中文摘要：

微球跟踪技术是生物学动态过程的重要研究工具之一。为获取相关生物学信息,需要对微纳米尺度的微球进行三维位置的测量。在实际测量中,由于液态环境中微球间及微球与其他物质间存在相互作用力,微球图像交叠的现象难以避免。交叠微球图像会导致圆环特征的交错,采用传统方法难以实现特征识别,进而无法对其定位。针对这一问题,提出了全息重构聚焦法（HRFM）,通过精确定位微球的横向位置,获取其三维位置。实验结果表明HRFM定位微球位置较传统方法更为精确,且尤其适用于交叠微球位置的测量,对单个微球和交叠微球的测量均能达到2nm的三维位移分辨力。

英文摘要：

Particle tracking technology is one of the most important research tools for dynamic process in biology.To obtain the relative biology information,three-dimensional position measurement of micro-nano scale particles is needed.During the actual measurement,due to the interaction force between particles and the interaction force between particles and other in the liquid environment,the overlap phenomenon of the particle patterns is unavoidable.Overlapped particle patterns lead to the feature cross of rings,and the feature is hard to be recognized by traditional methods.So we can not obtain the position of the particles.In order to solve this problem,holographic reconstruction focusing method（HRFM）is proposed,as it can measure three dimensional position of particles by accurately locating their horizontal position.According to the experimental results,HRFM for locating the position of particles is more accurate than traditional method,especially for the measurement of overlapped particle position.The three-dimensional displacement resolution of the proposed method for single particle measurement and overlapped particles measurement can both reach 2 nm.