标题: | 准焦与散焦雷射镊夹之设计与应用 Design and Application of In-focus and Off-focus |
作者: | 张博睿 Bo-Jui,Chang 徐琅 Long Hsu 电子物理系所 |
关键字: | 雷射镊夹;散焦雷射镊夹;准焦雷射镊夹;捕捉一群微粒子;雷射镊夹系统设计;样品浓缩;捕捉力与捕捉范围实验;电磁波模型;optical tweezers;In-focus optical tweezers;Off-focus optical tweezers;capture a group of particles;Design of optical tweezers system;sample concentration;Trapping force and trapping range experiment;EM model of optical tweezers |
公开日期: | 2000 |
摘要: | 过去十年,利用光梯度力捕捉微小物体的雷射镊夹被广泛的应用在捕捉与搬运微生物体、及微小粒子的操控上。它的捕捉力强度约在10-12牛顿,所能捕捉的微小物体的大小约在几十nm到几十μm。雷射镊夹目前已成为生物科技研究上一个重要且非常有用的工具。 传统的雷射镊夹是将雷射光束准确地聚焦在样品平面上形成一光点,我们称之为准焦雷射镊夹。过去,准焦雷射镊夹主要被运用于单一微粒子的操控及研究上。为提升捕捉效率,我们首创了散焦雷射镊夹,可一次捕捉一群微粒子。在本论文中,我们刻意让雷射光束偏离样品平面,使得雷射光束在样品平面上变成一个大光圈,扩大了捕捉范围。在本实验中,我们将实际展现准焦雷射镊夹分别捕捉单一塑胶珠子、绿脓杆菌、精虫等的实例操作,同时也展示散焦雷射镊夹捕捉一群塑胶珠子的功能。 我们利用雷射镊夹的电磁波模型,模拟了准焦与散焦雷射镊夹的捕捉力与捕捉范围。此外,我们还设计了一个流速与捕捉范围关系的实验,可同时观察雷射镊夹捕捉力及捕捉范围。我们发现散焦雷射镊夹与准焦雷射镊夹最大的不同在于,散焦雷射镊夹捕捉范围较准焦雷射镊夹大,但捕捉力较弱。最后,我们提出一个应用散焦雷射镊夹系统提升样品浓度的装置设计。 另外,在本论文中我们还叙述了完整的雷射镊夹的设计指南,可供未来欲架设雷射镊夹的读者详细的参考。我们诚挚地希望本论文不仅能做为研究雷射镊夹的入门,更能激荡出更多对于雷射镊夹的应用。 In the past decade, optical tweezers, which is capable of capturing micro objects via the gradient force produced by a converging laser beam, have been widely used in the capture, move, and manipulation of microbiological objects and micro particles. Typically, the force generated by an optical tweezers system is of the order of pico-Newton (10-12 N). The sizes of captured tiny objects range from a few tens of nano-meters to a few tens of micrometers. Optical tweezers have just become an important and powerful tool in biotechnology research. Traditionally, an optical tweezers system is operated by precisely focusing a laser beam into a focal point on the sample plane, which we call an in-focus optical tweezers system. It is commonly used to capture and manipulate a single particle at a time. In order to capture more particles in a short period of time, we innovate an off-focus optical tweezers system for the first time, which captures a group of micro particles at a time. In this thesis, we purposely shift the laser focal point slightly away from the sample plane. This leaves a relatively larger laser spot on the sample plane, which increases the capturing range. In this work, we will show the manipulation of a single polystyrene bead, a pseudomonas aeruginosa, and a spermatozoon, separately, by an in-focus optical tweezers system. Also, we will demo the capture of a group of polystyrene beads by an off-focus optical tweezers system. Based on the EM model of optical tweezers, we simulate the capturing range and the capturing force for the in-focus optical tweezers and the off-focus optical tweezers, separately. Besides, we also design an experiment to measure the relationship between the drift velocity of the solution relative to the captured beads and the capturing range by an optical tweezers system. The variation of the drift velocity clearly illustrates the relationship between the capturing range and the capturing force of an optical tweezers system. We conclude that the off-focus optical tweezers system has a longer trapping range but a weaker trapping force than the traditional in-focus optical tweezers system does. At last, we propose a design for sample concentration utilizing the off-focus optical tweezers. In addition, we present a detailed guideline for the design of optical tweezers. This may be helpful for those who are interested in setting up an optical tweezers system. We hope that this thesis is not only a useful reference on optical tweezers, but also a stimulation for further applications. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT890429006 http://hdl.handle.net/11536/67248 |
显示于类别: | Thesis |