渐变折射率光纤长程光镊研究
发布时间：2018-10-21 20:32
【摘要】：光纤光镊具有体积小、易于使用、成本低等特点,可用于捕获和操作微纳粒子,这种捕获和操作技术可以广泛的应用与生物学和医学。对于一般的光纤光镊,捕获细胞时都会一定程度的接触细胞,这会对生物样品造成一定的损伤。因此,具有长操作距离的光纤光镊对于实现非接触式的光学捕获具有重要的意义。长距离的光镊操作距离可以很大程度的提高光镊应用性和不接触的捕获细胞的灵活性,本文对长距离操作细胞的光纤光镊即长程光镊进行了研究。本文提出了一种新型的光纤锥角在58°操作距离在40μm之上的渐变折射率光纤长程光镊。根据光纤光镊的原理和光在渐变多模光纤中的传输特性来设计此种光镊。在现有的渐变折射率光纤光镊的基础上,在单模光纤和多模光纤中加入了一段空气腔来实现光镊的长操作距离。调节空气腔的长度,可以使得光在渐变折射率光纤锥头的汇聚距离发生改变,也能使得任意长度的渐变多模光纤都能稳定的捕获细胞,提高了腐蚀出来的渐变多模光纤的使用率。通过数值仿真计算了空气腔中、渐变多模光纤中和光纤锥附件的光场分布。仿真研究了渐变折射率光纤长度和空气腔的长度对光在锥尖外聚焦距离的影响。仿真结果显示通过调节渐变多模光纤长度和空气腔的长度,可优化光纤光镊捕获细胞的效果。实验中通过化学腐蚀法得到锥角较大的渐变折射率光纤锥,用毛细玻璃来制作空气腔结构。作为验证,实验中当调节空气腔的长度为100μm时,在稳定的在有恒定流速12μm/s溶液中成功的捕获了酵母细胞。实验捕获细胞的距离超过了40μm,是之前渐变折射率光纤光镊捕获距离的10倍以上;并且在稳定捕获后,快速移动锥尖到细胞,细胞很快恢复到原有稳定的位置,这证明了捕获细胞的稳定性;在有恒定流速的溶液中,稳定捕获的情况下,增加光功率能增大细胞的捕获距离,这证明了可以通过该种光镊长距离的操作细胞。通过上述实验,成功的证明了这种设计的光镊的可行性,实现了操作简单、重复性好的长程光镊。在实验之后,运用米氏散射模型中光轴向力的计算公式来计算此种光镊轴向力的分布,当合力和细胞受到粘滞力的大小相等时,细胞计算出来的捕获距离和实验的捕获距离接近,进一步证明了此种长程光镊的合理性。这种光纤长程光镊具有成本低,易于制作和易于使用的特点,是一种较为理想的光纤长程光镊。
[Abstract]:Fiber optic tweezers have the advantages of small size, easy to use and low cost. They can be used to capture and operate micro and nano particles, which can be widely used in biology and medicine. For general optical fiber tweezers, the cells are caught in contact with the cells to a certain extent, which will cause certain damage to biological samples. Therefore, fiber optic tweezers with long operating distance are of great significance for non-contact optical capture. Long distance optical tweezers can greatly improve the application of optical tweezers and the flexibility of non-contact trapping cells. In this paper, the optical fiber tweezers of long distance operating cells, that is, long range optical tweezers, are studied. In this paper, a new type of fiber tapered fiber long range tweezers with a tapered angle of 58 掳operating distance of 40 渭 m is proposed. The optical tweezers are designed according to the principle of optical tweezers and the transmission characteristics of optical fiber in a graded multimode fiber. Based on the existing graded refractive index optical tweezers, a section of air cavity is added to the single-mode fiber and multi-mode fiber to realize the long operating distance of the optical tweezers. Adjusting the length of the air cavity can change the convergent distance of the light in the tapered tip of the graded refractive index fiber, and it can also make the graded multimode fiber of any length be able to steadily capture the cells. The utilization rate of the corroded multimode fiber is improved. The field distribution of graded multimode fiber and fiber cone attachment in air cavity is calculated numerically. The effects of the length of graded refractive index fiber and the length of air cavity on the focusing distance of the light outside the cone tip are simulated. The simulation results show that the effect of optical fiber tweezers can be optimized by adjusting the length of multimode fiber and the length of air cavity. In the experiment, a gradient refractive index fiber cone with large cone angle was obtained by chemical etching method, and capillary glass was used to fabricate the air cavity structure. As a validation, yeast cells were successfully captured in a stable solution with a constant flow rate of 12 渭 m / s when the length of the air chamber was adjusted to 100 渭 m. The distance of the trapping cells was more than 40 渭 m, which was more than 10 times the distance of the graded-index fiber optical tweezers, and after the steady capture, the cells quickly moved the tip of the cone to the cells, and the cells quickly returned to the original stable position. This proves the stability of the trapping cells, and in the case of steady trapping in the solution with constant flow rate, increasing the optical power can increase the trapping distance of the cells, which proves that the long distance operating cells can be obtained through this kind of optical tweezers. Through the above experiments, the feasibility of the designed optical tweezers is proved successfully, and the long range optical tweezers with simple operation and good repeatability are realized. After the experiment, the distribution of the axial force of the optical tweezers is calculated by using the formula of optical axial force in the Michlet scattering model. When the force and the cell are subjected to the same viscous force, the distribution of the axial force of the optical tweezers is calculated when the force is equal to that of the cell. The calculated trapping distance is close to the experimental trapping distance, which further proves the rationality of the long-range optical tweezers. This kind of fiber long-range optical tweezers has the characteristics of low cost, easy to manufacture and easy to use, so it is an ideal fiber long-range optical tweezers.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253
本文编号：2286291
[Abstract]:Fiber optic tweezers have the advantages of small size, easy to use and low cost. They can be used to capture and operate micro and nano particles, which can be widely used in biology and medicine. For general optical fiber tweezers, the cells are caught in contact with the cells to a certain extent, which will cause certain damage to biological samples. Therefore, fiber optic tweezers with long operating distance are of great significance for non-contact optical capture. Long distance optical tweezers can greatly improve the application of optical tweezers and the flexibility of non-contact trapping cells. In this paper, the optical fiber tweezers of long distance operating cells, that is, long range optical tweezers, are studied. In this paper, a new type of fiber tapered fiber long range tweezers with a tapered angle of 58 掳operating distance of 40 渭 m is proposed. The optical tweezers are designed according to the principle of optical tweezers and the transmission characteristics of optical fiber in a graded multimode fiber. Based on the existing graded refractive index optical tweezers, a section of air cavity is added to the single-mode fiber and multi-mode fiber to realize the long operating distance of the optical tweezers. Adjusting the length of the air cavity can change the convergent distance of the light in the tapered tip of the graded refractive index fiber, and it can also make the graded multimode fiber of any length be able to steadily capture the cells. The utilization rate of the corroded multimode fiber is improved. The field distribution of graded multimode fiber and fiber cone attachment in air cavity is calculated numerically. The effects of the length of graded refractive index fiber and the length of air cavity on the focusing distance of the light outside the cone tip are simulated. The simulation results show that the effect of optical fiber tweezers can be optimized by adjusting the length of multimode fiber and the length of air cavity. In the experiment, a gradient refractive index fiber cone with large cone angle was obtained by chemical etching method, and capillary glass was used to fabricate the air cavity structure. As a validation, yeast cells were successfully captured in a stable solution with a constant flow rate of 12 渭 m / s when the length of the air chamber was adjusted to 100 渭 m. The distance of the trapping cells was more than 40 渭 m, which was more than 10 times the distance of the graded-index fiber optical tweezers, and after the steady capture, the cells quickly moved the tip of the cone to the cells, and the cells quickly returned to the original stable position. This proves the stability of the trapping cells, and in the case of steady trapping in the solution with constant flow rate, increasing the optical power can increase the trapping distance of the cells, which proves that the long distance operating cells can be obtained through this kind of optical tweezers. Through the above experiments, the feasibility of the designed optical tweezers is proved successfully, and the long range optical tweezers with simple operation and good repeatability are realized. After the experiment, the distribution of the axial force of the optical tweezers is calculated by using the formula of optical axial force in the Michlet scattering model. When the force and the cell are subjected to the same viscous force, the distribution of the axial force of the optical tweezers is calculated when the force is equal to that of the cell. The calculated trapping distance is close to the experimental trapping distance, which further proves the rationality of the long-range optical tweezers. This kind of fiber long-range optical tweezers has the characteristics of low cost, easy to manufacture and easy to use, so it is an ideal fiber long-range optical tweezers.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253
【参考文献】
相关期刊论文 前1条
1 霍鑫;潘石;;近场纳米光纤探针腐蚀制备技术概述[J];电子显微学报;2006年05期
，本文编号：2286291
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