

A new organic photochromic compound—pyrrylfulgide is studied as a new type of rewritable holographic recording medium in this paper. The pyrrylfulgide/PMMA film is prepared by casting method resulting in 10 μm thickness. The bleach state of the film has absorption peak at 373 nm. When irradiated by UV light the bleach state converts into colored state, which has absorption peak at 626 nm. The colored state can also return the bleach state when irradiated by He-Ne laser. The two states are stable at room temperature. Experiments of two laser beams interference and four waves coupling are setup to measure the parameters of the sample. The spatial resolution of the film can reach at least 1680 lines/mm. The first order diffraction efficiency is above 2%. The best exposure is about 1 J/cm2. The characteristic curve of the diffraction efficiency versus exposure is measured. The changes of diffraction intensity and diffraction beam patterns with exposure are analyzed.