Shangraw Maxwell, Ling Hangjian
Appl Opt. 2021 Aug 20;60(24):7099-7106. doi: 10.1364/AO.435021.
One shortcoming of digital in-line holography (DIH) is the low axial position accuracy due to the elongated particle traces in the reconstruction field. Here, we propose a method that improves the axial localization of DIH when applying it to track the motion of weak phase particles in dense suspensions. The proposed method detects particle positions based on local intensities in the reconstruction field consisting of scattering and incident waves. We perform both numerical and experimental tests and demonstrate that the proposed method has a higher axial position accuracy than the previous method based on the local intensities in the reconstructed scattered field. We show that the proposed method has an axial position error below 1.5 particle diameters for holograms with a particle concentration of 4700/. The proposed method is further validated by tracking the Brownian motion of 1µ in dense suspensions.
数字同轴全息术（DIH）的一个缺点是，由于重建场中粒子轨迹拉长，轴向位置精度较低。在此，我们提出一种方法，当将DIH应用于追踪稠密悬浮液中弱相位粒子的运动时，可提高其轴向定位精度。所提出的方法基于由散射波和入射波组成的重建场中的局部强度来检测粒子位置。我们进行了数值和实验测试，结果表明，与基于重建散射场中的局部强度的先前方法相比，所提出的方法具有更高的轴向位置精度。我们表明，对于粒子浓度为4700/的全息图，所提出的方法的轴向位置误差低于1.5个粒子直径。通过追踪稠密悬浮液中1µ的布朗运动，进一步验证了所提出的方法。
