在分析数字全息系统的最小分辨距离和再现像平面上的采样间隔的基础上,提出了一种在用菲涅耳变换法再现数字全息图时,能清楚显示再现像细节的简单方法,这种方法能有效地提高再现场的显示分辨率。通过给由CCD记录的数字全息图补零,可使再现像平面上采样间隔减小,使再现像具有更多的像素,得到保留了更多记录信息的高质量再现像。用同样的方法,也可以矫正由于CCD靶面尺寸在水平和竖直方向上的不一致造成再现像的视觉畸变。实验结果表明此方法有很好的效果。

Based on analyzing resolution of digital holographic system and sampling space in reconstructed image plane, a simple, convenient and effective method is presented, which can increase the display resolution of the reconstructed field in Fresnel-transform reconstruction of digital holograms. By padding zeros operation to a digital hologram recorded by charge-coupled device (CCD), sampling space in the reconstructed image plane is decreased and pixel numbers in the reconstructed image are increased, and then the reconstructed image with high quality is obtained. With similar method, the vision aberration of reconstructed images resulted from the difference of CCD size in horizontal and vertical direction is rectified. Experimental results show a good agreement with the theoretical analysis.