Imaging of particles with 3D full parallax mode with two-color digital off-axis holography
Imaging of particles with 3D full parallax mode with two-color digital off-axis holography
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DOI：
10.1016/j.optlaseng.2017.09.002
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发表时间：
2017-10
影响因子：
4.6
通讯作者：
Soumaya Kara-Mohammed;L. Bouamama;P. Picart
中科院分区：
文献类型：
--
作者：
Soumaya Kara-Mohammed;L. Bouamama;P. Picart
本文提出了一种基于两个正交视图和两个波长的方法来记录离轴双色全息图。该方法允许区分沿视线轴排列的粒子。实验装置基于双马赫-曾德尔架构，其中两种不同的波长提供参考光束和物光束。从颗粒获取图像的数字处理基于卷积，以获得不依赖于波长的图像。角谱传递函数的空间带宽被调整以增加通常限制在几十毫米的最大重建距离。为了获得 3D 体积中的粒子图像，提出了一种基于调制定理的校准过程，以将两个视图完美地叠加在共同的 XYZ 轴上。该实验装置适用于平均直径约为 150μm 的移动非校准不透明颗粒的双色全息图记录。通过图像重建和视图校准处理双色全息图后，可以获得粒子在 3D 体积中的位置。特别是，可以消除有关近距离粒子的模糊性，在单视图方案中生成隐藏粒子，以确定感兴趣区域中粒子的确切数量。
This paper proposes an approach based on two orthogonal views and two wavelengths for recording off-axis two-color holograms. The approach permits to discriminate particles aligned along the sight-view axis. The experimental set-up is based on a double Mach-Zehnder architecture in which two different wavelengths provides the reference and the object beams. The digital processing to get images from the particles is based on convolution so as to obtain images with no wavelength dependence. The spatial bandwidth of the angular spectrum transfer function is adapted in order to increase the maximum reconstruction distance which is generally limited to a few tens of millimeters. In order to get the images of particles in the 3D volume, a calibration process is proposed and is based on the modulation theorem to perfectly superimpose the two views in a commonXYZaxis. The experimental set-up is applied to two-color hologram recording of moving non-calibrated opaque particles with average diameter at about 150 µm. After processing the two-color holograms with image reconstruction and view calibration, the location of particles in the 3D volume can be obtained. Particularly, ambiguity about close particles, generating hidden particles in a single-view scheme, can be removed to determine the exact number of particles in the region of interest.