锥形单光纤光镊的多次捕获研究.docVIP

  A study about multi-trapping of a tapered-tip single fiber optical tweezers LIU Zhihai, LIANG Peibo, ZHANG Yu* 5 10 15 20 25 30 35 40 (Key Laboratory of In-Fiber Integrated Optics, School of Science, Harbin Engineering University, Harbin 150001, China) Abstract: We develop and accomplish a study about multi-trapping characteristic of a tapered-tip single fiber optical tweezers. The finite difference time domain (FDTD) method is employed to simulate the trapping force characteristic of this single fiber optical tweezers, and the results show that the quantity of the trapped particles depending on the refractive index and the size of the particles. Besides that the trapping forces of this tapered-tip single fiber optical tweezers have been calibrated by the experiment method, and the experimental results are consistent with the theoretical calculation results. The multi-trapping capability realized by the tapered-tip single fiber optical tweezers will be practical and useful for some applications in biomedical researching fields. Key words: optical trapping; microstructures and particles; optical tweezers; multi-trapping 0 Introduction Optical tweezers (OTs) had been widely applied for noninvasive manipulation of a variety of biological specimens [1-5] including viruses, bacteria, cells, and sub-cellular organisms in biology and biophysics researching fields since it were invented by Ashkin et al in 1986 [6]. When the light from OTs is incident and deflected by the surface of an object, optical forces will be produced and exert on the object due to the photon momentum change. Besides biological field, OTs also offer powerful new possibilities to handle microscopic particles revolutionized different areas, such as atomic physics [7-9], chemistry[10, 11] and MEMS (Micro-Electro-Mechanical Systems) [12]; even the study of the optical trapping itself resulted in interesting new physics [13, 14]. At the outset, optical trapping is achieved by traditional lens optica