菲涅耳数字全息成像系统的脉冲响应分析

数字全息成像由CCD记录数字全息图后经过计算机数值重建物光波场,这个过程从傅里叶变换角度看等同于数字全息图的频谱分析。讨论了数字成像系统的脉冲响应函数,并分别推导了其实像、虚像、零级像在平面波和球面波照射下的波前复振幅分布。结果表明,实像和虚像是移位的夫琅和费衍射分布,而零级像是CCD光瞳的菲涅耳衍射分布,且与参考光波前分布无关。

Impulse response analysis of Fresnel digital holographic imaging system

In digital holography,holograms are digitally recorded of by a CCD array and the reconstruction of the wave fields are performed numerically on the computer.From the perspective of the Fourier transform,the process is equivalent to spectral analysis of the digital holograms.The impulse response function of a coherent optical imaging system is determined.And complex wave filed of the real image,virtual image and dc terms are examined,under plane reference wave and spherical reference wave illumination.The results show that the real and virtual image can be interpreted as a shifted Fraunhofer diffraction,while the dc terms represent a Fresnel diffraction of the CCD array,which has nothing to do with the reference wave.