双光阱法测量光阱横向力场分布  

Measuring the Lateral Force Distribution of the Optical Trap by Using the Double Optical Trap Method

作　　者：王忠[1] 李银妹[1] 楼立人[2] 王浩威[2] 龚錾[1] 

机构地区：[1]合肥微尺度物质科学国家实验室,安徽合肥230026 [2]中国科学技术大学物理系,安徽合肥230026

出　　处：《中国激光》2006年第2期195-198,共4页Chinese Journal of Lasers

基　　金：国家自然科学基金(20273065;10474094);中国科学院知识创新工程(KJCX1)资助项目

摘　　要：提出了用双光阱法测量光阱外缘区力场的方法,建立了双光阱实验装置,其特点是利用一个光阱作为标尺完整测量待测光阱外缘区横向力场分布,测量空间分辨率为10 nm。结合流体力学方法,从实验上给出了完整的光阱横向力场分布。光阱横向力场分布的实验结果与理论计算相符合,对实验结果与理论值存在的差异也进行了分析和讨论,指出了除已有的理论计算采用的几何光学近似模型与实验条件有差别外,粒子在实验过程中伴随的轴向位移也是造成这种差异的主要原因。Double optical trap method is proposed to measure the lateral force distribution in the outer edge region of an optical trap, by using another optical trap as the force ruler. Combining the proposed method with the drag force method the whole lateral force distribution of the optical trap is measured. The results of experiment are consistent well with the reported theoretical results. The difference between the results of experiment and theory is analyzed and discussed, and the reason which causes the difference is that there exists an axial displacement accompanying with the lateral displacement during the measuring process, besides that the ray-optics approximation used in the theoretical calculation does not well accord with the condition of experiment.

关 键 词：几何光学 光阱 双光阱法 力场分布 轴向位移 

分 类 号：O435[机械工程—光学工程]