摘要
光镊技术是利用高度聚焦的激光束所形成的梯度力势阱对微纳粒子进行捕获和操控的技术,在生物、物理、化学和医学等领域有着非常广泛的应用。基于4π聚焦系统,理论研究了径向偏振高斯光束的紧聚焦特性及其对金属微粒的辐射力,并与传统的单透镜聚焦系统结果进行比较;还详细讨论了不同离焦和离轴距离对光阱刚度的影响。研究结果表明,与传统的单透镜聚焦系统相比,4π聚焦系统通过选择合适的光学参量,可以获得具有三维球形结构的聚焦光斑,显著增大了横向和纵向的梯度力,从而显著增强光镊系统捕获金属微粒的稳定性。
Optical tweezer has become a powerful and flexible tool for trapping and manipulating the micro-nano particles through a gradient force well formed by a highly focused laser beam, and it has a wide applications in the fields of biology, physics, chemistry, and medicine. Based on the 4π focusing system, the tight focusing characteristics of the radially polarized Gaussian beam and its radiation force to the metal particles are theoretically studied and compared with the results of traditional single-lens focusing system. Furthermore, the influence of the off-focus distance and the off-axis distance on the trap stiffness is also investigated in detail. Numerical results show that a focal spot with three-dimensional and spherical structure can be obtained in the 4π focusing system via the suitable parameters. This spherical focal spot can largely enhance the transverse and longitudinal trapping forces, and consequently enhance the trapping stability of metal particles of optical tweezer system.
作者
徐华锋
崔巍
张洲
Xu Huafeng, Cui Wei, Zhang Zhou(School of Mechanics and Optoelectronic Physics, Anhui University of Science and Technology, Huainan, Anhui 232001, China)
出处
《激光与光电子学进展》
CSCD
北大核心
2018年第10期321-327,共7页
Laser & Optoelectronics Progress
基金
国家自然科学基金理论物理专项(11747065)
安徽省自然科学基金(1808085QA10)
国家级大学生创新创业训练计划(201710361092)
关键词
物理光学
光镊
光学捕获力
4π聚焦系统
光阱刚度
physical optics
optical tweezers
optical trapping force
4π focusing system
trap stiffness
