北京信息科技大学 光电测试技术北京市重点实验室,北京 100192
光阱刚度是描述光镊对粒子进行操控的重要力学指标,实际使用过程中会受到激光功率的影响。采用均方位移法及玻尔兹曼统计法对搭建的光镊系统进行光阱刚度的标定,利用图像采集方法进行微粒位移的测量,并对两种方法的测量结果进行了比较。为了提高光阱刚度的标定结果的准确性,分析了光路放大倍数、温度变化对最后标定结果的精度影响。结果表明,两种方法进行标定的结果基本相同; 光阱刚度在低激光功率(1 mW ~20 mW)范围时随功率近似线性增加,在高功率情况下(25 mW~60 mW)随功率增加不再线性增加,而是趋于一个饱和值。此外,光路放大倍数标定的精确性对标定的精度影响较大,10%的相对误差时,标定结果产生23%的变化,温度对标定的精度影响较小,±0.1 ℃的温度变化导致标定结果0.034%的变化。
光镊 光阱刚度 均方位移法 玻尔兹曼统计法 optical tweezers optic trap stiffness mean square displacement Boltzmann statistics
Author Affiliations
Abstract
1 The Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Biomedical Engineering, Xi'an Jiaotong University, Xi'an 710049
2 School of Science, Xi'an Jiaotong University, Xi'an 710049
The dynamical equation of a trapping cell is solved to find calibration methods for the trapping force, and two methods are compared by synthetic experiment data. Results indicate that: Boltzmann distribution method (BDM) is available for the force calibration of non-spherical or anisotropic cells in arbitrary trap potential; the mean square displacement method (MSDM) is available only for a symmetric harmonic optical trap. The spatial resolution requirement of the calibration system is about a nanometer. The results agree with the reported experiments.
生物医学光子学 光镊势阱 细胞光镊阱力 标定 玻尔兹曼统计法 均方位移法 170.0170 Medical optics and biotechnology 170.4580 Optical diagnostics for medicine Chinese Optics Letters
2006, 4(12): 722