【作者】 谈爱玲；

【导师】 史锦珊；

【作者基本信息】 燕山大学 ， 测试计量技术及仪器， 2004， 硕士

【摘要】 激光生物学是一个多学科交叉的新兴学科，其中以激光微束的光阱效应为基础的光镊技术是生命科学和生物工程研究的有力工具。高度聚焦的激光微束所形成的梯度力可以将大小从nm到μm级的电介质材料的中性粒子捕陷于其焦点上。由于光镊可实现生物活体样品的非实体接触无损伤操纵，光镊技术已成为当前生物物理学中新方法和新仪器的研究热点之一。本课题内容包括基于激光微束的光镊原理、光阱力的定量计算和数值仿真及分析、单光阱光镊仪器和单光源双光阱光镊仪器的设计以及双光阱系统在三维方向上对光阱位置进行操纵时，系统的稳定性和操纵的有效性等关键技术的研究。在光阱力的定量计算方面，本文基于几何光学原理，以射线光学计算模型为基础，对几何尺寸远大于光波长的米氏球状粒子所受轴向沿z轴方向和横向沿y轴方向的光阱力进行了计算。在给定参数条件下，进行了数值仿真，并根据仿真结果，讨论了光束束腰半径、相对折射率、激光波长及功率等系统主要参数与光阱品质特性的关系。对显微镜物镜浸油与媒质水溶液折射率不同所产生的球差对光阱力的影响进行了定量计算与数值分析。通过改善激光束形状，在保证轴向光阱力的同时，可有效提高光镊系统横向稳定性，提高对光阱横向位置操纵的速度。对几何尺寸远小于光波长的瑞利球状粒子，描述了基于电磁场理论的EM光阱力计算模型为基础的计算结果。在仪器设计方面，设计了单光阱光仪器系统，并在此基础上设计了单光源双光阱光镊仪器系统。双光阱微操纵系统在三维方向上对光阱位置进行调节时，对光阱的特性和系统的稳定性以及操纵的有效性进行理论论证。本文为三维独立可调双光阱光镊仪器的研制做了理论和技术的前期准备工作，对光镊仪器的设计以及在生命科学与生物技术中的推广应用具有促进作用和重要参考价值。更多还原

【Abstract】 Laser Biography is a multi-discipline crossed new area, and the optical tweezers technology based on microbeam laser is an effective tool in the research of life science and bioengineering. The gradient force formed by a strongly focused laser beam can capture the dielectric neutral particles on its focus point, the size of the particles ranges from nm to μm. Optical tweezers can be used to manipulate biological animate specimens without physical contact and invasion. It has now become one of the research hot spot of new method and new instrument in biophysics.In this thesis, the theory of optical tweezers based on microbeam laser is described. The quantitative calculation and simulation results and analysis of optical trapping force is given. The optical tweezers instrument with one optical trap and two optical traps is designed respectively. The stability and effective of the system are also studied.By using the RO model, which is based on the theory of geometric optics, the optical trapping force on the microsphere particles in the Mie scattering field is calculated quantitatively. The simulation results under given parameters are described. According to the simulation results, the relations between the optical trapping force and the main parameters of the system, including focus spot radius, the relative refractive index, the laser wave-length and power and so on, is discussed. Effects of spherical aberration caused by the refractive mismatch between objective oil and medium water on optical trapping force is calculated quantitatively and also analyzed. The transverse trapping force can be increased effectively by modifying laser profile, while the longitudinal stability of the system is still assured. It will improve the steering speed of optical trap. For the particles in the Rayleigh scattering field, the optical trapping force calculation result based on the theory of electromagnetic field is also described.In the apparatus design aspect, at first we design an optical tweezers instrument with one optical trap. On this basis, then we design an optical <WP=6>tweezers instrument with two optical traps using a single light. We described the stability and effective of this system of each optical trap in detail when steering the optical trap in three dimension independently. This paper is a preparatory job in terms of theory and technology for constructing a fully steerable dual optical trap tweezers. It is of importance reference value to optical tweezers research in instrument design and its wider application in life science and biography technology.更多还原