Study on Dark Enhancement in Holographic Photopolymer
全息存储用光致聚合物材料的暗增长现象研究

According to the mechanism of grating formation in photopolymers,the dark enhancement was investigated for a novel photopolymer by using the method of mathematic model combine with experimental measurements.The result indicates that the weaker intensity of writing light resulted in more dark enhancement,even though the same saturation was reached for diffraction efficiency with different writing intensity.In order to exploit this effect to enhance diffraction efficiency,experiments of non-continuous holographic exposure were designed and conducted,The diffusion time constant of the material was obtained to be 21 s by fitting the experimental data of dark enhancement with theoretical model.Based on the measured diffusion time constant,the period of non-continuous holographic exposure was determined.The experimental result indicates that the diffraction efficiency of a non-continuously exposure is higher than that of continuously one in the same recording condition.