刘冬梅^1,2，王彤旭^1a，陈 亚^1a，温演柔^1a，文瀚泽^1a，韩 鹏^1,2

(1.华南师范大学 a.物理与电信工程学院;b.广东省光电检测仪器工程技术研究中心，广东 广州 510006；2.华南师大(清远) 科技创新研究院,广东 清远 511517)

DOI:10.13732/j.issn.1008-5548.2022.04.004

收稿日期： 2022-01-07， 修回日期：2022-05-12，在线出版时间：2022-06-22。

基金项目：国家自然科学基金项目，编号：61975058；广东省自然科学基金项目，编号：2019A1515011401。

第一作者简介：刘冬梅(1981—)，女，副教授，博士，硕士生导师，研究方向为光电技术与系统。E-mail：dmliu@scnu.edu.cn。

通信作者简介：韩鹏(1976—)，男，教授，博士，博士生导师，研究方向为光电技术与系统。E-mail：hanp@scnu.edu.cn。

摘要：利用环形相位光学衍射结构产生贝塞尔-高斯光束，将其投影到作布朗运动的聚苯乙烯小球溶液中；基于共轴差分动态显微技术，测量粒径为813 nm的聚苯乙烯小球在不同光功率下的扩散系数，研究贝塞尔-高斯光束对小球扩散运动的影响，并与高斯光束作用下的小球扩散系数相比较。结果表明：不论是在高斯光束还是在贝塞尔-高斯光束作用下，作受限布朗运动的聚苯乙烯小球的扩散系数均小于无激光作用时的；在相同激光功率照射下，贝塞尔-高斯光束作用下小球的扩散系数均大于高斯光束作用时的；随着激光功率的增加，2种光束照射下的小球扩散系数均出现先减小后略有增加的现象。

关键词：扩散系数；贝塞尔-高斯光束；受限布朗运动；差分动态显微术

Abstract：A Bessel-Gaussian beam was generated by a ring-shaped phase optical diffraction structure and projected into a solution of polystyrene spheres undergoing Brownian motion. Based on coaxial differential dynamic microscopy, the diffusion coefficients of polystyrene beads with a particle size of 813 nm under different optical powers were measured. The influence of the Bessel-Gaussian beam on the diffusion motion of the ball was studied and compared with that of the ball under the action of the Gaussian beam. The results show that the diffusion coefficients of the restricted Brownian motion of polystyrene spheres are smaller than those of without laser action, whether under the action of Gaussian beam or Bessel-Gaussian beam. Under the same laser power, the diffusion coefficients of the balls under the action of Bessel-Gaussian beams are all larger than those under the action of Gaussian beams. With the increase of laser power, the diffusion coefficients of the spheres under the irradiations of the two beams first decrease and then increase slightly.

Keywords：diffusion coefficient; Bessel-Gaussian beam; confined Brownian motion; differential dynamic microscopy

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