【作者】 浦东林；

【导师】 王策；

【作者基本信息】 苏州大学 ， 光学工程， 2003， 硕士

【摘要】 采用电寻址液晶空间光调制器作为存储系统的组页器，常规CCD探测器作为重构图像的检测器件，实验研究了在光刻胶干板上记录黑白二值条纹图像的傅里叶全息图时，记录条件对重构图像信噪比的影响。实验结果表明，对于给定的系统及记录介质存在一定的最佳离焦量和曝光量，而对于不同空间频率的黑白二值条纹图像还需要采用不同参—物光比以最终获得最佳的信噪比。对此结果进行了分析和讨论。此外，本课题还研究了傅里叶全息存储在防伪上的实际应用，提出了三种防伪存储方案：(1)运用图像编码方案，存储了具有隐藏信息的编码黑白二值图像；(2)运用旋转复用方案，在同一存储点用不同方向的参考光存储了多幅图像；(3)运用空间复用技术，在一定区域内紧靠着记录一系列特定图像的傅里叶全息图。利用本课题前一部分获得的最佳记录条件，对这三种方案在光刻胶上做了傅里叶存储实验，实验结果显示了独特的防伪效果。更多还原

【Abstract】 The influences of recording conditions on the SNR of the black-white digital images retrieved from Fourier transform holograms were experimentally studied. The holograms were recorded on photoresist plates using an electrical addressed TFT-LCSLM as a data input device, and a normal CCD camera was applied for detecting reconstructed images. The experiment results show that there are optimal defocus distance and exposure for the given system and recording material, and to obtain the best SNR different reference-to-object beam ratios are also needed for black-white digital images of different space frequencies. The discussions on the experimental results are given.Furthermore, three Fourier storage schemes were proposed for practical anti-counterfeiting: (1) store black-white digital images with hidden information made by image coding method, (2) store several images on the same spot with reference beams of different directions (peristeophic multiplexing), (3) store a serious of given images recorded closely (space multiplexing). Three different Fourier holograms were recorded on photoresist plates following the above three schemes using the optimized recording conditions obtained in the first part of this study work. The reconstructed images form the holograms showed some special anti-counterfeit effects.更多还原