相移同轴无透镜傅里叶数字全息的分析与实验

应用菲涅耳衍射和全息理论，详细分析了无透镜傅里叶变换数字全息图的记录、再现方法和再现像的特点，分析了相移数字全息图的记录和再现方法，并进行了相应的实验验证。结果表明：直接对无透镜傅里叶数字全息图进行傅里叶逆变换可同时得到与物体完全相同的再现像及其共轭像；同轴无透镜傅里叶数字全息术能最大程度满足CCD对采样条件的要求，从而可以增大记录物体的尺寸，减小记录距离，明显提高再现像的清晰度和分辨率；相移数字全息术能有效地消除数字再现光场中的零级光场和共轭像，显著提高再现像的信噪比。条件许可时，相移同轴无透镜傅里叶数字全息术是目前解决数字全息术中再现像的分离与满足采样条件之间矛盾的最佳方法。

Analysis and Experiment of Phase-Shifting Coaxial Lensless Fourier Digital Holography

By using Fresnel diffraction and holographic theory, some detailed analysis of the recording, numerical reconstructing method and the characters of the reconstructed image about lensless Fourier digital holography and phase-shifting digital holography is given. The experimental result shows: In the digital Fourier holography, the reconstructed image and the conjugate image can be obtained by use of Fourier inverse transform directly. Coaxial lensless Fourier digital holography can satisfy the sampling condition of CCD maximumly to enlarge the size of the object and decrease the distance between the object and CCD, so the resolution and definition of the reconstructed image are improved expediently. By using of phase-shifting digital holography, the zero-order diffraction and the conjugate image are deleted effectively, and the ratio of signal to noise is improved obviously. If the recording condition permit, phase-shifting coaxial lensless Fourier digital holography is optimal method to solve the difficulty between the separation of reconstructed images and the recording sampling condition in digital holography.