自由基聚合型光致聚合物中全息图像质量的动态特性研究  

Experimental Research on the Dynamics of the Image Quality Reconstructed from Holographic Dual-Monomers Photopolymer

作　　者：宋伟[1] 陶世荃 王大勇[1] 万玉红[1] 

机构地区：[1]北京工业大学应用数理学院,北京100124

出　　处：《光学学报》2012年第12期109-115,共7页Acta Optica Sinica

基　　金：国家自然科学基金(60477004);北京市自然科学基金(4071001)资助课题

摘　　要：用实验方法研究了光致聚合物中全息存储再现图像质量的动态特性,以信噪比损失作为图像质量变化的衡量指标,进行了暗增长和均匀后曝光过程监测图像实验。实验结果表明,在暗增长和均匀后曝光过程中,再现图像强度和质量经历先增长后下降的动态过程。以噪声光栅的形成和发展对实验结果进行了初步的解释。以信噪比损失不大于3dB为判据考察了全息图对暗反应和均匀后曝光过程的宽容程度,对于不同的记录条件确定了暗反应和均匀后曝光过程的特征时间。在特征时间内,再现图像的质量和强度都是可以接受的。在复用记录时,为保证所有全息图有均衡的衍射效率和良好的图像质量,必须考虑再现图像质量和强度的动态变化因素。The dynamics of the image quality reconstructed from holographic photopolymer is experimentally investigated. In experiments, the intensity and quality of reconstructed images are monitored during dark enhancement and uniform post-exposure. The quality of reconstructed images is quantitatively evaluated based on the loss of signal-to-noise ratio. The experimental results show that the intensity and quality of reconstructed images suffers from non-monotonic changes during dark enhancement and uniform post-exposure, that is, increases at first, but decreases later from the highest value. These experimental results can be explained by the formation and development of noise gratings. The tolerance of image quality on uniform post-exposure and dark enhancement is evaluated based on the characteristic time, at which the signal-to-noise ratio of reconstructed images decreases a half of the original value. The experimental data show that during the characteristic time, both of quality and intensity of reconstructed images are acceptable. In multiplexed holographic storage, the dynamics of image quality should be considered in order to ensure uniform diffraction efficiency and good quality to all holograms.

关 键 词：全息 光致聚合物 信噪比 暗增长 均匀后曝光 

分 类 号：O438.1[机械工程—光学工程]