在数字全息研究中, 为了充分利用CCD器件有限的空间带宽积, 常采用同轴全息记录。然而用同轴全息图再现时, 再现物光波和共轭物光波是混在一起无法分开的。有效消除同轴全息图再现光波场中的共轭像是数字全息应用中的一项关键技术。基于菲涅耳衍射运算和逆运算, 提出一种用同轴数字全息图重构物光波面的迭代算法。该方法利用同轴全息图再现时, 再现物光波和共轭物光波衍射特性的不同来剔除共轭物光波成分, 从而将再现物光波成分有效分离出, 实现单幅同轴全息图的物光波面数值重构。计算机模拟实验证明了该方法简单易行。

In the study of digital holography, an in-line optical arrangement is often made to record holograms so as to exploit the finite space band-width product of CCD sensor sufficiently. However, when an in-line hologram is used to reconstruct original object wave, its conjugate wave will coexist in the diffracted field. Separating desired component from conjugate component is very difficult. The effective elimination of conjugate image during numerical reconstruction through in-line hologram has been a crucial technique, which facilitates and promotes the application of digital holography. Based on Fresnel diffraction calculation and its inverse calculation, an iterative algorithm to reconstruct object wave from in-line digital hologram is presented. According to this method, conjugate component can be removed from reconstruction to get original object wave by utilizing the difference of their diffractive characteristics. The object wave can be reconstructed numerically through single in-line hologram. The computer simulation demonstrates that the method proposed here is feasible and easy to operate.