利用传统全息片实现合成孔径数字全息的研究

分析了传统全息片的微观结构，介绍了细光束成像和合成孔径数字全息记录、再现的基本原理，研究了利用传统方法拍摄的散射物体透射式、振幅型全息片实现合成孔径数字全息的方法，给出了实验结果。理论分析和实验结果表明，利用传统透射式、振幅型全息片，通过光学显微镜放大制作子数字全息图和合成孔径数字全息图，经计算机处理是可以得到完整再现像的，其性质与细激光束照射成像一致。用子全息图再现像的复振幅叠加方法和采用子全息图再现像的强度叠加方法均可实现合成孔径数字全息图的再现，且强度叠加方法的视觉效果要好些，但它们对缩小再现像中散斑的尺寸没有帮助。用子全息图拼接成的合成孔径全息图得到的再现像效果最好，可以缩小再现像中散斑的尺寸，信噪比、分辨率均有提高。要得到更好的再现像，需要用更多的子数字全息图拼接成尺寸更大的合成孔径数字全息图。

Study of recording and reconstruction synthetic aperture digital holography utilize traditional hologram

This paper analyzes the micro - structure of traditional hologram, introduces the fundamental principle of the recording and numerical reconstructing of the synthetic aperture digital holography and the characters of the reconstructed image of a hologram illuminated by a narrow laser beam. The methods of recording and reconstructing synthetic aperture digital holography utilize traditional transmission amplitude hologram are studied. The experimental research results show： Recording synthetic aperture digital holography by magnify traditional hologram is possible, and the character of its reconstructed images same as hologram illuminated by a narrow laser beam. Both reconstructed methods, namely complex amplitude superposition and intensity superposition from a single sub - hologram, can improve the resolution of reconstructed images, but cannot shrink the speckle size. The larger size synthetic aperture digital holography can be gained by combining numbers of sub - holograms directly, and the quality of its reconstructed image is the best, since the speckle size is shnmk evidently. In order to gain high quality reconstructed image sub - holograms are needed.