Optimal beam diameter for lateral optical forces on microspheres at a water-air interface
Optimal beam diameter for lateral optical forces on microspheres at a water-air interface
复制标题
水-空气界面微球上横向光学力的最佳光束直径
DOI：
10.3788/col201412.011403
复制
发表时间：
2014
影响因子：
3.5
通讯作者：
Li Yin-Mei
中科院分区：
文献类型：
--
作者：
Wang Xi;Zhou Jin-Hua;Wang Zi-Qiang;Li Yin-Mei
利用具有低数值孔径显微镜物镜的光镊在水-空气界面上对微球进行了操纵。在这封信中，我们确定了最佳的光学陷阱的横向操纵微球在水-空气界面。实验结果表明，在物镜后孔径处，俘获光束的扩展对俘获力有一定的影响。对于水-气界面的侧向光学操纵，最佳填充比为0.65。采用光线光学模型对水-气界面上的横向捕获力进行了理论研究。数值结果表明，通过缩小囚禁光束的直径，可以改变横向囚禁力的大小。数值计算结果与实验结果基本一致。
Optical tweezers with a low numerical aperture microscope objective is used to manipulate the microspheres at the water-air interface. In this letter, we determine the optimal optical trap for the lateral manipulation of microspheres at a water-air interface. The experimental results show that the trapping force is influenced by the expansion of the trapping beam at the back aperture of the objective. The optimal filling ratio of 0.65 is suggested for lateral optical manipulation at the water-air interface. The lateral trapping forces at the water-air interface are theoretically investigated with the ray-optics model. The numerical results show that the lateral trapping forces can be changed by shrinking the diameter of the trapping laser beam. The numerical results are in accordance with the experimental results.