矢量贝塞尔波束对瑞利粒子的光学操控研究

发布时间：2018-05-09 22:20

本文选题：矢量贝塞尔波束 + 捕获力　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：基于光的力学效应,光镊可以对微小粒子实现非接触、无损伤的捕获和操控。近年来,该技术已得到了快速发展,并广泛应用于生物学、化学、医学、物理学和微流控光学等各个领域,同时各领域对其也提出了新的要求和挑战。贝塞尔波束可以弥补高斯波束在光学操控中的不足,并实现一些全新的功能。综合考虑贝塞尔波束的无衍射性、自重建性及其极化特性,本文研究了矢量贝塞尔波束对瑞利粒子的力学效应,主要研究工作如下:1.基于角谱展开理论,推导了轴棱锥产生的矢量贝塞尔波束电磁场的数学描述,并在此基础上推导了对应的光强和坡印亭矢量。光强和坡印亭矢量的数值研究发现:贝塞尔波束的极化状态影响波束光强取最大值的位置和对应入射波束的能量流动范围。2.利用瑞利模型研究了波束作用在瑞利粒子上的光学力,推导了矢量贝塞尔波束对瑞利粒子的径向、角向和轴向的光学力。在公式推导的过程中,我们分别讨论了线极化、圆极化、径向极化、角向极化和非极化贝塞尔波束对聚苯乙烯球形粒子的光学力各个分量的特点,研究了贝塞尔函数的阶数l、波束的极化状态和傍轴度(或半锥角)对光学力的影响,并分析了能稳定捕获粒子的个数。计算结果表明:贝塞尔波束的极化状态影响各个方向上稳定捕获粒子的位置。3.研究了矢量贝塞尔波束对瑞利粒子的力矩,包含粒子的外禀力矩和内禀力矩。同样研究了贝塞尔函数的阶数l、极化状态和傍轴度(或半锥角)等因素对粒子的合力矩、轨道力矩和内禀力矩的影响。数值分析可知:波束的极化状态影响力矩的大小和正负。
[Abstract]:Based on the mechanical effect of light, optical tweezers can capture and manipulate tiny particles without contact and damage. In recent years, this technology has been developed rapidly and has been widely used in biology, chemistry, medicine, physics and microfluidic optics. Bezier beam can make up for the deficiency of Gao Si beam in optical manipulation and realize some new functions. Considering the non-diffraction, self-reconstruction and polarization characteristics of Bezier beam, the mechanical effects of vector Bezier beam on Rayleigh particles are studied in this paper. The main research work is as follows: 1. Based on the theory of angular spectrum expansion, the mathematical description of the vector Bezier beam electromagnetic field generated by the axial pyramid is derived, and the corresponding light intensity and Poynting vector are derived. The numerical study of light intensity and Poynting vector shows that the polarization state of Bezier beam affects the position of maximum beam intensity and the energy flow range of incident beam. The optical force of beam acting on Rayleigh particles is studied by using Rayleigh model, and the radial, angular and axial optical forces of vector Bezier beam on Rayleigh particles are derived. In the process of formula derivation, we discuss the characteristics of the optical forces of linear polarization, circular polarization, radial polarization, angular polarization and non-polarized Bezier beam on polystyrene spherical particles, respectively. The effects of the order l of the Bessel function, the polarization state of the beam and the paraxial degree (or semi-cone angle) on the optical force are studied, and the number of trapped particles is analyzed. The results show that the polarization state of the Bezier beam affects the position of the trapped particles in all directions. The moment of vector Bezier beam on Rayleigh particle, including intrinsic moment and intrinsic moment, is studied. The effects of the order of Bessel function, polarization state and paraxial degree (or semi-cone angle) on the resultant moment, orbital moment and intrinsic moment of particles are also studied. Numerical analysis shows that the polarization state of the beam affects the magnitude and the positive value of the moment.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O43;O441.4

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