The Study and Fabrication of Optical Tweezers Using Optical Fibers

• Main Authors: Kuo-Liang Chen, 陳國良
• Other Authors: Shin-Kun Liu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/36680796789345916345

碩士 === 國立高雄應用科技大學 === 光電與通訊研究所 === 97 === Optical tweezers are widely studied in Biotechnology. This technology provides a non-contact means to capture particles, and to move them in accordance with our control. The traditional optical tweezer system is complex, so our goal is to build a compact system with less optical elements involved. This system utilizes a lensed fiber to serve as the main component of the optical tweezer system. We made optical lens on optical fiber by using a buffered oxide etchant (BOE) to etch one end of a commerical multimode optical fiber, and then by using an optical fiber fusion splicer to arc-heating the tip of the etched region. The fiber was then called the lensed fiber. A Matlab code is used to analyze the image of the lensed fiber so that the radius of curvature of the lensed fiber can be extracted. Another software Zemax is used to analyze the focal length and numerical aperture of lensed fiber. A laser of wavelength of 635nm and the sample particle sizes of 10μm and 15μm is used in this study. Two lensed fibers with different radius of curvature are used to trap particles. In the experiment, the output power from the end of the lensed fiber is fixed. The dependence of the insertion angle that is an angle between the fiber and the horizontal place on the effect of trapping is observed. A numerical calculation conducted is to study the trapping effect at various insertion angle. The experiment has successfully shown that our homemade optical tweezer system can trap and move micro particles at will. A quantitative analysis on the trapping effect is conducted to optimize our optical tweezer system.