Hu Jiaqi, Li Qi, Cui Shanshan
Appl Opt. 2014 Oct 20;53(30):7112-9. doi: 10.1364/AO.53.007112.
In terahertz inline digital holography, zero-order diffraction light and conjugate images can cause the reconstructed image to be blurred. In this paper, three phase retrieval algorithms are applied to conduct reconstruction based on the same near-field diffraction propagation conditions and image-plane constraints. The impact of different object-plane constraints on CW terahertz inline digital holographic reconstruction is studied. The results show that in the phase retrieval algorithm it is not suitable to impose restriction on the phase when the object is not isolated in the transmission-type CW terahertz inline digital holography. In addition, the effects of zero-padding expansion, boundary replication expansion, and apodization operation on reconstructed images are studied. The results indicate that the conjugate image can be eliminated, and a better reconstructed image can be obtained by adopting an appropriate phase retrieval algorithm after the normalized hologram extending to the minimum area, which meets the applicable range of the angular spectrum reconstruction algorithm by means of boundary replication.
在太赫兹同轴数字全息术中，零级衍射光和共轭像会使重建图像模糊。本文基于相同的近场衍射传播条件和像面约束，应用三种相位恢复算法进行重建。研究了不同物面约束对连续波太赫兹同轴数字全息重建的影响。结果表明，在相位恢复算法中，对于透射型连续波太赫兹同轴数字全息术，当物体不孤立时，对相位施加限制是不合适的。此外，研究了零填充扩展、边界复制扩展和切趾操作对重建图像的影响。结果表明，通过将归一化全息图扩展到最小面积后采用适当的相位恢复算法，可以消除共轭像，并获得更好的重建图像，通过边界复制使其满足角谱重建算法的适用范围。
