Sheng Jian, Malkiel Edwin, Katz Joseph
Johns Hopkins University, Baltimore, Maryland 21210, USA.
Appl Opt. 2006 Jun 1;45(16):3893-901. doi: 10.1364/ao.45.003893.
Better understanding of particle-particle and particle-fluid interactions requires accurate 3D measurements of particle distributions and motions. We introduce the application of in-line digital holographic microscopy as a viable tool for measuring distributions of dense micrometer (3.2 microm) and submicrometer (0.75 microm) particles in a liquid solution with large depths of 1-10 mm. By recording a magnified hologram, we obtain a depth of field of approximately 1000 times the object diameter and a reduced depth of focus of approximately 10 particle diameters, both representing substantial improvements compared to a conventional microscope and in-line holography. Quantitative information on depth of field, depth of focus, and axial resolution is provided. We demonstrate that digital holographic microscopy can resolve the locations of several thousand particles and can measure their motions and trajectories using cinematographic holography. A sample trajectory and detailed morphological information of a free-swimming copepod nauplius are presented.
更好地理解颗粒-颗粒和颗粒-流体相互作用需要对颗粒分布和运动进行精确的三维测量。我们介绍了在线数字全息显微镜的应用，它是一种可行的工具，可用于测量深度为1-10毫米的液体溶液中密集的微米级（3.2微米）和亚微米级（0.75微米）颗粒的分布。通过记录放大的全息图，我们获得了约为物体直径1000倍的景深和约为10个颗粒直径的减小的焦深，与传统显微镜和在线全息术相比，这两者都有显著改进。提供了关于景深、焦深和轴向分辨率的定量信息。我们证明数字全息显微镜可以分辨数千个颗粒的位置，并可以使用电影全息术测量它们的运动和轨迹。展示了自由游动的桡足类无节幼体的样本轨迹和详细形态信息。
