基于Hough变换处理方法的光镊光阱刚度标定

摘要

The stiffness of optical trap is an important parameter to describe the mechanical properties of the optical tweezers,whose measurement accuracy is almost determined by the calibration accuracy of trap stiffness.A calibration method of optical trap stiffness based on Hough transform is proposed.Firstly,the basic principle to solve the displacement and calibrate the stiffness based on the mean square displacement method by using the Hough transform was introduced.Then,the optical tweezers system was built,and a feasibility analysis was carried out.The measured results are compared with those using the traditional CCD correlation algorithm.When the optical magnification is 120,and the average value of the stiffness measured by the Hough transform method is,and that using CCD correlation algorithm is about.The results are almost the same.The research results show that the Hough method is stable and reliable,and can be used to calibrate the optical trap stiffness.%光阱刚度是描述光镊力学特性的一个重要指标,其标定的精确度直接决定了光镊测力的精确度.研究了一种基于Hough变换处理方法的光阱刚度标定方法.首先,介绍了基于均方位移法利用Hough变换求解位移实现刚度标定的基本原理;然后,搭建了光镊系统,进行了可行性分析.测量结果与传统的CCD相关算法进行了比较,当光的放大倍数为120时,Hough变换处理法标定的光阱刚度平均值为1.604±0.02,CCD相关算法标定的光阱刚度平均值为1.781±0.05,两种方法标定的结果基本相同.研究结果表明,Hough变化处理法具有一定的稳定性和可靠性,是标定光阱刚度可选择的方法之一.