无透镜傅里叶变换数字全息图再现像质的影响因素分析

Analysis of the influence factors of the reconstructed image quality in lensless fourier transform digital holography

依据相干成像理论,从分析数字全息系统点扩散函数入手,研究无透镜傅里叶变换数字全息系统中影响再现像像质的因素。主要分析了对一给定的 CCD 和记录波长,记录距离对系统点扩散函数的影响,进而分析了对再现像像质的影响,得出了在满足抽样定理的条件下,应尽量使记录物体靠近 CCD,并给出了最小允许的记录距离数学表达式。计算机模拟结果证明了理论分析的正确性.

Based on the coherent image theory,starting with the analysis of point spre.ad function of lensless Fourier transform digital holography,the influence factor of the reconstructed image quality in digital holography is studied.The main analysis is that,for a certain CCD and the recording wavelength,the point spread function is influenced by the recording distance,and the reconstructed image quality is also investigated.It comes to a conclusion that the object should be placed as close as possible to the CCD target in the digital recording of hologram while the sampling theorem is fulfilled.The mathematical description of the minimum allowable recording distance in lensless Fourier transform digital holography is given.The validity of theoretical analysis is verified by the simulating results with computer.