体全息存储图像的信噪比研究  

Study on Signal to noise Ratio of Images Retrieved from Volume Holographic Memories

作　　者：唐斌[1,2,3] 陶世荃 杨兴昌 沈兰荪[1,2,3] 

机构地区：[1]北京工业大学电子工程系 [2]中国科技大学电子工程与信息科学系 [3]北京工业大学应用物理系

出　　处：《中国激光》1999年第3期273-278,共6页Chinese Journal of Lasers

摘　　要：根据全息存储二值图像的特性，提出了评价重构图像信噪比的方法，并对掺铁铌酸锂晶体中角度复用全息存储图像的信噪比作了详尽的定量研究，包括存储过程中图像信噪比的动态演变，以及页内和页间串扰对重构图像信噪比的影响。测量结果表明，串扰噪声引起的信噪比下降趋势与理论分析一致，图像信噪比的恶化主要是由于相干光学噪声和测量仪器的噪声；实验结果还表明即使在较小的衍射效率下也可获得较好的存储图像信噪比。A method for estimating the signal noise ratio (SNR) of digital images retrieved from volume holographic memories stored in Fe∶LiNbO 3 crystals is proposed in this paper, which is applicable to the image detection array (CCD) of entertainment quality. Based on this method the dynamic development of the image SNR during recording is measured for the first time to our knowledge. The degradation of SNR due to both intrapage and interpage cross talk noises is quantitatively studied in detail. The experimental results show the same descending trend on SNR as the result from a theoretical analysis. The degradation of the SNR is mainly caused by the optical noises in optical systems and the electrical noises in the measuring instrument. The experimental results also show that images can be retrieved with satisfactory SNR even the diffraction efficiency is very low. Therefore, an optimal compromise between the storage capacity and the retrieved image quality is possible.

关 键 词：体全息存储 图像信噪比 衍射效率 存储技术 

分 类 号：TP333.42[自动化与计算机技术—计算机系统结构]